Zhongquan Sui

Physicochemical properties of starches from diverse rice cultivars varying in apparent amylose content and gelatinisation temperature combinations.

The physicochemical properties of starches isolated from 14 rice cultivars produced in China were investigated. These rice starches showed a non-random combination of AAC and GT. Rice starches showed a typical A-type diffraction pattern with the degree of crystallinity ranging from 32.3% (a high AAC rice) to 45.5% (a waxy rice). AAC was significantly correlated with the pasting, thermal and textural properties. The positive correlations were found with PV, HPV, CPV, SB and HD (p<0.05), while the negative corrections were found with SP, ADH, COH, T(o), T(p), T(c) and ΔH (p<0.05). However, AAC had no correlations with BD, PTime and percentage of retrogradation (R%). The degree of crystallinity and GT had a positive correlation with the retrogradation properties. It could be concluded that although AAC was the major factor affecting the physicochemical properties of rice starch, the retrogradation property of rice starch was mainly determined by the degree of crystallinity and GT.

Effects of heat-moisture treatment reaction conditions on the physicochemical and structural properties of maize starch: moisture and length of heating.

Changes in the properties of normal maize starch (NMS) and waxy maize starch (WMS) after heat-moisture treatment (HMT) under various reaction conditions were investigated. NMS and WMS were adjusted to moisture levels of 20%, 25% and 30% and heated at 100 °C for 2, 4, 8 and 16 h. The results showed that moisture content was the most important factor in determining pasting properties for NMS, whereas the heating length was more important for WMS. Swelling power decreased in NMS but increased in WMS, and while the solubility index decreased for both samples, the changes were largely determined by moisture content. The gelatinisation temperatures of both samples increased with increasing moisture content but remained unchanged with increasing heating length. The Fourier transform infrared (FT-IR) absorbance ratio was affected to different extents by the moisture levels but remained constant with increasing the heating length. The X-ray intensities increased but relative crystallinity decreased to a greater extent with increasing moisture content. This study showed that the levels of moisture content and length of heating had significant impacts on the structural and physicochemical properties of normal and waxy maize starches but to different extents.

Absorption, Metabolism, Anti-Cancer Effect and Molecular Targets of Epigallocatechin Gallate (EGCG): An Updated Review.

ABSTRACT Green tea is one of the most popular beverages in the world, especially in Asian countries. Consumption of green tea has been demonstrated to possess many health benefits, which mainly attributed to the main bioactive compound epigallocatechin gallate (EGCG), a flavone-3-ol polyphenol, in green tea. EGCG is mainly absorbed in the intestine, and gut microbiota play a critical role in its metabolism prior to absorption. EGCG exhibits versatile bioactivities, with its anti-cancer effect most attracting due to the cancer preventive effect of green tea consumption, and a great number of studies intensively investigated its anti-cancer effect. In this review, we therefore, first stated the absorption and metabolism process of EGCG, and then summarized its anti-cancer effect in vitro and in vivo, including its manifold anti-cancer actions and mechanisms, especially its anti-cancer stem cell effect, and next highlighted its various molecular targets involved in cancer inhibition. Finally, the anti-cancer effect of EGCG analogs and nanoparticles, as well as the potential cancer promoting effect of EGCG were also discussed. Understanding of the absorption, metabolism, anti-cancer effect and molecular targets of EGCG can be of importance to better utilize it as a chemopreventive and chemotherapeutic agent.

Effects of Fermented Edible Seeds and Their Products on Human Health: Bioactive Components and Bioactivities

There is a long history of using fermentation in food production. Edible seeds, such as certain beans and cereal grains, are important in the human diet and provide many health benefits. Various microbes, such as lactic acid bacteria, molds, and yeasts, considered as generally recognized as safe (GRAS) microbes, are commonly used to ferment edible seeds and their products. Fermentation can change bioactive components and produce new bioactivities. In order to highlight the importance of fermentation on bioactive components and bioactivities in edible seeds, this review, therefore, summarizes recent relevant studies and discusses fermentation procedures and influences of fermentation on their bioactive components and bioactivities. Overall, fermented edible seeds and their products contain enhanced bioactive components, especially γ-aminobutyric acid and natural phenolics, and they possess versatile bioactivities, such as antioxidant and anti-cancer effects, and, therefore, can be recommended as an important part of the human diet, or they can be developed into functional foods to help in the prevention of certain chronic diseases.

Physicochemical properties and starch digestibility of Chinese noodles in relation to optimal cooking time

Changes in the physicochemical properties and starch digestibility of white salted noodles (WSN) at different cooking stage were investigated. The noodles were dried in fresh air and then cooked for 2-12 min by boiling in distilled water to determine the properties of cooking quality, textural properties and optical characteristic. For starch digestibility, dry noodles were milled and sieved into various particle size classes ranging from 0.5 mm to 5.0 mm, and hydrolyzed by porcine pancreatic α-amylase. The optimal cooking time of WSN determined by squeezing between glasses was 6 min. The results showed that the kinetics of solvation of starch and protein molecules were responsible for changes of the physicochemical properties of WSN during cooking. The susceptibility of starch to α-amylase was influenced by the cooking time, particle size and enzyme treatment. The greater value of rapidly digestible starch (RDS) and lower value of slowly digestible starch (SDS) and resistant starch (RS) were reached at the optimal cooking stage ranging between 63.14-71.97%, 2.47-10.74% and 23.94-26.88%, respectively, indicating the susceptibility on hydrolysis by enzyme was important in defining the cooked stage. The study suggested that cooking quality and digestibility were not correlated but the texture greatly controls the digestibility of the noodles.

Effects of gamma irradiation on physicochemical properties of native and acetylated wheat starches

Effects of gamma irradiation on the physicochemical and crystalline properties of the native and acetylated wheat starches were investigated. Peak, hot paste, cool paste and setback viscosities of both native and acetylated wheat starches decreased continuously and significantly with the increase of the irradiation dose, whereas breakdown viscosity increased after irradiation. However, gamma irradiation only exerted slight effects on thermal and retrogradation properties of both native and acetylated wheat starches. X-ray diffraction and fourier transform infrared spectroscopy revealed that acetylation modification had considerable effects on the molecular structure of wheat starch, and the crystallinity of both untreated and acetylated starches increased slightly with the increase of irradiation dose. However, the V-type crystallinity of amylose-lipid complex was not affected by gamma irradiation treatments with doses up to 9kGy.

Physicochemical and crystalline properties of heat–moisture-treated rice starch: combined effects of moisture and duration of heating

BACKGROUND Currently there is much interest in the application of physical modification techniques such as heat-moisture treatment (HMT). The effects of HMT on normal and waxy rice starches, subject to different levels of moisture content and duration of heating, were investigated. RESULTS Water solubility index (determined at 90 °C) decreased after HMT for normal and waxy rice starches, while swelling power (determined at 90 °C) showed inconsistent results (decrease for normal type, increase for waxy type) after HMT. Values in pasting parameters of normal and waxy rice starch increased initially, but the extent of increase slowed down with moisture content and length of treatment increasing. HMT decreased gelatinization temperatures with 4 h and 8 h treatment, but when length of treatment was prolonged to 16 h gelatinization temperature increased. Degree of crystallinity decreased for all treatments, and decreased much more at higher levels of moisture content. CONCLUSION Variations in levels of moisture content and duration of heating had significant effects on physicochemical and crystalline properties to different extents.

Optimization of reaction conditions for improving nutritional properties in heat moisture treated maize starch

Impact of heat-moisture treatment (HMT) on nutritional properties of normal maize starch (NMS) under various reaction conditions was investigated. NMS was adjusted to moisture levels of 20%, 25%, 30% and 35% and heated at 80, 100, 120 and 140°C for 4, 8, 12 and 16h. Response surface methodology (RSM) based on Box-Behnken design (BBD) was employed to obtain the optimal combination of moisture level (X1: 20-30%), length of heating (X2: 4-12h), and temperature (X3: 100-140°C). The optimum reaction condition decreased rapidly digestible starch (RDS) from 87.10% to 82.21%, when NMS was subjected to HMT at 23.6% moisture content and heated at 114.8°C for 9.04h. The ANOVA measurement and confirmation experiments were performed to verify the predictive value and the RSM model, indicating that temperature was the main factor to determine the digestion rate of HMT NMS. The results suggested that RDS was not correlated to heating length but positively correlated to temperature and moisture content. Reaction condition had no correlations with slowly digestible starch (SDS) and resistant starch (RS). This study could provide more information for producing low-glycemic index products.

Diversity in Antioxidant Capacity, Phenolic Contents, and Flavonoid Contents of 42 Edible Beans from China

Edible beans are among the most important grain legumes consumed by humans. To provide new information on the antioxidant phenolics of edible beans, the antioxidant capacity, total phenolic content (TPC), and total flavonoid content (TFC) in both soluble and bound fractions of 42 edible beans from China were systematically evaluated, with main phenolic compounds identified and quantified in 10 beans possessing the highest TPC. Edible beans contained a wide range of total antioxidant capacity and TPC generally comparable with common grains, fruits, and vegetables, and their bound fractions had significant antioxidant capacity, TPC, and TFC. Red sword bean was found for the first time to show extremely high total antioxidant capacity (ferrous[II] at 235 ± 13.2 μmol/g and Trolox at 164 ± 10.5 μmol/g) and TPC (1767 ± 58.3 mg of GAE/100 g). Phenolic compounds such as catechin, ferulic acid, gallic acid, p-coumaric acid, and protocatechuic acid were widely detected in selected beans. A positive correlation was ...

Extraction and characterization of starch granule-associated proteins from rice that affect in vitro starch digestibility

Starch granule-associated proteins (SGAPs) including granule-surface proteins and granule-channel proteins in waxy, low- and high-amylose rice starch were extracted and identified. The in vitro digestibility of starch was investigated before and after the extraction of granule-channel proteins or total SGAPs. The results showed that 10 types of major differentially expressed proteins (DEPs) including 14-3-3-like protein and ribosomal protein were found among starches. In addition, the lack of only granule-channel proteins or total SGAPs led to significant and different changes in the levels of rapidly digestible starch, slowly digestible starch and resistant starch. Possible mechanisms are related to the accessibility of amylase into starch granules and structural properties of SGAPs. This study provides more information about DEPs in rice starch with different amylose content and supports further study on the relationship between SGAPs and in vitro starch digestibility.