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Optimization of hot water extraction of roselle juice using response surface methodology: a comparative study with other extraction methods
Author(s) -
Wong PengKong,
Yusof Salmah,
Ghazali Hasanah Mohd,
Che Man Yaakob bin
Publication year - 2003
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.1416
Subject(s) - ascorbic acid , chemistry , anthocyanin , extraction (chemistry) , food science , response surface methodology , hot water extraction , chromatography , jams , polyphenol , antioxidant , biochemistry
Roselle has regained the attention of many fruit juice manufacturers in Malaysia as a product that contains high ascorbic acid and anthocyanins. However, ascorbic acid and anthocyanin pigments can be easily destroyed during processing of fruit juice. Therefore, in the present study, the effects of different processing methods, namely hot water extraction (HWE), hot water blending, cold water blending and screw press, on the changes in anthocyanins and ascorbic acid contents of roselle juice were evaluated. The anthocyanins and ascorbic acid contents of roselle were determined using the pH differential method and high‐performance liquid chromatography respectively. The physico‐chemical characteristics and sensory properties of roselle juice were also evaluated. The results of the study indicate that the HWE method is the most effective extraction method, resulting in high anthocyanins and ascorbic acid contents of 43 g l −1 (as delphinidin‐3‐glucoside) and 2.34 g kg −1 respectively. The optimum juice extraction conditions were 3.5 h at 60 °C. Copyright © 2003 Society of Chemical Industry