This study comparatively investigated the effects of ferulic acid (FA-H), caffeic acid (CA-H), and green tea polyphenols (GTP-H) interventions (300 mg/kg body weight) on lipid metabolism, intestinal epithelial barrier, and gut microbiota in high-fat diet (HFD)-induced overweight mice. The reduced body weight, improved lipid levels and alleviated hepatic steatosis were obtained by all the three polyphenols interventions, and the body weight of FA-H, CA-H and GTP-H group was significantly decreased by 18.19%, 16.03% and 20.02%, respectively, compared with HFD group (P < 0.05). The results indicated that serum total cholesterol (TC) and LDL-C levels for GTP-H group was significantly lower than (P < 0.05) those of FA-H and CA-H group. Tight-junction proteins Claudin-1 and Occludin of GTP-H group were also markedly higher than that of FA-H and CA-H group (P < 0.05), thus intestinal barrier function in GTP group was significantly improved. Beneficial bacteria such as Bifidobacterium and Lactobacillus were enriched, while potentially harmful taxa such as Desulfobacterota were decreased, therefore gut microbiota composition was optimized. Akkermansia abundance in the cecum and colonic diversity were significantly raised by GTP intervetntion(P < 0.05). The improvement of lipid metabolism in high-fat diet-induced overweight mice, which were intervented by these three polyphenols, might be closely related to gut microbiota. This study provides a basis for further exploration of the effect of different polyphenols on lipid metabolism and supports the application of polyphenols in the development of functional foods aimed at preventing overweight -related metabolic disorders.​

High temperature and high pressure treatment has been widely applied as an efficient physical modification method in studies on the structural and functional modification of cereal starches. This paper reviews the research progress on the effects of high temperature and high pressure treatment on cereal starch properties from three perspectives,including treatment methods and mechanisms, effects on starch structure, and effects on starch physicochemical properties. In terms of starch structure, the review analyzes the reconstruction patterns of starch under high temperature and high pressure conditions from four aspects,including crystalline structure transformation, molecular chain rearrangement and cross-linking, granule morphology, and short- and long-range order. High temperature and high pressure treatment can induce the transformation of starch crystalline types from A-type or B-type to V-type or A+V composite structures, resulting in varying degrees of crystallinity change. During cooling, amylose chains realign through hydrogen bonding to form stable double helices and composite crystalline structures, which promotes the formation of resistant starch. Regarding physicochemical properties, high temperature and high pressure treatment can improve the hydration characteristics and gelatinization properties of cereal starch, reduce digestibility and glycemic index, enhance thermal stability and water absorption/retention capacity, and increase enzyme resistance and resistant starch content. Finally, the paper discusses the potential applications of high temperature and high pressure treatment in the development of functional cereal-based foods, aiming to provide reference and guidance for the application of this technology in starch modification and functional food innovation.

As an innovative method in flour product processing, vacuum dough mixing technology has attracted widespread attention in recent years for its ability to optimize the structure formation and quality characteristics of dough through the regulation of a low-pressure environment. The variation laws and underlying mechanisms of key dough components, including proteins, starch, and moisture, during the vacuum dough mixing process were systematically reviewed, and the application effects of this technology in various flour products were examined. Vacuum treatment significantly enhanced the rheological properties and freeze-thaw stability of dough by promoting gluten protein cross-linking, optimizing moisture distribution and state transitions, and inhibiting excessive starch swelling. Furthermore, the synergy between vacuum dough mixing and auxiliary processes such as superheated steam and freeze-thaw could effectively inhibit lipid oxidation, improve product texture, and extend shelf life.

Superheated steam, as an emerging thermal treatment technology, has garnered significant attention in the field of grain processing due to its high thermal penetration in an oxygen-free environment. This article has reviewed the research progress on the effects of superheated steam treatment on the properties of grain components, edible quality, and storage characteristics. Superheated steam treatment can promote the breaking of disulfide bonds in proteins, altering their conformation, increasing disorder, and enhancing random coil structures. Moreover, the gluten protein network structure can be changed more loose by this treatment, thereby affecting the elasticity and extensibility of the dough. The crystalline structure within starch was also destroyed by superheated steam treatment, promoting the dissolution and swelling of starch molecular chains, causing partial gelatinization of starch, and thus affecting the swelling power and peak viscosity of starch granules. During the treatment process, the presence of an oxygen-free environment helped slow down oxidation reactions and reduce the loss of bioactive substances. The cooking time of grains can be shortened and the production of unpleasant odors can be effectively reduced by superheated steam treatment with high temperature and high permeability. This review also explored the application research of superheated steam technology in inactivating enzyme and grain-related oxidases, and improving the sterilization ability and storage quality of grains. This may provide references for further exploration of the application of superheated steam technology in the field of grain processing in the future.

The impact of solid-state fermentation by Lactiplantibacillus plantarum CICC 21793 and Lacticaseibacillus rhamnosus CICC 21773 on the structural and functional properties of rice bran dietary fiber (DF) was investigated. Optimal extraction conditions for soluble dietary fiber (SDF) were determined through single-factor and orthogonal tests, achieving a maximum yield of 12.05 % for fermented SDF (SSDF). After fermentation, SSDF exhibited a rough, porous surface, whereas fermented insoluble dietary fiber (SIDF) displayed increased folds and concave contours. Although the spectral characteristics of DF remained largely unchanged, the monosaccharide composition was altered. The particle size of DF decreased, the crystal structure exhibited increased disorder, and thermal stability decreased as a result of fermentation. Furthermore, the physical and chemical properties of SIDF were improved as follows: water swelling capacity (2.48 mL/g), oil holding capacity (7.44 g/g), and water holding capacity (7.47 g/g). The adsorption properties of SSDF were improved as follows: cation exchange capacity (1237.74 mmol/g), cholesterol adsorption capacity was determined to be 3.61 mg/g under gastric conditions and 4.68 mg/g under intestinal conditions, nitrite ion adsorption capacity (3.38 mg/g). Both fermented SDF and IDF displayed enhanced antioxidant activity, adsorption properties, and effective hypolipidemic and hypoglycemic effects. Solid-state fermentation with Lactiplantibacillus plantarum CICC 21793 and Lacticaseibacillus rhamnosus CICC 21773 effectively modifies DF.

This study aimed to investigate the interactions of phenolics from three varieties of brown rice with starch digestive enzymes, the starch-iodine complex, and their impact on rice starch digestion. The results indicated that all phenolics markedly inhibited rice starch digestion, with bound phenolics from indica rice showing the most pronounced inhibition. The observation of static fluorescence quenching with a concentration-dependent effect suggested the potential for an interaction between phenolics and starch digestive enzymes. Furthermore, the bound phenolics exhibited enhanced quenching properties in comparison to their corresponding free forms, which is consistent with the starch-iodine binding affinity experiment. The formation of starch-iodine complexes was found to be impeded in the presence of phenolics, which resulted in an alteration of the microstructural arrangement of starch molecules by the phenolics. Moreover, the phenolics resulted in a significant increase in the proportion of resistant starch (RS), accompanied by a concurrent decrease in rapidly digestible starch (RDS). Of these, the effects of indica rice bound phenolics were particularly noteworthy, with a substantial increase in RS content from 7.15% to 24.63%, representing a 2.45-fold increase. The findings highlighted that brown rice phenolics could be an effective means of modulating starch digestibility in starchy foods.

The development of the whole grain industry in China is a key measure in implementing the “Food Security Guarante Law” strategy and the “Healthy China” strategy. It also aligns with practicing the broader concept of food security. Rice is a staple food for Chinese residents, and substituting white rice with brown rice is an effective way to increase whole grains intake. Studies have shown that whole grain brown rice provides health benefits in blood glucose and lipid regulation, as well as weight control. These effects attributed to the effects of dietary fiber, various micronutrients, and bioactive compounds abundant in brown rice. Additionally, these health effects also result from alterations in the digestion and absorption efficiency of dietary nutrients like carbohydrates and proteins, mediated by these bioactive compounds. The digestion process of food is a key link related to the aforementioned effects. Current research methods for characterizing the digestion process of brown rice mainly static and dynamic in vitro static simulations, as well as in vivo digestion. This article systematically reviews the macro and micronutrient components and bioactive substances of rice. It also explores the effects of different processing accuracy and brown rice processing techniques on rice starch digestion characteristics and their potential mechanisms. The aim is to provide reference for the development and selection of processing technologies for whole grain brown rice.

The purpose of this study was to investigate the effects of five different stabilization methods on the physicochemical properties of rice bran and to evaluate the quality of brown rice cakes prepared from stabilized rice bran. The results showed that the brightness of rice bran was decreased and the color darkened after stabilization treatments, and the lipase activity was significantly decreased. The water holding capacity and swelling capacity of rice bran treated with atmospheric pressure cooking and high-pressure cooking were significantly increased. Compared with control group, the quality (texture, cell structure and sensory) of BRCs with stabilized rice bran was improved. The BRC containing atmospheric pressure cooked rice bran showed the advantages of low hardness, enhanced elasticity, improved palatability and overall acceptability. In addition, the stabilized rice bran could improve the gel morphology by strengthening the interaction with starch, and the formation of starch-lipid complex also affected the performance of BRCs. Therefore, stabilization treatment of rice bran can effectively improve the physicochemical properties, and play a positive role in enhancing the quality of whole grain brown rice cakes.

Brown rice cake (BRC) is one of the traditional whole grain foods. This study mainly investigated the effect of freezing pretreatment (-20, -40 and -80 degrees C for 120 min) and different thermal stabilized rice bran on water distribution and migration, starch retrogradation and microstructure of BRCs. The results showed that the low temperature freezing pretreatment (-80 degrees C) of BRC containing stabilized rice bran could synergically enhance the binding ability of BRC with water molecules during freezing storage, and significantly increase the content of tightly bound water in BRCs. It was found that the lower temperature freezing pretreatment (-40 and -80 degrees C) for BRC and the presence of thermal stabilized rice bran in BRC could synergically retard the retrogradation of starch in BRCs, reduce the order of short-range structure in starch, and inhibit the recrystallization of starch. The microstructure results confirmed that lower temperature freezing (-40 and -80 degrees C) effectively limited the growth of ice crystals and greatly maintained the integrity of the internal structure of BRCs with different thermal stabilized rice bran. Therefore, the combination of thermal stabilized rice bran and low temperature rapid freezing is promising to obtain high-quality BRCs.

Rice bran was modified by steam explosion (SE) treatment to investigate the effect of different steam pressure (0.4, 0.8, 1.2, 1.6, and 2.0 MPa) with rice bran through 60 mesh and rice bran pulverization (60, 80, and 100 mesh) with the steam pressure of 1.2 MPa on the functional properties and structure of soluble dietary fiber (SDF) from SE-treated rice bran. SE pretreatment enhanced glucose and cholesterol adsorption capacity, water-holding capacity, oil-holding capacity, lipase inhibition capacity and anti-oxidation properties of SDF. However, functional properties of SDF were adversely affected when steam pressure was 2.0 MPa or crushing degree of rice bran was 100 mesh. The results showed that some glycosidic and hydrogen bonds were broken, resulting a porous honeycomb structure and decreased polymerization degree of the crystalline regions and relative crystallinity in SDF from SE-treated rice bran. In general, the optimum condition for obtaining better properties of SDF was treated for rice bran at the steam pressure of 1.2 MPa and sieve size of 60 mesh. This finding emphasizes essential information on SE treatment of rice bran in modifying the properties of SDF, which is helpful to the development and utilization of SDF from SE-treated rice bran.

Background and ObjectivesRice bran is enriched with bioactive compounds, which makes it more competitive as a functional food raw material. The stabilization of rice bran can inhibit the activity of endogenous enzymes, reduce its oxidation sensitivity, and change its physical and chemical properties, providing more possibilities for its application in the food industry. In this study, rice bran from five stabilization treatments (atmospheric pressure cooking, high-pressure cooking, atmospheric steam, microwave heating, and extrusion cooking) were investigated for their effect on the gel properties of indica rice flour.FindingsStabilized rice bran could enhance the hydration properties and increase the enthalpy value of rice flour. The gelatinization properties indicated that the viscosity and fluidity of the rice paste were increased, and the aggregation and rearrangement of rice starch were promoted. From the rheological properties, stabilized rice bran enhanced the viscoelasticity of the rice flour gel. In addition, the stabilized rice bran could also reduce the yield of freeze-thawing water of the rice flour gel. Rice bran with thermal treatments can significantly improve the gel properties of indica rice flour.ConclusionsIndica rice flour mixed with stabilized rice bran showed significant improvements in hydration, gelatinization, rheological properties, and freeze-thaw stability.Significance and NoveltyIt is potential for the application of the gel from rice flour with stabilized rice bran in the starch-based food industry.

This study aims to investigate the effect of different ratios of soluble and insoluble dietary fiber (0/100, 25/75, 40/60, 55/45, 70/30, 85/15, 100/0) in rice bran treated with or without extrusion cooking on the physicochemical and structural properties of rice starch. As the ratio of soluble dietary fiber (SDF) increases, the PV (peak viscosity), FV (final viscosity), SB (setback value), and BD (breakdown value) of starch are significantly decreased, indicating that a higher SDF ratio can delay the short-term retrogradation of starch. Compared with the unextruded rice bran SDF/IDF starch gel, the content of weak bond water and free water in the extruded rice bran SDF/IDF starch gel is higher while the content of strong bond water in the starch gel is lower at the same SDF/IDF ratio. Meanwhile, for the results X-ray diffraction (XRD) and fourier transform infrared spectrum (FTIR), the rice starch with the extruded rice bran SDF/IDF ratio of 25:75 shows the lowest relative crystallinity of 3.48% and the lowest peak to height ratio of FTIR (1047 cm-1/1022 cm-1) of 1.0746, suggesting that the inhibition effect on rice starch retrogradation is better. This may be beneficial for the utilization of different ratios of SDF/IDF from extruded rice bran and physicochemical properties improvement of rice starch gel. Compared with the unextruded rice bran SDF/IDF starch gel, the PV, FV, enthalpy, and hardness of the extruded rice bran SDF/IDF starch gel are decreased significantly with the increase of the SDF ratio. Rice starch with 25:75 ratio of SDF/IDF from extruded rice bran shows the lowest relative crystallinity, suggesting the stronger inhibition effect on rice starch retrogradation. image

Background and ObjectivesGrain and oil processing by-products contain dietary fiber with high quality, but most of them have not been utilized due to their high content of insoluble dietary fiber and coarse texture, which are detrimental to the quality improvement of cereal food.FindingsSteam explosion treatment can transfer dietary fiber from insoluble to water-soluble resulting in a high content of water-soluble dietary fiber. The content of soluble dietary fiber in cereal processing by-products with steam explosion treatment is increased from 27.48% to 171% via optimal conditions of steam explosion treatment. The structure of dietary fiber from cereal processing by-products is disrupted to a honeycomb porous shape, therefore, the physicochemical properties of dietary fiber are improved, such as hydration capacity, oil, cholesterol, and bile salts binding capacity, hypoglycemic capacity, and antioxidant activity.ConclusionsSteam explosion treatment is a rapidly developing and extremely promising pretreatment technology for physicochemical properties enhancement of dietary fiber from grain and oil processing by-products.Significance and NoveltyThis review can provide some useful references for the properties improvement of soluble dietary fiber in grain and oil processing by-products by steam explosion pretreatment. It may facilitate the application of soluble dietary fiber in the food industry.

This study aimed to investigate the effect of the interaction of black rice anthocyanins (BRA), soluble dietary fiber from extruded rice bran (ES) and waxy rice starch (WRS) on the physicochemical properties of starch gels, including gelatinization properties, rheological properties, freeze-thaw stability, water migration, molecular structure and gel microstructure. The results showed that the pasting temperature (PT) of the mixtures was increased, and the peak viscosity (PV), trough viscosity (TV), final viscosity (FV) and setback viscosity (SV) were significantly reduced when ES and BRA were added to WRS in different proportions (ES:BRA, 4:0, 4:0.4, 4:1, 4:2, 8:0, 8:0.8, 8:2, 8:4). Both ES and BRA could enhance the viscosity of WRS gels, and ES exhibited strong ability on improving the strength of gels. The presence of ES and BRA improved the water retaining capacity of WRS gels, but weakened the freeze-thaw stability. ES, BRA and WRS formed non-covalent bonds (hydrogen bonds) through hydrophilic groups during gelatinization, which improved the gel properties. In addition, the steric hindrance formed by ES and BRA inhibited starch retrogradation. These results might contribute to the development of starch-based food formulations with good quality.

Chronic diseases inclding diabetes have been important public health problems worldwide.Starch intake is one of the main causes of postprandial blood glucose elevation.Recent studies have demonstrated that polyphenols can slow down the rate of starch digestion.Brown rice is rich in phenolics,and its nutritional health benefits are widely recognized around the world as an essential source of whole grains.The unique functional groups of phenolic substances in brown rice,such as phenolic hydroxyl,have a certain inhibitory effect on digestive enzymes.Changes in the structure of starch during processing also decrease the effect of digestive enzymes on it.This not only affects the digestion rate and digestibility of starch in an effective way,but also improves food quality.This paper reviews several aspects of phenolics in brown rice and their antioxidant activities,the process of starch digestion,the effects of brown rice polyphenols on starch digestive properties and their mechanisms of action.The aim of this review is to elucidate the scientific basis of whole grain brown rice polyphenols to retard starch digestion,and provide theoretical references for the development of whole grain brown rice-based and starch-based foods which are beneficial for populations of chronic disease,obesity,overweight,elderly,etc.

SummaryThis work evaluated the combined influence of cold plasma pretreatment and germination on phytic acid, GABA, γ‐oryzanol, phenolics, antioxidant activity, in vitro starch digestibility and texture characteristics of brown rice cakes. The contents of GABA, total γ‐oryzanol, total phenolics, total flavonoids, individual phenolic acid, individual flavonoid and antioxidant activity in germinated brown rice cake with cold plasma pretreatment (CGRC) were significantly higher than those in white rice cake (WRC) and brown rice cake (BRC), and the phytic acid content of CGRC was lower than that in BRC. Compared with WRC and BRC, CGRC had the highest content of resistant starch and the lowest starch in vitro digestibility. Additionally, the textural characteristics of CGRC were enhanced with lower hardness and higher elasticity compared to WRC and BRC. The combination of cold plasma pretreatment and germination may be the prospective approach for enhancing the nutritional quality and textural properties of brown rice cakes.

目前,我国稻谷加工业存在过度加工、产品结构不能很好满足居民消费需求、副产物增值利用率低等问题.解决这些问题要系统施策,引导稻谷加工企业发展适度加工工艺;积极推广柔性智能碾米技术、蒸谷米加工技术等;大米产品向多样化、功能化、健康化、方便化的方向发展;加强科技创新,提高米糠等副产物的增值利用.建议完善大米产品的标准体系,开展大米加工损失的学术研究,加强科普宣传,倡导营养健康消费观念.

我国糯米制品种类繁多,因高水分含量、淀粉回生老化及微生物等因素限制了该类淀粉基产品在工业化食品中的应用.速冻是一种能有效延缓糯米制品品质劣变的方法,研究冷冻体系下糯米制品的品质变化及其机理,可为发展速冻类糯米制品提供一定理论基础.本文综述了糯米制品在速冻及冷冻储藏过程中水分、淀粉等成分的变化以及对其品质的影响,同时总结了冷冻体系下微生物对该类制品的潜在风险,并进一步提出了糯米制品品质控制与改良的建议,以期促进速冻糯米制品产业的发展.

Summary This work evaluated the influence of phenolics from Black, Indica and Japonica rice bran (2.5–10%) on pasting and retrogradation properties of rice starch. The breakdown, setback, enthalpy values and retrogradation percentage of rice starch were decreased, and the pasting temperature was enhanced with the phenolics from three varieties of brown rice. X‐ray diffraction results suggested that new V‐type crystal at 13.1° was formed and relative crystallinity of rice starch was decreased. The results from fourier transform infrared spectroscopy exhibited that the 1047/1022 cm −1 values of rice starch were decreased with the content increase of phenolics from three varieties of brown rice. The phenolics from three varieties of brown rice resulted in loose surface structure of rice starch. This work may provide evidences for utilisation of phenolics from different varieties of brown rice to improve quality of rice products and inhibit retrogradation of rice starch.

Background and Objectives:Germination pretreatment is an effective way to improve the nutritional quality and sensory quality of germinated brown rice (GBR). Cold plasma pretreatment (CPP) has been demonstrated to improve the physicochemical properties of GBR. The effects of CPP on reducing phytic acid and improving nutrient composition in GBR have not been evaluated, and there are few studies on the changes of phytic acid and phytase, especially the changes of the forms and compositions of gamma-oryzanol, phenolics, and flavonoids in GBR with CPP. Therefore, this study evaluated the changes of phytase, phytic acid, gamma-aminobutyric acid (GABA), gamma-oryzanol, flavonoids, phenolics, and antioxidant activity in GBR with or without CPP. Findings:The phytic acid content in CPP-treated GBR for germination of 72 h was lower (7.60 mg/g, dry basis weight [DW]) than that in untreated GBR (9.01 mg/g DW). At the same germination time, the phytase activity and GABA, total gamma-oryzanol contents in CPP-treated GBR were higher than those in untreated GBR. However, total flavonoids and phenolics levels, flavonoid compositions and phenolic acids contents, and T-AOC and DPPH antioxidant capacity in CPP-treated GBR were lower than those of untreated GBR. Conclusions These results indicated that CPP for brown rice was an effective method for decreasing the phytic acid and enhancing GABA and gamma-oryzanol in GBR compared with non-CPP of brown rice for germination. Significance and novelty:CPP is beneficial to reduce phytic acid and improve the GABA and gamma-oryzanol contents of GBR, which provides a theoretical basis for producing functional and nutritious GBR foods.