Mudau Masala, Mashau Mpho Edward, Ramashia Shonisani Eugenia
Department of Food Science and Technology, Faculty of Science, Engineering and Agriculture, University of Venda, Thohoyandou 0950, Limpopo Province, South Africa.
Foods. 2022 Apr 27;11(9):1265. doi: 10.3390/foods11091265.
Finger millet (FM) is a nutritious and gluten-free cereal grain which is rich in dietary fibre, minerals and antioxidant properties, thereby making it an ideal raw material for preparing gluten-free foods for people suffering from celiac disease. Spontaneous fermentation of FM grains has shown improved nutritional and functional properties of its flour and can be used as a functional ingredient for gluten free biscuits. The aim of this study was to determine the effect of spontaneous fermentation (SF) on the nutritional quality, antioxidant, microstructural, and sensory characteristics of gluten-free FM biscuits obtained from light and dark brown FM flours. Results showed that SF decreased ash, crude fibre, and crude fat contents as well as total phenolic and flavonoids contents. Protein content, carbohydrates content, energy values, antioxidant activity (DPPH and FRAP), and mineral content of FM biscuits increased due to SF. The colour properties such as lightness (L*), showed a significant increase as SF period increased in light brown FM biscuits, however dark brown FM biscuits showed no significant difference. The hue angle and colour differences (ΔE) of FM biscuits increased with the increasing period of SF, ranging from 43.20 to 53.76° and from 0.67 to 7.96, respectively. Spontaneous fermentation also decreased physical properties of biscuits such as diameter (4.76 to 4.54 cm), weight (12.77 to 11.99 g), and spread ratio (7.25 to 6.05), while an increase in thickness and hardness was noted. Spontaneous fermentation also induced changes on the microstructure of FM biscuits. Among the fermented biscuits, panelists preferred 24 h gluten-free fermented FM biscuits since they had better sensory properties. Overall, SF enhanced the nutritional value and health promoting compounds of gluten-free FM biscuits.
龙爪稷是一种营养丰富且不含麸质的谷物，富含膳食纤维、矿物质和抗氧化特性，因此使其成为为患有乳糜泻的人制备无麸质食品的理想原料。龙爪稷籽粒的自然发酵已显示出其面粉的营养和功能特性得到改善，并且可作为无麸质饼干的功能成分。本研究的目的是确定自然发酵（SF）对由浅褐色和深褐色龙爪稷面粉制成的无麸质龙爪稷饼干的营养品质、抗氧化、微观结构和感官特性的影响。结果表明，自然发酵降低了灰分、粗纤维、粗脂肪含量以及总酚和黄酮类化合物的含量。由于自然发酵，龙爪稷饼干的蛋白质含量、碳水化合物含量、能量值、抗氧化活性（DPPH和FRAP）以及矿物质含量增加。浅褐色龙爪稷饼干的明度（L*）等颜色特性随着自然发酵时间的增加而显著增加，然而深褐色龙爪稷饼干则没有显著差异。龙爪稷饼干的色相角和颜色差异（ΔE）随着自然发酵时间的增加而增加，分别为43.20至53.76°和0.67至7.96。自然发酵还降低了饼干的物理性质，如直径（4.76至4.54厘米）、重量（12.77至11.99克）和铺展比（7.25至6.05），同时注意到厚度和硬度有所增加。自然发酵还引起了龙爪稷饼干微观结构的变化。在发酵饼干中，小组成员更喜欢24小时无麸质发酵的龙爪稷饼干，因为它们具有更好的感官特性。总体而言，自然发酵提高了无麸质龙爪稷饼干的营养价值和健康促进化合物。
