Effects of incorporation of camel milk casein hydrolysate on quality, oxidative and microbial stability of goat meat emulsion during refrigerated (4 ± 1 °C) storage

Abstract

The objective of present study was to explore the effects of incorporation of camel milk casein hydrolysates in goat meat emulsion. Camel milk casein hydrolysed by Alcalase was incorporated into goat meat emulsion at three different levels viz. T1: 0.03%, T2: 0.06% and T3: 0.09% (w/w) and compared with control (C: 0% hyrolysate) and positive control (PC: 0.02% Butylated Hydroxy Toluene (BHT), w/w) for its physico-chemical, antioxidant potential and antimicrobial effect against selected food spoilage and pathogenic microorganisms. During storage at refrigeration temperature (4±1°C), pH increased while water activity, extract release volume and emulsion stability decreased significantly (P<0.05) on 6th day, however, all these properties were improved in treated emulsions. The antioxidant potential of treated emulsions were improved in a dose-dependent manner, however, PC had significantly higher antioxidant activities. The peroxide value, TBARS and free fatty acid values were significantly (P<0.05) lower than untreated emulsion throughout the storage period. The lightness (L*), redness (a* value) and yellowness (b*) values decreased with the advancement of storage period; however, treated emulsions had better instrumental colour profile than control. In treated emulsions, the standard plate and coliform counts were initially reduced during storage, and on 6th day of storage, it was significantly lower than C and PC. In microbial challenging test (MCT), the colony forming units of all the tested pathogens in treated emulsions decreased upto 4th day, thereafter increased significantly on 6th day, whereas, in C and PC groups, the counts of all microorganisms increased significantly throughout the storage period. The findings suggested that camel milk casein hydrolysate could be a potential food ingredient which not only improves the physico-chemical properties of meat emulsion thereby increased yield, it also provides oxidative and microbial stability during refrigerated storage.