Effects of Processing on Starch Structure, Textural, and Digestive Property of “Horisenbada”, a Traditional Mongolian Food

Horisenbada, prepared by the soaking, steaming, and baking of millets, is a traditional Mongolian food and is characterized by its long shelf life, convenience, and nutrition. In this study, the effect of processing on the starch structure, textural, and digestive property of millets was investigated. Compared to the soaking treatment, steaming and baking significantly reduced the molecular size and crystallinity of the millet starch, while baking increased the proportion of long amylose chains, partially destroyed starch granules, and formed a closely packed granular structure. Soaking and steaming significantly reduced the hardness of the millets, while the hardness of baked millets is comparable to that of raw millet grains. By fitting digestive curves with a first-order model and logarithm of the slope (LOS) plot, it showed that the baking treatment significantly reduced the digestibility of millets, the steaming treatment increased the digestibility of millets, while the soaked millets displayed a similar digestive property with raw millets, in terms of both digestion rate and digestion degree. This study could improve the understanding of the effects of processing on the palatability and health benefits of Horisenbada.

Texture, microstructure and in-vitro starch digestibility of waxy rice cooked with hydrocolloids

Waxy rice which has been soaked in excessive water was cooked with hydrocolloid solutions, corresponding to hydrocolloid concentrations of 0.3, 0.5 and 0.7 g/100 g rice. Hydrocolloids studied were guar gum (GG), xanthan gum (XG) and sodium alginate (SA). The hydrocolloid-cooked rice and the control sample, cooked in water without any hydrocolloid, were determined for their starch retrogradation, texture, microstructure and in-vitro starch digestion rate. It was found that hydrocolloid-cooked rice exhibited more retrograded starch than the control, providing high melting enthalpies. Retrograded starch caused the increased hardness of the cooked rice during storage, while adhesiveness and springiness tended to decrease. Although, hydrocolloid-cooked rice retrograded more during storage, it showed a lower hardness than the control sample due to the phase separation of hydrocolloids. SEM images revealed that intact starch was completely gelatinized. The control sample provided denser microstructure than the hydrocolloidcooked samples. While air cells were observed in the hydrocolloid-cooked samples especially with XG. The hydrocolloid-cooked rice exhibited lower starch digestion rate than the control. SA provided the lowest starch digestion rate, followed by GG and XG respectively

The Effect of Protozoa on the Bacterial Composition and Hydrolytic Activity of the Roe Deer Rumen

The purpose of this study was to compare the effect of the presence of protozoa in the rumen of wild roe deer (Capreolus capreolus) on the bacteria composition and digestion rate of the main carbohydrates of forage. The research material involved rumen content and rumen fluid, which were collected in the autumn-winter season, from eight adult males of roe deer with an average body mass of 22.6 kg. The microscopic analysis demonstrated that there were only protozoa in 50% of the animals sampled. Qualitative analysis revealed the presence of protozoa belonging to the genus Entodinium. The density of protozoal population varied from 6.5 to 38.7 × 105/mL rumen fluid. The analysis of bacteria composition indicated that protozoa did not have an effect on bacterial diversity. Furthermore, the results of hydrolytic activity revealed that the fastest digestion of carbohydrates was for pectin, while the slowest was inulin. The pH and redox potential in the rumen varied from 5.9 to 6.1 and from −248.1 to −251.1 mV, respectively. In summary, the presence of protozoa in the rumen of wild roe deer does not have an effect on the bacterial population and has no effect on the digestion rate of carbohydrates in the rumen.