Abstract

Bio-preservation of Nigerian soft-white cheese (wara) in submerged consortium of bacteriocinogenic lactic acid bacteria (LAB) culture was investigated. Lactobacillus acidophilus PIT17 and Lactococcus lactis PIT30 were isolated from pito using the pour plate technique on MRS medium. The selection of L. acidophilus PIT17 and L. lactis PIT30 for the bio-preservation studies were based on their ability to produce acidophilin and nisin to inhibit the growth of the test isolates. The ‘wara’ were submerged in consortia of the L. acidophilus PIT17 and L. lactis PIT30 culture and were kept/stored at 2, 4, 6, 8, and 10°C and at room temperature. The shelf-life of the wara alongside control was determined. Physico-chemical and proximate analysis, microbial counts and organoleptic characteristics of the wara were also carried out before and after the bio-preservation. The shelf life of the wara were observed with a significant difference (p < 0.05) at storage temperatures of  2°C (5 days), 4°C (6 days), 6°C (4 days), 8°C (3 days), 10°C (6 days) and 24±1°C (3 days). The proximate analysis of wara showed significant difference (p < 0.05) at different storage temperatures employed. The total viable bacterial count (TVBC) of the cheese (wara) decreased significantly (p < 0.05) after 24 h of submerged bio-preservation of wara from 9.8 × 10⁵ cfu/ml, 1.3 × 10⁶ cfu/g to between 6.2 × 10⁵ and 7.5 × 10⁵ cfu/g. The organoleptic characteristics of wara revealed that there were significant difference (p < 0.05) in colour, texture, aroma, taste, and general acceptability.

Key words: Organoleptic characteristics, proximate, physico-chemical, cheese, consortium.