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Comparison of different drying methods on the physical properties, bioactive compounds and antioxidant activity of raspberry powders
Author(s) -
Si Xu,
Chen Qinqin,
Bi Jinfeng,
Wu Xinye,
Yi Jianyong,
Zhou Linyan,
Li Zhaolu
Publication year - 2016
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.7317
Subject(s) - blowing a raspberry , food science , chemistry , dehydration , antioxidant , polyphenol , flavonoid , anthocyanin , freeze drying , water activity , spray drying , solubility , maltodextrin , bioactive compound , water content , chromatography , biochemistry , organic chemistry , geotechnical engineering , engineering
BACKGROUND Dehydration has been considered as one of the traditional but most effective techniques for perishable fruits. Raspberry powders obtained after dehydration can be added as ingredients into food formulations such as bakery and dairy products. In this study, raspberry powders obtained by hot air drying ( HAD ), infrared radiation drying ( IRD ), hot air and explosion puffing drying ( HA‐EPD ), infrared radiation and microwave vacuum drying ( IR‐MVD ) and freeze drying ( FD ) were compared on physical properties, bioactive compounds and antioxidant activity. RESULTS Drying techniques affected the physical properties, bioactive compounds and antioxidant activity of raspberry powders greatly. FD led to significantly higher ( P < 0.05) values of water solubility (45.26%), soluble solid (63.46%), hygroscopicity (18.06%), color parameters and anthocyanin retention (60.70%) of raspberry powder compared with other drying methods. However, thermal drying techniques, especially combined drying methods, were superior to FD in final total polyphenol content, total flavonoid content and antioxidant activity. The combined drying methods, especially IR‐MVD , showed the highest total polyphenol content (123.22 g GAE kg −1 dw) and total flavonoid content (0.30 g CAE kg −1 dw). Additionally, IR‐MVD performed better in antioxidant activity retention. CONCLUSION Overall, combined drying methods, especially IR‐MVD , were found to result in better quality of raspberry powders among the thermal drying techniques. IR‐MVD could be recommended for use in the drying industry because of its advantages in time saving and nutrient retention. © 2015 Society of Chemical Industry