Modelling design of cuts for enzymatic peeling of mandarin and optimization of different parameters of the process

Abstract

 A process for enzymatic peeling of mandarin was optimised. Enzymatic peeling was completed by means of infusion under vacuum of a commercial preparation of pectolases and cellulases (Rohament PC), followed by a period of incubation with the prepared enzymatic solution, elimination of the skin and separation of the segments. Distinct designs of the cuts of the flavedo were studied, by analysing characteristics of enzymatic saturation at distinct pressures and times of vacuum. Based on the data obtained, a mathematical model was developed which allowed us to predict the infusion of enzyme reached as a function of pressure and time of vacuum. The best peeling results were achieved in those combinations of pressure and time of vacuum that allowed a saturation of approximately 90% in less than 10 min. The design of an ideal cut (a cut in the equatorial zone, the removal of part of the peel of the calycinal and peduncular zones and two longitudinal cuts), two suitable vacuum conditions (defined using the mathematical model; 400 mm Hg and 500 mm Hg during 5 min), the effect of distinct concentrations of Rohament PC and incubation times on the main attributes of peeling quality (ease of separation of the remains of the residual peel, ease of segment separation, percentage of viable segments and percentage of albedo not attacked by the enzyme) were studied. The greatest quantity of viable segments and the best quality of enzymatic peeling were achieved by using an enzymatic concentration of 5 g/l of Rohament PC and an incubation time of 20 min. Under these conditions, 90% and 85% of viable segments were obtained, less than 10% of the albedo was not attacked, an easy separation of the remains of the residual peel and easy separation of the segments were achieved.