Formulation of Mixed Probiotic Starter Culture for the Production and Extending the Shelf Life of Ergo (Spontaneously Fermented Milk)

Abstract

Probiotics are live microorganisms that confer a beneficial effect on the host when administered in enough amounts and in appropriate conditions. They can modulate the intestinal biome of the consumer. This study aimed to formulate probiotic starter culture and evaluating their antagonistic effect on some foodborne pathogens such as Escherichia coli, Staphylococcus aureus, Salmonella Typhimurium, and Listeria monocytogen. The study also aimed at evaluating the impact of the formulated starter cultures on the sensory acceptability and shelf life of ergo. Accordingly, seven lactic acid bacteria L. rhamnosus(GB-15), L. paracasei(SB-7),  L. reuteriG-23), L. sake(BB-60), L. curvatus(NZ-44) L. plantarum(NN-33), L. casei(BZ-26) and one yeast species S. cerevisiae (Y-72) were used. The selected isolates were combined in different proportions to formulate the starter cultures for the production of ergo. Nine formulations were made in different proportions based on the compatibility of the isolates. Ergo prepared in this study was observed to have a pH of 3.99 - 4.38 with titratable acidity of 0.60 - 0.97 after 48 hrs of fermentation. The formulate F2 (GB-15,G-23, NZ-44, BB-33, NZ-26, Y-72) and F6 (GB-15, BB-60,NZ-44,NZ-26,Y-72) showed complete inhibition against all the test pathogens after 48 hrs of fermentation, except for Staphylococcus aurous with F6. The ergo products with starter culture formulate F2, F4 and, F6 were found to have better overall sensory acceptability with a mean score value of 3.75, 3.56, 3.73, and 4.03/5.00, respectively. Ergo products with formulate F2and F6 had a shelf life of more than 12 days and 15 days, respectively, at an ambient temperature of 18-24^oC. Our starter culture formulates in addition to retaining the typical sensory quality of homemade ergo, they improved the shelf life and safety of the product.

Keywords: Bio-protective; Ergo; Probiotics; Shelf life; Starter Culture

DOI: 10.7176/JNSR/13-6-02

Publication date:March 31^st 2021