Characterization and functional properties of proteins from coconut (Cocos nucifera L.) and their use in cheese-like products

Research was conducted to determine the feasibility of utilizing coconut proteins for manufacture of cheese-like products. The coconut proteins were fractionated and then characterized to obtain information on their physicochemical properties for possible application in coconut-based foods. The production of coconut protein concentrate (CPC) was attempted by ultrafiltration membrane processing, and their functional properties were determined. The technology for manufacture of cheese-like products was developed, and textural properties of products were evaluated.;Albumin and globulin were the predominant coconut protein fractions. Native proteins consisted of polypeptides ranging from 22 kilodaltons (kD) to greater than 100 kD. The albumin and globulin fractions were composed of three and two major polypeptides, respectively. Coconut proteins consisted of at least three types of polypeptides linked via disulfide bonds. Isoelectric focusing indicated that coconut proteins had pI values between 4 and 8. The coconut protein had a relatively high level of glutamic acid, arginine, and aspartic acid.;The rate of heat-induced gelation was affected by temperature and protein-modifying reagents. Sodiumdodecylsulfate polyacrylamide gel electrophoresis showed that with increasing temperature soluble intermediary aggregates were broken to form insoluble aggregates of high molecular weights. It was confirmed that the free sulfhydryl (SH) groups are involved in the formation of protein gel structure. Coconut proteins were polymerized and gelatinized by the microbial transglutaminase, which indicates feasibility of application for gel-based foods.;The functional properties and total essential amino acid content of CPC prepared by combining aqueous extraction and ultrafiltration membrane processing were comparable to those for soy protein concentrate and Na-caseinate. Especially, the good emulsifying properties of CPC suggested possible application in emulsified food. As for factors influencing emulsifying capacity (EC), temperature did not significantly (P ;Studies on textural properties of cheese-like products showed that various protein ingredients, and different levels of coconut protein ingredients had a significant effect on cheese-analog characteristics. In general, compared with commercial cheeses, coconut cheese-like products displayed unique textural characteristics, higher adhesiveness and cohesiveness, lower springiness, and no fracturability. Levels of guar gum affected the textural properties of products made from coconut curd.