Feasibility of replacing waxy rice with waxy or sweet-waxy corn viewed from the structure and physicochemical properties of starches.

To explore the feasibility of substituting waxy rice with waxy or sweet-waxy corn, eight varieties of waxy and sweet-waxy corns were selected, including three self-cultivated varieties (Feng nuo 168, Feng nuo 211, and Feng nuo 10). Their starches were isolated and used as research objects, and commercially available waxy rice starch (CAWR) and waxy corn starch (CAWC) were used as controls. X-ray diffraction, scanning electron microscopy, differential scanning calorimetry, rapid viscosity analyzer, and rotational rheometer were used to analyze their physicochemical and structural characteristics. The morphologies of all corn starch granules were generally oval or round, with significant differences in particle size distributions. All ten starches exhibited a typical A-type crystal structure; however, their relative crystallinity varied from 20.08% to 31.43%. Chain length distribution analysis showed that the A/B ratio of Jing cai tian nuo 18 and Feng nuo 168 was similar to that of CAWR. Peak viscosities of corn starches were higher than that of CAWR, except for Feng nuo 10, while their setback values were lower than that of CAWR. Except for Feng nuo 10, the paste transparency of corn starches was higher than that of CAWR (10.77%), especially for Jing cai tian nuo 18 (up to 24%). In summary, Jing cai tian nuo 18 and Feng nuo 168 are promising candidates to replace CAWR in developing various rice-based products.

Effects of dual modification by cationization and acetylation on the physicochemical and structural characteristics of glutinous rice starch.

In this research, the effects of cationization, acetylation and dual modification by cationization and acetylation on the physicochemical and structural characteristics of glutinous rice starches were investigated. The rapid viscosity analyzer revealed a substantial increased paste viscosity post modification. Particularly, for dually modified starch, the peak viscosity increased from 3071.67 to 4082.00 cP. The freeze-thaw stability substantially enhanced, with both single cationic and dually-modified starches standing out by exhibiting no water syneresis even at 21 freeze-thaw cycles, while native starch exhibited higher syneresis, up to 74.55 %. Both single cationization and cationization-acetylation destroyed the starch granules, characterized by the roughness and cracks. But, for single acetylation, there was no notable changes on granules' morphology. Fourier transform infrared spectroscopy exhibited notable shifts after modification, both acetylation and dual modification, resulting in a new peak at 1728 cm-1. 13C cross-polarization magic angle spinning nuclear magnetic resonance spectra displayed new peaks at 52-55 and 19-22 ppm following cationization and acetylation, respectively. These structural alterations indicate the successful incorporation of functional groups during modification. Overall, this study provides valuable insights for the industrial utilization of these three modified glutinous rice starches.

Starch Modification with Molecular Transformation, Physicochemical Characteristics, and Industrial Usability: A State-of-the-Art Review.

Starch is a readily available and abundant source of biological raw materials and is widely used in the food, medical, and textile industries. However, native starch with insufficient functionality limits its utilization in the above applications; therefore, it is modified through various physical, chemical, enzymatic, genetic and multiple modifications. This review summarized the relationship between structural changes and functional properties of starch subjected to different modified methods, including hydrothermal treatment, microwave, pre-gelatinization, ball milling, ultrasonication, radiation, high hydrostatic pressure, supercritical CO2, oxidation, etherification, esterification, acid hydrolysis, enzymatic modification, genetic modification, and their combined modifications. A better understanding of these features has the potential to lead to starch-based products with targeted structures and optimized properties for specific applications.

Effect of Heat-Moisture Treatment on the Physicochemical Properties and Starch Digestibility of Mix Powder (Wheat Flour-Black Soybean Flour) and Corresponding Cookies.

In order to improve the nutritional value and reduce starch the digestibility of black soybean cookies, superfine black soybean flour was modified by heat-moisture treatment (HMT). The physicochemical properties, structure analysis of the flour samples and corresponding dough, and nutritional, physical, and textural properties of the cookies were investigated. After HMT, the water and lactic acid retention capacity and the oil binding capacity of mix powder dramatically increased, being almost twice the value of the untreated sample. HMT increased gelatinization temperature by about 10 °C but decreased gelatinization enthalpy. HMT had no apparent effect on the morphology and size of granules, but some cracks and pores appeared on the HMT-mix powder granules and corresponding dough. Fourier transform infrared spectroscopy analysis showed that the ordered structure of dough was unaffected during HMT. After HMT, the thickness, density, and baking loss of the cookies increased, and the spread ratio decreased. HMT dramatically increased the chemical score of cookies from 12.35% in mix powder cookies to 19.64% in HMT-mix powder cookies. HMT decreased the rapidly digestible starch content, while the slowly digestible starch increased from 45.97% in mix powder cookies to 49.31% in HMT-mix powder cookies, and RS increased from 21.64% to 26.87%. Overall, HMT did not have a negative effect on the processing properties and microstructure and secondary structure of the dough, or the physical properties and quality of the cookies, but significantly improved the nutritional properties and decreased the starch digestibility of the cookies.