Detection of protein aggregation markers in raw meat and finished products

The effect of animal and plant proteases as well as starters, or starter cultures, on protein aggregates for- mation in raw pork and beef as well as meat products was studied. The proteomic analysis of raw meat revealed that animal proteases – pepsin and trypsin – caused the aggregation of isoform 2 of protein 1 containing 4.5 LIM domains. Vacuum packaged meat showed the same results during storage, while unpacking led to the acceleration of the aggregation process due to autolysis. In addition, mixed aggregated fragments, such as muscle creatine phos- phokinase and glutathione-S-transferase, actin and perilipin, and type II keratin appeared in those samples. Starters with Pediococcus pentosaceus 31 from the Russian National Collection of Industrial Microorganisms (VKPM-8901) caused myoglobin and troponin I aggregation, while the formation of soy proteins aggregates (glycinin G1 and glyci- nin A3B4) was detected in meat products as a result of the autolysis process and the use of cholesterol-lowering star- ters. All in all, proteases which cause protein aggregation may be less effective for raw meat tenderization, whereas the proteins identified may be used as quality biomarkers.