Formal and Informal Red Meat Industry in the Western Cape

Hidden in Plain Sight: A Regional Inquiry into the Size, Scope and Socioeconomic Effects of the Western Cape’s Formal and Informal Red Meat Industries

Industry Sector: Cattle and Small Stock

Research Focus Areas: Animal Health and Welfare; Animal Products, quality and safety, nutritional value and preference; The economics of red meat consumption and production in South Africa

Research Institute: Agriculture Research Institute – Animal Production Institute

Researcher: Dr Nick Vink PhD (Agric)

Title Initials Surname Highest Qualification
Mr. Michael McCullough M

Completion Date 23 August 2018

Aims Of The Project

  • 3.1 To determine and report the size and scope of the informal red meat I industry as well as the informal industry’s effects on food safety, animal health and l welfare and food security with an initial focus on the Western Cape.
  • 3.2 To determine and report the size and scope of the formal red meat industry as well as the formal industry’s effects on food safety, animal welfare and food security with a primary focus on the Western Cape.
  • 3.3 To create and test a combined quantitative and qualitative methodology for determining the size and scope of the red meat industry in South Africa with a primary emphasis on the informal sector, a secondary emphasis on the formal sector as well as recommendations for improving current levels of food safety, animal welfare and food security.

Executive Summary

The genesis of Hidden in Plain Sight was two previous studies of red meat marketing systems: one in a rural Municipality in the Western Cape that discovered an informal shadow industry operating alongside a formal system of abattoirs, supermarkets and independent butcheries; the other in the townships and informal settlements of Cape Town that described an informal marketing system filling a vacuum created by the abdication of the formal system of supermarkets and butcheries. Beyond the scope of both studies was an appreciation of the size and scope of the Province’s informal systems of red meat production, processing and distribution. Hidden in Plain Sight attempts to determine size and scope of the Province’s informal red meat industry, its effects on food security, food safety and animal health and welfare.

Informal livestock farmers pasturing cattle and sheep primarily on Municipal land as well as raising pigs in improvised piggeries furnish livestock for informal processing; i.e. outdoor slaughter and indoor butchery in unlicensed facilities such as home kitchens and food stands. One and two kilo ‘value paks’ are then sold from kitchen butcheries in rural communities. Braai stands located near taxi ranks, train stations and major intersection in the former townships of Khayelitsha, Gugulethu and Nyanga in the Cape Town Metropole receive live animals directly from informal producers located on City land surrounding these communities. The animals are slaughtered on the sidewalk in front the stands or in any other adjacent open space. The muscle meat is sliced into strips and braaied, the heads are skinned, split and charred and the offal is piled on the counter for sale to hawkers or take-home consumers.

The informal system exists in both urban and rural areas to serve the 2.6 million low to very low income households in the Western Cape. In addition to low incomes many urban and rural households live in virtual ‘food deserts’ where, in the absence of transportation either public or private access to food sellers is at best difficult.  Low to very low incomes and lack of access expose over half of the Province’s households to food insecurity and place 29 percent at risk of hunger.

An expectation at the inception of this study was that size and scope of the informal system although unknown would rival the formal red meat system and would be sufficient to serve a significant percentage of the Province’s food insecure households. Such was not the case. Survey data based on inspections of informal production sites throughout the Province, census  and interview data from the Veterinary Service and the Farmer Support and Development programmes of the Western Cape Department of Agriculture and interviews with Municipal Social Development officials yield numbers of informal produced livestock clearly insufficient to serve a fraction of households at risk for hunger. Three recommendations are offered to increase the capacity of the informal industry to serve food insecure households: conduct a comprehensive inventory of public land suitable for informal production; establish an informal production, processing and distribution pilot project in each District Municipality; investigate existing parallel formal – informal marketing systems in Latin America; develop a prototype two tiered regulatory frame work to facilitate food security whilst ensuring food safety.

Please contact the Primary Researcher if you need a copy of the comprehensive report of this project – Dr Nick Vink  on nv@sun.ac.za

Effects of growth enhancers on residues in lamb

The effects of steroidal growth implants and β- adrenergic agonist, alone, or in combination on feedlot performance and residues in lamb

Industry Sector: Cattle and Small Stock

Research Focus Area: Animal Products, Quality and Value-adding

Research Institute: University of Pretoria

Researcher: Prof Edward Webb

Title Initials Surname Highest Qualification
Dr A.L. Le Riche BVSc, MScAgric
Dr Shaun Morris BVSc(Hons), MScAgric

Final Report Approved: 23 August 2018

Aims Of The Project

  • To investigate the feedlot performance of feedlot lambs treated with different steroidal growth implants, alone or in combination with oral beta-agonist supplementation
  • To investigate the effects of different steroidal growth implants, alone or in combination with oral beta-agonist supplementation on the residues in the meat
  • To investigate the effects of different steroidal growth implants, alone or in combination with oral beta-agonist supplementation on carcass and meat quality

Executive Summary

The objective of this study was to compare four commonly used growth promotants in a commercial sheep feedlot. The steroidal growth promotants chosen for this trial were Ralgro (zeranol), Revalor G (Rev G; TBA/oestrogen- 17β), Revalor H (Rev H; TBA/oestrogen- 17β) and Zilmax® (zilpaterol hydrochloride). The growth promotants were compared with one another and within three sex groups, namely ewe, ram and wether (castrates), to determine which molecule or combination of molecules, if any, had the most benefit and profitability when measured against a control group.  Sheep were stratified based on initial weights and then randomly allocated to treatment groups in a completely randomised control study. All sheep originated from the same farm, and they were of  similar age, breed,  transport method,  processing method, feed ( the only difference being  the groups receiving Zilmax® during the last 18 days of feeding, making provision for 3 days withdrawal), weather conditions, housing and time on feed. A time constant termination date was used in this study, in order to measure the performance of lambs in treatment groups over time.

The experimental groups were compared over a 10 weeks feeding period according to growth and carcass parameters. The parameters that were measured were gain, FI (feed intake), FCR (feed conversion ratio), ADG (average daily gain), WCM (warm carcass mass), DP (dressing percentage), CL (carcass length) and CC (carcass compactness). Data was recorded in an Excel spread sheet and checked for accuracy. The effect of experimental treatments on growth and production parameters were analysed by means of the GLM ANOVA procedure in SAS (2006). Differences between treatment means were tested at the P<0,05 level of significance by means of the Bonferroni multiple range test in order to correct for unbalanced data (missing values). Correlations between variables were analysed by means of the Pearson product moment procedure in SAS.

Data was analysed within weeks, treatment phases and also over the entire experimental period. Effects of sex, steroid treatment and beta-agonist treatment and interaction effects were calculated. In terms of growth and slaughter parameters the use of zilpaterol hydrochloride alone proved most effective. The latter can be explained by the repartitioning effect of the BAR which increased protein accretion as a result. Benefits gained were not always statistically significant, however taking cost of treatment into account, there is a definite financial significance when choosing which combination of growth promotants to use. Muscle and liver samples were collected for residue analyses, which indicated no significant residue’s in any of the treatment groups. The current data indicate that the use of the various combinations of growth enhancing molecules in sheep pose no risk to consumers in terms of the presence of residue’s, provided that the molecules are used according to prescribed procedures and dosages.

Please contact the Primary Researcher if you need a copy of the comprehensive report of this project – Prof Edward Webb on edward.webb@up.ac.za

Genetic study on wet carcass syndrome

Detection of quantitative trait loci affecting wet carcass syndrome in sheep

Industry Sector: Cattle and Small Stock

Research focus area: Animal Products, Quality and Value-adding

Research Institute: Agricultural Research Council – Animal Production Institute

Researcher: Lené van der Westhuizen

Title Initials Surname Highest Qualification
Prof MM Scholtz D.Sc.
Prof MD MacNeil Ph.D.
Prof FWC Neser Ph.D.
Prof A Maiwashe Ph.D.
Mrs A Theunissen M.Sc.
Ms M le Roux M.Sc.

Final report approved: 23 August 2018

Aims of the project

  • To map quantitative trait loci affecting wet carcass syndrome.
  • To identify specific loci affecting the predisposition to wet carcass syndrome (detection of a major gene).
  • To develop a diagnostic test for the genetic predisposition to wet carcass syndrome (if a candidate gene can be identified as the cause).
  • If a major gene is not responsible for wet carcass syndrome the second phase of the project will have the aim to develop a polygenic prediction equation for the predisposition of sheep to wet carcass syndrome.

Executive Summary

Wet carcass syndrome (WCS) is a condition predominantly found in sheep, which negatively affects the quality of their carcasses. During the pre-slaughter period, the animal appears to be clinically normal, showing no symptoms of an abnormality. However, after the removal of the skin during the slaughter process the carcass appears to be “wet”. When the description and results of prior research are taken into account, no physiological, environmental or management system was conclusively identified as the causative agent of WCS. Previous research has also not considered a potential genetic basis for WCS or the potential for an interaction of genotype with the environment (stress). Furthermore, the tentative breed-specificity, i.e. Dorper sheep breed, of the condition lends some credence to a potential genetic basis for it. The current study employed the Ovine Infinium® HD SNP BeadChip and a genome-wide association analysis approach to scan the genomes of both afflicted- and unafflicted sheep in search of putative quantitative trait loci associated with the WCS phenotype. This study was not only one of the first in Southern Africa to make use of this specific BeadChip but also the first to investigate the role of genetics as a causative factor of WCS. Muscle samples from sheep carcasses (33 afflicted and 36 unafflicted) were collected from three different abattoirs.

Using a candidate gene approach it was possible to map genetic loci, RYR1 (Chromosome 14) and PRKAG3 (RN¯; Chromosome two) causative of phenotypically similar conditions such as porcine stress syndrome and red, soft and exudative meat to the ovine genome, respectively. The positions of these loci mapped to the ovine genome were not in accordance with the loci showing significant association with the WCS phenotype; and no relationship was found between single nucleotide polymorphisms located within these genes and WCS. Furthermore, along with the latter approach, the test of runs of homozygosity presented similar results as well as providing plausible evidence that WCS is not a recessive inherited condition.

To test for an association between the phenotype (WCS) and a genetic marker(s) i.e. SNPs, a case-control study design was implemented. Given the relatively small sample size of the current study, the results obtained from the GWAS attested strong evidence of at least two loci, oar3_OARX_29903534 and oar3_OARX_113973214 positioned within the non-homologous region of the X chromosome for WCS carcasses. All afflicted animals, both males and females, carried at least one allele for marker oar3_OARX_113973214, which was shown to be related to the WCS phenotype. On the contrary, some of the unafflicted animals also carried this specific allele.  Given the apparent influence of stress on WCS, these unafflicted males and females in all likelihood did not experience adequate levels of stress to manifest the condition post-slaughter. The results of the current study also indicated that WCS may possibly be a rare X-linked inherited condition, provided only female individuals are considered. Finally, two possible major loci involving two major genes, HTR2C and DMD, positioned on the non-homologous region of the X chromosome have been identified as novel positional and functional candidate genes for WCS in sheep.

Please contact the Primary Researcher if you need a copy of the comprehensive report of this project – Lené van der Westhuizen on PienaarL@arc.agric.za

Lamb and Mutton Quality Audit

South African Retail Lamb and Mutton Quality Audit

Industry Sector: Cattle and Small Stock

Research focus area: Animal Products, Quality and Value-adding

Research Institute: Agricultural Research Council – Animal Production Institute

Researcher: Dr Michelle Hope-Jones

Title Initials Surname Highest Qualification
Dr PE Strydom Ph.D Animal Science
Title Initials Surname Highest Qualification
Dr L Frylinck Ph.D Biochemistry
Dr SM van Heerden Ph.D Home Economics
Prof A Hugo Ph.D Biochemistry
Ms J Anderson N D Analytical Chemistry
Mrs JD Snyman N D Food Technology

Final report approved: 23 August 2018

Aims of the project

  • o measure the instrumental/physical quality (shear force tenderness, water holding capacity/cooking loss, fat and muscle colour, collagen properties, oxidative status (rancidity)), sensory qualities and chemical composition of lamb and mutton rib or loin chops (M. longissimus dorsi) from various retail outlets (including brand names and generic products).
  • To determine the reasons for variation in quality by chemical, histological, physical and biochemical tests.
  • To use the information from 3.1 and 3.2 to arrive at a list of factors needed to be addressed in research and/or technology transfer to improve meat quality in South Africa.

Executive Summary

Twenty three products (lamb loin chops) were identified and collected from the shelves of five major retail outlets and twelve smaller butcheries on 14 different dates over a three month period (n=306, certain products where not always available due to drought conditions). Products varied in type, namely Karoo lamb (lamb valued for it unique flavour attributes due to grazing on herbaceous bushes and shrubs from a particular region of South Africa), free range or feedlot. Products also varied in packaging (Modified atmospheric packaging: MAP, PVC overwrap, to openly displayed on shelves) and retailers and butcheries were spread over various socio-economic areas. Price was recorded and shear force tenderness, sensory evaluation (tenderness and flavour), colour of meat, drip loss, cooking losses and meat/fat/bone ratios were measured as properties valued by consumers at or after purchase. Physical, histological and biochemical measurements (proximate and fatty acid analyses, lipid oxidation and collagen) were performed in an attempt to explain variations in consumer related properties.

  • Both instrumental and sensory evaluations showed tenderness to be at a high level of acceptance across the board. The Karoo samples were the most tender with the free-range samples performing the worst especially with regard to sensory tenderness.
  • Karoo lamb stood out for ‘barnyard’ aroma and flavour while free-range samples stood out for ‘Karoo bossie” aroma and flavours meaning they could be distinguished from the other samples and from each other. In both cases however, the scores were of a low intensity. Karoo and free-range lamb are purchased for their distinctive flavour.
  • Karoo and free-range samples lost less drip during cooking compared to the remaining products. Thawing loss was very low in general for all the products.
  • Karoo and free-range products have more loin muscle and less fat per chop compared to feedlot products.
  • Colour of all products was at an acceptable level with no distinct pattern showing for any particular product.
  • Lipid oxidation was at a good level over all products and fatty acid profile were consistent with free-range vs. grain-fed products. This makes the lack of free-range and Karoo flavours more perplexing.
  • Karoo and free-range products were more expensive. Regarding the remaining products, price correlated more with socio-economic area and butchery vs. retailer.
  • In general lamb is of a good quality except for drip loss which needs to be attended to. This could be due to incorrect abattoir practices. Karoo lamb is sold at a premium and its lack of flavours is of concern. The consumer however is able to consistently buy tender loin chops at any retailer or butchery.

Please contact the Primary Researcher if you need a copy of the comprehensive report of this project – Michelle Hope-Jones on hopejonesm@arc.agric.za

Nutrient content of lamb and mutton offal

The nutritional composition of South African lamb and mutton offal

Industry Sector: Cattle and Small Stock

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

Research Institute: University of Pretoria

Researcher: Dr JL Linde du Toit

Title Initials Surname Highest Qualification
Prof HC Schönfeldt PhD

Ms C Muller MSc
Dr N Hall PhD
Ms M Bester MSc
Ms D Human Matric

Final report approved: 23 August 2018

Aims of the project

  • To determine the nutritional composition of South African lamb and mutton offal products (raw and cooked)
  • To determine yield, retention and physical composition of the different cooked offal products to ultimately determine the edible portion of each product
  • To incorporate the nutritional composition data and physical composition data into the national food composition tables as well as the food quantities manual of the Medical Research Council

Executive Summary

Offal, also called variety meats, or organ meats or the ”fifth quarter”, have been overlooked in the past in dietary guidelines and recommendations, irrespective of their potential contribution to food and nutrition security. This study focussed on understanding the physical and nutrient composition, as well as the potential nutritional contribution of lamb and mutton offal, when used in the correct amounts, to South African diets.

Significant amounts of protein, iron and zinc (three nutrients of concern in South Africa) can be found in selected organ meats which compared favourably with beef and lamb muscle meat cuts. The most significant findings of the study were the high levels of protein (>10g/100g) found in all cooked lamb and sheep offal cuts ranging from 14.26g/g (cooked lamb intestines) to 32.6g/100g (cooked sheep kidneys). High levels of total iron were found in cooked sheep lungs (TFe=10.73mg/100g); cooked sheep spleen (TFe=11.71mg/100g); cooked sheep liver (TFe=7.95mg/100g) cooked lamb lungs (TFe=8.368mg/100g) and lamb spleen (TFe=22.83mg/100g).

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. 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. Foods containing all essential amino acids (indispensable amino acids) are referred to as a complete protein. The sum of the essential amino acids for lamb and mutton offal varies between 4.2 g/100g and 8.1 g/100g for mutton tongue and liver respectively. The study found that South African lamb and mutton offal adheres to the requirements as set out by the Department of Health to be labelled and proclaimed as a complete, quality protein.

Offal products contribute consistently to the diet not only in terms of essential fatty acids such as linoleic acid (C18:2n-6) and arachidonic acid (C20:4 n-6), but also eicosanoic (arachidic) acid (C20) and docosanoic acid (C22) polyunsaturated fatty acids. Ruminant meats and oily fish are the only significant sources of preformed and C22 PUFA in the diet (Enser, et al., 1998; Wyness, et al., 2011). Although human beings have the metabolic capacity to synthesize C20 and C22 fatty acids from the n-6 or n-3 precursors of linoleic and α-linolenic acid respectively, an increase in the consumption of C20 and C22 n-3 polyunsaturated fatty acids could overcome the perceived imbalance in the ratio of n-6:n-3 polyunsaturated fatty acids in modern diets.

Based on the results of this study South African lamb and mutton offal cuts can be considered a good source of protein and also a nutrient dense food source. Due to the current state of nutrition in South Africa such foods are important commodities and the promotion thereof should be prioritised.

Please contact the Primary Researcher if you need a copy of the comprehensive report of this project – Beulah Pretorius on beulah.pretorius@up.ac.za

Slaughter conditions to optimise chevon meat quality

Determination of slaughter conditions to optimise chevon visual and eating quality

Industry Sector: Cattle and Small Stock

Research focus area: Animal Products, Quality and Value-adding

Research Institute: Agricultural Research Council – Animal Production Institute

Researcher: Dr L Frylinck PhD

Title Initials Surname Highest Qualification
Prof PE Strydom PhD
Prof EC Webb PhD Animal Science
Dr P Pophiwa PhD Animal Science
Prof LC Hoffman PhD Animal Science
Ms GL van Wyk MSce (Registered for PhD)
Ms JD Snyman ND Histologie

Final report approved: 23 August 2018

Aims of the project

  • 3.1.1 To determine the expression of genomic markers in five South African purebred genotypes – Bos indicus
  • To determine the optimum slaughter procedures (electrical stimulation for 15 – 60 seconds or delayed/step wise chilling – time determined by optimal pH) for carcasses from castrated and intact male goats of two breed types: Boer Goats and Indigenous Veld Goats (IVG, Eastern Cape Xhosa or Northern Cape Speckled Goats
  • To evaluate the tenderness and connective tissue characteristics in six different muscles m. longissimus thoracis et longissimus (LTL), m. semimenbranosus (SM), biceps femoris (BF), supra spinatus (SS), infra spinatus (IS) and semitendanosus (ST) in electrical stimulated carcasses of Boer Goats and IVG from castrated and intact male goats.
  • To evaluate the tenderness and calpain system ageing related characteristics in m. longissimus thoracis et lumborum (LTL) and m. semimembranosus (SM) muscles of electrical stimulated and non-stimulated carcasses of Boer Goats and IVG from castrated and intact male goats.
  • To evaluate sensory attributes and other meat quality characteristics of chevon from the respective post-slaughter treatments in m. longissimus thoracis et lumborum (LTL) and m. semimembranosus (SM) muscles of electrical stimulated and non-stimulated carcasses of the two breed types; Boer Goats and IVG from castrated and intact male goats

Executive Summary

The demand for goat meat in South Africa is relatively low because of traditional perceptions of off smells, off flavours and expected toughness. Perceptions also exist that Indigenous Veld Goat (IGV) produce tougher meat than Boer Goat (BG) specially bred to be a meat producing breed. The name indigenous goat is perceived as being small and not suitable for meat production. It is now discovered that some Indigenous Eco-types of Southern Africa, compare well with the Boer goat in size, can also produce good meat products if good farming and rearing practices are followed. Except for the advantage to preserve the indigenous breeds for the future generations, these breeds are well adapted to the harsh climate conditions in Southern Africa and are hardy with minimum need for veterinary intervention. Production and slaughter procedures should be adapted to suit the characteristics such as the low glycolytic potential and low carcass fat of goat carcasses. There is therefore a need to optimise the pre- and post-slaughter procedures in order to optimise the chevon (goat meat) visual and eating quality.

The first aim were investigated by applying different pre- and post slaughter procedures such as castration or not, applying electrical stimulation for 20 and 30 seconds or apply stepwise chilling. The monitoring of the muscle pH and temperature, muscle energy, meat colour and tenderness showed that either controlled step wise chilling or electrical stimulation of at least 30 sec will prevent cold toughening and produce ideal conditions for the intra muscular proteolytic enzymes to optimally function. It was found that castrated animals produced more tender meat than intact carcasses, but that more subcutaneous fat were produced, which could be advantageous to its eating experience. Both breed types: Boer Goats and Indigenous Veld Goats (IVG, Eastern Cape Xhosa or Northern Cape Speckled Goats, showed the same advantage in tenderness and colour if slaughter conditions were optimised.

The intrinsic characteristics of the six different muscles m. longissimus (LTL), m. semimenbranosus (SM), biceps femoris (BF), supra spinatus (SS), infra spinatus (IS) and semitendanosus (ST) differed from each other as expected, but castrated muscles had an higher intramuscular fat content – up to 4% than that on intact carcasses – similar in both breed-types tested. Percentage collagen solubility did not differ between the different muscles, but the total collagen measured in each muscle type did differ. Thus is optimal cooking method important.

Evaluating the tenderness and calpain system ageing related characteristics in m. longissimus thoracis et lumborum (LTL) and m. semimembranosus (SM) muscles of electrical stimulated and non-stimulated carcasses of Boer Goats and IVG from castrated and intact male goats confirm that the breed types did not differ in tenderness, but castration do have an advantageous effect on tenderness. It is said for beef that sarcomere length (SL) longer than 1.7 µm does not influence tenderness, but in this project it was obvious that the shorter 1.8 µm sarcomere length compared to that of our first subproject of 2 µm could have influenced meat tenderness. It is said that the calpain system works more effectively when the SL length is longer.

Sensory panel evaluation showed attributes and other meat quality characteristics of chevon from the respective post-slaughter treatments in m. longissimus (LTL) and m. semimembranosus (SM) muscles of electrical stimulated and non-stimulated carcasses of the two breed types; Boer Goats and IVG from castrated and intact male goats. Overall it seems like the sensory panel found the LTL and SM muscles tough, although the shear force measurements was not exactly inline with their findings. As mentioned before, the slaughter conditions could have been chosen better, for instance the ES should have been 30 sec and not 20 sec. Delayed/stepwise chilling could have given better results. I do recommend though that if a future sensory panel study is being done, mutton should be included to remove the possibility of biasness. Although I have no reason to doubt the professionalism of the panel, I do think that there could be a possibility of a negativity towards goat meat.

The evaluation of carcass characteristics and yield of electrical stimulated and non-stimulated carcasses of the two breed types; Boer Goats and IVG from castrated and intact male goats (additional aim) showed more differences between castrated and non-castrated carcasses than between carcasses of the two breed types. The dressing percentages did not differ between the castrated breeds, but was a bit higher that that of the intact carcasses. There was no significant differences in the percentage meat yield between breeds, although the different commercial cuts could differ a bit in sizes, mainly because of different ratios and form of different parts of the carcass that is genotypic-ally expected.

From this project a better understanding is formed on how goat temperament differ from other farm animals, that pre and post slaughter conditions must be adapted to take their unique characteristics into account. A small change in slaughter practice can have a mayor impact on the end product. Information acquired from these and future research should be disseminated to the farmers, producers and specific abattoirs that apply to special slaughter facilities and management for chevon production.

.Development of the market for chevon in South Africa would offer more diversity of species for red meat producers and especially benefit emerging farmers who produce over 90% of the goats in South Africa. There are good indications that goats can yield chevon or kid of acceptable quality to consumers, providing that animals of an appropriate age and sex group are slaughtered, handled and fed well during production and slaughter so as to minimise stress and prevent cold shortening.

Please contact the Primary Researcher if you need a copy of the comprehensive report of this project – Lorinda Frylinck on lorinda@arc.agric.za

Brine injection of beef

The effect of moisture enhancement by brine injection on the chemical, microbial and sensory quality of beef

Industry Sector: Cattle and Small Stock

Research focus area: Animal Products, Quality and Value-adding

Research Institute: Animal Production Institute, Agricultural Research Council (API-ARC)

Researcher: Dr Phillip Strydom PhD Animal Science

Research Team: Prof Arnold Hugo PhD, Dr C Bothma PhD, Dr C Charimba PhD, Mr M Cluff M.Sc Agric, Ms E Roodt M.Sc Agric, Mr Z Kuhn B.Sc Agric Hons, Mr H Steyn B.Sc Agric Hons, Ms E Moholisa M.Sc Agric, Dr M Hope-Jones PhD, Ms MM Magoro, Mr CA Seomane, Mr WK Seanego, Dr SM Van Heerden PhD, Ms OC Sehoole, Ms TM Mokhele, Ms JH Masilela

Final report approved: 14 September 2017

Aims of the project

  • To determine the effect of injection of non-nitrite moisture enhancing injection brines on the nutritional value of beef.
  • To determine the effect of injection of non-nitrite moisture enhancing injection brines on the chemical and microbial stability of beef under refrigerated and frozen storage.
  • To determine the effect of injection of non-nitrite moisture enhancing injection brines on the textural and sensory properties of beef.

Executive Summary

The effect of different injection levels of non-nitrite brines on meat quality characteristics of unaged and aged beef loins was investigated. Beef loin cuts aged for 3 or 10 days were injected with 5, 10, 15 or 20 % brine (weight basis) and compared with non-injected loins with regards to nutritional value, sensory and textural quality, water holding properties, and colour, chemical and microbial stability.

The results illustrated that brine injected in beef loin are retained between 50 to 70 % of injection levels. This resulted in a clear nutrient dilution, best illustrated by the decrease in protein content from 21.1 % in the Control loins to 18.5 % in the loins injected to a target yield of 20 %. The dilution of protein became evident only at an injection level of 10 % and higher but did not increase further with higher levels of injection. Brine injection also increased the levels of phosphate (35 %) and salt (50 %) and the effect was consistent across all injection levels. This is very important since salt and sodium content of especially meat products are currently under the spotlight with new legislation on sodium levels of meat products being implemented on 30 June 2016.

The chemical stability of beef loin as measured by TBARS (measurement of rancidity) was not affected by brine injection.  Neither fresh samples, displayed for 6 days, or frozen samples, stored for 180 days, were affected, despite the fact that salt is a pro-oxidant and chemical deterioration was expected with brine injection.

Colour and colour stability were affected by brine injection.  Initial colour (just after treatment) measured as chroma (typical colour of fresh meat) was negatively affected only at injection levels above 10%.  However, as days on display continued (up to 6 days), all injected samples showed poorer colour stability (lower chroma values) than Control samples.  Likewise, injected samples were duller (lower values for lightness, L*).

Brine injected samples tended to show higher initial (day of injection) total aerobic micro-organism counts (0.5 – 0.7 of a log) likely due to the recirculation of the brine during application. However, microbial growth was later (day 6 on the shelf) inhibited, probably by the potassium lactate in the brine mix, eventually leading to the brine injected samples having lower total aerobic bacteria loads (between 0.5 and 0.8 of a log) than Control samples.  Also because of recirculation of brine, yeasts and molds were higher in injected samples (0.8 to 1.0 log) after injection, but differences between Controls and injected samples became insignificant after 6 days on the shelf.

Both Warner Bratzler shear force and sensory tenderness showed beneficial effects due to brine injection even at levels as low as 5 %. A slight linear increase (lower shear force and higher tenderness score) was observed with increasing level of injection although the effect was not statistically significant above 10 % injection level. The taste panel also scored injected samples higher for juiciness and although these scores increased slightly with level of injection, no significant effect was observed above 10% levels. As expected, the taste panel also scored injected samples higher for saltiness, but no off-flavours were identified.

Another advantage of brine injection was a reduction in thawing and total cooking losses. The maximum effect was observed at 5 % injection level and cooking loss slightly increased as injection level increased.

In conclusion, it seems that the advantages and disadvantages of brine injection is correctly balanced by the 10% brine injection limit enforced by the Agricultural Product Standards Act, 1990 (ACT No. 119 of 1990; 30 January 2015) for beef. Brine injection levels above 10% showed no additional effect on eating quality. Likewise, the negative effect on colour of freshly displayed meat deteriorated at levels above 10%, while the protein dilution effect also became evident at 10% level. Higher salt irrespective of injection level may be a health concern.

Please contact the Primary Researcher on the project if you need a copy of the comprehensive report – Philip Strydom on PStrydom@arc.agric.za

Amino acid composition of South African beef

Full Title of the Project

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

Researcher: Prof Hettie Schönfeldt PhD

Team members: Dr Nicolette Hall PhD and Dr BeulahPretorius PhD

Research Institute: Animal and Wildlife Science, University of Pretoria

Final report approved: 14 SEPT 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

Popular articles and media

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.

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

Blackfly outbreak predictive model

Full Title Of The Project

Development of a predictive management model for Orange River blackfly outbreaks.

Industry Sector: Cattle And Small Stock

Research Focus Area: Animal Products, Quality and Value-adding

Research Institute: University of KwaZulu-Natal

Researcher: Dr Nicholas Rivers-Moore PhD

Research Team: Dr Helen Dallas PhD, Dr Robert Palmer PhD, Mr Sashin Naidoo BSc (Hons), Ms Esther Ndou BSc (Hons)

Final report approved: 14 SEPT 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

Blackfly outbreaks on the Orange River impact on the agricultural sector through loss in conception, stock mortalities and loss in body weight gain, with losses of over R333 million pa. The Blackfly Control Programme has been in place for some twenty years, using a combination of bacterial and organophosphate applications at river breeding sites. This should have resulted in as many years worth of monitoring data, which, in analysis with flow data, would have provided a useful long-term dataset. Given acknowledged challenges, this has not been the case to the degree hoped for, with periodic outbreaks of blackfly continuing to occur, and the monitoring dataset being patchy and seldom evaluated. New thinking is needed that builds on existing research to reduce the chances of repeated outbreaks.

The aims of this study were threefold: to test and refine an existing Bayesian network predictive model of blackfly outbreaks; to undertake climate change scenario analyses to assist with future planning; and to provide an evaluation framework for blackfly monitoring data.
Fourteen sites between Douglas and Blouputs were monitored over four surveys: November 2015; March 2016; July 2016 and December 2016.

Data collected were blackfly samples (by species, density and relative abundances), hydraulic data (current velocities associated with multiple sample points per site), and water quality data (spot measurements of pH, conductivity, turbidity). Hourly air temperature data has been collected for 13 sites using Hobo TidBit data loggers, for 4 November 2015-5 December 2016. Water quality was fairly consistent between sites, but showed seasonal variation. Conductivity and pH had little impact on blackfly species patterns, with the exception of very high (> 1000μS.cm-1) conductivities in the irrigation return flow channels. Diatom data do, however, suggest that conductivities in the main Orange River have been increasing. Turbidity was a key driver in triggering ecosystem switching between dominance of pest blackfly species, and other blackfly species co-occurring with benthic algae.

Data confirm that the Orange River system switches between two states, viz. a high turbidity state favouring pest blackfly, and a clearer state favouring algal growth and where blackfly numbers are lower. Flow volumes and water temperatures affect turbidity levels, efficacy of larvicides, and availability of habitat for various ecosystem components (benthic algae, blackfly species). Thresholds were successfully identified from the abiotic-biotic relationships, which were incorporated into a Bayesian network model to predict the probability of blackfly outbreaks.

A predictive management framework was successfully constructed. An evaluation framework where ongoing monitoring by the Department of Agriculture, Forestry and Fisheries, and stakeholder involvement has been integrated through the development of a mobile phone App with an associated website. These are available through the Google Play App store (search for “Muggies”) and at www.muggies.org respectively. These also include links to two YouTube videos explaining how to download the App and to upload data, with explanations of the scoring systems. All data uploaded makes use of Google Pins, so that the data are geo-referenced. Model predictions are available to users.

Additional comments

A follow up article in Landbouweekblad has been confirmed with Landbouweekblad staff. Both MSc studies are due to be submitted in the next 1-3 months respectively. Two scientific papers from this research are currently being prepared for submission and review.

Aims of the project
To test and refine the recently developed pilot probabilistic blackfly outbreak model by inclusion of temperature and turbidity data, and using previous flows and monitoring data
To undertake climate change scenario analyses to assist future management planning
To provide an evaluation framework for monitoring data of blackfly larval densities, based on the outbreak model

Please contact the Primary Researcher if you need a copy of the comprehensive report of this project –
Nicholas Rivers-Moore on blackfly1@vodamailcom

 

The food composition of raw and cooked beef offal

The food composition of raw and cooked beef offal (A Pilot study, as a pro-active activity)

Industry Sector: Cattle and Small Stock

Research focus area: Red Meat Safety, Nutritional Quality and Value

Research Institute: ARC-Animal Production Institute

Researcher: Dr SM van Heerden

Research Team: Dr LE Smit, Mrs MM Magoro, Dr IB Zondagh, Mrs JM van Niekerk, Mrs J Masilela, Mrs C Rapelego

Final report approved: 2017

Aims of the project

  • To determine selected nutrients in a pilot study of raw and cooked, red and white South African beef offal
  • To determine the total profile of nutrients should the results from the pilot study indicate the need for this?
  • To make the data on the nutrient composition of South African beef offal available to the MRC to be included
  • Into the South African Food Composition Tables of the Medical Research Council (MRC)
  • To compile and publish a comprehensive booklet on the nutrient content of South African beef offal

Executive Summary

Scientific literature on the nutrient content and food composition tables of offal is relatively scarce. However the nutritive value of all food products including meat and meat products is important, in view of the consumer interest and demand for a healthier lifestyle (Pearson & Tauber, 1984). Therefore, there is a great need for more detailed information on food with adequate nutritive value, especially protein, for the informal and poorer sections of the population in South Africa.

With the WHO’s estimation that 5 million people are dying every year from starvation, more attention should be given to the possibility of using proteins such as offal (beef, sheep), as protein sources in the diet (Poonam & Lawrie, 1986:144).

Offal, or organ meats, refers to the internal organs and entrails of a butchered animal, makes up a substantial portion of an animal’s meat weight. The word does not refer to a particular list of edible organs, but includes most internal organs other than muscle and bone. http://en.wikipedia.org/wiki/Offal). It is also described as those parts of a meat from a carcass which are used as food but which are not skeletal muscle. It covers insides including the heart, liver, and lungs (collectively known as the pluck), all abdominal organs and extremities: tails, feet, and head including brains and tongue. In the USA the expressions “organ meats” or “variety meats” are used instead (http://www.offalgood.com/what-is-offal).

In South Africa offal is mostly enjoyed by South Africans of diverse backgrounds. Due to the popularity of this dish, it is one of the few customs that white (especially Afrikaners) and black South Africans share. Offal dishes in South Africa include stomach, hooves, shin, intestines, liver, head, tongue and very rarely in certain communities, testicles, and are consumed ‘fresh’ (i.e. not frozen).

Please contact the Primary Researcher if you need a copy of the comprehensive report of this project – Ina van Heerden on Ina@arc.agric.za