A simulated gastrointestinal tract study of texturized rice grains: Impact of texturization on starch digestibility

Physicochemical, Structural, and Digestive Properties of Banana Starch Modified by Ultrasound and Resveratrol Treatments

Ultrasonic treatment combined with resveratrol modification was used to improve banana starch's solubility, thermal stability, and digestion resistance. The solubility and freeze-thaw stability of the modified starch complex significantly increased. The oil-absorption capacity increased by 20.52%, and the gelatinization temperatures increased from 64.10-73.92 °C to 70.77-75.83 °C. The storage modulus (G') and loss modulus (G″) increased after ultrasound and resveratrol treatment, and the proportion of viscosity was increased after composition with resveratrol. Additionally, the in vitro digestibility decreased from 44.12% to 40.25%. The modified complexes had release-control ability for resveratrol. X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) spectroscopy demonstrated that complex structures became more compact and organized, whereas crystalline patterns were unchanged. Scanning electron microscopy (SEM) showed that the resveratrol modification caused physical change on the granular surface by creating pores and fissures. The findings can help develop antioxidant functional foods using banana starch.

Effect of Homogenization Modified Rice Protein on the Pasting Properties of Rice Starch

Modification of plant-based protein for promoting wide applications is of interest to the food industry. Rice protein from rice residues was modified by homogenization, and its effect on pasting properties (including gelatinization and rheology) of rice starch was investigated. The results showed that homogenization could significantly decrease the particle size of rice protein and increase their water holding capacity without changing their band distribution in SDS-PAGE. With the addition of protein/homogenized proteins into rice starch decreased peak viscosity of paste. The homogenized proteins decreased breakdown and setback value when compared with that of original protein, indicating homogenized protein might have potential applications for increasing the stability and inhibiting short-term retrogradation of starch paste. The addition of protein/homogenized proteins resulted in a reduction in the viscoelasticity behavior of starch paste. These results indicate that homogenization would create a solution to alter the physicochemical properties of plant proteins, and the homogenized proteins may be a potential candidate for development of protein-rich starchy products.

Effect of chlorogenic acid on the structural properties and digestibility of lotus seed starch during microwave gelatinization

The structural evolution of lotus starch (LS)-chlorogenic acid (CA) complexes was investigated after microwave-heating treatment, to reveal the relationship between the interactions of lotus starch and chlorogenic acid molecules, and the digestive properties of the starch, after microwave gelatinization. During the early stage of microwave gelatinization (65, 70 °C), CA was mainly participating in the rearrangement of starch molecules in a weakly-bound form, and at that stage, the LS-CA complex acted as an inhibitor of digestion, under small intestine conditions, mainly through the release of CA, which inhibited amylase. However, during the late stage of microwave gelatinization (85 °C), many chlorogenic acid molecules entered the hydrophobic helical cavity of the starch, promoting formation of the V-type starch helical structure in the LS-CA complex, which made a major contribution to inhibiting digestion under oral digestion conditions.

Preparation and characterization of soybean protein isolate/pectin-based phytosterol nanodispersions and their stability in simulated digestion

In this study, stigmasterol was nanoencapsulated in soy protein isolate -pectin-based nanodispersions. Based on the particle size and zeta-potential, the optimal pectin/SPI ratio of stigmasterol nanodispersion was determined to be 1:10. At this ratio, nanodispersions was manufactured with an average particle size of 477 ± 33 nm, an encapsulation efficiency of 89.37%, and a loading amount of 17.87%. The physical properties and morphology of the nanodispersion were investigated. Fourier transform infrared spectroscopy and differential scanning calorimetry analysis revealed that stigmasterol was loaded in nanodispersions successfully. The pectin, which was used to stable nanodispersion, could restrict the release of stigmasterol in the simulated gastric fluid. This experiment indicated that the presence of pectin can improve the stability of the nanodispersion and can be used to achieve controlled release of bioactive compounds.

Impact of processing techniques on the glycemic index of rice

Rice is an important starchy staple food and generally, rice varieties are known to have a higher glycemic index (GI). Over the years, the significance of GI on human health is being better understood and is known to be associated with several lifestyle disorders. Apart from the intrinsic characteristics of rice, different food processing techniques are known to have implications on the GI of rice. This work details the effect of domestic and industrial-level processing techniques on the GI of rice by providing an understanding of the resulting physicochemical changes. An attempt has been made to relate the process-dependent digestion behavior, which in turn reflects on the GI. The role of food constituents is elaborated and the various in vitro and in vivo approaches that have been used to determine the GI of foods are summarized. Considering the broader perspective, the effect of cooking methods and additives is explained. Given the significance of the cereal grain, this work concludes with the challenges and key thrust areas for future research.

The influence of processing parameters of parboiled rice on its physiochemical and texture properties

The impact of different parboiled rice process conditions on physical (whiteness and yellowness), chemical (amylose and fat contents), and texture (hardness and toughness) properties was studied. The parboiled rice was produced from the Suphanburi 1 variety. The correlation between chemical and texture properties was also analyzed. To study the effect of the soaking process, the time (2, 3, and 6 hr) and temperature (65 and 75°C) of soaking were altered, while the steaming condition was fixed at 100°C for 20 min. To study the effect of the steaming process, the soaking condition was fixed at 65°C for 6 hr while steaming condition was altered, including time (10 and 20 min) and temperature (90 and 100°C). The results show that the different conditions influenced the physical and chemical properties of parboiled rice. The amylose content was negatively correlated (Hardness, r = -0.52) (Toughness, r = -0.38) and fat content was positive low correlated (Hardness, r = 0.20) (Toughness, r = 0.12) with textural properties. Due to the specification of parboiled rice for exportation varying according to customer requirements, the results of this research provided some useful information for parboiled rice factories.