Effects of Ascorbic Acid on Display Life of Ground Beef

Fresh ground beef containing 20 and 25% fat was either treated with 0.01, 0.05 or 0.10% crystalline ascorbic acid or remained as non-treated controls. Samples were displayed in polyvinyl chloride (PVC) film for up to 10 d (24 h/d) at 2 to 3°C under 1076 lux G. E. Natural light. Measures of display life included visual color scores, reflectance measurements, sensory panel scores, thiobarbituric acid (TBA) values and microbial standard plate counts (SPC). At days 1, 3 and 5 of display, average and worst point visual color scores were judged brighter for all ascorbic acid treatments compared to controls. Lower metmyoglobin percentages, higher %R630nm/%R580nm and higher CIE a^* readings at days 3, 5 and 10 for the ascorbic acid-treated product supported visual color results. Higher fat (25%) and higher ascorbic acid levels (0.05 and 0.10%) gave brighter visual color responses at 5 d of display than the 20% fat product and that containing 0.01% ascorbic acid. More intense sensory panel beef flavor was associated with the 0.05 and 0.10% ascorbic acid treatments. More off-flavor was found in the higher fat product (25%). TBA values were not different for fat level comparisons, but were lower for the 0.05 and 0.10% ascorbic acid treatments. At day 5 of display, SPC were not affected by ascorbic acid treatment. The 25% fat product had lower SPC at day 5.