Nutritional and rheological properties of swet potato based infant food and its preservation using antioxidants

Sweet potato based infant food was developed according to micro-diet database program, 2000, Down lee Systems Limited. Two sweet potato based recipes were formulated and their nutritional properties and digestibility measured using standard analytical methods. The viscosity or consistency of a baby food was critical and was determined by measuring the rheology of the product. The oscillation technique was used to determine the elastic energy stored (G’) and the energy dissipated due toviscosity (G’’). The effects of antioxidants on lipid oxidation of the developed products on storage were also investigated. The recipes were compared with two commercial infant food products; Heinz baby food and cerelac®. The mean ± SD for moisture, total carbohydrate, protein, crude fat, and ash per 100 g dry weight were 8 ± 0.4, 66 ± 0.2, 20.4 ± 0.1, 2.0 ± 0.1, 3.2 ± 0.8 g, respectively for recipe A, and 8.4 ± 0.6, 58 ± 1.4, 28 ± 0.4, and 3.4 ± 0.5, 2.0 ± 0.0 g, respectively for recipe B. The in vitro digestibility for recipes A, B and commercial food (cerelac®) were 69.5 ± 0.2, 67.4 ± 0.1 and 64.9 ± 1.9% respectively. The G’ values of the formulated products A, B, Heinz baby food and cerelac® on heating and cooling were 564, 492, 346, 21 Pa. The rheological characteristics of the two formulations were comparable to a commercial Heinz baby food obtained from local super market. The G’ and G’’ values of commercial infant food product cerelac® were very low compared with the formulated product. The results indicated that nutritional characteristics of sweetpotato based products were comparable to the commercial baby food, cerelac® used in Uganda. The formulated food was within the accepted consistency (< 500 Pa) after heating and cooling and hence may be a potential complementary food. The lipid oxidation for recipe A with fish was significantly reduced by using antioxidants (500 mg Vitamin C, 500 mg Vitamin E and 100 mg of Citric acid) whereas recipe B did not need any antioxidants