Shiga toxin-producing Escherichia coli in beef

Prevalence and risk factors of Shiga toxin-producing Escherichia coli serotypes in beef at abattoirs and retail outlets in Gauteng

Industry Sector: Cattle and Small Stock

Research focus area: Red Meat Safety, Nutritional Value, Consumerism and Consumer Behaviour

Research Institute: Department of Production Animal Studies, University of Pretoria

Researcher: Prof. Peter Thompson Ph.D.

The Research Team

TitleInitialsSurnameQualification
ProfA.A.AdesiyunPh.D
DrE.MadorobaPh.D
DrL.O.OnyekaM.Sc

Year of completion : 2017

Aims of the project

  • To determine the prevalence O157 and non-O157 Shiga-toxin producing Escherichia coli (STEC) in beef abattoirs in Gauteng
  • To determine the prevalence O157 and non-O157 STEC in beef and beef products at retail outlets in Gauteng
  • To identify the important STEC serotypes present in beef and beef products in Gauteng
  • To identify risk factors for STEC contamination of carcasses and beef products in Gauteng

Executive Summary

Shiga toxin-producing Escherichia coli (STEC), particularly the O157 strains, are food-borne zoonotic pathogens of public health importance worldwide. Foods of cattle origin have been implicated in various outbreaks and epidemiological studies have revealed that cattle are major reservoirs of STEC. We conducted cross-sectional surveys from Nov 2015 to Nov 2016, to investigate the prevalence and molecular characteristics of O157 and non-O157 strains of STEC in beef and beef products in the Gauteng province of South Africa.

A total of 265 swab samples of beef carcasses from 12 abattoirs and 399 beef products from 31 retail outlets were screened for STEC using a multiplex PCR. The overall prevalence in abattoir samples was 37% (55/149) in summer and 34% (39/116) in winter. In beef products at retail outlets it was 20% (27/137) in autumn, 14% (18/130) in winter and 17% (22/132) in summer; the highest prevalence was detected in boerewors (35%) followed by mincemeat (21%). The predominant serotypes detected were O113 (19.4%) and O157 (14.9%) in beef products, and O113 (14%) from abattoirs.

Our results demonstrate that STEC is present in South African beef and beef products, and that this may pose a real food-borne disease threat. Further investigation of the epidemiology of the pathogen is required; it is proposed that this take the form of longitudinal studies to investigate the prevalence of shedding of STEC by cattle in the feedlot, following them through to the abattoir to determine factors associated with carcass contamination.

Additional Comments

As this is part of a PhD project, further molecular work is still to be done on the isolates, resulting in further planned publications. The samples also provided material for an MSc student (funded by UP research funds) to work on Salmonella contamination – these results will also be made available to RMRDSA once finalized.

Popular Article

Assessing the prevalence of shiga toxin-producing escherichia coli in beef at abattoirs and retail outlets in gauteng

Dr Lorinda Frylinck, Senior Navorser, LNR-Diere Produksie, Irene.

Introduction

The production of safe and wholesome beef and beef-derived food products is the highest priority for the beef industry in South Africa. There are potential risks associated with the possible presence of harmful pathogens in the food production chain; however, clear guidelines and regulations have been implemented to reduce these risks to a minimum and ensure a safe product for consumers. Nevertheless it remains important to continually assess these risks and to ensure effective implementation of control measures.

Shiga toxin-producing Escherichia coli (STEC) are bacteria associated with food and waterborne diseases and have been recognized as causing public health problems worldwide. The WHO Foodborne Disease Burden Epidemiology Reference Group (FERG) reported that ‘Foodborne STEC’ caused more than 1 million illnesses and 128 deaths in 2010 (8).

Of the over 470 different serotypes of STEC detected in humans, the O157:H7 serotype is the most frequently associated with large food and water-borne outbreaks (7). However, non-O157 STEC have been increasingly isolated from cases of haemorrhagic colitis (severe GIT infection and bloody diarrhoea) and as well as some fatal kidney failure (HUS; haemolytic uraemic syndrome) cases.

Although the first report of the occurrence of HUS in South Africa dated as far back as 1968 (6), the causative agent was poorly understood at that time. The first clinically proven incidence of E. coli O157:H7 in South Africa was later linked with haemorrhagic colitis (3). The importance of the pathogen in South Africa and other southern African countries has, however, been highlighted by subsequent major outbreaks of bloody diarrhoea in which E. coli O157 strains were implicated (4). Of particular interest was a study in Gauteng province in 2011, in which 7.7% of children with diarrhoea were positive for E. coli O157 (5).

Epidemiological investigations have revealed that cattle are a major reservoir of STEC. Many outbreaks of E. coli O157:H7 have been associated with beef, in particular ground beef, and analyses of some cases have identified undercooked beef as a significant risk factor. However, the fact that E. coli-associated conditions in humans, such as HUS, are not as yet notifiable in South Africa may mean that the occurrence of STEC-associated disease in humans is under-reported. In addition, given the weight of evidence from elsewhere in the world, it is possible that contamination of beef products is also a risk factor in South Africa.

Research problem and objectives

There is a dearth of current information on the frequency of occurrence of O157 and non-O157 strains of STEC, and on the risk they pose to consumers of beef products, in South Africa. Hence, the objective of this study was to determine the prevalence and characteristics of O157 and non-O157 STEC strains in beef carcass and beef products sold at retail outlets in the Gauteng province of South Africa.

Materials and Methods

During a one-year period from Nov 2015 to Nov 2016, two independent cross-sectional surveys were carried out to determine the prevalence of STEC at abattoirs as well as at retail outlets where beef-based food products are sold.

Study 1: Twelve abattoirs (six high throughput and six low throughput) were selected and each was visited during summer and winter months for sample collection. Five animals were randomly selected in each abattoir and tagged for sample collection. Firstly, samples were collected by swabbing the skin of the perineal area immediately after slaughter. Thereafter, carcass swab samples were collected from different parts of the carcass at various stages during processing, including pre-evisceration, post-evisceration, post-washing and 24 hours post-chilling.

Beef carcass sampling and processing at the abattoir

Study 2: A total of 31 retail outlets including both large supermarket chains and smaller butcheries were randomly selected. Visits were made to each of these outlets during autumn, winter and summer months of 2016 for sample collection. Sampling of five types of popular beef products (brisket, boerewors, mince, cold meat, and biltong) was done at each outlet during each visit.

Each sample was analyzed for the presence of Shiga toxin-encoding genes (stx1and stx2) using conventional multiplex PCR. All samples positive for stx genes based on PCR were screened for the following O-serotypes: O26, O91, O103, O111, O113, O145 and O157 using a multiplex PCR assay.

Results and Discussion

Overall, the prevalence of STEC in beef carcass swabs collected from 12 red meat abattoirs across Gauteng province during summer and winter months was 35.5% (94/265). The highest prevalence (50%) was detected in perineal samples, which is hardly a surprise because cattle are an established reservoir of STEC; this may therefore reflect the prevalence of the pathogen in cattle arriving at abattoirs. Transportation stress is known to increase the shedding of enteric pathogens and could therefore be a contributing factor to the observed high prevalence in perineal samples. STEC was found in 39% of both pre-evisceration and post-evisceration carcasses, while washed carcasses and 24 hour chilled carcasses had a lower prevalence of 23% and 20% respectively. Therefore, although washing of carcasses at the abattoir removed much of the STEC contamination, the fact that the bacteria were still present on the surface of some chilled carcasses is of potential food safety significance, since cuts from these carcasses end up for sale in various forms at retail outlets.

Boerewors on display in a retail outlet

Of the 399 beef products sampled from 31 retail outlets, 67 (16.8%) were contaminated by STEC strains, an observation that is of food safety significance if such products were to be improperly cooked and consumed by highly susceptible individuals.

The highest prevalence of STEC was detected in boerewors (35%), followed by minced meat (21%). Ground beef ordinarily includes meat from many carcasses; consequently a few infected livestock could potentially contaminate a great quantity of ground beef. Biltong had the lowest prevalence of contamination (5%), while brisket and cold meat had 11% and 6% respectively. These results are in contrast to a previous study in South Africa, in 2009, involving biltong, cold meat and minced meat at retail outlets, which found that 2.8% of the samples were positive for E. coli O157 (1).

The prevalence of STEC in abattoir and retail outlet samples was somewhat higher during the summer months compared to the winter months. While many factors are believed to affect the prevalence of E. coli O157:H7, only season has been consistently shown to impact the shedding of this bacterium by cattle (2), and some previous studies have also observed a higher prevalence of shedding during the warmer months than the winter months.

The serotype analysis showed that O113 was the post prevalent serotype both on beef carcasses (14%) as well as in beef-based products (19%). This observation is of particular interest considering that O113 is an emerging serotype associated with human illness and sometimes with HUS in several countries including Spain, Belgium and Australia. Serotype O113 of STEC may therefore potentially be important in human diseases in South Africa and this requires further studies. Some of the other serotypes detected  have also previously been implicated in human diseases elsewhere in the world.

Unlike in abattoir samples where the prevalence of serotype O157 was very low (1%), a higher prevalence of 15% was detected in retail meat samples. This finding may be explained in part by the fact that the current study was cross-sectional by design (giving a “snapshot” at a particular point in time) and not a longitudinal study. Therefore serotype O157-contaminated beef products may have originated from abattoirs not sampled in the current study, and the prevalence may vary greatly between places and over time. There is also a possibility that it may partially also be a result of contamination from other sources at the retail outlet level.

Mince meat on display in a retail outlet

Conclusion

This study has shown that contamination of beef products with potentially harmful bacteria can occur during different processing stages. The low numbers of reported cases of food-associated disease in South Africa suggest that the risk to consumers is low; however, it is not known whether all cases are reported, or that all cases are correctly diagnosed. Therefore, further research is needed in order better understand the dynamics of foodborne pathogens in South Africa, to accurately assess the risk they pose, and to accurately inform control measures.

It is well known that efficient implementation of control measures during slaughter and processing procedures can greatly reduce meat surface microbial contamination and ensure the safety of the final product. The South African Meat Safety Act (2000) has addressed potential risk factors by adopting several internationally recognized preventive measures such as the Hazard Analysis Critical Control Point (HACCP) system and Good Manufacturing Practices (GMP) in order to promote safe meat for consumers. The application of GMP and HACCP principles during handling and processing of products, as well as the proper cooking of meat products before consumption, will effectively reduce the threat of food borne disease.

Acknowledgments

We thank Red Meat Research and Development South Africa (RMRD SA) for funding this research and the Gauteng Department of Agriculture and Rural Development for granting us access and assistance to carry out the cross-sectional survey at the abattoirs.

References

  1. Abong’o, B.O. and Momba, M.N., 2009. Prevalence and characterization of Escherichia coli O157: H7 isolates from meat and meat products sold in Amathole District, Eastern Cape Province of South Africa. Food Microbiology, 26(2), pp.173-176.
  2. Berry, E.D. and Wells, J.E., 2010. Escherichia coli O157: H7: recent advances in research on occurrence, transmission, and control in cattle and the production environment. Advances in Food and Nutrition Research, 60, pp.67-117.
  3. Browning, N.G., Botha, J.R., Sacho, H. and Moore, P.J., 1990. Escherichia coli O157: H7 haemorrhagic colitis. Report of the first South African case. South African Journal of Surgery, 28(1), pp.28-29.
  4. Effler, E., Isaäcson, M., Arntzen, L., Heenan, R., Canter, P., Barrett, T., Lee, L., Mambo, C., Levine, W., Zaidi, A. and Griffin, P.M., 2001. Factors contributing to the emergence of Escherichia coli O157 in Africa. Emerging Infectious Diseases, 7(5), p.812.
  5. Galane, P.M. and Le Roux, M., 2001. Molecular epidemiology of Escherichia coli isolated from young South African children with diarrhoeal diseases. Journal of Health, Population and Nutrition, 19(1), pp.31-38.
  6. Kiibel, P.J., 1968. The haemolytic-uraemia syndrome: a survey in Southern Africa. South African Medical Journal, 42(27), pp.692-698.
  7. Mora, A., Herrera, A., López, C., Dahbi, G., Mamani, R., Pita, J.M., Alonso, M.P., Llovo, J., Bernárdez, M.I., Blanco, J.E. and Blanco, M., 2011. Characteristics of the Shiga-toxin-producing enteroaggregative Escherichia coli O104: H4 German outbreak strain and of STEC strains isolated in Spain. International Microbiology, 14(3), pp.121-141.
  8. WHO [World Health Organization], 2015. WHO estimates of the global burden of foodborne diseases. Available at http://apps.who.int/iris/bitstream/10665/199350/1/9789241565165_eng.pdf

Please contact the Primary Researcher if you need a copy of the comprehensive report of this project – Peter Thompson onpeter.thompson@up.ac.za

Improved red meat marketing in South Africa

Improving the effectiveness of the red meat industry in meeting the needs of the modern consumer within South Africa as a developing country with socio-economic diversity

Industry Sector: Cattle and Small Stock

Research focus area: 

  • Red Meat Safety, Nutritional Value, Consumerism and Consumer Behaviour
  • The economics of red meat consumption and production in South Africa

Research Institute: Bureau for food and agricultural policy (BFAP)

Researcher: Mrs Hester Vermeulen

Research Team

Title Initials Surname Highest Qualification
Prof Ferdi Meyer PhD Agricultural Economics
Prof HC Schönfeldt PhD
Dr B Pretorius PhD

Completion: 2017

Aims of the project

  • Improving the effectiveness of the South African red meat industry in meeting the needs of the socio-economical diverse consumer market in South Africa through the development of scientifically based recommendations to guide policy development and product development / improvement.
  • To identify and characterize consumer market segments among low-, middle- and high LSM consumers in South Africa based on consumers red meat perceptions and behavior – considering a variety of species and meat cuts guided by data availability.
  • To develop scientifically based recommendations for the promotion of red meat in South Africa through appropriate marketing messages delivered through suitable communication channels to maintain and / or improve consumers’ perceptions and acceptance of red meat – considering a variety of species and meat cuts guided by data availability.
  • To engage in GAP analysis in order to identify the discrepancies between the actual current characteristics and ideal characteristics (demanded by consumers) of the red meat product offering on South African retail shelves – considering beef and mutton/lamb and a selection of fresh meat cuts guided by data availability.

Executive Summary

Meat purchasing and preparation behaviour:

  • Meat purchasing roles:
    • Marketing information on red meat should have a strong focus on adult women (‘wife’ or head female in households) as the primary red meat purchasers, but still keeping in mind that all age and genders groups within the household could influence her red meat purchase decision. Given the increased role of the husband / head male on meat purchasing during weekends and when selecting meat to entertain guests, red meat information related to these more social settings should be targeted at both male and female adults.
  • Factors considered when purchasing red meat:
    • Across the socio-economic spectrum, for both raw beef and raw mutton/lamb the following factors were important to consumers when making a purchase – and are thus important factors to focus on in terms of red meat production and marketing, no matter which socio-economics group is targeted:
      • Affordability: Price.
      • Appearance: General appearance, colour of meat, colour of fat.
      • Food safety: Food safety in general, expiry date, clean meat (no blood).
      • Quality: Quality guarantee, fresh, fresh not frozen.
      • Sensory acceptability: Tasty, tender, juicy, eaten by all in household.
      • Convenience: Convenience in general, preparation time.
      • Fat: Fat-to-meat ratio, low fat / lean meat.
      • Store where meat is purchased.
    • Among the low-income sample value-for-money considerations such as bone-to-meat ratio, amount of meat per packet and packaging size were also important. The importance of branding and nutritional value increased towards the middle- and high-income samples.
  • Meal planning:
    • As consumers across the socio-economic spectrum usually choose the meat for the meal first and then the other dishes it is critical to ensure that red meat is positioned as a popular ‘spontaneous’ choice in consumers’ minds.
    • Consumer education on red meat meal preparation ideas should rely on multiple sources with the dominant sources being ‘social’ sources and radio for the low-income sample, and recipes, ‘social’ sources (such as friends, mother), television and magazines for the middle- and high-income samples.
  • Red meat preparation and cooking:
    • For beef the most popular cooking methods were stewing, frying and braai. For the low-income group stove-top boiling was also prominent, while roasting and grilling popular cooking methods among middle-income and high-income consumers.
    • When preparing mutton/lamb low-income consumers used frying, boiling and braai, while middle-income consumers mainly used casserole, potjie, braai, roasting and stewing (in order of importance). High income consumers used stewing, braai, roasting, frying and grilling (in order of importance) for lamb/mutton.
    • Among middle- and high-income consumers the time allocated to meat preparation increased during weekends and even more so when entertaining guests. Thus, when targeting these segments with meat preparation information and recipes for more ‘social’ meals, more complex and longer preparation time can be used. However, during the week these consumers want meat options that are easy and fast to prepare.

Meat consumption behaviour:

  • Perceived importance of protein food intake:
    • Considering the statement: ‘It is important to eat animal protein foods daily’, the majority of high- and middle-income consumers were in agreement (96% of high-income sample versus 86% of middle-income sample).
    • Considering the statement: ‘It is important to eat red meat 3 to 4 times per week’, a smaller share of high- and middle-income consumers were in agreement (65% of high-income sample versus 39% of middle-income sample).
    • There seems to be a gap for consumer education particularly among middle- and high-income consumers on the recommended healthy intake of red meat and the health benefits associated with red meat.
  • Protein food intake:
    • The animal protein food options consumed in largest quantities were (in order of importance):
      • Low-income consumers: Chicken, eggs, beef, chicken offal, fish and beef.
      • Middle-income consumers: Chicken, eggs, fish and beef.
      • High-income consumers: Chicken, beef, eggs and fish.
    • The most frequently consumed animal protein food options were (in order of importance):
      • Low-income consumers: Eggs, chicken offal, chicken meat, canned fish, polony / viennas, boerewors, beef liver and stewing beef with bone.
      • Middle-income consumers: Chicken, eggs, beef mince, fish, boerewors, beef (stewing, steak, roast, sausage), cold meats, mutton/lamb (chops, stew).
      • High-income consumers: Chicken, eggs, beef (mince, stew, steak, sausage), cold meats, pork, fish, mutton/lamb.
    • The results in terms of the most popular meat option and red meat cuts could provide the red meat industry with important market intelligence in terms of actions to ensure the continued popularity of prominent cuts as well as the identification of ‘underutilised’ cuts. Furthermore, the meat intake data presented in this report could be very valuable from a food intake / nutritional / food security perspective, as it provides more detailed information on the meat consumption patterns of South African consumers.
  • Changes in red meat intake over time:
    • A significantly larger share of the low-, middle- and high-income consumers indicated that they consumed less red meat than 2 years before the survey (Beef: 87% of low-income consumers, 75% of middle-income consumers and 80% of high-income consumers; Mutton/lamb: 72% of low-income consumers, 85% of middle-income consumers and 88% of high-income consumers). These shares are significantly higher than previous research (2003) where 45% of the total sample reported reduced beef intake. Red meat was mainly replaced by chicken meat and some fish. The main reasons for reduced red meat intake (similar to past studies) were high prices (expensive) and some health concerns.
  • Popularity of red meat among household members:
    • Red meat was generally more popular among adult consumers than among children and teenagers. There might be a growth opportunity for the red meat industry if red meat could be made more appealing to younger consumers, e.g. through innovative product formats, child-friendly recipes and consumer health education.

Meat perceptions:

  • About a third of the low-income consumers remove all visible fat before cooking, while about 15% remove some visible fat before cooking beef and chicken. The serving of meat ‘pan drippings’ originating from the cooked meat applied to about half of the low-income consumers.

Red meat safety:

  • When defining red meat safety consumers across the socio-economic spectrum focused on clean meat, clean purchase environment, meat colour, freshness, grading, expiry date, healthiness and good quality.
  • Considering the relationship between red meat quality and red meat safety a large share of respondents perceived the terms to the basically the same and being equally important when purchasing red meat.
  • The large majority of all respondents (78% to 98% of the various socio-economic sub-samples) perceived food safety as an important factor considered when purchasing red meat. However, only about 13% of the low-income consumers and about a third of the middle- and high-income consumers had red meat safety concerns. It could be argued that consumers ‘control’ for food safety by carefully selecting their red meat purchase outlets. It is also important to note that food safety seems to be a ‘non-negotiable’ attribute to consumers – it has to be in place, implying a responsibility on the red meat industry and retailers to ensure the safety of red meat sold to South African consumers.
  • The low- and middle-income consumers were most concerned about the safety of beef, followed by chicken, while the high-income consumers were most concerned about safety of chicken and beef.
  • The most trusted purchase outlets for red meat are dominated by specific trusted butchery shops and formal major retail chain store, while the most risky purchase outlets for red meat are dominated by hawkers / street vendors, spaza shops, small independent retailers, certain butchery shops and certain chain retailers.

Food-away-from-home:

  • The purchasing frequency of take-away meals differed significantly between income groups, with weekly take-away food purchasing observed for 5% of low-income consumers, 19% of middle-income consumers and 29% of high-income consumers. The results confirmed the dominance of chicken as a popular meat choice among all socio-economic groups, even though beef is also a prominent choice among high-income consumers when purchasing take-away meals.
  • The purchasing frequency of restaurant meals differed significantly between income groups, with weekly restaurant food purchasing observed for 6% of low-income consumers, 11% of middle-income consumers and 9% of high-income consumers. In terms of meat types chicken is the dominant option purchased from restaurants by the middle-income group, even though the popularity gap between chicken and beef is less prominent than for take-away meals. Among the high-income sample beef is the most popular option, followed by fish/seafood.
  • Challenges facing the red meat industry includes increasing the appeal of beef within take-away- and restaurant meals, particularly among the middle-income group; and increasing the appeal of mutton/lamb within restaurant meals, among middle- and high-income consumers.

Red meat information sources:

  • The most highly used and trusted red meat information sources for the particular socio-economic sub-segment were the following:
  • Low-income consumers: TV, radio, advertising, doctors, newspapers;
  • Middle-income consumers: TV, family, friends, doctors, recipe books, radio, food labels;
  • High-income consumers: Family, friends, food labels, recipe books, butcheries, doctors, dieticians.
  • Doctors are among top 10 most used and most trusted meat info sources for all income sub-segments;
  • TV and radio are the top 10 most used and most trusted meat info sources for middle income and low income sub-segments. However, the particular channels / stations will vary between LSM groups.
  • Family and friends (possibly linked with social media), recipe books and food labels are among the top 10 most used and most trusted meat info sources for middle income and high income sub-segments.
  • Advertising and newspapers are among the top 10 most used and most trusted meat info sources for low income sub-segment only, while butcheries and dieticians among top 10 most used and most trusted meat info sources for high income sub-segment only.

Red meat classification:

  • Among low LSM consumers there is a very limited understanding and attention given to red meat classification. Even though middle LSM and high LSM consumers also have a limited understanding of red meat classification, around half of these sampled consumers check the grading / classification mark sometimes or often when buying beef or mutton/lamb.
  • The association of red meat classification with meat quality and safety was limited. Even though many respondents did not mention red meat classification / grading directly when defining red meat quality and safety, many aspects related to it was mentioned such as freshness, meat colour, appearance, smell, tenderness, taste and leanness.
  • Among an extensive range of red meat decision factors ‘grading / classification’ was not among the top 20 most important factors. However, many aspects related to red meat grading / classification was important such as appearance, taste, flavour, quality guarantee, meat colour, fat content, juiciness and tenderness.
  • It is interesting to note that the results presented on the radar plots in terms of consumers’ red meat decision factors, the place of purchase is a stronger quality cue to consumers than the certification marks on the meat. This is an important observation and should be further investigated.

Credence / intangible red meat attributes:

  • The most popular intangible attributes among the middle-income consumers were (in order of importance) (% of sample perceiving attribute as ‘very important’ indicated in brackets): environmentally friendly production (54%), free range (49%), no growth hormones given to animals (44%), animal friendly production (44%), breed of animal (43%) and no GM feed given to animals (43%). The question however arises whether these consumers have the purchasing power to afford the price premiums associated with these attributes.
  • The most popular intangible attributes among the high-income consumers were (in order of importance) (% of sample perceiving attribute as ‘very important’ indicated in brackets): no growth hormones given to animals (56%), no GM feed given to animals (49%), environmentally friendly production (48%), animal friendly production (39%) and free range (36%).
  • In terms of demographic variables (LSM group, gender, age, ethnicity, marital status, household income level and education level), within the middle- and high-income samples, the segments deeming intangible attributes as ‘very important’ did not differ significantly from the alternative segments.
  • The most highly used and highly trusted red meat information sources among the middle- and high-income consumer samples for consumers who perceived at least four or more of the intangible attributes as ‘very important’ were TV, family friends, advertising, food labels, recipe books, newspapers, butchers, radio, magazines, retailers, dieticians, food industry, public health recommendations, doctors, farmers and consumer organisations. These results (presented for each intangible attribute separate in the particular chapter) present marketers of red meat with a valuable overview of the marketing channels to use when marketing red meat products with particular intangible product traits.

Market segmentation for specific beef and mutton/lamb cuts:

  • Market segmentation for individual red meat cuts were based on respondents’ consumption frequency for the various cuts, considered at four consumption frequency levels: weekly (‘weeklies’), 1 to 3 times per month (‘monthlies’), occasionally (‘occasionals’) and never (‘non-users’).
  • Among the low-income consumers the most popular red meat cuts (with the highest shares of ‘Weeklies’ and ‘Monthlies’ combined) were: offal in general (78.8%), beef stew (67.1%), beef mince (46.7%) and beef steak (43.0%). Offal was significantly more important among the low-income sample compared to the wealthier samples.
  • Among the middle-income consumers the most popular red meat cuts (with the highest shares of ‘Weeklies’ and ‘Monthlies’ combined) were: beef mince (89.6%), beef stew (84.2%), beef steak (59.1%), beef roast (48.5%), mutton/lamb chops (39.7%), offal in general (32.8%) and mutton/lamb roast (31.6%).
  • Among the high-income consumers the most popular red meat cuts (with the highest shares of ‘Weeklies’ and ‘Monthlies’ combined) were: beef mince (95.1%), beef stew (83.8%), beef steak (79.9%), mutton/lamb chops (69.4%), beef roast (60.5%), mutton/lamb stew (56.0%) and mutton/lamb roast (28.7%).
  • In terms of demographic variables the results indicated that consumers’ consumption frequency of red meat cuts did not generally differ in terms of household’s size and income as well as the respondent’s gender, age and ethnic group. However, the more aggregated wealth level of consumers (in other words whether they were among the low-, middle- or high-income samples) did make a differences in terms of their red meat intake frequency – with more frequent intake generally associated with higher income brackets.
  • In terms of typical weekly expenditure on particular red meat cuts, more regular low-income consumers revealed a tendency to spend more on red meat considering the segments for beef mince and beef steak. More regular middle-income consumers revealed a tendency to spend more on beef mince, beef steak, beef stew, beef roast, mutton/lamb chops and mutton/lamb roast.
  • In terms of typical quantity of raw red meat consumed per week, more regular middle-income consumers revealed a tendency to consume a larger weekly quantity of beef mince, mutton/lamb chops, mutton/lamb roast, mutton/lamb stew. More regular low-income consumer revealed a tendency to consume a larger weekly quantity of beef offal and mutton/lamb offal. The lack of significant differences for the other cuts within the three main samples once again imply that since more regular consumers and less regular consumers of red meat consume a similar quantity of red meat per week, the more regular segments could be consuming smaller quantities per (more regular) eating occasion.
  • For the various red meat cuts, considered for the low-, middle- and high-income samples, this section also presented information on consumers’ perceptions regarding beef and mutton/lamb, purchase factors, and best information sources to use to provide consumers with red meat information.
  • Across red meat cuts and socio-economic samples, consumers were very consistent in terms of their requirements for red meat labels, with preferences for detailed information and reliable information, date information (use-by date, sell-by date, last day of processing) and information pertaining to production processes (particularly in terms of the use of antibiotics / hormones and also free range in some cases).

Red meat labelling – What do consumers want and what do they see on labels?

  • The red meat labelling aspects that are highly desired by consumers and were widely observed on fresh red meat labels were: price, quality guaranteed, sell-by date and brand.
  • Despite being very important to consumers, labelling information relating to fat content, nutritional value and classification were not commonly observed on the fresh red meat labels.
  • In terms of date information packaging date, sell-by date and expiry date were the most commonly found on fresh red meat labels.

POPULAR ARTICLE

Red meat consumer education – key messages and marketing channels focusing on beef

Mrs Hester Vermeulen, Bureau for Food and Agricultural Policy

Prof Hettie Schönfeldt, University of Pretoria

Dr Beulah Pretorius, University of Pretoria

 Acknowledgements: Project funding provided by Red Meat Research and Development SA (RMRD-SA)

PLEASE NOTE:

‘Background’ pictures /photos of the following could work well with this article:

  • Consumer buying beef in a shop
  • Consumer preparing beef in kitchen
  • Eating beef in a restaurant
  • Braai with beef on the grid
  • Example of a nutritional label from a beef product

Introduction:

The share of South African adults within the various socio-economic sub-groups changed significantly from 2005 to 2015, with the marginalised consumers decreasing by 52%, the middle class increasing by 50% and the more affluent consumer group increasing by 32%. The future of the South African red meat industry relies on an industry that are profitable and able to adapt to changes in consumer demand, the production environment and sustainability.

In 2012 the South African red meat industry commissioned a comprehensive consumer study to investigate the red meat behaviour and perceptions of the South African low-, middle- and high-income consumers in Gauteng amongst 586 consumers. The study sample was designed to reflect the income, ethnic and age groups of the South African population. The focus of this article is specifically on the identification of key marketing messages and marketing channels for red meat marketing.

How do South African consumers perceive beef?

Respondents were asked to indicate their level of agreement with a series of statements involving potential attributes of beef, pertaining to health / nutrition, affordability, product usage, product procurement, preparation, sensory quality and potential negative aspects.

Considering the positive perceptions of consumers regarding beef, there is significant overlap between income groups involving the following:

  • Product procurement: Beef is easy to obtain.
  • Product usage: Consumers know how to prepare beef, it is easy to cook the meat, it is versatile, good for entertaining and ideal for braai.
  • Sensory quality: Beef is tasty and tender and it does not smell bad.
  • Health / nutrition: Beef is a source of good quality protein and iron, it is nutritious and helps the body grow.
  • Product origin: Beef is locally produced and not imported.

The aspects which dominated the ‘positive’ set for beef of all income groups were: versatile, tasty, know how to prepare it, easy to obtain, good for entertaining, easy to cook and good quality protein source. Popularity when eating in a restaurant was also applicable to the middle-class and more affluent group, with higher importance in the latter group. Furthermore the more affluent group was also positive about further health / nutrition aspects (such as ‘healthy’ and ‘contains iron’), shelf life at home (‘does not go off fast’) and affordability (‘value for money’ and ‘not a luxury’).

Among marginalised and middle-class groups the major concerns (i.e. negative perceptions) focused on beef being expensive, having long cooking times and could cause health problems. Among the more affluent consumers the major beef concerns focused on specific health aspects (high in cholesterol, could cause health problems, can make me ill) and long cooking times required. A significantly larger share of the low-income sample was negative towards beef in terms of the following beef aspects: expensive, long cooking times required, can make me ill, high in fat and ‘not good for the heart’. In general a higher share of the marginalised group was in agreement with these negative aspects pertaining to beef, in contrast to a lower share of the more affluent consumers. As would be expected, consumers’ concerns regarding the affordability of beef decreased as income levels increased.

How do these perceptions translate into marketing messages to promote SA beef?

To enhance beef consumption in the South African context key marketing messages needs to take these observed perceptions into account. Beef product attributes and perceptions and translated marketing messages are proposed in

Table 1.

Product usage and preparation:

Across the socio-economic spectrum consumers were very positive about beef being versatile, easy to cook, knowing how to prepare it, good for entertaining and ideal for braai. The industry could invest or continue to invest in product- and recipe development to ensure that beef remains versatile, familiar, easy-to-cook, ‘trendy’ and a number one choice when entertaining of having a braai. Innovative ways to reduce beef cooking time for consumers with limited time should also be investigated, as well as innovative and tasty recipes to ‘stretch’ beef in dishes. However, it is important to consider the varying life styles, preferences and budgets of the socio-economic sub-groups in the process.

Sensory appeal:

All consumer segments were very positive about beef being tasty and not smelling bad. The middle-class was more positive about the tenderness of beef, even though tenderness was among the positive perceptions of all sub-groups. Sensory appeal is a critical product attribute for beef, even more so given its price premium about chicken meat. Production and product handling practices should continuously be improved, based on sound scientific research, to ensure ‘better beef’ – satisfying the sensory enjoyment needs of consumers of all income groups (e.g. in terms of taste, tenderness, smell and visual appeal).

Health – food safety:

Only the more affluent group was very positive about beef not spoiling fast at home. The lack of cold-storage facilities in the homes of lower-income consumers could contribute to this observation. However, there seems to be a need for consumer education on safe meat handling practices, particularly among the marginalised and middle-class groups.

Health – nutritional value:

All consumers perceived beef as being nutritious, a good quality protein source, helps the body grow and being a source of iron. Only the more affluent group were very positive about beef being ‘healthy’. The research results suggest that consumers (across the socio-economic spectrum) need to be educated on the nutritional value of beef, pertaining to various aspects such as macro-nutrients (i.e. protein, fat) and micro-nutrients (i.e. vitamins and minerals). However, it should be kept in mind that the complexity of nutritional information communicated to consumers should be tailored to their typical educations levels.

Health – fat & cholesterol:

Over the last decade or two a growing body of scientific publications confirm the trend of consumers moving towards leaner red meat cuts. In this study consumers were concerned about beef in terms of fattiness, being high in cholesterol and the intake of beef linked to heart disease – with the marginalised group being particularly negative. Addressing consumers’ red meat fattiness concerns is critical, even more so in the light of the rising prevalence of overweight and obesity in South Africa. Corrective actions could include the following:

  • Presenting consumers with leaner beef cuts (e.g. through animal production processes and / or trimming of fat from beef cuts before sale).
  • Consumer education on the tasty preparation of leaner beef cuts (including aspects such as fat trimming at home and avoiding excessive fat intake through actions such as serving pan-drippings with meat with a high fat content).
  • Presenting consumers with a balanced and scientifically sound view on issues pertaining to beef fattiness, cholesterol and heart disease.

Product origin:

All consumers were positive that the beef they buy is usually local meat, suggesting some loyalty to locally produced beef. This is even more important if the large quantity of chicken being imported into the country is considered. The industry could do much more to communicate the origin of beef to consumers and extract some value from consumers’ loyalty towards locally produced meat.

Table 1: Proposed key marketing messages translated from consumers’ perceptions regarding beef meat

Product attributes and perceptions Key marketing strategies and messages
Product usage and preparation:
•     Versatile

•     Easy to cook

•     Knowing how to prepare

•     Good for entertaining

•     Ideal for braai

ü Continuous product- and recipe development to ensure that beef remains versatile, familiar, easy-to-cook, ‘trendy’ and a number one choice when entertaining or having a braai

ü Tasty recipes to ‘stretch’ beef in dishes

ü Innovative ways to reduce beef cooking time

Sensory appeal:
•     Beef is tasty

•     Beef is tender

•     Does not smell bad

ü Improved production and product handling practices based on sound scientific research, to ensure ‘better beef’
Health – food safety:
•     Beef do / does not spoil fast ü Consumer education on safe meat handling practices
Health – nutritional value:
•     Beef is nutritious

•     Beef is a good quality protein source

•     Beef helps the body grow

•     Beef is a source of iron

•     Beef is too fatty

•     Beef is high in cholesterol

•     Eating beef causes heart disease

ü Consumer relevant education on the nutritional value of beef, pertaining to various aspects such as macro-nutrients (i.e. protein, fat) and micro-nutrients (i.e. vitamins and minerals).

ü Leaner beef cuts

ü Consumer education on the tasty preparation of leaner beef cuts

ü Presenting consumers with balanced and scientifically sound messages on issues pertaining to beef fattiness, cholesterol and heart disease

Product origin & Affordability:
•     Beef is locally produced

•     Expensive

ü Communicate the origin of beef to consumers

ü Address affordability issues through promoting it as an ‘essential luxury’ or by providing more affordable meat cuts to the consumer

Which communication channels are most suitable to communicate these marketing messages to SA consumers?

Being presented with a list of potential red meat information sources, consumers were asked to evaluate the usage and trust of these sources. Table 2 summarised the most used and trusted information sources amongst the different consumer groups to use in marketing strategies. However, given the diversity of the market the specific channels (e.g. which television channels or which newspapers) as well as the complexity of marketing messages has to be tailored to the behaviour and education levels of the targeted consumers.

Table 2: Highly used and highly trusted red meat information sources (Source: Survey data) 

Category: Information source: Marginalised

group:

Middle-class

group:

More affluent

group:

Printed information sources: Magazines

 

ü
Newspapers

 

ü û
Recipe books

 

ü
Food labels

 

ü
Advertisements

 

ü ü
Medical information sources: Doctors

 

Dieticians

 

û ü ü
Retail information sources: Retail stores

 

ü ü û
Butchers

 

ü ü
Social information sources: Family

 

ü
Friends

 

û
Broadcasting information sources: Television

 

Radio

 

û
Other information sources: Public health recommendations

 

ü ü ü
The food industry

 

û û ü

(NOTES: : Indicates red meat information sources that dominates for the particular sub-group)

Conclusions and implications

Red meat consumption lags behind white meat consumption in South Africa and is losing ground steadily. Marketing efforts to stimulate the consumption of red meat among consumers should build upon aspect where consumers are already positive about beef such as: versatility, know how to prepare, good for entertaining, taste and nutrition (a nutritious meat and a good quality protein source). Furthermore the negative perceptions (affordability, fat and cholesterol content, long cooking time and could be a cause of health problems) should be improved.

Given the dynamic nature of the South African consumer environment with constant socio-economic changes and the influence of global consumer trends, the preferences and behaviour of South African consumers have a very dynamic nature. Subsequently it could be particularly valuable for the South African red meat industry to engage in follow-up surveys of this nature every few years in order to keep track of these dynamic changes.

Please contact the Primary Researcher on the project if you need a copy of the comprehensive report – Hester Vermeulen on hester@bfap.co.za

Amino acid composition of South African beef

Determining the amino acid profile of selected cuts from four age groups of South African beef, as additional to the previously approved project on the nutrient content of South African beef, in order to determine protein quality.

Industry Sector: Cattle and Small Stock

Research focus area: Red Meat Safety, Nutritional Value, Consumerism and Consumer Behaviour

Research Institute: Animal and Wildlife Science, University of Pretoria

Researcher: Prof Hettie Schönfeldt PhD

Team members

Title Initials Surname Qualification
Dr N. Hall Ph.D
Dr B. Pretorius Ph.D

Year of completion : 2017

Aims Of The Project

  • To determine the amino acid profile of South African beef
  • To determine the validity of using nitrogen and a specific Jones factor to define protein quantity
  • To determine the protein quality of South African beef in the context of human nutrition

Executive Summary

Globally protein quality is under the spotlight. The importance of protein quality was emphasized by both the 2007 and the 2011 Food and Agriculture Organization/ World Health Organization (FAO/WHO) Protein and amino acid requirements in human nutrition reports. These reports questioned the validity of current measures to determine crude protein content and protein absorption, and called for more research. Locally, the national Department of Health Directorate Food Control’s most recent legislation on food labelling and advertising requires that in order to make protein content claims, amino acid data in addition to crude protein (nitrogen), is needed.

During this project, raw and cooked beef cuts (prime rib, rump and shoulder) from all four age groups according to the South African classification system were sent for amino acid analyses at the ARC Irene Analytical laboratory.

Aligning with international debates, a literature review was completed to investigate existing literature on the validity of using the Jones factor of 6.25 to quantify the amount of protein from nitrogen within the red meat matrix. Amino acid data obtained was also compared to the use of the Jones factor to quantify the total protein content of red meat, and alternative factors were explored – similar to what has been done by Sosulki et al. in 1990. Mariotti et al (2008) also queried the use of 6.25 as the converting factor for red meat. Our study found that complete amino acid profiles of local beef amounted to 91% on average of protein based on total Nitrogen content (in weight). This indicates that there is an overestimation of protein in beef when the conversion factor of 6.25is used.

For local legislative purposes, the study found that all cuts from all age groups contain adequate quantities of the essential amino acids as required by the R.429 Food Labelling Legislation. This provides the scientific evidence required for South African beef to make protein content and functional protein claims on packaging and in marketing activities.

Technology transfers

  1. Participation of the Human Nutrition and Health Committee Meeting of the International Meat Secretariat (Canada, 1-3 July, 2015) (Addendum 2)
  2. Participation of the Human Nutrition and Health Committee Meeting of the International Meat Secretariat (Oslo, Norway, 15-18 July, 2016) (Addendum 2)

Reports to Industry

  1. NRF-THRIP progress report 2014
  2. NRF-THRIP final report 2015
  3. RMRD SA Progress report 2014
  4. RMRD SA Progress report 2015

Scientific articles

  1. Schönfeldt H.C., Pretorius B. and Hall, N. (2016) ‘Bioavailability of Nutrients’, In: Caballero, B., Finglas, P., and Toldrá, F. (eds.) The Encyclopedia of Food and Health vol. 1, pp. 401-406. Oxford: Academic Press.
  2. Article to be submitted after presenting “Updating and expanding the Food Composition Table for Western Africa“ at International Food Data Conferences (IFDC) – Official INFOODS conference. Center for Science in the Science and Technology Pole, Buenos Aires, Argentina. 11-13 October 2017.
  3. Article to be submitted after presenting “Amino acid and protein content of lean beef“ at International Food Data Conferences (IFDC) – Official INFOODS conference. Center for Science in the Science and Technology Pole, Buenos Aires, Argentina. 11-13 October 2017.

Theses

  1. Hall, N. 2015. Sustainable red meat from a nutrition perspective. University of Pretoria.

Conferences, symposia

  1. Co-author FAO/INFOODS (2017) Updating and expanding the Food Composition Table for Western Africa. 12th International Food Data Conference (IFDC) – Official INFOODS conference.
    Center for Science in the Science and Technology Pole, Buenos Aires, Argentina. 11-13 October 2017.
  2. Schönfeldt, H.C., Hall, N., Pretorius, B. and Van Deventer, M.M. (2017) Amino acid and protein content of lean beef. 12th International Food Data Conference (IFDC) – Official INFOODS conference. Center for Science in the Science and Technology Pole, Buenos Aires, Argentina. 11-13 October 2017.

Literature review

  1. Hall, N.G. and Schönfeldt, H.C. (2013) ‘Total nitrogen vs amino-acid profile as indicator of protein content of beef’, Food Chemistry. 140 (3): 608-612.

Popular Article

Globally protein quality is under the spotlight

Hettie Schönfeldt, Beulah Pretorius, Nicolette Hall, Maricia van Deventer

Department of Animal and Wildlife Sciences, Institute of Food, Nutrition and Well-being, University of Pretoria.

There has been much discussion regarding protein and amino acid requirements for both adults and children over the past few years.

Conventionally, protein content is determined by analysing the total nitrogen content in a food, and multiplying this by a standard conversion factor to obtain protein quantity – referred to as “crude protein”. Because proteins are made up of chains of amino acids, they can be hydrolysed and the separate amino acids can then be measured. The sum of the amino acids then represents the protein content (by weight) of the food. This is sometimes referred to as a “true protein”. This method however needs sophisticated equipment and is more expensive.

A project at the University of Pretoria aimed to determine the protein content and amino acid profile of South African beef (raw and cooked) and to establish if different cuts in the carcass and/or age of the animal influences the amino acid profile of South African beef.

Crude protein and amino acid analyses were done on 36 meat samples from Bonsmara carcasses from fat code two and all four age groups according to the South African Carcass Classification System. Three cuts (rump, prime rib and shoulder) were selected from each carcass and analyses were done on both raw and cooked meat.

Age had no significant effect on the sum of all amino acids (true protein) in both raw and cooked cuts. In the cooked cuts crude protein were found to be significantly different between the age groups for the different cuts. It should however be noted that these differences, although statistically significant, probably have little relevance in terms of human dietary requirements for protein as they differ by less than 2 g per 100 g cooked meat.

The data generated by this study is of further interest as discussions regarding the validity of nitrogen analyses for protein quantity determination and methods used to assess protein quality unfold. Table 1 shows the percentage of total amino acids to protein calculated with the Jones factor. It would be more appropriate to base estimates of protein on amino acid data.

Table 1: Percentage of sum of amino acids (‘true protein’) to protein calculated from total nitrogen using the Jones-factor (‘crude protein’)

Cut Raw / Cooked Percentage (Sum of amino acids / protein calculated from total nitrogen x 100)
Rump Raw 95%
Cooked 89%
Prime rib Raw 97%
Cooked 90%
Shoulder Raw 94%
Cooked 89%

Instead of simply focussing on total protein, attention has shifted to the greater importance of protein quality than actual quantity, emphasising the presence of individual amino acids in a food. One method of measuring protein quality is determining the quantity of the total essential amino acids and the digestibility of the protein source (PDCAAS). Data on the amino acid composition of foods is therefore essential in order to contribute to the current global discussion.

Protein quality answers two important questions namely, how much protein as well as what kind of protein should be consumed. Dietary proteins are classified as either being complete or incomplete. Some foods, such as animal source food, contain all indispensable (essential) amino acids and are referred to as a complete protein. Plant foods, on the other hand, lack one or more essential amino acid, which renders these sources of protein “incomplete”. Amino acids containing sulfur (including methionine and cysteine) and lysine most commonly limit the nutritional value (quality) of proteins in the human diet. Concentrations of these amino acids are, generally, considered lower in plant foods than in food of animal origin. In table 2 the lysine, methionine and cysteine content of commonly consumed food products is reported. Other essential amino acids, lysine and tryptophan, are also consistently found at lower concentrations in plant-based rather than animal-based foods. For example, tryptophan and lysine are limiting in corn; lysine in wheat, sorghum, and other cereals; and methionine in soybeans and other legumes. Including a small amount of lean beef in combination with plant-based foods can increase the protein quality of the meal.

Table 2: Lysine, methionine and cysteine content of commonly consumed food products

Food source  Food Range (mg/100g) from different studies
Lysine Methionine Cysteine
Animal products Beef and Veal (edible flesh) 531–591 147–182 78–182
Chicken (edible flesh) 384–606 88–215 64–114
Offal 375–506 138–181 62–132
Mutton and lamb (edible flesh) 438–589 131–198 63–144
Hen eggs 375–467 181–249 113–189
Fish (fresh, all types) 380–689 120–290 28–144
Legumes Chick-pea 406–463 34–106 50–94
Cowpea 394–479 50–119 48–106
Soya bean 313–477 53–114 51–114
Cereals & grain products Barley 159–250 63–250 81–194
Maize 100–214 53–175 38–200
Millet 100–244 84–246 69–169
Rice (brown or husked) 198–263 117–194 30–79
Rye (whole meal) 151–281 59–181 85–156
Wheat (whole grain) 131–249 63–156 111–212
Roots and tubers Potato 163–488 54–125 7–81

The protein and indispensable amino acid profile of lean beef is reported in table 3. This is compared to the recommended protein requirement of 0.66 g/kg body weight/ day and the amino acid scoring pattern for children older than 3 years, adolescents and adults. According to the South African Food Based Dietary Guideline a serving of red meat can be eaten daily, but should not be more than 90g/day.

Table 3: Dietary protein and indispensable amino acid profile of cooked beef, cow’s milk, cooked soya beans compared to the recommended amino acid scoring pattern for children (3-10years), adolescents and adults

Cooked lean beef Full cream cow’s milk Cooked soya beans Recommended protein and amino acid scoring pattern for older children, adolescents and adults
“Crude” protein (g/100g) 31.8 3.25 18.21 0.66 g/kg/day50kg person = 33g

70 kg person = 46g

Amino acid
(mg/g total protein)
Histidine (His) 28 28 25 16
Isoleucine (Ile) 44 54 44 30
Leucine (Leu) 74 94 74 61
Lysine (Lys) 97 79 61 48
Sulphur amino acids (SAA) Methionine (Met) + Cysteine (Cys) 63 39 27 23
Aromatic amino acids (AAA) Phenylalanine (Phe) + Tyrosine (Tyr) 73 97 83 41
Threonine (Thr) 44 48 40 25
Tryptophan (Thp) 16 12 13 6.6
Valine (Val) 46 59 46 40

The study found that South African beef from all age groups adheres to the requirements as set out by the Department of Health to be labelled and proclaimed as a complete, quality protein.

It is of interest to note that the true protein was consistently lower in the cooked meat compared to the raw meat and that the different cuts varied in the respective amino acid profiles. While the measurement of crude protein (total nitrogen multiplied by a factor) is adequate for many purposes, amino acid data would provide a better assessment of the nutritional value of a food. Through this study the amino acid profile of South African lean beef was determined and is available for future studies.

Acknowledgement: This study was funded by Red Meat Research and Development of South Africa (RMRD SA) and the National Research Foundation Technology and Human Resources for Industry Programme (NRF-THRIP) (Project id: Tp1208076284).

Please contact the Primary Researcher if you need a copy of the comprehensive report of this project – Prof H.C. Schonfeldt on hettie.schonfeldt@up.ac.za