Optimizing the processing factor and formulation of oat-based cookie dough for enhancement in stickiness and moisture content using response surface methodology and superimposition

Despite the utilization of dusting flour and oil to reduce dough stickiness during the production process in food industry, they do not effectively help in eliminating the problem. Stickiness remains the bane of the production of bakery and confectionery products, including cookies. In addition, the high moisture content of cookie dough is unduly important to obtain a high breaking and compression strengths (cookies with high breaking tolerance). This study was conducted in light of insufficient research hitherto undertaken on the utilization of response surface methodology and superimposition to enhance the stickiness and moisture content of quick oat-based cookie dough. The study aims at optimizating, validating and superimposing the best combination of factors, to produce the lowest stickiness and highest moisture content in cookie dough. In addition, the effect of flour content and resting time on the stickiness and moisture content of cookie dough was also investigated, and microstructure analysis conducted. The central composite design (CCD) technique was employed and 39 runs were generated by CCD based on two factors with five levels, which comprised flour content (50, 55, 60, 65, and 70%), resting time (10, 20, 30, 40, and 50 min) and three replications. Results from ANOVA showed that all factors were statistically significant at p < 0.05. Flour content between 56% and 62%, and resting time within 27 and 50 min, resulted in dough with high stickiness. High-region moisture content was observed for flour content between 60% and 70%, and within 10 and 15 min of resting time. The optimized values for flour content (V1) = 67% and resting time (V2) = 10 min. The predicted model (regression coefficient model) was found to be accurate in predicting the optimum value of factors. The experimental validation showed the average relative deviation for stickiness and moisture content was 8.54% and 1.44%, respectively. The superimposition of the contour plots was successfully developed to identify the optimum region for the lowest stickiness and highest moisture content which were at 67–70% flour content and 10–15 min resting time

Effect of oat to flour ratio on stickiness of the cookie dough

Texture attributes, such as stickiness of grain-based food is important to consumers and manufacturers (McManuis, 2001). Descriptive method such as Texture Profile Analysis (TPA) is used in order to describe the textural properties of the cookie dough. By using TPA, the structure of the food can be emphasize. Mixture formulation of cookie dough based on five different cup ratios of oat to flour which are 1:1, 1:1.25, 1:1.5, 1:1.75 and 1:75. The ratio of 1:1.5 is the basic mixture formulation provided by the SME’s cookies company. The calculated weight was rounded off to the nearest whole number. Example, for 1.8 cups of oat at ratio 1:1.5, the total weight required was 1.8 cups times 94 grams which equal to 169.2 grams. After rounded off to the nearest whole number, the weight required was 169 grams. Similar calculation method was used to calculate the weight of flour. For each ratio of oat to flour, the total cup required for every mixing process was 4.5 cups. As results, different ratio of oat to flour had a significant effect on the dough stickiness where cookie dough with ratio 1:1.75 flour have the highest stickiness value while cookie dough with ratio 1:1.25 have the lowest stickiness value. This is because the higher flour content contains higher starch which contribute to higher moisture content. Hence, the dough with more flour is more sticky. The current study indicated a high potential in developing fiber-rich cookies with large inclusion with composition of 1:1.25 of oats and flour respectively which produced a less sticky dough. Thus, the increasing of oat and flour content in the formulation show a significant effect on dough stickiness