INFLUENCE OF PRESSURE AND TEMPERATURE STRESS DURING VACUUM PRE-COOLING ON THE QUALITY OF FRESH LEAFY VEGETABLE

2001 Fiscal Year Final Research Report Summary

• Project/Area Number: 12460111
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: 農業機械学
• Research Institution: THE UNIVERSITY OF TOKYO
• Principal Investigator: SEO Yasuhisa GRADUATE SCHOOL OF AGRICULTURAL AND LIFE SCIENCES, DEP. OF BIOLOGICAL AND LIFE ENGINEERING, THE UNIVERSITY OF TOKYO, PROFESSOR, 大学院・農学生命科学研究科, 教授 (80011914)
• Co-Investigator(Kenkyū-buntansha): KAWAGOE Yoshinori GRADUATE SCHOOL OF AGRICULTURAL AND LIFE SCIENCES, DEP. OF BIOLOGICAL AND LIFE ENGINEERING, THE UNIVERSITY OF TOKYO, LECTURER, 大学院・農学生命科学研究科, 助手 (80234053)
• Project Period (FY): 2000 – 2001
• Keywords: pre-cooling / vacuum / pressure / temperature / stress / L-ascorbic acid / leafy vegetable / freshness

Research Abstract

The stress conditions due to rapid decrease in pressure and temperature during vacuum pre-cooling of spinach were investigated. The specific influence of pressure and temperature were isolated to determine their contributions to quality degradation. The rapid decline in temperature rather than pressure was found to be responsible for the decline in L-ascorbic acid (AsA). By modifying pressure profile at 0.61 kPa, gradual pressure reduction rate retained the level of AsA. The critical final pressure affecting quality of spinach ranged from 0.61-0.8 kPa. Vacuum pre-cooled spinach respired more than the not pre-cooled and chilled water pre-cooled spinach using similar vacuum pre-cooling curve. Similar findings were obtained for spinach samples subjected to the same pressure condition but at different initial temperatures in a 4-day storage at 5℃.