Hot air convective drying of hog plum fruit (Spondias mombin): effects of physical and edible-oil-aided chemical pretreatments on drying and quality characteristics.

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.

Production of a Complementary Food: Influence of Cowpea Soaking Time on the Nutritional, Antinutritional, and Antioxidant Properties of the Cassava-Cowpea-Orange-Fleshed Potato Blends.

Soaking and incorporation of legumes for fortification are essential to a complementary food production process. Cassava, orange-fleshed potato, and cowpeas are sustainably cheap, locally available, and underutilized for food biofortification. This study investigated the effect of cowpea soaking time (3, 6, and 9 h) on different composition ratios of cassava, cowpea, and orange-fleshed sweet potato (CCP) blends (50 : 40 : 10 (EC), 50 : 30 : 20 (FC), 50 : 20 : 30 (GC), and 50 : 50 : 0 (HC)). Each blend was assayed for pH, antinutrient, antioxidant, and proximate contents. Results obtained showed that the CCP blends were significantly influenced by the length of cowpea soaking. Moisture and fiber content decreased significantly (P ≤ 0.05) with increased steeping time (3 to 9 h) for the cassava-cowpea-OFSP blends. The blends were significantly different (P ≤ 0.05) in terms of their protein, fiber, fat, ash, and carbohydrate contents. The moisture content of the EC blend was significantly different from only FC and HC blends, respectively. Six (6) hours of soaking showed no significant difference in the nutritional composition of the flour samples compared with 9 hours. The soaking length optimizes the health and nutrient-promoting factors in the various blend samples while also reaffirming cowpeas as a viable biofortification option for use in complementary food production.