Yogurt drink spoilage profiles: Characterization of physico-chemical properties and coliform potability analysis

Abstract This study aims to determine the yogurt drink spoilage profiles and its physico-chemical properties correlation as to investigate the coliform potability level upon exposure to an open air (unsealed condition). The commercially available three induced contamination of fruit (berry) flavoured yogurt drinks (labelled as A0 (original-flavoured Farm Fresh™), A1 (Farm Fresh™), A2 (Marigold™) and A3 (Nestle®)) were created to pre-run a spoilage indicator model system with regards to the colony formation unit (cfu) and its physico-chemical properties. Physio-chemical analysis (e.g., Brix, pH, colour and contact angle) and microbiological analysis were performed at 30 min intermittently for up to 4.5 h as soon as the food sample was unsealed (room environment condition: 27 ± 2 °C; relative humidity (RH): 73 ± 1%). The results showed the presence of yeast and fungus in yogurt drinks after all samples were opened and exposed to the environment. The total formation of yeast colonies and fungi of all three-yogurt berry drink brands on DRBC agar were inevitably high during the treatment (p