The study evaluated the effects of convective hot air drying temperatures (40, 50, 60 and 70 °C) with different pre-treatments (Potassium metabisulphite (KMS) and KMS + Citric acid) on drying as well as rehydration kinetics, color, texture and calcium oxalate content of elephant foot yam (EFY) cubes. Moisture diffusivity (6.69 × 10−8-3.41 × 10−7 m2/s) and activation energy (25.18–32.46 kJ/mol) increased with pre-treatments and increase in drying temperature. Rehydration ratio increased with increase in drying as well as rehydration temperature compared to room temperature. Page and modified peleg models suited the best to describe drying and rehydration kinetics of EFY cubes, respectively. Color value ‘L’ decreased with increase in drying temperature and opposite trend was observed for ‘a’ and ‘b’ value. However the dried samples treated with KMS + blanching showed higher ‘L’ value and the highest L value (90.35) was observed at 50 °C. Sample hardness (94.34–349.57 N) and rupture energy (18.42–191.35 N/mm2) decreased with increase in drying temperature. Significant (p < 0.05) reduction in calcium oxalate (120–13.5 mg/100g) was observed during drying. Sample dried at higher temperatures had lower oxalate content and hardness which can be potentially used in curry making, bakery and confectionary products.
|Number of pages||9|
|State||Published - Jan 2019|
Bibliographical noteFunding Information:
We thank Drs. Earl Homsher and Theresa Chen for their comments on the manuscript. We appreciate the generosity of Drs. William and Peggy Hamner for instruction on and use of their ExpertVision track- ing system. We also thank Drs. Jim Sellers, Taro Uyeda, James Spu- dich, and David Warshaw for helpful comments on setting up the in vitro motility assay. This work was supported by National Institutes of Health grant AR- 22031 and National Science Foundation grant DMB 89-05363. Doug-las D. Root was supported by a U. S. Public Health Service National Institutional Research Service Award (CA-9056).
© 2018 Elsevier Ltd
- Calcium oxalate
- Moisture diffusivity