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Quality Changes and Respiration Rates of Fresh‐Cut Sunchoke Tubers ( H elianthus tuberosus L .)
Author(s) -
Wang Qingguo,
Cantwell Marita
Publication year - 2015
Publication title -
journal of food processing and preservation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.511
H-Index - 48
eISSN - 1745-4549
pISSN - 0145-8892
DOI - 10.1111/jfpp.12271
Subject(s) - polyphenol oxidase , shelf life , respiration , chemistry , respiration rate , dehydration , food science , limiting , browning , polyphenol , horticulture , botany , biology , biochemistry , antioxidant , enzyme , peroxidase , mechanical engineering , engineering
Changes in quality attributes (discoloration, surface dehydration, translucency, color values, texture), respiration, phenolics and phenylalanine ammonia lyase ( PAL ) and polyphenol oxidase activities of sunchoke tuber slices were studied at 0, 5 and 10 C . Cleanly cut smooth surfaces had less wound‐induced discoloration and surface drying than rougher cut surfaces. The main quality defect was red discoloration, and a * and hue color values were highly correlated to this defect. The time course of discoloration was related to wound‐induced respiration and PAL activity but not polyphenol oxidase activity or concentrations of soluble phenolics. Respiration rates of slices at 0, 5 and 10 C averaged 5, 14 and 26 μ L CO 2 /g‐h, respectively, during 7 days. No decay was observed under any condition. Storage at 0 and 5 C effectively retarded surface discoloration, but 0 C was clearly better. A shelf life of 9–12 and 6–8 days was obtained with sunchoke slices at 0 and 5 C , respectively, while shelf life was 3 days at 10 C . Practical Applications Sunchoke tubers contain indigestible inulins and have potential as a fresh‐cut product or a component in fresh‐cut mixtures to be consumed raw or cooked. Sliced tubers retain quality when held at 0–5 C , but discoloration, the main defect limiting shelf life, will occur more rapidly at 5 C . The rate and severity of discoloration was related to storage temperature and to wound‐induced increases in respiration and PAL activity. With this information, strategies to effectively control discoloration can be implemented.