46G-20 |
Stability of jerky from beef supplemented with alpha-lipoic acid |
A. D. CLARKE1, E. J. Kim1, K. Chaiwat1, L. N. Fernando1, and E. P. Berg2. (1) Food Science Department, University of Missouri, 256 Stringer Wing, Columbia, MO 65211, (2) Animal Science Department, University of Missouri, Columbia, MO 65211 Beef jerky is a high-protein snack that is in great demand, but is subject to deterioration by oxidative changes. Supplementation with the antioxidant alpha-lipoic acid may inhibit lipid oxidation and development of off-flavors in processed meat products. The objective was to determine if oxidative deterioration could be reduced in jerky prepared from beef supplemented with alpha-lipoic acid. Outside rounds (biceps femoris) from beef (n=25) supplemented with alpha-lipoic acid (0, 8, 16, or 24 mg/kg live body weight) were used to prepare jerky utilizing commercial methods for shaping, seasoning and thermally processing. Jerky was sealed in barrier pouches with ambient air and a subset stored at 37-39 C and the remainder at 23-25 C. Samples were tested at 0, 4, 12 and 20 weeks of storage to determine TBARS value (distillation method) and hexanal content (automated headspace SPME-GC method) as indicators of oxidative deterioration. A sensory panel using 15 cm unstructured line scales was used to determine intensity of staleness and off-flavor characteristics. TBARS and hexanal results had no significant difference (P>0.4 and P>0.15, respectively) due to alpha-lipoic acid supplementation. Staleness (P>0.5) and off-flavor (P>0.2) scores confirmed no impact due to alpha-lipoic acid. However, significant differences (P<0.0001) were found due to week of storage with hexanal increasing from 0.020 to 0.061 µg/g, staleness from 1.6 to 4.9, and off-flavor from 2.2 to 5.4 in the period. Elevated storage temperature also resulted in a higher (P<0.0001) intensity of staleness (3.9), off-flavor (4.3), and hexanal (0.046 µg/g) than room temperature storage (2.2, 2.3 and 0.030 µg/g, respectively). TBARS values were higher (P<0.05) for jerky stored at room temperature (0.38 mg/kg) than elevated temperature (0.31 mg/kg). While alpha-lipoic acid may improve meat quality, there is no impact on oxidation in jerky by supplementation of beef with alpha-lipoic acid.
Session 46G, Muscle Foods I
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