Study On Processing Technology Of Coconut Milk Concentrate By Centrifugation

Coconut milk concentrate is produced by fresh coconut milk after emulsification, concentration, sterilization and other processes, which contain large amounts of plant protein,17kinds of essential amino acids and zinc, calcium, iron and other trace elements. Coconut milk concentrate is a kind of raw material in dairy industry and beverage industry. In order to meet the market demand, it is important to improve the quality, flavor and texture of coconut milk concentrate.The parameters of coconut milk concentrated by centrifugation were studied. The results showed that coconut milk concentrate was obtained under20bar on the room temperature, including81.27%soluble solids,72.50%fat,1.01%protein and the yield was31.60%.By the single factors and orthogonal experiments, the best formula of emulsifiers and stabilizers of coconut milk concentrate were determined as follows:0.35%monoglyceride,0.07%sodium caseinate,0.05%span60and0.05%carrageenan. It was found that monoglyceride was more effective than other emulsifiers, and it was more stable when pH was adjusted to7-8.Then coconut milk concentrate was homogenized twice at pressure of20MPa and lOMPa and the best sterilization condition was121℃for20min. The final product was delicious, smooth and stable.The flavor and fatty acid composition of coconut milk concentrate were analyzed and identified by gas chromatography-mass spectrometry (GC-MS). The results showed that21kinds of aroma components were identified in coconut milk concentrate, including7kinds of esters,4kinds of alcohols, ketones, and organic acids,1kind of aldehydes, and the other two. The proportion of total content of esters was60.5%, followed by5.57%alcohol. Obviously, aroma of coconut milk concentrate mainly came from esters;8kinds of fatty acids in coconut milk concentrate were isolated and identified. There were five kinds of saturated fatty acids, accounting for72.31%of the total fatty acids, including decanoic acid(8.40%), lauric acid(54.60%), myristic acid (18.99%), palmitic acid (8.68%), stearic acid (3.40%); contains three kinds of unsaturated fatty acids, accounting for27.69%of total fatty acids, including palm define acid(0.08%), oleic acid (4.93%), linoleic (0.92%).Coconut milk concentrate was stored at room temperature, its conventional physical and chemical indicators, including pH, acid value, peroxide value, the total number of colonies, mold and yeast, E. coli were measured The results showed that with the extension of storage time, pH value is gradually reduced, peroxide value, acid value showed an upward trend, while the total number of bacteria, molds and yeasts, and E. coli had no significant change.