Antioxidants are important ingredients that are present in fruits and vegetables (FAV). With increased consumption of FAV in its raw and processed form, a predominantly plant-based diet rich in FAV could reduce the risk of the development of chronic human diseases. This review highlights the potentials of the various types of antioxidants containing FAV; their impact on human health as nutraceuticals, pharmaceuticals, and phytoceuticals; as well as prospects in tackling some chronic human diseases. The structures and activity relationship of the antioxidant compounds, as well as their mechanism of action, are examined from current scientific investigations. Information provided herein will give more insight into the roles of antioxidant ingredients present in FAV.

The increasing consumption of dried fruits requires further attention on the quality parameters. Drying has become necessary because most fruits are highly perishable owing to their high moisture content and the need to make them available all year round and at locations where they are not produced. In addition to preservation, the reduced weight and bulk of dehydrated products decreases packaging, handling and transportation costs. Quality changes associated with drying of fruit products include physical, sensory, nutritional, and microbiological. Drying gives rise to low or moderate glycemic index (GI) products with high calorie, vitamin and mineral contents. This review examines the nutritional benefits of dried fruits, protective compounds present in dried fruits, GI, overview of some fruit drying methods and effects of drying operations on the quality properties such as shrinkage, porosity, texture, color, rehydration, effective moisture diffusivity, nutritional, sensory, microbiological and shelf stability of fruits.

Dptimization of microwave drying conditions of Luvhele and Mabonde banana varieties were studied using response surface methodology. The drying was performed using a central composite rotatable design for two variables: microwave power level (100, 200 and 300 W) and drying time (40, 26, and 12 min.) for Luvhele; (100, 200 and 300 W) and (42, 27, and 12 min) for Mabonde. The colour and texture (hardness) data were analyzed using ANDVA and regression analysis. The fitness of the models obtained was good as the lack of fit for each of the models was not significant. The coefficient of determination R 2 of the models was relatively high, hence the models obtained for the responses were adequate and acceptable. Drying conditions of 178.76 W, 12 min. drying time were found optimum for product quality at a desirability of 0.91 for Luvhele; while 127.67 W, 12 min. with a desirability of 0.86 was predicted for Mabonde. The result of this study could be used as a standard for microwave processing of Luvhele and Mabonde banana varieties.Keywords: banana; Luvhele; Mabonde; microwave; drying; response surface methodology; colour; hardness; models; optimization.Practical Application: Drying refers to the removal of moisture from a material with the primary aim of reducing microbial activity and product deterioration. Drying of agricultural products offer other advantages such as reduced packaging, handling, storage and transportation costs. Microwave drying has advantages of high drying rates, high energy efficiency, better product quality and efficient space utilization. Response surface methodology has important application in the design, development and formulation of new products, as well as in the improvement of existing product design.

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The response surface method (RSM) has an important application in formulation of new products. This study determined the effect of electric hot-air drying on the functional properties of flour made from orange-fleshed sweet potato (OFSP). Flour from the cultivars Bophelo (B) and Impilo (IM) were treated with 13 temperature-time combinations designed by STAT EASE software version 8.01.0. Bophelo flour dried at 70 °C for 8.6 hrs and Impilo at 70 °C for 14.4 hrs showed the lowest gelatinization temperatures and enthalpy of gelatinization (ΔH), indicating ease of cooking. The highest swelling power of 12.45 g/g for Bophelo and 8.16 g/g for Impilo were significantly higher than the remaining samples. Flours for Bophelo and Impilo at drying temperatures and times at 70 °C for 4.4 hrs, 56 °C for 6.5 hrs and 60 °C for 6.5 hrs indicated favourable gelling properties and cost of drying, implying that these can be used at household level and in food industries as thickeners from both cultivars.