Evaluation of whey protein coating containing free and Pickering emulsion forms of <i>Trachyspermum copticum L</i> . essential oil on quality of refrigerated beef

The purpose of the present research was to prepare a novel biodegradable coating of whey protein (whey) and essential oil of <i>Trachyspermum copticum L.</i> (forms of free (EO) and Pickering emulsion (NEO)) to improve the shelf life of beef. In this study, various microbiological, chemical, and sensory analyses were performed. The results showed that after 18 days, the highest and lowest microbiological counts were related to control samples and whey-NEO treatments, respectively. The total viable count (TVC) was 8.2 and 6.8 log CFU/g, the total psychrotrophic count (TPC) was 8.5 and 6.7 log CFU/g, and the lactic acid bacteria (LAB) count was 7.7 and 6.5 log CFU/g for control and whey-NEO treatments, respectively. Chemical analysis of whey-NEO treatment and control sample were 6.3 and 7.5 for pH, 9.8 and 13.9 meq/kg for PV (peroxide value), 5.45 and 8.85 mg/kg for TBARS (thiobarbituric acid reactive substances), and 25.1 and 39.4 mgN/100 g for TVB-N (total volatile basic nitrogen), respectively. The best result was associated with the whey-NEO treatment; consequently, coatings with whey and EO Pickering emulsion should be considered as a potential active coating in the meat industry.