Effect of Spray Drying Air Temperature to the Changes of Properties of Skimmed Coconut Milk Powder

Abstract

This study investigated different conditions for producing suitable skimmed coconut milk powder using spray drying process. Skimmed coconut milk is a by-product of the virgin coconut oil extraction process. The skimmed coconut milk was composed of 6.4% protein, 0.27% fiber, 6.27% sugar, 3.6% fat and 86.93% moisture content. Spray drying involved an inlet flow rate of 0.27 m3/s, temperatures between 190 and 210°C and the use of 15 and 20% maltodextrin as drying aid. As inlet and outlet temperatures increased, the product yield, moisture content, bulk density and wettability reduced. The particle size of skimmed coconut milk powder was found to be 250 μm. The average percentage of solubility of the skimmed coconut milk powder in the current study was 39.57%. The amino acid content analysis was carried out using the HPLC method to reveal the glutamic acid and arginine acid as non essential amino acid. The color of skimmed coconut milk powder at high inlet temperatures caused significant changes in L* and b* and high maltodextrin concentrations caused significant changes of a* (p < 0.05). The optimum yield of skimmed coconut milk powder was 18.65% when using 20% maltodextrin with an inlet temperature of 190°C and an outlet temperature of 80°C for spray drying.