<OL> <LI> To utilize beef gelatin to increase water holding capacity (WHC), reduce oxidation, and reduce microbial growth on freshly harvested beef carcasses and wholesale cuts. <BR>Discussion: Gelatin solutions will be generated from commercial beef gelatins at multiple concentrations and bloom strengths. Preliminary work has demonstrated that beef gelatin concentration should be approximately 25 percent because of the lower Bloom. Gelatin incorporation will increase WHC via creating a barrier upon contact with post harvest carcasses and through absorption into the outer most layers of wholesale cuts via vacuum tumbling. Due to its hygroscopic nature gelatin will reduce water loss in the form of purge. Since the surface will be hydrated, there will be fewer free radicals available for lipid oxidation as well as minimal oxygen-meat surface interaction. Microbial growth will also be reduced due to less surface/free water on the meat as well as less available gasses needed for growth. Carcasses and wholesale cuts will be obtained and processed at Mississippi State University or Auburn University. The participating university will be chosen dependent upon their slaughter capacity and allowed treatment to the carcasses and cuts. <LI> To evaluate ingredient additives (such as antimicrobials (acidified sodium chlorite, cetylpyridinium chloride, etc.), antioxidants (plant extracts (garlic and rosemary) and processing aids (sodium bicarbonate, sodium triphosphate) to further increase WCH and reduce bacterial populations. <BR>Discussion: Ingredient additives will be utilized to increase the pH of the meat. By increasing the pH, WHC will automatically increase since the proteins will be able to physically and chemically bind more water. These additives will also aid in the reduction of "warmed-over" flavors while stabilizing meat color. Antimicrobials in the gelatin solution will further suppress or kill bacteria on the basis that ASC converts chlorite ions into chlorous acid to inhibit cellular protein synthesis through the attack of sulphide and disulphide linkages of amino acids in the bacterial proteins (Schmidt et al., 1984 and Kross, 1984) while CPC permeates and degrades bacterial cell walls due to its positively charged cetyl group binding to the negatively charged bacterial cell walls (Huyck, 1944; Maeda et al., 1996). Antioxidants will bind free radicals to arrest the oxidation process of lipids on the surface of carcasses and wholesale cuts. Multiple concentrations of additives will be evaluated for their functionality in order to meet all objectives. These steps will create a synergistic effect against microbial growth, purge, and oxidation to increase financial return for the industry while increasing quality for consumers.
NON-TECHNICAL SUMMARY: Consumer confidence is a major factor in repeat purchases in that if a previous product was not convenient, microbially safe, acceptable or a value the consumer will not repeat that purchase. This project will show that, utilization of gelatin as a coating ingredient will increase quality and meat repeat purchases by increasing water holding capacity and yield while reducing oxidation and microbial growth. This system of processing utilizing gelatin will not require added labeling to the whole carcass as it is considered a process similar to acidification treatments for pathogenic bacteria and extra labeling will not be required in wholesale cuts as gelatin (if same species) is allowed to be added on an "as needed" basis. Some labeling queries may arise in regards to antioxidant/antimicrobial use, but that will be addressed by using those already approved for use at or below accepted levels. Increased yield and quality will be directly beneficial to the industry as more meat will be sold on a pound basis due to yield and more meat will be purchased as a result of increased quality.
APPROACH: Beef carcasses will have gelatin applied via a pressurized hand sprayer to one side of the carcass. Time after slaughter will be utilized for three slaughter treatments (0 time = immediately after slaughter, 1 time = thirty minutes after slaughter and 2 time = one hour after slaughter) so that carcass surface temperatures can be monitored to understand the coating capabilities of different gelatin concentrations. Treatments of 1 and 2 time will be applied while the carcass is in a cooler (<40C). After aging for 14 days, wholesale cuts will be separated from the carcass and will be marinated in a vacuum tumbler (510 mm Hg) for 25 min at 4C in with 10% and 20% (vol/wt) solutions with meat (similar to Alvarado and Sams, 2004). The control gelatin marinade will consist of gelatin manufactures recommendation for gelatin preparation with possible treatments consisting of 10, 25 and 50% (w/v) concentrations. These concentration differences will be evaluated on the basis of pH, WHC, shear and sensory analysis. Antioxidants in the form of plant extracts will be incorporated into the multiple gelatin concentration solutions as well as combined with antimicrobials to achieve overall objectives. Microbial growth will be measured using generic cultures of Escherichia spp. and Listeria spp. which will be swabbed upon marked sample areas on fresh beef carcasses and wholesale cuts. WHC will be measured according to the Carver Press method. The WHC is the ratio of the water to meat areas. Lower ratios are desired, indicating the ability of the sample to bind more water. Lipid oxidation will be determined using thiobarbituric acid (TBARS) values. pH measurements will be recorded from lipid and protein samples prior to 0, 1, and 2 time treatments on the whole carcass and on wholesale cuts prior to treatment and immediately post treatment. Shear force (N) will be measured using a Brookfield LFRA Texture Analyzer. Descriptive analysis will be performed to evaluate appearance, odor, texture and taste of samples from cooked wholesale cuts subjected to the treatment regimen. A factorial structure within a randomized complete block design will be replicated three times to evaluate the ability of to increase the pH, improve the texture and improve WHC in vacuum tumbled cuts. When significant differences occur among treatments (P<0.05), the least significant difference test will be utilized to separate treatment means.