ABSTRACT

Three garden egg varieties (Solanum marcrocarpon, S. aethiopicum and S. gilo) were process into powder by steam blanching a portion for 30 sec and dried at 60oC in an oven until constant weight was obtained while the remaining portion was dried without any pretreatment to serve as control. Evaluation of the functional, nutritional, phytochemical, anti-nutritional and sensory characteristics of powder samples were carried out with standard analytical methods. The results showed the proximate composition of both the steam blanched and controlled powder samples were as follows; moisture content ranged from 5.40% to 6.15%. Crude protein of 11.35% to13.05%, crude fat of 1.45% to 1.85%, crude fibre of 11.93% to 12.75%, crude ash of 7.50% to 8.00% and carbohydrate of 59.55% to 61.23%.  Functional properties ranged from 6.90 mL/g to 11.50 mL/g water absorption capacity, 11.20 to 11.70 mL/g oil absorption capacity, 0.48 to 0.53 g/mL bulk density, 25.02 to 35.40 emulsion capacity and 6.52 to 11.33 mL/100g foam capacity, 1.47 to 3.92 ml swelling index and 11.00secs to 15.50 secs wettability. Mineral contents ranged from 718.75 to 811.18 potassium, 30.30 to 40.60 magnesium, 21.46 to 33.46 calcium, 328.13 to 431.14 sodium, 94.40 to 129.74 phosphorus and 12.65 to 27.18 Iron. The powder samples recorded higher concentrations (mg/100g) of retinol ranging from 17.89 to 56.11, but lower range of concentration of thiamine 0.03 to 0.22, riboflavin 0.02 to 0.17, niacin 0.51 to 1.21, ascorbic acid 1.05 to 6.00 and tocopherol of 0.03 to 0.46. The phytochemical analysis revealed that the garden egg powder sample contained 0.14 to 0.75 flavonoid, 0.02 to 0.23 mg/100g alkaloids, 0.22 to 1.52 mg/110g phenols, 0.78 to 1.92 mg/100g steroids and 0.07 to 0.34 mg/100g. Anti-nutritional content ranged from 0.41 to 1.40 saponin, 0.03 to 0.18 tannin, 0.07 to 0.14 oxalate, 0.08 to 0.26 phytate and 5.23 to 22.10 cyanogenic glycosides. Sensory scores of the sample showed that steam blanching the samples reduced the scores of colour, taste, flavour and general acceptability. Sensory scores of the samples showed the score range of 4.60 to 7.48 colour, 5.12 to 6.80 taste, 5.12 to 7.28 flavour, 4.60 to 5.88 Texture and 5.68 to 7.28 general acceptability. From the result, maximum nutritional content was observed in steam blanched Solanum aethiopicum followed by S. macrocarpon  then S. gilo. Minerals and vitamins content were highest in S. gilo while S. macrocarpon had the highest phytochemical and anti-nutritional properties compared to the other two eggplant varieties used in this study as such is suggested as the optimum eggplant with good nutritional and phytochemical properties retention as well as appreciable levels of minerals and vitamins content. S. macrocarpon  therefore is a potential ingredient for food enrichment and preparation of food with functional properties since it is rich in pharmacologically important phytochemicals.