The Effect of Inlet Temperature on Starter Culture Properties of Spray-DriedPediococcus acidilactici

Abstract

Functional foods, including fermented foods, have gained an increasing demand recently due to the consumers’ awareness of the health benefits offered. To produce fermented food, a starter culture is required. Pediococcus acidilactici has recently gained research attention due to its potential starter culture and probiotic properties. Commercial starter cultures are commonly present in a dry form, and spray drying is a common method used for producing stable and long shelf-life dry cultures. However, spray drying involves a very high inlet temperature which leads to heat and osmotic stress that may damage the cells’ cell wall, DNA, and metabolic activities. However, the spray drying effect on P. acidilactici’s starter culture properties has not been studied. Therefore, spray drying with different inlet temperatures (120 o C, 150 o C, and 170 o C) were performed in this study to investigate its effect towards the P. acidilactici’s starter culture properties, including milk coagulation, acidification, and proteolytic properties. The results showed that all samples still retained the starter culture properties. Samples had 42.16 to 42.28% curd yield and 3.90 to 4.49 mg/mL soluble protein left from milk coagulation, pH of 5.38 to 5.49, and proteolytic index ratio of 0.57 to 0.67. However, different inlet temperatures did not have a significant effect (P>0.05) towards the properties. This finding suggests that spray drying of P. acidilactici is considerable as a method to produce starter culture powder in the future.