Comparative Effect of an Iron-based In-Pack Oxygen Scavenger on Lipid Oxidation, Proteolysis and Microbial Deterioration of Fresh Deboned Pork and Cooked Pork Nuggets Tray-Packaged in Food-Grade Polypropylene Trays under Refrigeration

Active packaging using oxygen scavengers is an established strategy to improve the chilled shelf life of muscle foods, but quantitative data comparing its effect across product matrices in a common packaging system are limited. The present study compared the effect of a food-grade iron-based oxygen scavenger sachet (O-SORB U100, 2.5 g) on the oxidative, proteolytic and microbiological deterioration of two pork products with markedly different intrinsic properties - fresh deboned pork chunks (raw, intact muscle) and cooked emulsion-based pork nuggets - tray-packaged in food-grade polypropylene trays sealed with HDPE wrap and stored at 4±1 °C. The HDPE wrap film was selected based on its superior performance among four wrap films (LDPE, LLDPE, HDPE, PVC) screened in companion experiments. The oxygen scavenger reduced day-of-spoilage TBARS by 16 % in fresh chunks (HDPE pair, day 8) and 5-9 % in pork nuggets (HDPE pair, days 19-21), and reduced microbial counts by 0.45 log CFU/g in fresh chunks. In fresh chunks, the dominant deterioration mode was microbial; the scavenger lengthened shelf life by 3 days (from 5 to 8 days; +60 %). In pork nuggets, the dominant deterioration mode was oxidative; the scavenger lengthened shelf life by 4 days (from 19 to 23 days; +21 %). The HDPE-plus-iron-based-oxygen-scavenger system therefore represents a single, commercially scalable platform suitable for both raw and processed pork retail.