Research On The Extraction Process Of Olive Juice And Its Microencapsulation

The olive is a kind of popular and specially fruit in south. Its health function, forexample humidified throat and promoted salivation, liver-protecting, and so on, hadbeen known and appreciated by more and more people. But there are still existedsome problems in its processing, for the olive itself contain a lot of cellulose and pec-tin substances. In this paper, the composite enzyme combined with ultrasonic tech-nology was selected to increase the juice extraction rate and the content of soluble solids;the spray drying technology was used to produce the microcapsule olive powder. Inaddition, the pray drying process was optimized by the response surface experimentaldesign based on the index of flour yield; scan electron microscopy was introduced toobserve the shape structure of the microcapsules olive powder. The main results are asfollows:(1) Study on the extraction process of olive juice by the composite enzyme com-bined with ultrasonicBased on the index of the juice extraction rate and soluble solids content of olive,The single factor experiment was used to explore and orthogonal test was used to op-timize the processing of the complex enzyme. The optimal conditions was: the massratio of Cellulose enzyme and Pectinase2:1; liquid-to-solid ratio1:3, amount of enzyme0.7%, enzymolysis temperature47.0℃, enzymolysis time4.25h and enzymolysis pHvalue3.0; The optimal parameters of ultrasonic treatment were as follows: Ultrasonicpower300.0w, temperature55.0℃, and ultrasonic time20.0min. Under this optimalprocessing, Olive juice extraction rate was90.55%, soluble solids content was5.0%,which compared with the control group, two indexes were increased by36.4%and2.5%, respectively.(2) Study on the Microencapsulated process of olive juice by spray dryingThe gum arabic was selected as microcapsule wall material and the maltodextrin as wall material and filler; and the monoglycerides and sucrose ester were used forcomposite emulsifier. Based on the indicator of emulsion stability of the microcapsuleemulsion, the single factor experiment was used to explore and orthogonal test wasused to optimize, obtained the optimal conditions for preparation of the microcapsuleemulsion were: Composite wall material ratio was1:6, core wall ratio was1:2, Com-posite emulsifier ratio2:2, the amount of emulsifier was0.5%, the homogenizationpressure was42.5.0MPa, and the number of homogenization was twice, under thiscondition the emulsion stability of the emulsion was90.26%.Based on the index of the powder rate, response surface methodology was usedto optimize the design of the spray drying conditions. The optimization resultsshowed that the factors the primary and secondary order of factors that affect the ex-traction rate is entering air temperature> feeding speed> feeding temperature; Inter-action analysis found that: the effect of entering air temperature and the interaction offeeding speed on flour yield reached a significant level, the rest factors of the interac-tion have no significant effect on the flour yield; the optional spray drying processparameters were as follows: feeding temperature74.0℃, entering air tempera-ture176.0℃, feeding speed12.0mL/min, atomizer speed20000.0r/min. Under thisprocess conditions, the flour yield of Microcapsules olive instant powder is41.56%.The experimental result is similar to the predictive value of41.54%, which verifiedthe reliability of the model.The result from scanning electron microscope photographs showed that thesurface of microcapsule particle was smooth, a more regular spherical or oval-shaped,basically free from cracks, and surface wall material structure has good continuity,and integrity of better encapsulation.