Improvement of Quality and Extension of Storage Life of carved fruits and vegetables

Abstract

The objective of this research was to find the suitable types of carving style for five fruits and vegetables, e.g., pumpkin, carrot, radish, cantaloupe and Japanese cucumber. Physiological changes and methods to improve quality and extend shelf-life were also studied. The results showed that the leave-carved operations stimulated the respiration rate, ethylene production and the electrolyte leakage more than flower-carved operations. These responses depended on the size of wound and surface area that contacted with atmospheric oxygen. Two concentrations of peroxyacetic acid (60 and 80 mg/L) solutions showed the efficacy in reducing microorganism populations better than sodium hypochlorite (50 and 75 mg/L). The three firming agents of calcium chloride (0.5-1.5%), calcium lactate (0.5-2%) and calcium propionate (0.5-2%) could improve texture at different concentrations. The combination effects of peroxyacetic acid (80 mg/L) and firming agents (0.5% calcium chloride, 1.5% calcium lactate and 2% calcium propionate) and/or 0.25 and 0.5% of chitosan coating were applied on rose and lotus-carved fruits and vegetables. All off flower-carved fruits and vegetables were stored at 5?1oC in clamshell container. Then, they were placed in a control temperature chamber at 25?1oC every day for 3 hours until the end of shelf-life. The results showed that 0.25 and 0.5% chitosan coating had the best coating solutions for extended shelf-life of carved pumpkin, carrot and cantaloupe. The control treatment, dipped in tap distilled water, showed the suitable treatment for rose-carved radish and lotus-carved Japanese cucumber. The best chemical treatment for each fruit and vegetable was repeated in the storage experiment and then they were stored at 5?1oC in clamshell containers to determine the shelf-life of three carved fruits and vegetables (rose, carnation and lotus). The shelf-life of two styles of flower from carved pumpkin did not exceed 6 days. Carved carrot in rose and carnation flowers had shelf-life for 12 days, while radish was not more than 9 days. The shelf-life of rose and carnation carved cantaloupe did not exceed 9 and 6 days, respectively. Lotus-carved Japanese cucumber had shelf-life for 6 days. Carved radish and Japanese cucumber were dipped in tap distilled water which had high initial microbial population that caused the short shelf-life. Thus, the application of 2% calcium propionate and 80 mg/L peroxyacetic acid was the suitable treatment for reducing microbial population and improving the appearance quality and extended shelf-life.