Influence of replacement of wheat flour with sweet potato powder on quality of cupcakes

Abstract

Cupcakes are snack cakes, which are largely consumed by many people every day. These bakery products are normally made from wheat flour, which are nutritionally poor. Therefore, the goal of this study was to evaluate the influence of the replacing of wheat flour with purple sweet potato powder at various proportions (0, 5, 10, and 15%) on the quality of the cupcakes. The following raw materials were used for making the cupcakes: wheat flour, eggs, sugar, vanilla sugar, cream (36% fat), baking powder, and salt. Also, cupcakes enriched with freeze-dried purple sweet potato powder. The experiment consisted of four treatments as follows: T1 - Control (100% wheat flour); T2 - 95% wheat flour + 5% sweet potato powder; T3 - 90% wheat flour + 10% sweet potato powder; T4 - 85 % wheat flour + 15% sweet potato powder. The cupcakes were analysed for moisture, ash and fibre using standard methods. The amounts of calcium, potassium, phosphorus of the cupcakes were established by inductively coupled plasma atomic emission spectrometry. Total phenolic was determined by the Folin–Ciocalteu spectrophotometric method. The firmness and springiness of cupcakes was estimated using a texture analyser TA.XT plus. The results revealed that cupcakes with 15% sweet potato powder had significantly higher amount of calcium (61.36 mg 100 g-1), potassium (251.19 mg 100 g-1) and phosphorus (207.03 mg 100 g-1), compared to cupcakes without sweet potato powder. Significantly the greatest amounts of ash and total phenolic were found in cupcakes enriched with 15% and 10 % sweet potato powder. However, the replacement of wheat flour with the sweet potato powder had no a significant effect on moisture. The cupcakes made from 85% wheat flour and 15% sweet potato powder were significantly softer and more elastic compared to control sample. In conclusion, that freeze-dried purple sweet potato powder can easily be applicated into cupcakes to replace wheat flour by up to 15%.