Nutritional Composition, Physicochemical Properties, Microbial Quality, Functional Properties and Risk Assessment of Organic and Inorganic Yoghurt

Abstract

The consumption of yoghurt is steadily increasing due to its recognized health benefits and versatility. However, the quality and nutritional content of yoghurt can vary depending on the source of milk used in its production. This study investigates the physicochemical, sensory, microbial, risk assessment and functional properties of fresh milk-based yoghurt and powdered milk-based yoghurt. 15 Samples of yoghurts coded: LZS, LZU, FFS, FFU, TYS, TYU, TSS, TJU, CYS, CYU, HYS, LZG, CGY, TJG and LZF were bought from supermarket in Nigeria. The ranges for physicochemical properties were pH (4.49 – 5.23), conductivity (3588 – 4988mS/cm), density (2.09 – 2.26g/cm³), viscosity (422 – 493mPa.S), titratable acidity (0.00011 – 0.00013%), moisture (70.40 – 89.30%), ash (1.37 – 5.70%), fat (4.3 – 4.81%), and protein (5.63 – 28.94%). The average concentration (mg/kg) of Na, Mg, K, Ca, Fe, Zn and Cu are 595.53, 280.00, 395.00, 1956.30, 12.14, 1.31 and 0.27 respectively, while Cd was not detected in all samples. Target Hazard Quotient, (THQ) for Fe, Zn and Cu in all samples were < 1 suggesting no potential health risk for consumers. B-glucan, inulin, pectin, gelatin and sodium alginate ranges from (5.48 – 65.6), (10.9 – 46.7), (8.70 – 28.3), (4.29 – 16.7), and (6.45 – 21.7) respectively. General acceptability ratings were between very good and excellent. Total viable bacterial count (TVBC) ranges from (6 – 79cfu/100mL), total viable lactic acid bacterial count (TVLBC) ranged between (12 – 18cfu/100mL) and total viable yeast and mold count (TVYMC) ranged between (2 – 31cfu/100mL). This study revealed that all yoghurt samples analyzed are safe and reliable sources of protein, minerals and nutrients.