Optimization of gluten free biscuit from foxtail, copra meal and amaranth

Abstract Optimization of proportion for minimally processed foxtail millet flour (FMF) (55g or 85%) and copra meal flour (CMF) (10g or 15%) through preliminary trials were done sensorially to have gluten free premix. Optimized premix (60g or 60%) work upon further with amaranth flour (AF) (40g or 40%) in the same way to have gluten free composite mix that works as base material. Further selected independent variables i.e. AF (30-40g/100g premix), fat (35-42 g/100g composite mix) and skim milk powder (SMP) (4-6g/100g composite mix) were used for standardization of ingredients level to formulate biscuits through central composite rotatable design (CCRD) of response surface methodology (RSM). Numerically optimized formulation were found to 40g/100g, 4g/100g and 42g/100g values were optimized for AF, SMP and fat respectively using series of responses viz. maximum spread ratio, fiber content, overall acceptability and with minimum of breaking strength values. Resultant biscuit was shown to have favorable characteristics of overall acceptability (7.55) with desirable responses (0.794) for celiacs.摘要 本研究通过感官初步试验，优化了轻度加工小米粉（foxtail millet flour, FMF）与椰子粕粉（copra meal flour, CMF）的配比：前者用量为55g或占比85%，后者为10g或占比15%，以制备无麸质预拌粉。将优化得到的预拌粉（60g或占比60%）与苋菜粉（amaranth flour, AF）按相同方式复配，苋菜粉用量为40g或占比40%，最终得到无麸质复合混合粉，作为后续制备的基础原料。后续研究选取3个自变量进行原料水平标准化以制备饼干，自变量分别为预拌粉基质中的苋菜粉（AF）添加量（30~40g/100g预拌粉）、复合混合粉中的脂肪含量（35~42g/100g复合混合粉）以及脱脂乳粉（skim milk powder, SMP）添加量（4~6g/100g复合混合粉），试验采用响应面法（response surface methodology, RSM）中的中心复合旋转设计（central composite rotatable design, CCRD）。基于最大铺展比、膳食纤维含量、整体接受度以及最小断裂强度等多项评价指标，通过数值优化得到最优配方：苋菜粉、脱脂乳粉与脂肪的最优添加量分别为40g/100g、4g/100g与42g/100g。最终制备的饼干具备优异的综合特性，整体接受度得分为7.55，且针对乳糜泻患者的适配响应值为0.794，各项指标均表现理想。