Dehydration-rehydration vegetables: Evaluation and future challenges.

In this review, the rehydration kinetics model, the quality factors affecting of vegetables during rehydration process, the future challenges and development direction of rehydration process were comprehensively analyzed. Based on the fitting equation for the change in moisture content during rehydration, a suitable rehydration model can be selected to describe the rehydration process of vegetables. Optimal pre-treatment, drying and rehydration methods were selected by considering quality, energy consumption and environmental aspects, and new technologies were developed to improve the quality characteristics of rehydrated vegetables. It is necessary to classify vegetables according to their shape and type to establish the criteria of rehydration processing through mathematical modeling. Industrial production from pre-treatment to product packaging will be precisely adjusted through process parameters. Furthermore, improvements the quality of rehydrated vegetables can be considered in terms of the structural and compositional aspects of the cell wall and cell membrane.

Study on the relationship between flavor components and quality of ice wine during freezing and brewing of 'beibinghong' grapes.

Ice wine has prominent fruity sweetness and unique, rich aroma compared to wine. The sweetness was accumulating, the acidity and astringency tended to soften of grape berry during the freezing period. The process gave the ice wine balanced taste, with prominent honey sweetness, accompanied by refreshing alcoholic taste, soft acidity and astringency. Eleven key aroma compounds were identified in ice wine through GC-MS and ROAV values. The key aroma compounds were analyzed with Pearson correlation coefficient and fragrance mechanism were speculated. Ethyl acetate and 1-octen-3-ol derived from the aroma of grape, are produced by anaerobic metabolism and lipoxygenase pathways of pyruvate and linoleic acid, respectively. Ester aromas, 2-phenylethanol and 2-methylbutanal were derived from the brewing process, were produced by octanoic acid, caproic acid, phenylalanine and isoleucine through lipid metabolism, Ehrlich pathway and Strecker pathway, respectively. Proposed corresponding control methods based on factors that affect the formation of ice wine aromas.