Gluten-free cookies with low glycemic index and glycemic load: optimization of the process variables via response surface methodology and artificial neural network.

This research investigates the effect of baking temperature and time on the resistant starch (RS), glycemic index (GI) and glycemic load (GL) of gluten-free cookies, optimized the processing parameter using a chemometrics approach of response surface methodology (RSM) and artificial neural network (ANN). The in-vitro starch digestibility of the formulated cookies exhibited a monophasic starch digestogram. Increase in resistant starch, and a decrease in the predicted GI of the cookies, was associated with low temperature and high baking time. The use of RSM and ANN modelling techniques accurately predict the RS, pGI and GL (coefficient of determinant, R2 > 0.93 and root mean square of error = 0.43-0.62) of the gluten-free cookies. The optimal condition for the production of cookies with high RS, low pGI and GL were baking temperature of 158 °C and baking time of 20 min with predicted RS value of 19.61 g/100g of dry starch, pGI value of 56.98 and GL value 52.64.

Texture profile analysis and stress relaxation characteristics of protein fortified sweetpotato noodles.

The mechanical stress relaxation and textual characteristics of starch noodles supplemented with soybean protein concentrate (SPC) was studied with an Instron texture analyzer. Noodles strength was observed to increase significantly with increased in SPC concentration from 0 to 20%. Noodles (ES30) formulated with the esterified starch and 30% SPC substitution had the highest deformation modulus index, initial break force, and maximum break force. The stress relaxation data was well fitted by the Maxwell and Peleg-Normand models though the latter was the most suited. The fitted parameters, F3 and λ1 had a higher sensitivity to changes in its viscoelastic properties when compared to k2 or %SR. A significant correlation was established between the stress relaxation index and textural parameters. The result of this study suggests that starch noodles with enhanced textural and break force characteristics can be formulated with 10-20% SPC substitution. PRACTICAL APPLICATIONS: Dried noodles are formulated from raw noodles which have been dehydrated either by hot-air drying or natural drying. It has the advantages of being low-cost, easy to cook, and longer shelf-life. Consumer's acceptance of cooked noodles depends majorly on its textural properties such as its elasticity, hardness, and smoothness. The extent of noodles hardness and its breakpoint features are an influencer of noodles breakage during packaging and shipping. The determination of modeling parameters describing these physical characteristics can help in the production of noodles with improved breakpoint index, textural features, and quality. Therefore, the effects of different percentage of SPC supplementation on the break force and stress relaxation characteristics of noodles formulated from sweet potato starch were evaluated in the present study.

Kinetics of starch digestion in native and modified sweetpotato starches from an orange fleshed cultivar.

Starch from orange-fleshed sweet potato cultivar was modified using dual autoclave retrogradation, annealing and lintnering modification treatment and their digestibility properties studied. The rate and extent of digestion were suitably predicted with a first-order kinetic model derived in the course of the study. The starches clearly displayed monophasic digestograms while modified starches were observed to have lower glycemic load and glycemic index when compared to the unmodified starch. This study clearly demonstrates the effect of various starch modification treatments on the digestibility of sweet potato starches and also predicted it digestion kinetics parameters.

Effect of gamma irradiation on physicochemical properties of stored pigeon pea (Cajanus cajan) flour.

The effect of gamma irradiation at various doses (5, 10, 15, 20 kGy) was observed on pigeon pea flour stored for 3 months on proximate composition, functional properties, and peroxide value. Sensory evaluation was also carried out on bean cake (moinmoin) made from nonirradiated and irradiated pigeon pea flour. The results showed that stored gamma-irradiated samples had significantly lower (P < 0.05) value of protein and little or no effect on moisture content. There were slight decreases in crude fiber and ash content of the irradiated samples compared with the control sample. The result of functional properties of the irradiated flours showed slight increase in water absorption capacity, swelling capacity and bulk density. The peroxide value of crude oil increased significantly with dose increases for the period of storage. The sensory evaluation of moinmoin samples prepared from irradiated pigeon pea flour showed no significant difference from the moinmoin sample prepared from nonirradiated flour. It can be concluded that gamma irradiation can extend the shelf life of pigeon pea flour.