Strategies to Extend the Shelf Life of Aerobically Stored Beef Trimmings

Abstract

Shelf life for fresh beef trimmings is often determined qualitatively based on color, lipid oxidation, microbial growth, and off odors and flavors. The first study was conducted to determine the number of storage days needed to reach the end of shelf life and to understand the interrelationships of spoilage mechanisms. Beef bottom round flats (Biceps femoris; BF) and chuck clod hearts (Triceps brachii; TB) were sliced to simulate trimmings. Trimmings were stored aerobically, at 5⁰C under fluorescent lighting for 12 days. Objective color, pH, microbial plate counts, and volatile compounds were measured on days 0, 3, 6, 9, and 12. The data showed that 6 storage days is the end of shelf life for color and 9 storage days is the end of shelf life for microbial and organoleptic spoilage. The second study was conducted to evaluate the efficacy of selected ingredients to extend the shelf life of aerobically stored beef trimmings. USDA select BF and TB were sliced to simulate trimmings and stored aerobically for 6 or 9 days. Samples were treated with ingredients selected to extend shelf life by addressing color, microbial spoilage, or off odor and flavor development. Samples treated with reduced nicotinamide adenine dinucleotide (NADH) and sodium erythorbate (NaE) had greater (P < 0.05) a* (redness) values (12.76 and 11.47 respectively) compared to day 6 control samples (7.93) and decreased (P < 0.05) percent metmyoglobin (MMb) (29.96 and 37.34 %, respectively) compared to day 6 control samples (57.02%) measured 2 hours post treatment. Color measurements taken 48 hours post treatment indicated that NaE treated TB samples retained improved a* value (9.48) and MMb % (41.17%) versus NADH treated TB samples (a* 7.82; MMb 51.72%). Cetylpyridinium chloride (0.5%) treated beef trimmings had lower (P < 0.05) aerobic mesophile plate counts (7.4 log10 CFU/cm^2) than day 9 control samples (8.0 log10CFU/cm^2). No significant differences (P > 0.05) were observed in volatile compound groups between treatments. However, beef trimmings treated with sodium bicarbonate (NaB) on storage day 9, had roughly 15 times less aldehydes present than day 9 control samples. Treatment solutions NaE, CPC, and NaB all performed better than other treatments for improving color, and reducing microbial counts and off odor volatiles. These treatment solutions can be used in combination to extend the shelf life of beef trimmings if applied near the end of shelf life.