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Understanding the interplay among salt ions, anthocyanin and starch within food matrices under thermal conditions is important for the development of starch-based foods with demanded quality attributes. However, how salt ions presence influences the microstructure and properties of starch/anthocyanin binary system remains largely unclear. Herein, indica rice starch (IRS) and rice anthocyanin (RA) were used to construct an IRS-RA binary system, with thermal treatment under different concentrations of Na + (10-40 mM) and types of salt ions (Na + and Ca 2+ ). The incorporation of salt ions induced the formation of a porous gel matrix, and destroyed the hydrogen bond between starch and anthocyanin through electrostatic interactions, reducing the storage modulus and radius of gyration of the binary system, and increasing the relative crystallinity (from 1.08 % to 1.51 % (20 mM Na + ) and 1.69 % (20 mM Ca + )) of the IRS-RA binary system at 90 °C. Also, the DPPH radical scavenging ability of the binary system at 90 °C was enhanced upon incorporating salt ions (0.93 for Na + condition and 0.94 for Ca 2+ condition at 20 mM ion concentration). It is noteworthy that Ca 2+ inclusion had more significant effects than the case for Na + presence, presumably due to the increased charge density., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Thermal processing with salt ions is widely used for the production of food products (such as whole grain food) containing protein and anthocyanin. To date, it is largely unexplored how salt ion presence during thermal processing regulates the practical performance of protein/anthocyanin binary system. Here, rice albumin (RA) and black rice anthocyanins (BRA) were used to prepare RA/BRA composite systems as a function of temperature (60-100 °C) and NaCl concentration (10-40 mM) or CaCl 2 concentration (20 mM). It was revealed that the spontaneous complexing reaction between RA and BRA was driven by hydrophobic interactions and hydrogen bonds and becomes easier and more favorable at a higher temperature (≤90 °C), excessive temperature (100 °C), however, may result in the degradation of BRA. Moreover, the salt ion presence during thermal processing may bind with RA and BRA, respectively, which could restrict the interaction between BRA and RA. Additionally, the inclusion of Na + or Ca 2+ at 20 mM endowed the binary system with strengthened DPPH radical scavenging capacity (0.95 for Na + and 0.99 for Ca 2+ ). Notably, Ca 2+ performed a greater impact on the stability of the system than Na + ., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

While brown rice (BR) has numerous nutritional properties, the consumption potential of which is seriously restricted since the poor cooking quality and undesirable flavor. Here, edible oils (pork lard and corn oil, 1-5 wt%) were incorporated during the cooking of BR following heat moisture treatment. Incorporating corn oil rather than lard significantly ameliorated the texture properties (e.g. hardness, cohesiveness, and chewiness) and sensory properties of cooked BR. Both lard- and corn oil-incorporated cooked BR showed obvious structural changes accompanied by the formation of amylose-lipid complexes during cooking. It was confirmed that the incorporation of lard and corn oil allowed a higher degree of short-range molecular order, more V-type starch crystallites, and elevated nano-structural arrangements. Additionally, a decreased hardness (from 559.04 g to 424.18 g and 385.91 g, respectively) and enriched resistant starch (RS) were also observed, the highest RS content (15.95 % and 16.32 %, respectively) was observed when 1 wt% of lard and corn oil were incorporated., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

High-fat diet is a risk factor for many chronic diseases, whose symptoms are probably regulated by ingesting food ingredients such as resistant starch. For cooked rice stored in cold-chain, the starch component can retrograde to generate ordered structures (helices and crystallites) and become resistant. However, the role of retrograded starch in managing hyperlipidemia symptoms is insufficiently understood. Here, compared to the normal high-fat diet, ingesting retrograded starch reduced the triglyceride and low-density lipoprotein cholesterol levels of high-fat diet mice by 17.69% and 41.33%, respectively. This relieved hyperlipidemia could be linked to the changes in intestinal bacteria. Retrograded starch intervention increased the relative abundance of Bacteroides (2.30 times higher), which produces propionic acid (increased by 8.26%). Meanwhile, Bacteroides were positively correlated with butyric acid (increased by 98.4%) with strong anti-inflammatory functions. Hence, retrograded starch intervention may regulate the body's health by altering intestinal bacteria., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Nowadays, resulting from disordered glucose and lipid metabolism, metabolic diseases (e.g., hyperglycemia, type 2 diabetes, and obesity) are among the most serious health issues facing humans worldwide. Increasing evidence has confirmed that dietary intervention (with healthy foods) is effective at regulating the metabolic syndrome. Whole grain rice (WGR) rich in dietary fiber and many bioactive compounds (e.g., γ-amino butyric acid, γ-oryzanol, and polyphenols) can not only inhibit starch digestion and prevent rapid increase in the blood glucose level, but also reduce oxidative stress and damage to the liver, thereby regulating glucose and lipid metabolism. The rate of starch digestion is directly related to the blood glucose level in the organism after WGR intake. Therefore, the effects of different factors (e.g., additives, cooking, germination, and physical treatments) on WGR starch digestibility are examined in this review. In addition, the mechanisms from human and animal experiments regarding the correlation between the intake of WGR or its products and the lowered blood glucose and lipid levels and the reduced incidence of diabetes and obesity are discussed. Moreover, information on developing WGR products with the health benefits is provided., (© 2022 The Authors. Comprehensive Reviews in Food Science and Food Safety published by Wiley Periodicals LLC on behalf of Institute of Food Technologists.)

Cold-chain cooked rice is an instant food consumed worldwide. Through inspecting rice structural alterations during digestion, this work discloses how microwave reheating tailors the starch digestibility of cooked rice following cold storage. The cold storage allowed approximately 2% of B-type (not V-type) starch crystallites, more nanoscale and short-range orders, and smaller pores in the rice matrix. These changes retarded the hydrolysis of structural domains (e.g., amorphous regions and short-range orders) during digestion, which increased the content of slowly digestible starch to about 38.16%. Then, microwave reheating partially disrupted the B-type crystallites and nanoscale orders, but unaffected the contents of V-type crystallites and short-range orders. Even with such structural disruptions, the resistant starch content was apparently increased to approximately 30.06%, as the structural domains became less susceptible to the digestion. Additionally, for the rice samples, the percentage of V-type crystallites could be largely increased from ca. 3% to 13%-14% during digestion., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Cold-chain cooked rice is a widely-consumed instant food. While the quality of cooked rice as affected by processing has been widely studied, it remains largely unexplored how concurrent cold-chain conditions (e.g., refrigeration time with specific water contents) tailor the structure and starch digestibility of cooked rice. Here, as shown by combined techniques (e.g., scanning electron microscopy and small angle X-ray scattering), the cold storage (1 to 3 days) of cooked rice at 1.1:1 w/w water-to-rice ratio increased the uniformity of the rice matrix, strengthened the nonperiodic structure, and allowed more B-type starch crystallites and short-range orders. This induced an increase in the slowly digestible starch (SDS) content (from ca. 33.7% to 38.5%) as the refrigeration time rose. In contrast, for cooked rice with 1.5:1 w/w water-to-rice ratio, the cold storage (mainly 1 day) strengthened the matrix uniformity and the nonperiodic structure, and eventually increased the resistant starch (RS) content from ca. 10.3% to 17.7%. The present data could facilitate the design of cold-chain cooked rice with tailored starch digestibility., (Copyright © 2021 Elsevier B.V. All rights reserved.)

This study explored how microwave reheating (to about 73 °C at different power levels) affects the microstructure and digestion characteristics of cooked rice with different water contents (1.1 and 1.5 times that of rice in weight). Irrespective of water content, mainly the V-type crystallites remained after microwaving reheating, with slight changes in other multi-scale structural features. Only at a relatively high water content (1.5) and with a power level high enough could short-range order be reduced. Such microwave reheating increased the digestion resistance of cooked rice. At a water content of 1.1 times, increasing the microwave power led to a decreased rapid digestible starch (RDS) content and an increased resistant starch (RS) content. With a higher water content (1.5), the enhancement of digestion resistance with higher microwave power was less significant but still, a reduced slowly digestible starch (SDS) content and a higher RS content were observed., (Copyright © 2021 Elsevier B.V. All rights reserved.)

This work concerns how starch-protein interplay affects the multi-scale structures (e.g., short- and long-range orders, nanoscale structure and morphology) of starch undergoing thermal processing (pasting) involving heating and cooling at high water content. An indica rice starch (IRS) and three proteins (whey protein isolate, WPI; soy protein isolate, SPI; casein, CS) were used. By inspecting rheological profiles of mixed systems before and after adding chemicals, IRS-WPI and IRS-CS showed mainly hydrophobic molecular interaction; and IRS-SPI exhibited hydrophobic, hydrogen bonding and electrostatic interactions. The RVA results revealed that, with starch and proteins as controls, starch-globular protein (WPI or SPI) interplay accelerated the swelling of starch granules (faster viscosity increase at initial pasting stage), and reduced the paste stability during heating (higher breakdown) and during cooling (higher setback); however, the starch-casein interactions resulted in opposed effects. Moreover, starch-protein interactions varied the multi-scale chain reassembly of starch into different structures during cooling. Observed could be fewer short- and long-range starch orders, and larger nonperiod structure (or colloidal clusters) on the nanoscale. On even larger scale to micron, IRS-globular protein molecules generated larger grids (with reduced number) in the gel network, and IRS-casein formed a more continuous gel network with less prominent tunnel-like features., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Colored brown rice shows better health benefits than polished rice, and there is great interest in the design of demanded cooking manners for brown rice. This investigation concerns how the change of cooking mode can slow starch digestion of colored brown rice by inspecting mainly starch structural changes during cooking. Compared to cooking Mode 1, the soaking of Mode 2, at higher temperature, probably enhanced water diffusion into rice matrices, thus strengthening starch lamellae without apparently altering rice morphology and ordered structures such as starch polymorphs and helices. The followed heating of Mode 2, with reduced time, more sufficiently disrupted rice structures, causing less prominent nonperiodic molecular organizations. At the final cooking stage, the braising of Mode 2, having faster temperature reduction for prolonged time, leading to similar rice morphology, reduced molecular orders (e.g., helices) and probably denser amorphous regions of nonperiodic organizations. Such features tended to increase packing density of molecular chains (mainly starch) in rice matrices, thus slowing the enzyme diffusion in rice matrices and associated binding and catalysis events. In this way, a reduced starch digestion rate and increased resistant starch (RS) and slowly digestible starch (SDS) were seen for the rice following Mode 2 cooking., (Copyright © 2020 Elsevier B.V. All rights reserved.)

This work concerns the multi-scale structures and digestion behaviors of indica rice starches with apparent amylose contents (AACs) of ca. 14%-24%. A higher AAC not always allowed a lower digestion rate (k), different from previous findings that starches containing more amylose normally show slowed digestion. Here, the proportion of stable molecular orders (melting temperature above ca. 73 °C) and AAC synergistically governed starch digestion rate. With a similar AAC, a higher amount of stable orders (R h/l , ratio of enthalpy of stable orders to that of the rest) led to a lower k. Also, with a similar R h/l , a larger AAC caused a lower k. Consistently, JPZ starch had almost the highest AAC and R h/l , showing the lowest k. Regarding this, amylose and stable orders played roles in increasing the bulk density of starch structure matrices, and eventually slow the diffusion, absorption and catalysis events of digestion enzymes within the matrices., (Copyright © 2019 Elsevier B.V. All rights reserved.)

By inspecting starch hierarchical structural evolutions, this work explores how microwave cooking with storage tailors the slowly digestible features of indica (IRS) and waxy (WRS) rice starches. Particularly, relative to conventional cooking-storage, the microwave treatment especially at high powers (8 and 10 W/g) increased the molecular orders (crystallites) and periodic amorphous-crystalline structures. Such changes facilitated the formation of domains with intermediately-densely packed starch chains, being modestly accessible to the diffusion, absorption and catalysis of enzymes and dominantly showing slowly digestible features. Consistently, the microwave processed starches showed a higher SDS (slowly digestible starch) level and a lower digestion rate. This microwave-enhanced SDS generation became more prominent for IRS, and the treated IRS at 10 W/g showed the highest SDS content (ca. 54%). This is related to the enhanced reassembly of glucan chains into ordered/semicrystalline structures and the formation of slowly digestible domains as induced by the increase of amylose molecules., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

From a supramolecular structure viewpoint, we concern how concurrent microwave and heat moisture treatment (M/HMT) tailors the pasting and digestion features of indica rice starch (IRS) and waxy rice starch (WRS), using combined analytical methods such as scanning electron microscopy and small-angle X-ray scattering. The results confirm that, for the starches (especially IRS), M/HMT led to a concave granule surface, weakened alignment of helices in lamellae, loosened packing of chains in amorphous regions, and somewhat disrupted crystallites. Consequently, the susceptibility of starch structures to hydrothermal effects was insignificantly altered, as reflected by unchanged pasting temperature; the enzyme absorption/hydrolysis could be properly accelerated, as affirmed by a modestly increased digestion rate and slightly reduced enzymatic resistance. Also, compared to WRS, IRS had more amylose with relatively long branches, which probably contributed to starch chain interactions during M/HMT. This tended to reduce the paste viscosity related to the swelling degree of starch granules, and increase the paste stabilities during heating and cooling related to the robustness of swelled granules and the reorganization of glucan chains., (Copyright © 2019 Elsevier B.V. All rights reserved.)