APPEARANCE AND TEXTURE CHANGES OF MODIFIED ATMOSPHERE-PACKED FRESH-CUT MANGOSTEEN AFTER PRESERVATIVE DIPS

The relationship between cell wall and postharvest physiological deterioration of fresh produce

Postharvest physiological deterioration (PPD) reduces the availability and economic value of fresh produces, resulting in the waste of agricultural products and becoming a worldwide problem. Therefore, many studies have been carried out at the anatomical structural, physiological and biochemical levels and molecular levels of PPD of fresh produces to seek ways to manage the postharvest quality of fresh produce. The cell wall is the outermost structure of a plant cell and as such represents the first barrier to prevent external microorganisms and other injuries. Many studies on postharvest quality of crop storage organs relate to changes in plant cell wall-related components. Indeed, these studies evidence the non-negligible role of the plant cell wall in postharvest storage ability. However, the relationship between cell wall metabolism and postharvest deterioration of fresh produces has not been well summarized. In this review, we summarize the structural changes of cell walls in different types of PPD, metabolic changes, and the possible molecular mechanism regulating cell wall metabolism in PPD of fresh produce. This review provides a basis for further research on delaying the occurrence of PPD of fresh produce.

Effect of antibrowning dips and controlled atmosphere storage on the physico-chemical, visual and nutritional quality of minimally processed "Rojo Brillante" persimmons

The combined effect of antibrowning dips and controlled atmosphere storage on fresh-cut "Rojo Brillante" persimmon quality was investigated. Persimmon slices were dipped in 10 g L^-1 ascorbic acid, 10 g L^-1 citric acid or water and were stored in different controlled atmospheres at 5 ℃. Controlled atmosphere conditions were 21 kPa O₂ + 10 kPa CO₂ (Atm-B), 21 kPa O₂ + 20 kPa CO₂ (Atm-C), 5 kPa O₂ + 10 kPa CO₂ (Atm-D) and 5 kPa O₂ in the absence of CO₂ (Atm-E). Air (Atm-A) was used as a control. Atmospheres with high CO₂ concentrations induced darkening, associated with a flesh disorder known as "internal flesh browning". Only the samples placed in Atm-E, and treated with 10 g L^-1 ascorbic acid or 10 g L^-1 citric acid, controlled enzymatic browning, reduced firmness loss and prevented the "internal flesh browning" disorder. The maximum limit of marketability was achieved in the samples treated with 10 g L^-1 citric acid and stored in Atm-E for nine storage days at 5 ℃. The total vitamin C, free radical scavenging activity, total phenolic content and total carotenoids of the fresh-cut "Rojo Brillante" persimmons were affected by maturity stage at harvest, whereas antibrowning dips and controlled atmosphere storage had no clear effect.