The impact of wheat (Triticum aestivum L.) bran on wheat starch gelatinization: A differential scanning calorimetry study

The effect of wheat bran on starch gelatinization temperature was investigated. Dynamic water vapour sorption and water retention capacity experiments showed that bran bound up to 3 times more water than starch. However, examining starch gelatinization in starch-bran-water mixtures with differential scanning calorimetry showed that the effect of substituting starch by bran differed from that of moving into a regime of limiting water. Modelling the effect of the mixture composition on starch gelatinization behavior indicated that the onset (To) and peak (Tp) gelatinization temperatures were positively impacted by the bran concentration in water. The conclusion temperature (Tc) was negatively affected by the water content. Fractionation experiments demonstrated that the increased To and Tp were mainly caused by the extractable wheat bran components, such as potassium and phosphorus, which decrease the plasticization capacity of the solvent. The mechanism behind our observations was explained with the side-chain liquid-crystalline polymeric model for starch.