Quality of Green Peas by Sous Vide Processing

Abstract

Quality of sous vide processed green peas were studied in relation to the differences of processing temperatures (80, 90 or 100°C) and degrees of vacuum (30 or 100 Torr) in packaging.Additionally, changes in quality during storage were also investigated. The surface color of sous vide processed green peas at 100°C was better than that with other processings. There were no considerable differences among processing temperatures on the total chlorophyll content. The content of total ascorbic acid, total sugar and soluble nitrogen compounds in sous vide processed green peas was higher than those in the green peas by conventional processing. Anaerobic bacteria increased after 4 days of storage at 20°C. The green peas were putrefied after 7 days of storage at 20°C. No bacteria were detected after 11 days of storage when the green peas were stored at 5°C. The surface color was discolored during storage, especially at 20°C, with a degradation of chlorophyll a. The ascorbic acid content showed no change during storage at 5 or 20°C. The total sugar content showed almost the same value at 5 or 20°C, and slightly decreased during storage. These results indicated that cooking under reduced pressures at 90°C or higher temperatures is good for the quality of green peas. Furthermore, it is also suggested that storage at 5°C or lower temperatures is good for maintaining quality.