Research progress in the application of catalytic infrared technology in fruit and vegetable processing.

Fruit and vegetable processing can effectively maintain the quality and safety of fruit and vegetable-based products while extending the shelf life of products and saving transportation costs. Infrared (IR) technology has been widely used in many operating units of fruit and vegetable processing because of its versatility of uniform heating, high heat transfer efficiency, and minimized damage to fruit and vegetable tissues. Catalytic IR (CIR), compared to traditional electric IR, is powered by natural gas or liquefied gas, which can improve thermal efficiency while significantly saving energy. However, there is no comprehensive overview discussing and summarizing the utilization and application of the CIR technology in fruit and vegetable processing. Therefore, this review aims to highlight recent advances in the application of CIR technology in fruit and vegetable processing. Specifically, a comprehensive discussion of the physicochemical properties and underlying mechanisms of CIR is provided, and its applications as a single method or in combination with other technologies in fruit and vegetable processes, such as blanching, peeling, microbial population reduction, and drying, are also presented. Besides, the currently used laboratory and pilot-scale equipment of CIR has also been summarized.

Research progress on extraction of active components from apple processing waste.

Apple waste (APW) is the residual product after apple processing, including apple peel, apple core, apple seed, and other components. A large quantity of APW produced is abandoned annually, leading to serious resource waste and environmental pollution. APW is rich in natural active compounds, such as pectin, polyphenols, fatty acids, and dietary fiber, which has a good use value. This paper reviewed the current research on recovering active components from APW. The traditional extraction methods (acid, alkali, physical, enzyme, etc.) and the novel extraction methods (SWE, UAE, MAE, RFAE, etc.) for the recovery of pectin, polyphenols, apple seed oil, apple seed protein, and dietary fiber from APW were systematically summarized. The basic principles, advantages, and disadvantages of different extraction methods were introduced. The requirements of different extraction methods on extraction conditions and the effects of different extraction methods on the yield, quality, and functional activity of extracted products were analyzed. The challenges and future study direction of APW extraction have prospected. This paper aims to provide a reference for other researchers interested in APW extraction, improve the utilization rate of APW and extend the value chain of the apple industry.