Volume 13, Issue 57 (0)                   FSCT 0, 13(57): 121-132 | Back to browse issues page

XML Persian Abstract Print

Abstract:   (3274 Views)
Abstract: Raspberry is a good source in terms of antocianines, polyphenols, vitamin C, fibers, proteins and minerals contents. Raspberry juice is susceptible to enzymatic and microbial reactions, because of its high moisture content (75-90%). Concentration of Raspberry juice increases its shelf life, while decreasing costs of storage and transport. In this study, extracts obtained from two raspberry cultivars of Amol (red) and Siyahkal (black) were concentrated by two methods, radiation (microwave) and convention (evaporator-rotary) applying three pressure levels: 12, 38.5 and 100 kPa. Changes in physicochemical properties including brix, acidity, pH, turbidity and color were assessed during the concentration process of two kinds of juice. Results showed decrease in acidity and color and increase in brix and turbidity of the juices, but rate and amount of changes were dissimilar in different methods and pressures. Samples concentrated by radiation using microwave in comparison with conventional method (evaporator-rotary) had superior quality. Furthermore, decrease in pressure led to better quality in product in both techniques.  
Full-Text [PDF 602 kb]   (1809 Downloads)    

Received: 2015/04/6 | Accepted: 2015/10/9 | Published: 2016/11/21

Rights and permissions
Creative Commons License This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.