TEXTURE AND PECTIC COMPOSITION DIFFERENCES IN RAW, COOKED AND FROZEN-THAWED CHINESE-CABBAGES DUE TO LEAF POSITION

Differences in texture of raw, cooked and blanched-frozen-then-thawed Chinese Cabbages and their leaf positions (10, 20, 30, 40, or 50th midribs from the outside) were investigated. Firmness and rupture strain of raw midribs were low, but increased after short cooking time. Crispness of tissues decreased and elasticity increased. The 20-30th midribs were slowest to soften during cooking, while the inner midribs from the 40th were more readily softened. The 40th contained more high methoxyl pectin than did the 20th. Therefore, they were more quickly softened because of pectic release by transelimination. After freezing-thawing, firmness decreased and rupture strain increased. Midribs with firmer texture contained more pectin. After freezing-thawing, amounts of pectin in midribs decreased.