Influence of temperature and time on microbial, physicochemical and functional quality of goat milk

Abstract

Microbial load in fresh milk has a significant effect on its keeping quality and nutritional value. From Prehistoric time, human used heat process to reduce microbials load in raw milk to improve its sensory characteristics. This research is proposed to treat fresh goat milk with heating process to provide optimal pasteurization conditions that does not influence the goat milk chemical composition to suite production of goat yogurt powder. The pasteurization conditions considered were: Temperature (72, 80, and 85°C) and time (5, 10 and 15s). These results showed there were a significant difference (P<0.05) between treated milk and Indonesia national standards on viscosity and pH; whereas there was no significant differences on density and titratable acidity. The study results concluded that the temperature and time during heat processing had a significant effect on nutritional compounds of goat milk, with increase in lactose and non-fat solids contents; therefore, treated goat milk at 85°C to 5 s is better than other treatments.

Chemical and Physical Properties of Bovine Colostrum and the Effect of some Pasteurization Treatments on Them

“…The explanation for the considerable rise in the amount of casein and immunoglobulins seen in colostrum is due to the fact that both of these components have significantly increased in quantity [22]. The reason for the decrease in the percentage of protein after the process of pasteurization may be due to the temperature and time that have an effect on the protein content, as the decrease in the percentage of protein with the increase in the pasteurization temperature is due to the concomitant decrease in moisture and thus an increase in protein denaturation [23], and the decrease in the percentage of protein with the increase in the time that has an effect on the protein content, as the decrease in the percentage of protein with the increase in the pasteurization. These results are also in agreement with [24] and [25], which stated that temperatures above 60 °C lead to a decrease in protein content due to the denaturation of whey proteins.…”

Effect of carboxymethylcellulose sodium addition as stabilizer for physicochemical characteristic of purple sweet potato fortified yogurt (Ipomoea batatas L.)

“…Further observation was done on formulas 1, 2, 4 and 5; including density, viscosity, and stability tests using the centrifugation method. It needed density evaluation to determine the purity and degree of polarity of all yogurt formulas (Ibrahim et al, 2020). The result told us that the product's density in all formulas was lower than water density, 1 g/mL (Table 3).…”