Lipid oxidation and protein co-oxidation in ready-to-eat meat products as affected by temperature, antioxidant, and packaging material during 6 months of storage

Ambient-storage-friendly, ready-to-eat (RTE) meat products are convenient in emergencies, such as earthquakes, flash floods and the current global Covid-19 lockdown. However, given the processing and long storage time of such food products, the lipid and protein components may be more susceptible to oxidation. Chicken serunding is a low-moisture, high-lipid, high-protein, RTE product that is prone to lipid oxidation and protein co-oxidation, causing product quality deterioration. The present study assessed the effects of storage temperature (25, 40, 60 °C), antioxidant (butylated hydroxyanisole, BHA), and multilayer packaging materials [metallised polyethene terephthalate (MPET) and aluminium] on the lipid oxidation and protein co-oxidation of chicken serunding during six months of storage. All lipid and protein markers elevated with increasing temperature (25 < 40 < 60 °C), indicating that storage of low-moisture meat at high temperature is not feasible. BHA was effective against lipid oxidation, as indicated by the significantly lower (p <0.05) extracted lipid content and delayed formation of malondialdehyde, a secondary lipid oxidation product. However, BHA is not effective against protein co-oxidation, as shown by the insignificant (p >0.05) effect on preventing tryptophan loss, protein carbonyl formation and Schiff base accumulation. MPET packaging with a superior light and oxygen barrier provided significant protection (p <0.05) compared to aluminium. In conclusion, low temperature (25 °C) storage of low-moisture, high-lipid, high-protein, cooked meat systems in MPET packaging is recommended for long-term storage to delay the progression of lipid oxidation and protein co-oxidation.

Comparison of the effect of freeze-dried acid whey on physicochemical properties of organic fermented sausages made from beef and fallow deer meat

The objective of this study was to compare the effect of freeze-dried acid whey on physicochemical properties and microbial changes of organic fermented sausages made from beef and fallow deer meat. Five formulations of sausages from each species were made. The results show that processing time and species of meat were the high significant factor on tested parameters. Variants and interactions between main factors influenced at different levels of significance on some tested attributes. At the end of processing fallow deer sausages were characterised by the lower pH (4.79 ± 0.01-4.90 ± 0.02 for fallow deer and 5.04 ± 0.00-5.25 ± 0.03 for beef sausages) and the content of 2-thiobarbituric acid reactive substances (1.54 ± 0.09-2.81 ± 0.23 and 1.64 ± 0.15-5.06 ± 0.25 respectively) than sausages made from beef meat. In conclusion, the addition of freeze-dried acid whey in varying amounts did not significantly affect the physicochemical characteristics of sausages from both fallow deer and beef. However, further research is needed to compare the effect of acid whey on the nutritional values of raw fermented sausages from fallow deer and beef.