Application of superheated steam under reduced pressure for dehydrofreezing and thawing of vegetables

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K08023
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Agricultural environmental engineering/Agricultural information engineering
• Research Institution: Tokyo University of Agriculture
• Principal Investigator: MURAMATSU Yoshiki 東京農業大学, 地域環境科学部, 教授 (60328549)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 減圧過熱水蒸気 / ブランチング / 脱水凍結 / 解凍 / 青果物

Outline of Final Research Achievements

Superheated steam under reduced pressure (SSRP) was applied for the branching and thawing. The blanched carrots were dehydrated, frozen, and thawed in several methods. The thawing time by the SSRP heating was shorter than that of air thawing. The dehydro-freezing (DF) treatment for the blanched vegetables improved the texture of the carrot. The DF treatment maintained the color of the sample’s surface after the rehydration. The dehydrated sample thawed by the SSRP had closer hardness to the hardness of the raw sample than the hardness of the sample thawed by air. The effect of DF treatment on some vegetables was also examined.
Three kinds of blanching methods were used in the experiments of the blanching of carrot. The results suggested that the blanching by the SSRP could be applied for the blanching of the carrot. Thawing of frozen chicken in several methods was examined. The results suggested that the SSRP thawing was one of the effective thawing methods for meat.

Free Research Field

ポストハーベスト工学

Academic Significance and Societal Importance of the Research Achievements

減圧過熱水蒸気は，通常100 ℃以下となるため，常圧の過熱水蒸気の利点も持ちつつ，熱感受性の強い食品の品質劣化を抑制できる可能性がある。減圧過熱水蒸気を用いた食品の乾燥に関する研究はいくつかある。しかし，乾燥以外の加工方法に減圧過熱水蒸気を適用した例はみあたらない。本研究では，減圧過熱水蒸気加熱法をブランチングや解凍処理に適用し，他の加熱方法・解凍方法とも比較して減圧過熱水蒸気加熱の優位性を検証した。また，減圧過熱水蒸気加熱法を組み合わせた青果物の脱水凍結に関する研究も行って，加工処理方法，条件と品質特性との関係を検証した。ここに本研究の学術的意義や特徴がある。