Hygroscopic Coatings Control Surface White Discoloration of Peeled (Minimally Processed) Carrots During Storage |
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| Authors: | LUIS CISNEROS-ZEVALLOS MIKAL E. SALTVEIT JOHN M. KROCHTA |
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| Affiliation: | Authors Cisneros-Zevallos and Krochta are with the Dept. of Food Science &Technology and author Saltveit is with the Dept. of Vegetable Crops, Mann Laboratory, Univ. of California, Davis, CA 95616. Address inquiries to Dr. John M. Krochta. |
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| Abstract: | White discoloration on peeled carrots is partially due to surface dehydration which can be controlled with hygroscopic coatings: e.g., polyhydric alcohols and salt solutions. This study was performed at 2.5, 7.5, 10, and 15°C, using a model system controlling relative humidity at 33, 75 or 98% or a commercial system with low-density polyethylene (LDPE) plastic film bags. The moisture sorption properties of propylene glycol, sorbitol, glycerol and calcium chloride enabled them to keep the carrot surface moist and maintain a transparent surface layer through which the underlying orange color was visible. This effect was only observed at high relative humidities (e.g., 98% RH). Similar effects were observed on treated peeled carrots stored in LDPE bags. The moisturized appearance provided by the hygroscopic coatings during storage was effective at several different temperatures. |
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| Keywords: | White discoloration coatings carrots surface dehydration |
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