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Candied Orange Peel Produced in Solutions with Various Sugar Compositions: Sugar Composition and Sorption Properties of the Product
Author(s) -
Witczak Teresa,
Witczak Mariusz,
Socha Robert,
StĘPień Anna,
Grzesik Mirosław
Publication year - 2017
Publication title -
journal of food process engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.507
H-Index - 45
eISSN - 1745-4530
pISSN - 0145-8876
DOI - 10.1111/jfpe.12367
Subject(s) - chemistry , sugar , sorption , sucrose , fructose , orange (colour) , water activity , food science , orange juice , chromatography , water content , organic chemistry , adsorption , geotechnical engineering , engineering
This study investigated the relationships between equilibrium water content and water activity for candied orange peel produced by saturation in sucrose‐based and glucose–fructose syrups, and for native orange peel. Dry matter loss due to candying was found to be the highest for glucose–fructose syrup dehydrated products. The greatest amount of sugars was absorbed by products candied in sucrose syrup. The sorption isotherms of candied orange peel corresponded with type III isotherms, according to Brunauer's et al . classification, whereas the sorption isotherm of native orange peel displayed a sigmoidal shape characteristic for type II isotherm. For products owing the highest sucrose content (above 40%), the sorption isotherms showed a discontinuity in the water activity range of 0.3–0.4. The results demonstrated that the sorption properties of the studied products depend on the levels of individual sugars they contain. Principal component analysis revealed marked differences between candied and native peel and between products candied in sucrose syrup and those prepared in glucose–fructose syrup. Seven most popular models used for describing the sorption process of foods were examined. Among those, the Lewicki model appeared to best describe the experimental data. The Peleg model was well fitted into the data for candied orange peel in the limited range of water activity (up to 0.86). Practical Applications Candied fruits have for centuries enjoyed huge popularity among the consumers. Their properties depend on the sugar composition of hypertonic solutions used during candying process. The present study was aimed to determine the relationship among the sugar composition of hypertonic solutions, and the sugar composition of the product, as well as examining the influence of those solutions on the relationship between equilibrium water content and water activity of candied orange peel. Identifying the sorption model that describes the changes in the product's water content as dependent on water activity in the widest possible range, it can be helpful to predict the quality of the product during storage and extending its shelf‐life, and thus in optimizing and enhancing the quality of the final product.