EFFECT OF SODIUM CHLORIDE CONCENTRATION ON THE SHORT-TERM PRESERVATION OF COW, GOAT, AND SOY MILK

Abstract

storage was investigated. Fresh milk samples were pasteurized at 72 oC and NaCl at concentrations of 0.004, 0.008, 0.012, and 0.016 g/ml were added at three replicates, then stored for five days under controlled conditions. Parameters evaluated included boiling point elevation, pH, viscosity, and electrical conductivity. Boiling point elevation increased progressively with NaCl concentration, reaching maximum values of approximately 19°C in Cow milk, 17.4°C in Goat milk, and 14.4°C in Soy milk at the highest concentration by Day 5, indicating enhanced thermal stability. pH trend was dependent on the milk type that is dairy and plant milk. Cow and Goat milk exhibited increasing pH during storage, whereas Soy milk showed acidification. Statistical analysis showed that NaCl had no significant effect on pH (p > 0.05), suggesting that storage time and intrinsic milk composition were dominant factors. Viscosity increased in all milk types over time, but higher NaCl concentrations significantly moderated viscosity development in Soy and Goat milk (p < 0.05), whereas Cow milk viscosity was less affected. Electrical conductivity increased remarkably with NaCl concentration (p < 0.001), reflecting enhanced ionic content, with Soy milk exhibiting the highest values. These results demonstrate that sodium chloride modifies thermal stability, flow behavior, and ionic characteristics of both dairy and plant-based milk systems. The study highlights NaCl’s effectiveness as a preservative while emphasizing the need for optimized concentrations to maintain quality and minimize adverse effects on the properties 
studied.