Study and modeling of enzymatic inactivation in the processing of green coconut water and clarified apple juice by means of capillary microreactors

Abstract

Green coconut water and clarified apple juice are thermally processed foods of great economic value but few processing alternatives. In acidic foods, the main purpose of the process is enzymatic inactivation. The product is heated at a certain temperature and kept at this temperature for a certain length of time and then it is cooled. Aiming lethality calculations, the heating and cooling steps cannot be taken into consideration, though they still contribute towards quality loss. Therefore, high rates of heat transference are desirable. The use of continuous flow microreactors in the chemical-pharmaceutical industry is a growing field. The advantages of using this technology are also interesting for the food industry and the heat treatment of low-viscosity liquids is already an interesting alternative to conventional forms, although still not broadly studied. The use of the microreactor in the flow heating step offers excellent temperature homogenization due to the high surface/volume ratio which increases heat exchange. Thus, this research project aims to study the feasibility of thermal processing of green coconut water and clarified apple juice using a capillary microreactor. The heat treatment in a capillary microreactor is going to be compared to a conventional process carried out in a pasteurization unit located at the Food Research Center-FORC. It will be used as peroxidase and polyphenoloxidase enzymes as process indicators. It is intended to conduct studies of fruit juice processing using other technologies at the School of Biosystems and Food Engineering, University College Dublin, Ireland. The microreactor process will also be studied through multiphysics modeling in computational fluid dynamics (CFD) software. (AU)