英文摘要 |
Da-Mo sugar apple (Annona squamosa L. cv. Da-Mo) is a unique and important economic fruit variety in Taiwan. It ripens and softens quickly after harvest, and therefore is not durable for storage and transportation. In addition, it produces a bitter taste after heat treatment, which limits its processing and application. This research adopts the emerging high hydrostatic pressure non-thermal processing technology, which can avoid the heat-induced bitter taste and retain the original flavor and nutrients to the greatest possible extent, creating more use and value of Da-Mo sugar apples. Da-Mo sugar apple fruit puree was treated under 4 conditions at a high pressure of 600 MPa. Compared with the traditional heat treatment at 90°C for 10 minutes, the effect on enzyme activity, functional components and antioxidant capacity, total bacterial count, as well as the change of color during storage was studied. The activity of polyphenol oxidase could become lower than 3% after repeated high-pressure treatment under 4 different conditions; the activity of peroxidase decreased by 65%, which was similar to the effect of heat treatment; the sucrose neutral invertase still retained its activity after repeated high-pressure treatment helped the conversion of sucrose to glucose and fructose. Compared with the heat treatment control group, repeated high-pressure treatment could retain or increase the content of total phenols, flavonoids, vitamin C, and antioxidant capacity, showing that it had the effect of thermal damage and the increase of components release. During storage at 4°C for 3 weeks, the bacteria count in the fruit puree after repeated high-pressure treatment met food safety and sanitation standards. Although high-pressure treatment could not completely inhibit the activities of polyphenol oxidase and peroxidase, it could avoid color deterioration during storage. |