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Ultrasonic and osmotic pretreatments followed by convective and vacuum drying of papaya slices
Author(s) -
Chandra Abhishek,
Kumar Sourabh,
Tarafdar Ayon,
Nema Prabhat K
Publication year - 2021
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.10847
Subject(s) - osmotic dehydration , chemistry , pectin , dehydration , food science , polyphenol , water content , phenols , moisture , fourier transform infrared spectroscopy , sonication , chromatography , antioxidant , biochemistry , chemical engineering , organic chemistry , geotechnical engineering , engineering
BACKGROUND Papaya fruit is highly nutritive, but very fragile, and thus has a limited shelf life. Drying is essential to preserve it for longer durations. In this work, osmotic dehydration (OD) with and without ultrasound (US) was applied to papaya slices as a pretreatment in conjugation with vacuum (VD) and convective air drying (AD). Drying was carried out in a novel dryer. Moisture content, drying time, water activity, total color change, total phenolic content, radical scavenging activity, texture, and Fourier‐transform infrared (FTIR) spectrums were evaluated for fresh and dried papaya slices. RESULTS It was observed that US‐assisted osmotic dehydration (USOD) followed by VD had the lowest drying time with highest retention of phenols and antioxidants as compared to other drying techniques. Higher phenols and antioxidants in US‐pretreated samples were attributed to the release of trapped intra‐cellular polyphenols by cavitation. However, the color characteristics and texture of OD pretreatment followed by convective AD slices were found to be better. Color retention could be due to carotenoid preservation, which would be degraded in other treatments, whereas lower brittleness was associated with lower pectin. Infrared spectroscopy confirmed the retention of phytochemicals and antioxidants in dried papaya slices that were subjected to pretreatment. Conclusion Pretreatment before drying enhances the end product quality of dried papaya slices. The results of this study highlight that USOD‐VD is effective for nutrition preservation while OD‐AD is suitable for preserving physical characteristics. © 2020 Society of Chemical Industry