Assessment of the quality of yoghurt produced from goat milk using natural and artificial starter culture as a function of storage time

Abstract

This study assessed the quality of yoghurt produced from goat milk using natural and artificial starter cultures. It determined its  physicochemical [total solids, ash, protein, fat, pH, and Lactic Acid Bacteria], antioxidant [total phenolic content, tannin,  phosphomolybdate assay, and vitamin C of milk], and mineral composition [calcium, zinc, phosphorus, potassium, and sodium] within 28- day duration of storage. The study revealed that those yoghurts produced from goat milk using natural starter cultures exhibited the highest Total solids TS [13.95 %], Total Ash TAC [0.69 %], Oil [5.3 %], Protein [3.31 %], pH [4.96 %], and Lactic Acid [1.07 %] at day 1. Also,  yoghurts produced from natural culture starter exhibited higher phenol [0.125 g/L], phosphomolybdate [0.082 g/L], and Tannin [0.082 g/ L]; while the one with artificial starter culture had higher Vitamin C [7.56 g/L] content. The yoghurts produced using natural starters were observed to have the best mineral contents [Phosphorus: 0.234 g/L, Potassium: 1.050 g/L, Sodium: 1.450 g/L, Zinc: 0.101 g/L and Calcium  0.697 g/L]. Yoghurts produced using artificial starter culture showed higher nutritional contents at a storage duration of 28 days. Natural  starter culture yoghurt exhibited the best physicochemical properties and mineral composition. While yoghurts from artificial starter  culture performed exhibited better storage capability and stability of shelf life. Certain fruits and mostly citrus can be employed to  improve the shelf-life of yoghurt samples as well as their nutritional composition.