Evaluation of low methoxyl pectin concentration and dough chilling treatment in enhancing okara-wheat flour-based cookies structure

Abstract

The effect of specific concentrations of low methoxyl pectin (LMP) (0, 0.5, 1 and 1.5 g/100g) and dough chilling treatments (with and without chilling) on the physicochemical properties of okara cookies were investigated. Addition of LMP increased the cookie dough viscoelastic properties due to formation of LMP gel network which strengthened the cookie overall structure. Cookies with a higher LMP concentration showed more compact and denser texture, as indicated in their microstructure. However, the cookie hardness was lowered with the chilling treatment and exhibited a lower fracturability. Chilling the dough facilitated the progressive development of LMP gel network and promoted a strong dough structure. Chilled dough with 1.5 g/100g LMP has the strongest structure where a larger strain value was required to deform the network compared to other formulations. The exothermic peaks disappeared when dough was chilled, meanwhile, the FTIR results revealed less variation in the spectral signals for all samples.