Preservative action of 11S (glycinin) and 7S (β-conglycinin) soy globulin on bovine raw milk stored either at 4 or 25 °C

Abstract

Considerable inhibitory antibacterial actions were exerted by the soybean 11S subunit comparable with nisin on the proliferation of total viable count, Pseudomonas count and Enterobacteriaceae count in bovine milk stored at 4 or 25 °C for 30 d and 48 h, while 7S and lysozyme were much less effective. The maximum magnitudes of bacterial reduction by 11S and nisin were in the range 2–4 log CFU/ml. The proliferation of 3 pathogenic bacteria (Listeria monocytogenes, Salmonella Enteritidis and Escherichia coli O157:H7) artificially inoculated into raw milk stored at 4 or 25 °C were particularly and significantly (P<0·05) reduced by 11S subunit and nisin (0·5% w/v), but only slightly by 7S and moderately by lysozyme. Lactose consumption, acidity development and casein degradation during storage of bovine raw milk were attenuated during storage at 4 or 25 °C and sensorial traits were better maintained by supplementation with 11S (0·5% w/v). 11S subunit may be used a safely food preservative, if permitted.