To develop a mixed starter culture of lactic acid bacteria for maize products, this study systematically investigated the effects of adding functional sugars (fructooligosaccharides, xylooligosaccharides, inulin, and trehalose) as auxiliary ingredients at different levels (0.5%, 1.0%, and 1.5%) on the processing quality and starch structure of fermented maize dough. The dough was examined for texture properties, microstructure, gelatinization characteristics, rheological properties, thermal properties, and moisture distribution, and the particle size, molecular mass, and crystallinity of starch extracted from the dough were measured. The results revealed that FOS resulted in a more compact and uniform dough microstructure. The dough added with 1.5% FOS exhibited the lowest hardness (80.93 N) and softest texture, along with the lowest breakdown and setback values. Meanwhile, it had the best thermal stability and the lowest retrogradation tendency. Its storage modulus (G’) and loss modulus (G”) decreased most significantly. FOS promoted the conversion of quasi-bound water to bound water and consequently enhanced water-holding stability. Starch isolated from the dough with 1.5% FOS had the highest amylose content (37.0%), the smallest weight-average/number-average molecular mass ratio and radius of gyration, and the highest crystallinity (37.55%). All four functional sugars enhanced the short-range ordered structure of starch and reduced the content of amorphous regions. Inulin significantly decreased the volume-average particle size of starch but had no significant effect on the surface-area-average particle size. These findings demonstrated that the four functional sugars improve the processing properties of dough by regulating the molecular structure of starch, with FOS exhibiting the most pronounced effect. This provides a theoretical basis and technical pathway for developing high-quality fermented maize-based foods.

The purpose of this study was to evaluate the physiological characteristics and nutritional quality of corn kernels during the post-ripening stage. Using principal component analysis (PCA), this study analyzed and comprehensively evaluated 14 physiological and quality traits of post-ripening corn kernels from two varieties (Zhengdan 958 and Xianyu 335), including water content and state, respiratory rate, soluble sugar content, α-amylase activity, catalase (CAT) activity, peroxidase (POD) activity, hexokinase (HK) activity, isocitrate dehydrogenase (IDH) activity, fatty acid value, starch content, 1000-grain mass and rapid digestible starch (RDS) content. The results showed significant variations in various quality traits of corn grains during the post-ripening process (P < 0.05). PCA extracted three principal components, namely storage intolerance factor, yield factor and digestive characteristic factor, which explained 53.436%, 18.466% and 12.857% of the total variance, respectively, 84.759% in total. The post-ripening quality and time of corn could be determined according to the changes of F-value. The post-ripening time of newly harvested corn grains from Zhengdan 958 and Xianyu 335 were 50 and 30 days, respectively. The results of this study could provide a reference for the evaluation of the post-ripening quality of newly harvested corn and the processing and utilization of corn.