Hot air convective drying of hog plum fruit (Spondias mombin): effects of physical and edible-oil-aided chemical pretreatments on drying and quality characteristics
John O. Ojediran,
Clinton E. Okonkwo,
Abiola F. Olaniran,
Yetunde M. Iranloye,
Adejoke D. Adewumi,
Oluwakemi Erinle,
Yemisi Tokunbo Afolabi,
Oladayo Adeyi,
Abiola Adeyi
Affiliations
John O. Ojediran
Department of Agricultural and Biosystems Engineering, College of Engineering, Landmark University, P.M.B 1001, Omu-Aran, Nigeria
Clinton E. Okonkwo
Department of Agricultural and Biosystems Engineering, College of Engineering, Landmark University, P.M.B 1001, Omu-Aran, Nigeria; Corresponding author.
Abiola F. Olaniran
Department of Food Science and Microbiology, College of Pure and Applied Sciences, Landmark University, P.M.B 1001, Omu-Aran, Nigeria
Yetunde M. Iranloye
Department of Food Science and Microbiology, College of Pure and Applied Sciences, Landmark University, P.M.B 1001, Omu-Aran, Nigeria
Adejoke D. Adewumi
Department of Agricultural and Biosystems Engineering, College of Engineering, Landmark University, P.M.B 1001, Omu-Aran, Nigeria
Oluwakemi Erinle
Department of Agricultural and Biosystems Engineering, College of Engineering, Landmark University, P.M.B 1001, Omu-Aran, Nigeria
Yemisi Tokunbo Afolabi
Department of Industrial Chemistry, College of Pure and Applied Sciences, Landmark University, P.M.B 1001, Omu-Aran, Nigeria
Oladayo Adeyi
Department of Chemical Engineering, Michael Okpara University of Agriculture, P.M.B 7267, Umudike, Abia State, Nigeria
Abiola Adeyi
Department of Mechanical Engineering, Ladoke Akintola University of Technology, Ogbomoso, P.M.B 4000, Oyo State, Nigeria; Forestry Research Institute of Nigeria, Jericho Hill, P.M.B 5054, Ibadan, Nigeria
This aim of this study was to evaluate the effects of pretreatments and temperature on the hot air drying characteristics of hog plum fruits. Hog plum fruits were pretreated with olive oil/K2CO3 or sunflower oil/K2CO3 at 28 °C and olive oil/NaOH cum blanching at 96 °C for 15s, hot water at 96 °C for 15s, and dried in a hot air drier at 50, 60, and 70 °C. Mathematical models were used to fit the data of drying and rehydration kinetics. Results showed that increase in temperature reduced drying time, increased effective diffusivity and shrinkage. Sunflower oil aided chemical pretreated sample had the shortest drying time (780 min) and highest effective diffusivity (6.3 × 10−8 m2/s) at 60 °C, faster rehydration ability at 60 °C, highest retention rate for ascorbic acid (15 %), phenolic content (29 %), and antioxidant activity (12.3 %), while olive oil aided chemical (K2CO3) pretreated sample had the shortest drying time at 50 °C (990 min) and 70 °C (600 min), lowest shrinkage (48.5 %), slower rehydration capacity at 40 °C, and lowest colour change (ΔE = 11.5). Modified Henderson and Pabis and Vega-Gálvez were superior to other fitting models in predicting the drying and rehydration kinetics. Sunflower oil/K2CO3 pretreatment could help improve the drying and quality characteristics of hog plum.
