Impact of Blanching Pretreatment on the Quality Characteristics of Three Varieties of Oven Dried Eggplant (Solanum melongena L)

Eggplant possesses appreciable reserve of nutrients and loads of phytochemical compounds. Processing will help minimize the wastage and increase consumption. In this study, three cultivars of eggplant were pre-treated, oven-dried and ground into coarse powders with the intent of retaining the nutrients. The functional properties, proximate, vitamin, mineral, phytochemical and anti-nutrient composition as well as the sensory characteristics were determined. The results showed that the eggplant powders had high water absorption capacity (6.90 - 11.50 ml/g), oil absorption capacity (11.20 - 11.70 ml/g), emulsion capacity (25.02 - 35.40 %) and wettability (11.00 - 15.50 sec). However, pre-treatment was found to reduce the functional properties of the eggplant powders compared to the control samples. The level of moisture (5.40 - 6.15 %) and ash (7.50 - 8.00 %) content was increased by blanching pre-treatment with concurrent reduction in fat (1.85 – 1.45 %), crude fibre (12.75 – 11.93 %) and protein (13.05 – 11.35 %) content. The mineral content was found to be higher in the blanched samples with potassium being the major mineral. Blanching pre-treatment resulted in reducing vitamin content in the samples. The studied eggplant varieties are poor sources of thiamin (0.02 – 0.22 mg/100g), riboflavin (0.02 – 0.17 mg/100g) and tocopherol (0.16 – 0.46 mg/100g), but contained high retinol content (17.89 – 56.11 mg/100g) and significant amount of vitamin C (1.05 – 6.00 mg/100g). Similarly, pretreatment resulted in reduced phytochemical and antinutritional properties in the eggplant powders. Organoleptically, the eggplant powders had better appearance with no change in taste, but reduced preference in terms of texture, flavour and general acceptability. The eggplant powders can be utilized as functional ingredient for food enrichment