Drying Kinetics Of Coconut Testa And Application Of Testaits’ Oil

In this study, Scraps of coconut testa which were generated by coconut processing industry were selected as experimental materials. Drying kinetics characteristics of coconut testa, optimization of coconut testa oil extraction, the physicochemical properties and fatty acid composition of coconut testa oil, enzymatic synthesis process of the xylose-lauric ester and washing products developing were investigated. The results of this paper can provide some data supportfor the traditional dryingmethodschanging, new drying equipment and cosmetic products development of coconut testa. Meanwhile, it has certain guiding role on broadeningthe comprehensive utilization way of the coconut testa, extending coconut processing industrial chain and improving the added value of coconut products. Besides, this research may produce an important impact on ecological environment protection, farmers’incomeincreasing and economic developmentenhancing.Firstly, drying kinetics of coconut testa was investigated by a simultaneous thermal analyzer (TG-DSC). Results show that, the moisture content decreased gradually with the extension of time, and the higher the temperature, the faster the moisture content decreased.It’s drying rate graphics rendering "bell". The Page model gave the best fit of all the drying models with the highest R2value (0.99964) and the lowest value X2value (3.38446X10"5). The predicted and experimental values had a good fit. So the Page model could predict the drying kinetics characteristics of coconut testa very well. Model calculations showed that the effective diffusion coefficient (Deff) of coconut testa varied between7.921×10-10m2/sand1.006×10-9m2/s, the drying activation energy for coconut testa was16.63kJ/mol. Analysis results of heat flow curves estimated that there was an obvious endothermic peak in the drying process of coconut testa. And the endothermic peak of coconut testa becomes stronger and moves to the left with the increase of temperature. This all showed that the heat requirement of coconut testa in drying process was used to the diffuse and evaporate its’water.Secondly, the coconut testa was drying at50℃for the optimization of coconut testa oil extraction in isopropyl alcohol solvent, the oil yield could reach to76.83%under the conditions of60℃, liquid ratio (1:4)and3h of extraction time. The obtained coconut testa oil was non-drying oil (Iodine value14.69g/100g) that has a certain flavor the acid value of which was13.37mg/g, peroxide value of1.72mmol/kg, and the lauric acid (42.28%) was the main component of the fatty acid. The saturated fatty acid of84.49%andthe content of short chain fatty acids (C8-C12) was51.45%.Finally, enzymatic synthesis process of the xylose-lauric ester was optimized, and then coconut testa oil xylose ester synthesized with such condition was developed into sugar ester surfactant and washing products.The results show that the optimum conditions for the synthesis of xylose-lauric ester was A3D2B3C3(Reaction time24h, Novozym4351ipase dosage0.4%, molecular sieve40g/L andmolar ratio oflaurel acid to xylose1:2.) in anhydrous isopropanol system. The lauric acid esterification rate was up to (98.70±0.04)%. Retention time of2.2and2.3min in the HPLC and strong absorption of1729.67cm-1in FTIR all showed the formation of ester bond. Coconut testa oil xylose ester obtained by the optimum conditionsA3D2B3C3was a W/O (water in oil) type emulsifier(HLB was4.39±0.02at25℃;<8). The foaming capacity, emulsifying and emulsion stability of coconut testa oil xylose ester at the concentration of0.5g/L the highest, and they were30.4%,97.4%and66.2%, respectively. While the foam stability of coconut testa oil xylose ester was the highest to82.7%at concentration of0.4g/L. At last, coconut testa oil xylose ester was developed into hand washing type detergent with no particle suspension, no smell; high stability; detergency met the national standard; the adhesion, cohesion and flexibility was no significant differences. Compared with commercial detergent, dishwashing detergent was in line with standards.