Enhancing the retention of -carotene and vitamin C in dried mango using alternative blanching processes

Microwave applications in the food industry: an overview of recent developments

Microwave radiation has the ability to heat a material with dielectric properties. Material absorbs microwave energy and then converts it into heat, which gives the possibility of a wide use of microwaves in many industry sectors or agricultural sciences. Microwaves are especially widely used in food industry. The main objective of this paper is to present an overview of recent development regarding microwave applications in food industry. Many techniques in food processing (pasteurization, sterilization, drying, thawing, blanching and stunning) are assisted by microwave energy. It should be mentioned also the use of microwaves in nutrients and nutraceuticals production. Waste generation is an integral part of food production. Microwaves have also application in wastes management. The results of experiments, factors affecting heating and their practical application have been discussed. Many cases have been compared with conventional process methods. The use of microwaves shows many advantages. The most important aspect is shortening the time of the thermal process (even by 50%) and reducing the costs of the operation. In addition, it allows to increase the efficiency of processes while maintaining high quality. The examples of microwave applications given in the article are environmentally- friendly because the conditions of thermal processing allow for reducing the use of solvents and the amount of sewage by decreasing the demand for water. It is anticipated that microwaves will become increasingly popular, with the development of new microwave technologies solving many problems in the future.

Radio frequency energy inactivates peroxidase in stem lettuce at different heating rates and associate changes in physiochemical properties and cell morphology

Radio frequency (RF) is an emerging technology applied in blanching treatment as alternative to conventional treatment. This study aimed to investigate the effects of RF heating rate on peroxidase (POD) inactivating efficiency, physiochemical properties (texture, color and vitamin C) and cell structure of stem lettuce. POD enzyme inactivation efficiency increased with increased RF heating rate. When POD activity was reduced to <5%, better physiochemical properties and less cell damage occurred in RF heating compared with conventional hot water (HW) blanching (HWB); Relative electrolyte leakage (REL) analysis and microscopic observation suggested that the loss of integrity of cell walls and membranes, the decrease in turgor pressure and the weakened connections between adjacent cells leaded to the deterioration of physiochemical properties. The degrees of cell destruction varied with RF heating rates, which provide a new idea for RF blanching for producing different types of fruits and vegetables products (Solid and juice products).