Effect of Hydrocolloids on Quality of Proso Millet Cookie

Abstract

The absence of gluten in proso millet offers difficulty to shape the dough for the preparation of products. The effects of hydrocolloids like gum acacia, guar gum, xanthan gum, carboxymethylcellulose (CMC) and hydroxypropylmethylcellulose (HPMC), and the thermal treatment of proso millet flour and doughs on cookie-making quality were studied. The product attributes that were determined included the sensory and textural properties of the product and compared them with the wheat cookie. Thermal treatment, as well as the addition of hydrocolloids markedly, changed the product qualities. Xanthan and guar gum-added doughs exhibited high instrumental adhesiveness and sensory stickiness which were undesirable for obtaining the appropriate shape of a cookie. The product made from untreated proso millet flour (PMF) showed the highest mass per unit piece followed by the refined wheat flour (RWF) product; the lowest mass and soft texture were displayed by the products made from the CMC and HPMC. The principal component analysis of the results indicated that untreated PMF and RWF products were placed in the opposite quadrants to behave in a different manner. The sensory quality of the product prepared with untreated PMF was inferior to that of the control sample and was not acceptable to sensory judges. The HPMC- and CMC-added products were distinctly different with respect to their volatile quality as per the e-nose analysis. The treated PMF with gum acacia-added product had the similar odour characteristics and were closely associated with firmness and overall quality to match the wheat product and also were best suited for dough-handling purpose.