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: Agriculture Research Institute – Animal Production Institute
Researcher: Dr Phillip Strydom PhD Animal Science
|Mr||Z||Kuhn||B.Sc Agric Hons|
|Mr||H||Steyn||B.Sc Agric Hons|
|Ms||JM||Boikhutso||MInst. Agrar: Food Production and processing|
|Mr||CA||Seomane||Grade 8, Meat Technology Research Assistant, 27 years’ experience|
|Mr||WK||Seanego||Grade 7,Meat Technology Research Assistant 11 years’ experience|
|Ms||OC||Sehoole||BSc Food management (4 years)|
|Ms||TM||Mokhele||BInstAgrar Food Processing (4 years)|
|Ms||JH||Masilela||Grade 9, sensory research assistant 26 years experience|
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.
Year of completion : 2017
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.
THE EFFECTS OF BRINE INJECTION LEVEL AND POST MORTEM AGING ON
SENSORY AND PHYSICAL CHARACTERISTICS OF BEEF LOIN
Phillip E. Strydom1,2*, Zarlus Kuhn3, Celia J. Hugo3 and Arno Hugo3
- Animal Production Institute, Agricultural Research Council of South Africa, Irene, 0062, South Africa
- Department of Animal Sciences, Stellenbosch University, Stellenbosch, 7602, South Africa.
- Department of Microbial, Biochemical and Food Biotechnology, University of Free-State, Bloemfontein, South Africa.
*Corresponding author email: email@example.com
Abstract – The enhancement of beef, pork and chicken with brine solutions has become common practice in many countries.
The combined effects of aging and brine injection level on beef quality is unknown. Our study investigated the effects of five
brine injection level (0, 5, 10, 15 20%) combined with post mortem aging period (3 and 10 days) on sensory characteristics of broiled beef loin. Injected samples were scored higher for saltiness but aging reduced the effect. Brine injection had no effect on flavour but tenderness was improved up to 15% injection level. Apart from 0 and 5 % injection levels, aging had no effect on tenderness score. Juiciness was improved up to 10% injection level after 10 days aging and up to 5 % injection level for 3-day aged cuts. The results suggest that a maximum of 15% brine injection will give the best sensory results and save on post mortem aging time.
Key Words – tenderness, juiciness, saltiness.
Brine injections have been used in the poultry industry since the 1950’s . Red meat processors saw this technology
as an opportunity to improve beef and pork palatability that deteriorated as a result of the production of increasingly
leaner animals that contain less fat [2,3,4], although atypical flavours may also develop [2, 3]. Hamling et al.  found
that post mortem aging could be substituted by brine injection. High levels of injection may not necessarily improve
eating quality while other negative effects such as purge may also occur . The abuse of brine injection of poultry meat
in the South Africa resulted in legislation stipulating a maximum of 10% to 15% brine for whole carcasses and portions,
respectively after extensive research. However, brine injection of beef in South Africa was limited to 10% without any
scientific verification . Our study investigated the effects of post mortem aging and brine injection levels on sensory
quality of loin cuts of young grain-fed beef.
I. MATERIALS AND METHODS
Sixty beef loin primal cuts were subjected to five brine treatments: a non-injected control and four groups respectively injected to 5, 10, 15, and 20% level with a salt, sodium tripolyphosphate (STPP), potassium lactate containing brine; and two aging periods: 3 and 10 days post mortem. Loin steaks were oven-broiled and evaluated by a ten-member trained sensory panel on an 8-point hedonic scale for aroma, juiciness, tenderness/texture, beef flavour intensity,
metallic/tin-like/bloody, chemical (salty), and sour off-flavours. Data were subjected to analysis of variance for a splitplot
design with injection level as whole plots and days post mortem as sub-plots.
II. RESULTS AND DISCUSSION
Despite adding salt to the control samples, injected steaks scored higher values for saltiness, although level of injection
did not have an effect (Table 1). The effect of injection was less for cuts aged 10 days than for those aged 3 days. Knock
et al.  reported higher scores for typical beef flavours, when beef loins were enhanced with KCl brine to 8.5% level,
especially after 9 days aging. Although the different brine levels in our study had similar levels of salt, Knock et al. 
showed higher scores for saltiness and rancidity when salt levels were increased. In contrast to our study, Grobbel et al
 reported off-flavours, such as salty, metallic or chemical descriptors for brine injected beef loin. Injected steaks
scored higher for tenderness in our study irrespective of aging period. Higher injection levels generally gave better
results, although the effect plateaued at 15% injection level for 3 day aged steaks and at 10% injection level for steaks
aged for 10 days. Injected steaks also scored higher for juiciness. The effect of injection level on juiciness plateaued at
10% for steaks aged for 3 and at 5% for steaks aged for 10 days. Knock et al.  found no effect of brine injection will follow later (8.5%) on beef loin tenderness or juiciness, while Hoffman et al.  reported similar results as our study for four unaged muscle types injected to a 15% level. Hamling et al.  reported higher scores for tenderness, flavor and juiciness at 20% injection levels and this was unaffected by aging to 14 days. In our study, added effects of aging on tenderness and
flavour were found at 5 % injection level. Aging had no effect on juiciness perception, but 10 day aged samples injected
to 10 and 15% levels scored lower than 3 day aged samples. Likewise, all 10 day aged injected samples, except 20%,
scored lower for saltiness than 3 day aged samples.
Ten percent seems to be the optimum injection level for improved juiciness and tenderness of loin primals, while flavour
is not affected by brine injection. Perception of saltiness due to brine injection is reduced when samples are aged. In
general, brine injection can save on post mortem aging time with regards to improvement of tenderness.
PE Strydom thanks Dr Ina van Heerden and her sensory team for sample testing.
1. Buchanan, B. F. (1955). Process for Treating Poultry. United States Patent Office. Patent 2 709 658, application 17
April 1951. https://docs.google.com/viewer?url=patentimages.storage.googleapis.com/ pdfs/US2709658.pdf.
2. Hoffman, L. C., Vermaak, A., & Muller, N. (2012). Physical and chemical properties of selected beef muscles
infused with a phosphate and lactate blend. South African Journal of Animal Science 42: 317–340.
3. Grobbel, J. P., Dikeman, M. E., Hunt, M. C., & Milliken, G. A. (2008). Effects of different packaging atmospheres
and injection-enhancement on beef tenderness, sensory attributes, desmin degradation, and display color. Journal of
Animal Science 86: 2697–2710.
4. Knock, R. C., Seyfert, M., Hunt, M. C., Dikeman, M. E., Mancini, R. A, Unruh, J. A., & Monderen, R. A. (2006).
Effects of potassium lactate, sodium chloride, and sodium acetate on surface shininess/gloss and sensory properties
of injection-enhanced beef strip-loin steaks. Meat Science 74: 319–326.
5. Hamling, A. E., Jenschke, B. E., & Calkins, C. R. (2008). Effects of aging on beef chuck and loin muscles enhanced
with ammonium hydroxide and salt. Journal of Animal Science 86: 1200–1204.
6. Miller, R. 1998. Functionality of non-meat ingredients used in enhanced pork. Pork Quality Facts. National Pork
Board, Des Moines, IA, pp. 1–12. http://articles.extension.org/pages/27340/functionality-of-non-meat-ingredientsused-
7. Government notice No. 55 of 30 January 2015. Regulations regarding the classification and marketing of meat.
Department of Agriculture, Forestry and Fisheries, Republic of South Africa. http://www.gov.za/sites/
Please contact the Primary Researcher if you need a copy of the comprehensive report of this project – Dr Philip Strydom on firstname.lastname@example.org