Resistant starch formation through intrahelical V-complexes between polymeric proanthocyanidins and amylose

Different interaction behaviors of rice glutelin with amylose and amylopectin within starch under the extrusion environment

Effects of rice glutelin (RG) on structural properties of amylose (AM) and amylopectin (AP) within rice starch and their interaction mechanism were revealed. At the same RG addition, AP had a greater binding capacity than AM. Adding RG increased the thermal stability and short-range orders of extruded amylose (EAM) and extruded amylopectin (EAP), as well as changed their surface morphologies. Extrusion destroyed the crystalline structure of AM and AP, while the relative crystalline of EAM and EAP increased with the increasing of RG. When RG content was 6 % and 8 %, RG mainly interacted with AM and AP via hydrogen bonds. The main driving force between RG and AP changed into hydrophobic interaction when RG content was 10 % and 12 %. These results contributed to a deep understanding of structural evolution of AM and AP within rice starch caused by the interaction with RG under the extrusion environment.

The effects of lecithin on the complexation between pea starch and aliphatic alcohols in aqueous medium

This study investigated the effect of lecithin on the complexation of pea starch with aliphatic alcohols (C10-C18). Alcohols (C10-C16) produced cooling-stage viscosity peaks, while 1-octadecanol only showed increased final viscosity in ternary systems with lecithin during the Rapid viscosity analyzer program. Differential scanning calorimetry and complex index analyses revealed enhanced complex formation, with enthalpy changes nearly doubled compared to corresponding binary systems. X-ray diffraction showed increased V-type crystallinity (3.88-12.22 % to 8.36-21.10 %), while Fourier transform infrared and Raman spectroscopies confirmed improved short-range molecular order. Enzymatic hydrolysis demonstrated reduced digestibility, with 35.86 % resistant starch content in PS-10-LE after cooking. SEM and rheology studies indicated that lecithin addition caused network collapse and weaker gelation, likely due to more complex formation. These findings validated lecithin's role in enhancing starch-alcohol complexation and highlighted its potential for developing resistant starches with guests and encapsulating different flavor compounds, offering promising applications in food science.

Effect of starch structuring and processing on the bioaccessibility of polyphenols in starchy foodstuffs: A review

Starch is the main polysaccharide in the human diet and is the major calory supplier. The digestibility of starch can be controlled by processing conditions, which produce the rearrangement of the polymer's multi-scale structure and interactions with other components in the food matrix. The interest in consuming functional foods with polyphenols is linked to the pursuit of overall well-being. Still, the bioaccessibility of the polyphenols can be limited by their interactions with starch, features that also affect the digestibility of the polysaccharide. The starch-polyphenol interactions produce different VI-type, VIIa-type, and VIIb-type complexes, which are generated depending on the polyphenol type (structure) and the processing for developing a food matrix. The complex formation between linear glucan chains and polyphenols produces crystalline and lamellar structures that modulate the starch digestion rate. The interactions with starch modulate the bioaccessibility of the polyphenols, and the starch-polyphenols complexes are not substrates for the digestive enzymes, leading to a reduction in intestinal glucose release and absorption. The release of polyphenols produces inhibition of the α-amylase, a phenomenon that may further decrease starch digestion. The type of processing and polyphenols present are crucial factors in determining the nature of the starch-polyphenol complex that will be formed. To prepare this review, The database from Scopus was used using the keywords Starch and Polyphenols. Articles from high-impact factor journals in the study area were selected (e.g. Food Hydrocolloids, Food Chemistry, Food Research International, Functional Foods, etc.).

A decade review on phytochemistry and pharmacological activities of Cynomorium songaricum Rupr.: Insights into metabolic syndrome

BACKGROUND

Cynomorium songaricum Rupr. (CSR), a perennial herb with a rich history in traditional medicine, has demonstrated therapeutic potential against metabolic syndrome (MetS) through its active compounds, including proanthocyanidins, polysaccharides, and triterpenoids. MetS, a global health concern, encompasses interlinked conditions such as obesity, type 2 diabetes mellitus (T2DM), and inflammation. This review synthesizes recent findings on CSR's pharmacological and phytochemical properties, focusing on its role in ameliorating MetS.

METHODS

Following Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines, relevant studies were retrieved from PubMed, Web of Science, and CNKI databases up to December 2024. Keywords included "Cynomorium Songaricum Rupr.", "Cynomorii Herba", "Suoyang", "Suo Yang", "Metabolic syndrome", "Proanthocyanidins", "Polysaccharides" and "Triterpenoids" and their combinations. Inclusion criteria emphasized studies exploring CSR's impact on MetS, while duplicate, low-quality studies and studies not written in Chinese, English, or unrelated were excluded.

RESULTS

A total of 92 studies were analyzed, revealing that CSR's active components exhibit multi-target effects. Proanthocyanidins reduce glucose absorption and oxidative stress, polysaccharides enhance insulin sensitivity and gut microbiota composition, and triterpenoids mitigate obesity and mitochondria damage. These mechanisms collectively contribute to the beneficial effects of CSR against MetS.

CONCLUSION

CSR presents a promising natural therapy for MetS, utilizing its pharmacologically active compounds to address core metabolic dysfunctions. Future studies should focus on clinical validation and safety assessments to facilitate CSR's integration into modern therapeutic regimens.

Removing internal lipids influences the interactions between blueberry anthocyanins and maize starch: Thermal and rheological properties, and digestibility

The interactions between blueberry anthocyanins (BA) and waxy (WMS) and normal amylose (NMS) maize starches before and after internal lipids removal were studied. With the addition of BA (0-10 %), gelatinization enthalpy (ΔH) of both WMS and NMS decreased, and ΔH of the starches without internal lipids was further reduced. Steady shear rheological analysis indicated that removing internal lipids reduced consistency coefficient (K) and increased flow behavior index (n) of NMS-BA complexes, while this was not observed in WMS-BA complexes. Rapidly digestible starch (RDS) content was decreased by 14.7 % and 16.1 % in WMS-BA and NMS-BA complexes as a function of BA (from 0 to 10 %), respectively, meanwhile, after removal internal lipids, RDS content was decreased by 21.3 % and 26.0 %, respectively. After removal of internal lipids, starch-BA complexes exhibited higher α-amylase inhibition activity and contained more amylose-BA complexes. These results suggested that the effect of BA on NMS was greater than that on WMS regardless of whether internal lipids were removed, but removal of internal lipids enhanced the interaction between BA and amylose/amylopectin within starch. This study also provided insights into the influence of internal lipids on BA modified starch.

The lotus seed starch-EGCG complex modulates obesity in C57BL/6J mice through the regulation of the gut microbiota

The starch-polyphenol complex, identified as RS5-resistant starch, has been shown to regulate the gut environment and inhibit metabolic diseases, including obesity. In a study with C57BL/6 obese mice fed LSE, potential anti-obesity effects were demonstrated through physiological and biochemical assessments, gut microbiota analysis, and mechanistic insights. The study showed that LSE reduced mice body weight, serum total cholesterol, and triglycerides (P < 0.05). Serum inflammatory markers (TNF-α, IL-6, IL-1β) and LPS levels were significantly decreased, while glucose tolerance (AUC reduced by 29.29 %) and insulin sensitivity (AUC reduced by 31.79 %) were improved. Histological analysis indicated reduction in adipocyte size and attenuation of hepatic steatosis. Gut microbiota profiling demonstrated LSE increased beneficial bacteria genera Faecalibacterium, Bifidobacterium, and Akkermansia. This correlated with enhanced SCFA production (acetate 41.53 %, propionate 45.52 %, butyrate 57.49 % increase). These findings demonstrate that LSE exerts anti-obesity effects through modulation of the gut microbiota-SCFA-metabolic axis, supporting starch-polyphenol complexes as functional food candidates.

Effect of microwave treatment on the structure and digestive characteristics of quercetin-added corn starch

The impact of microwave treatment (MT) on corn starch-quercetin complex (CS-Q) is investigated in this study. The results indicate that MT significantly increased the complexation index (CI) of quercetin with corn starch from 36.08 % to 47.73 %. Structural and digestive properties were also investigated. Scanning electron microscopy (SEM) revealed that microwave-treated corn starch-quercetin complex (MT-CS-Q) formed a more compact complex than CS-Q. Fourier-transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) analyses confirmed that MT-CS-Q exhibited a highly ordered structure, with the crystalline conformation of starch transitioning from A-type to A + V-type. Moreover, the dense structure formed by quercetin and starch after microwave treatment significantly reduced the in vitro digestibility of the complex, resistant starch content increased from 11.91 % to 19.06 % compared to the non-microwave treated complex. During simulated gastrointestinal digestion, MT-CS-Q reduced quercetin release in the stomach and increased its absorption in the intestine. These findings demonstrate that microwave treatment is an effective method for enhancing the CI of quercetin with corn starch. The results provide a theoretical basis for the development and utilization of functional starch.

Interactions between polyphenols and polysaccharides/proteins: Mechanisms, effect factors, and physicochemical and functional properties: A review

Polyphenols have attracted much attention in the food industry and nutrition because of their unique biological activities. However, the health benefits of polyphenols are compromised due to their structural instability and sensitivity to the external environment. The interaction between polyphenols and polysaccharides/proteins largely determines the stability and functional characteristics of polyphenols in food processing and storage. Hence, this topic has attracted widespread attention in recent years. This review initially outlines the basic properties of polyphenols and their applications in food. Subsequently, the interaction mechanisms between polyphenols and polysaccharides/proteins are discussed in detail including non-covalent bonding, covalent modification, and conformational changes. These interactions can display profound impacts on the nutritional value, taste, stability, and safety of food. Additionally, this article also systematically reviews the influencing factors (type, concentration, temperature, pH, and other factors) of interaction between polyphenols and proteins/polysaccharides. Finally, this paper also summarizes systematically the effects of the interaction between polyphenols and polysaccharides/proteins on the physicochemical and functional properties of polyphenols/proteins. The findings provide prospects for the application of composite materials in food preservation, functional food development, and nanocarrier development, which can provide theoretical references for the in-depth development of polyphenols in the food industry.

Strategy for Making Starch-Polyphenol Complexes with Multifunctional Properties

Starch-phenol complexes are of interest due to their potential for health-related functional properties in addition to resistance to enzymic digestion. However, the preparation of such complexes remains a challenge due to the structural features and low solubility of the phenols. The present study sets out a novel protocol to prepare amylose (AM)-polyphenol complexes by forming an AM-lipid complex that incorporates the polyphenol. Three polyphenols (resveratrol, curcumin, and quercetin), which by themselves do not form complexes with AM, were successfully encapsulated by AM through the addition of lauric acid (LA) to form AM-LA-polyphenol complexes. These ternary complexes had a more ordered structure and better functional properties, including antioxidant activity, slower enzymatic digestion, and controlled release of polyphenols, compared with the polyphenols alone or the AM-LA complex. Of the three polyphenols, more curcumin and quercetin were captured through interhelical rather than intrahelical associations. Our study opens up a new way to prepare starch-polyphenol complexes using polyphenols that do not form complexes with AM alone, which will be of great significance for creating novel resistant starches with desirable functionalities.

The molecular mechanisms and new classification of resistant starch - A review

Diabetes is one of the major chronic diseases endangering human health. Because of the low glycemic index, RS(resistant starch) plays an important role in the intervention and treatment of diabetes. Based on our previous studies, the mechanism of RS is systematically discussed from the molecular level (the relationship between starch molecular conformation and RS, the relationship between double-helix structure and RS, and the relationship between molecular complexation and RS) and granular level (the relationship between amylase penetration and RS, the relationship between crystallinity and RS, and the relationship between amylose/amylopectin content and RS). In addition, with more in-depth studies in the preparation and formation reason of RS, the current classification of RS may not satisfy our current understanding of RS. In this paper, a new classification of RS is proposed. RS is classified into 10 types from two aspects (reparation methods and formation reasons), which may make it easier to understand the different RS. This paper may provide a reference for the research of RS.

Effect of isoflavone structures on the formation of starch-isoflavone complexes: Experimental and molecular dynamics analysis

Isoflavones were the commonly polyphenols capable of forming inclusion complexes with starch to slow starch enzymatic digestion. However, the impact of isoflavone structures on the formation of starch-isoflavone complexes was not well understood. In this study, isoflavones with distinct structurally differences, including daidzein, genistein, biochanin A, genistin, and puerarin, were selected to examine the interaction between starch and these isoflavones utilizing both experimental and molecular dynamics analysis. The experimental findings showed that daidzein and genistein produced more V-type crystallites with starch, resulting in a greater decrease in starch digestibility compared to other isoflavones. Molecular dynamics simulations suggested that daidzein and genistein, which had smaller molecular size and less hydroxyl groups, formed fewer hydrogen bonds but more inclusion complexes with starch. It appeared that the number of hydroxyl groups and molecular size of isoflavones played a crucial role in the interaction between starch and isoflavones, ultimately influencing the formation of V-type starch crystallites.

Hydrolysis and transport characteristics of starch inclusion complexes with long-chain alkyl gallates: Controlled two-step release of gallic acid and retardation of starch digestion

Corn starch inclusion complexes of alkyl gallates (typical phenololipid representatives), including stearyl gallate, dodecyl gallate, octyl gallate, and hexadecyl gallate, were synthesized by using a heat treatment method. Such inclusion complexes exhibited significantly improved two-step release properties for gallic acid. In other words, gallic acid was generated via the breakdown of alkyl gallates that were released from inclusion complexes in an everted rat intestinal sac model, as determined by HPLC-UV analysis. The produced gallic acid could subsequently pass through intestinal membranes. On the other hand, a glucose oxidase-peroxidase analysis revealed that starch inclusion complexes can slow down starch digestion by increasing the proportion of resistant starch (from 12.2 % to 14.5-30.8 %) and decreasing the proportion of rapidly digestible starch (from 51.2 % to 39.4-49.2 %). Importantly, the two-step release characteristics of gallic acid and the retardation behavior of starch digestion can be easily regulated by modifying the acyl carbon chain length.

Wheat starch-Lonicera caerulea berry polyphenols complex regulates blood glucose and improves intestinal flora in type 2 diabetic mice

Resistant starch (RS) reduces or delays the digestion of carbohydrates and glucose synthesis, thereby lowering postprandial blood glucose levels. The wheat starch-Lonicera caerulea berry polyphenols (WS-LCBP) complex was constructed using high hydrostatic pressure (HHP). The effects of intragastric administration of WS or WS-LCBP on blood glucose in T2DM model mice. RS in the composite preparation formed by HHP and 10 % LCBP at 600 MPa for 30 min increased from 7.65 % to 49.66 %. WS-LCBP formed an A + V-type crystal structure of the polyhydroxyl non-inclusion complex, which hindered the digestion of WS into glucose. Compared with LCBP intake, which caused 8.3 % reduction in 2-h postprandial blood glucose (p < 0.05), Homeostatic model assessment for insulin resistance demonstrated a 35.3 % decrease (p < 0.001) with WS-LCBP administration. Western blotting demonstrated that exposure to WS-LCBP activated the GLP-1R/PI3K/AKT signaling pathway in the liver tissue of T2DM mice, reducing insulin resistance. Furthermore, the concentration of short-chain fatty acids was markedly elevated. The structure and abundance of the intestinal flora were enhanced. The WS-LCBP complex demonstrated a more pronounced improvement than LCBP supplementation alone. This study offers a novel perspective and theoretical foundation for the regulation of postprandial blood glucose levels by polyphenol starch-based food biomacromolecules and their potential applications in starchy foods.

Effects of phenolic acid incorporation on the structure, physicochemical properties, and 3D printing performance of rice starch gel: Exploring underlying mechanisms

This study aimed to investigate the effects of incorporating ferulic acid (FA) or gallic acid (GA) on structural, physicochemical, and 3D printing properties of rice starch gel, while also exploring underlying mechanisms. These phenolic acids were incorporated into rice starch at varying concentrations. The addition of FA or GA reduced the gel's viscoelasticity, leading to significant decline in 3D printing accuracy. The printing accuracy of the starch decreased from 98.64 % for the native starch to 83.85 % for the FA-starch complex and 72.40 % for the GA-starch complex. Structural analysis revealed that FA and GA formed single-helical complexes with starch, disrupting the formation of a double-helical gel network and consequently reducing the gel's viscoelasticity. Additionally, the incorporation of FA and GA significantly increased the resistant starch content in the 3D-printed products, rising from 22.02 % in the native starch to 46.37 % in the FA-starch complex and 53.42 % in the GA-starch complexes. These single-helix complexes improved both the stability and bioavailability of the polyphenols. Findings of this study provide valuable insights for advancing the development of functional 3D-printed foods.

Modulation of starch-polyphenol complex thermal stability and antioxidant activity: The role of polyphenol structure

Polyphenols are closely related to human health, but thermal treatment causes the loss of polyphenol activity. Complexation between amylose and polyphenol prevents oxidation and degradation of polyphenols during thermal treatment. And the functional properties of the complex are affected by the polyphenol backbone. Therefore, this study compared the complexation between pre-formed V-amylose (V6a) and polyphenols with different backbones (C6-C1, C6-C3, and C6-C3-C6). Specifically, a non-inclusion complex was formed between V6a and PHBA through intermolecular hydrogen bonding, whereas p-coumaric acid (PCA, C6-C3 backbone) and 6-hydroxyflavone (HF, C6-C3-C6 backbone) formed V-type inclusion complexes with V6a. In addition, V6a-PCA possessed greater relative crystallinity (42.70 %), higher thermal stability (136.2 °C), higher encapsulation efficiency (22.8 %), and stronger antioxidant activity (2, 2-diphenyl-1-picrylhydrazyl radical scavenging activity = 62.80 %). Finally, the molecular dynamic simulation corroborated the effect of the polyphenol backbone on the complex type. This study suggested that C6-C3 backbone polyphenols facilitated the formation of inclusion complexes with V-amylose compared to hydrophilic C6-C1 backbone polyphenols and C6-C3-C6 backbone polyphenols. V-type inclusion complexes are effective encapsulation carriers, which can be used in the future to enhance the bioactivity of polyphenols in food processing.

In vitro hydrolysis of V-type starch inclusion complexes of alkyl gallates: the controlled two-step release behavior of gallic acid and its beneficial effect on glycemic control

The heat treatment method was used to synthesize starch inclusion complexes from starch and short-chain alkyl gallates (a typical representative of phenololipids), such as butyl gallate, propyl gallate, ethyl gallate and methyl gallate. In an everted rat gut sac model, HPLC-UV analysis revealed that the released alkyl gallates from inclusion complexes were degraded to produce gallic acid. Gallic acids (0.009455-0.014160 nmol min-1) and alkyl gallates (0.2695-0.9441 nmol min-1) were both able to pass through intestinal membranes. After transmembrane transfer, alkyl gallates could also be hydrolyzed to produce gallic acid (1.947 × 10-5-2.290 × 10-5 min-1). It was evident that such an inclusion complex demonstrated superior dual sustained-release characteristics for phenolic compounds. Meanwhile, starch inclusion complexes can also slow down starch digestion by raising resistant starch (from 12.2% to 27.2-46.0%) and lowering rapidly digestible starch (from 51.2% to 22.2-51.2%), according to a glucose oxidase-peroxidase analysis. The delayed digestion behavior of starch in inclusion complexes is very beneficial for blood glucose control. Thus, our work effectively established a theoretical foundation for modifying the dual sustained-release behavior of phenolic compounds and the retardation of starch digestion by adjusting the carbon-chain length in starch inclusion complexes.

Current advances in the interaction mechanisms, nutritional role and functional properties of phenolic compound-starch complexes

This review explores starch-phenolic compound complexes' formation mechanisms, structural characteristics, and functional roles. These complexes alter starch properties, enhance its resistance to digestion, and modulate enzyme activity, with significant implications for glycemic control. A critical discussion of preparation methods and characterization techniques is presented, emphasizing their application in functional food design and health-oriented products. The review highlights the potential of these complexes to address metabolic disorders, offering valuable insights for advancing food science and nutrition.

Preparation and evaluation of novel Agriophyllum squarrosum starch nanoparticles for encapsulation of lycopene with enhanced retention rate and bioactivity during simulated in-vitro digestion

In this study, we developed novel Agriophyllum squarrosum starch nanoparticles (ASSNPs) for the encapsulation of lycopene (LYC), aiming to enhance its stability and bioactivity under adverse environmental and digestive conditions. The small-granule starch extracted from A. squarrosum seeds was processed using ionic liquids (ILs) as an effective "green" solvent, followed by a systematic treatment involving ultrasonication and pullulanase to prepare the ASSNPs. The resulting nanoparticles exhibited small size, narrow particle size distribution, negative zeta potential, and high encapsulation efficiency of up to 64.3 %. The structures of ASSNPs were characterized using Fourier transform infrared spectroscopy, X-ray diffraction, differential scanning calorimetry, scanning electron microscopy, and transmission electron microscopy. These analytical techniques confirmed the successful encapsulation of LYC and revealed increased intermolecular interactions. Stability and degradation experiments demonstrated that the retention of the LYC in the complexes was significantly higher than that of the unencapsulated LYC, highlighting the superior protective effects of ASSNPs on the storage and digestive stability of LYC. This research elucidated the structural features of the complex between ASSNPs and LYC, underscoring the potential of ASSNPs as a food-grade delivery system. This approach offers a sustainable method for enhancing the bioavailability of hydrophobic nutraceuticals.

Assessing the effects of dual functional V-type cornstarch films added with kiwifruit peel extracts on preservation of fresh-cut kiwifruits: A metabolomics study

Fresh-cut fruit, with nutrition and convenience, has a broad market demand. However, its shelf life is shortened due to its tissue damage. Therefore, the development of cost-effective and eco-friendly multifunctional packaging materials to extend the shelf life of fresh-cut fruits is urgently needed. A cornstarch-based film (CS film) was successfully prepared using V-type corn starch as an ethylene scavenger and kiwifruit peel extract (KPE) as an antioxidant. The film containing 4.00 % (v/v) KPE had a DPPH radical scavenging capability of 52.1 % ± 2.4 % and ABTS radical scavenging capability of 70.4 % ± 4.4 %. The amount of ethylene harvested was 17.27 cm3 g-1. In addition, the malondialdehyde content of fresh-cut kiwifruits covered by CS film decreased by 42.82 % compared with PE film after 72 h, and the hardness increased 71.20 %. And the CS film could regulate ethylene and oxygen concentration, and extending the fresh life of kiwifruit from 3 days to 15 days. Metabolomics and transcriptomic analyses revealed that the CS film regulated ethylene self-promotion and the balance of reactive oxygen species metabolism. As a result, these reduced sugar synthesis and metabolism, which helped to maintain the freshness of fresh-cut kiwifruit. These findings can serve as a reference for developing techniques to preserve the packaging of fresh-cut fruits.

Dynamic/static pressure-induced copolymerization and property changes of lotus seed starch with chlorogenic acid

Pressure promotes the formation of starch-polyphenol complexes, but their classification and properties are still unclear. This study aimed to elucidate the effects of dynamic high-pressure homogenization (10-50 MPa) and static hydrostatic pressure (100-500 MPa) on the copolymerization behavior and properties of lotus seed starch (LS)-endogenous polyphenol chlorogenic acid (CA) complexes. The results showed that both pressures induced LS-CA to form stable inclusion-type complexes and easily destructible noninclusion-type complexes. Increased pressure promoted the formation of inclusion-type complexes, with dynamic pressure having a particularly strong effect. However, noninclusion-type complexes began breaking down at 20 MPa under dynamic pressure and 300 MPa under static pressure. Inclusion-type complexes primarily improve starch ordering, and noninclusion-type complexes enhance water holding capacity, but excessive proportions of either type affect pasting performance. These findings offer insights into transforming specific starch structures through small molecular components and provide a theoretical basis for controlling functional starch product processing.

Can agriculture and food waste be a solution to reduce environmental impact of plastic pollution? zero-waste approach for sustainable clean environment

Agriculture and food waste, especially from fruits, vegetables, and plant byproducts like banana peels, avocado seeds, and durian seeds, have emerged as promising alternatives for bioplastic production. These materials, rich in polysaccharides and cellulose, offer a sustainable solution to reduce plastic pollution and mitigate the environmental impact of traditional plastics. This review focuses on the potential of utilizing agricultural and food waste to create starch-based bioplastics, emphasizing the importance of a zero-waste approach to enhance the economic value of these byproducts while promoting a cleaner environment. We include a SWOT analysis of this innovative approach, assess the environmental implications of bioplastic production, and highlight the potential for turning agricultural waste into a key player in the fight against plastic pollution. This review also explores the future prospects of harnessing agriculture and food waste as valuable resources for sustainable bioplastics, contributing to a greener, more sustainable world.

Liquid nitrogen ball-milled mechanochemical modification of starches with typically selected A, B and C crystal types on multiscale structure and physicochemical properties

This study investigated the effect of liquid nitrogen ball-milled mechanochemical treatment on multiscale structure and physicochemical properties of starches with typically selected A (rice starch, ReS), B (potato starch, PtS) and C (pea starch, PeS) crystal types. The morphology of starch samples changed from integral granules to irregular fragments, and the interaction between the exposure OH bonds led to a serious agglomeration. As the treatment times extended, the crystalline structure of starch samples was gradually destroyed, and the excessive treatment approached amorphization. Moreover, the thermal stability of starch samples showed the downward tendency; and with amorphization increased, the swelling power (SP), solubility (S), water absorption capacity (WAC), oil absorption capacity (OAC) and hydrolysis rate of starch samples gradually increased. The obtained results provided a theoretical foundation for broadening the application range of ball-milled starches with different crystal types.

Sorghum starch review: Structural properties, interactions with proteins and polyphenols, and modification of physicochemical properties

Sorghum, a gluten-free carbohydrate source with high antioxidants and resistant starch, contains anti-nutrients like phytic acid, tannin, and kafirin. Interactions with starch and proteins result in polyphenol-starch, starch-kafirin, and tannin-protein complexes. These interactions yield responses such as V-type amylose inclusion complexes, increased hydrophobic residues, and enzyme resistance, reducing nutrient availability and elevating resistant starch levels. Factors influencing these interactions include starch composition, structure, and Chain Length Distribution (CLD). Starch structure is impacted by enzymes like ADP-glucose pyrophosphorylase, starch synthases, and debranching enzymes, leading to varied chain lengths and distributions. CLD differences significantly affect crystallinity and physicochemical properties of sorghum starch. Despite its potential, the minimal utilization of sorghum starch in food is attributed to anti-nutrient interactions. Various modification approaches, either direct or indirect, offer diverse physicochemical changes with distinct advantages and disadvantages, presenting opportunities to enhance sorghum starch applications in the food industry.

Impact of waxy protein deletions on the crystalline structure and physicochemical properties of wheat V-type resistant starch (RS5)

This study investigated the effects of waxy (Wx) protein on wheat V-type resistant starch (RS5) formation, molecular structure, and physicochemical properties. We discovered that waxy protein deletions led to a rise in B- and C-type starch granules, while reducing A-type starch granules, amylose, and slowly digestible starch contents. Further, dodecyl gallate (DG) addition significantly increased RS5 content, and molecular dynamics simulations indicated that amylose and DG can form stable complexes. Molecular docking indicated that DG could potentially aid in protecting wheat starch from digestion by human α-glucosidase. RS5 content was significantly reduced by waxy protein deletions. X-ray powder diffraction, Fourier-transform infrared spectroscopy, and laser confocal microscopy-Raman analyses revealed that waxy protein deletions decreased long-range crystalline structures and relative crystallinity and increased short-range crystalline structures，and full width at half maximum at 480 cm-1 of RS5. Pearson correlation analysis showed that RS5 content was highly correlated with its crystal structure, functional characteristics, and digestive characteristics. Principal component analysis revealed that five parameters (amylopectin, long-range crystalline structures, amylose, relative crystallinity, and RS5 content) had significant effect on the crystalline structure and functionality of RS5.

Effects of glutathione on the physicochemical properties of high hydrostatically pressure gelatinized maize starch

This research prepared gelatinized waxy maize starch (WMS), low-amylose maize starch (LAS), and high-amylose maize starch (HAS) with different glutathione (GSH) content (5, 10, and 15 %) using high hydrostatic pressure (HHP) at 600 MPa. Scanning electron microscopy (SEM) revealed damaged morphology of WMS and complete swelled granules of LAS and HAS with different degree of gelatinization (DG) values, 92.86, 59.36, and 17.45 %, respectively. Fourier transform infrared spectroscopy (IR spectra), laser confocal micro-Raman (LCM-Raman) spectroscopy, and X-ray diffraction (XRD) results suggested that the crystallinity content of gelatinized WMS and HAS with addition of GSH was higher than that of LAS, and the gelatinized LAS and HAS were mainly of C type and V type, respectively. The resistant starch of LAS (25.15 %) and HAS (34.76 %) increased with GSH addition. The crosslinking between GSH and amylose/amylopectin caused changes in physicochemical properties. This study will provided theoretical basis for GSH usage in food industry.

Investigation of physicochemical properties and structure of ball milling pretreated modified starch-ferulic acid complexes

In this study, the formation mechanism, physicochemical properties, and intermolecular interactions of ball milling pretreated high amylose corn starch (HACS)-ferulic acid (FA) complexes were elucidated by density functional theory (DFT) calculations, and examined their structural and digestive properties. The results showed that the average molecular weight decreased to 92.155 kDa during ball milling pretreatment. The complexation degree of the ball milling pretreated HACS-FA complexes was increased, the relative crystallinity was increased by 11.74 %, and the short-range ordering was significantly improved. Notably, the content of single helix and double helix showed an increasing trend, indicating that HACS-FA complexes had a more compact V-type structure, which corresponded to a 22.39 % increase in resistant starch. DFT calculations further showed that the intermolecular interactions between HACS and FA were mainly hydrophobic, hydrogen bonding, and van der Waals forces. This study is expected to provide a new method for the efficient preparation of HACS-FA complexes.

Variations in the Impact of Gingerols' Conversion to Shogaols on the Properties of Corn Starch with Different Amylose Contents

The polyphenol-starch complex has become a hot research topic since it is evident that this modification method can alter the physicochemical properties of starch as well as improve its nutritional value. This work aimed to evaluate the effect of ginger polyphenol gingerols (GNs) and shogaols (SNs) on the structure of starch with different amylose content (WCS, CS, G56, G80). Textural and rheological results indicated that GNs and SNs had more pronounced inhibitory retrogradation effects for relative low-level amylose starches (WCS and CS) compared to relative high-level amylose starches (G56 and G80). GNs and SNs improved the freeze-thaw stability of starch gels. FT-IR and XRD results revealed that GNs and SNs decreased the (short- and long-range) ordered structure of starches through a non-covalent interaction. Moreover, DSC results proved that the gelatinisation temperature of CS/G56/G80 significantly increased, and the enthalpy (ΔH) decreased by the incorporation of GNs and SNs. Overall, this in-depth study is beneficial in providing valuable pathways for starch-polyphenol interactions to improve the quality of starchy foods.

Resistant Starch Type 5 Formation by High Amylopectin Starch-Lipid Interaction

The formation of resistant starch type 5 (RS5), primarily associated with amylose-lipid complexes, is typically attributed to starches with high-amylose content due to their affinity for lipid interactions. Recently, studies have also investigated the potential of amylopectin-rich starches to form amylopectin-lipid complexes (ALCs), expanding RS5 sources. This study explores the capacity of waxy corn starch (WS), which is rich in amylopectin, to develop ALCs with oleic acid (10% w/w) under different thermal and mechanical conditions. Specifically, WS was treated at temperatures of 80 °C, 85 °C, and boiling, with stirring times of 0 and 45 min. Results demonstrated significant ALC formation, reaching a peak complexation index (CI) of 59% under boiling conditions with 45 min of stirring. Differential scanning calorimetry (DSC) identified a notable endothermic transition at 110 °C, indicating strong ALC interactions. FTIR spectra further evidenced starch-lipid interactions through bands at 2970 cm-1 and 2888 cm-1. X-ray diffraction (XRD) analysis confirmed the presence of orthorhombic nanocrystals in native WS, with ALC samples exhibiting a V-type diffraction pattern, supporting effective complexation. This study advances knowledge on starch-lipid interactions, suggesting ALCs as a promising RS5 form with potential food industry applications due to its structural resilience and associated health benefits.

Effect of sorghum bran addition on antioxidant activities, sensory properties, and in vitro starch digestibility of Chinese southern-style steamed bread

BACKGROUND

Chinese steamed bread (CSB) is one of the most important staple foods in China and is also popular in South-East Asia. Developing functional CSB could improve people's resistance to inflammatory and non inflammatory diseases. This work investigated the effect of sorghum bran addition on antioxidant activities, sensory properties, and in vitro starch digestibility of Chinese southern-style steamed bread (CSSB).

RESULTS

In this study, the enhanced CSSB with 0-200 g kg-1 of fine black and tannin (sumac) sorghum bran addition was developed. A small change in phenol content and antioxidant activity was observed at various stages in the processing procedure before steaming. Moreover, a high retention of antioxidant phenolics CSSB with sorghum bran addition was observed. Sorghum bran addition significantly increased the total phenol content and antioxidant activity of CSSB by 4.5-10 times, on average, relative to control. Sorghum bran addition significantly also increased the content of resistant starch, and significantly decreased in vitro starch digestibility in CSSB; these effects were likely due to the joint inhibitory effect of tannins and ferulic acid on starch digestibility. Interestingly, the sorghum bran breads scored higher or similar to control in sensory color preference and overall appearance, but lower on most textural and mouthfeel attributes.

CONCLUSION

Sorghum bran addition significantly increased the antioxidant activity of CSSB and significantly decreased starch digestibility. Moreover, the color and appearance properties were maintained or improved. However, the sensorial textural attributes were negatively impacted by the sorghum bran substitutions. Strategies to improve the texture of bran-fortified breads would likely enhance their consumer acceptability. © 2024 Society of Chemical Industry.

Structural properties and antioxidant capacity of different aminated starch-phenolic acid conjugates

Different aminated starch (AS) [EEAS (introducing ethylenediamine into starch using cross-linking-etherification-amination method (CEA)), EPAS (introducing o-phenylenediamine using CEA), OEAS (introducing ethylenediamine using cross-linking-oxidation-amination method (COA)), and OPAS (introducing o-phenylenediamine using COA)] were synthesized. The AS-phenolic acids [gallic acid (GA), syringic acid (SA), and vanillic acid (VA)] conjugates were prepared by laccase-catalyzed reaction. The grafting efficiency of EEAS on GA, SA, and VA was 36.59%, 69.71%, and 68.85%, respectively. SA reduced the maximum depolymerization rate of EEAS. The relative crystallinity of EEAS and EPAS grafted phenolic acid increased, and their particles showed severe breakage in appearance. OEAS-phenolic acid conjugates lost its granular structure and behaved as flakes and lumps, while the surface of OPAS-phenolic acid conjugates remained smooth after grafting phenolic acid. GA increased the DPPH· scavenging efficiency of EEAS from 16.12% to 79.92%. The increased antioxidant capacity of the conjugates suggested that AS-phenolic acids conjugates have high potential for applications.

Removal of internal lipids enhances the effect of proanthocyanidins on maize starch retrogradation

Internal lipids of normal amylose (NMS) and two high amylose (HMS56, HMS72) maize starches were removed to investigate the effect of proanthocyanidins (PA) on starch short-term (1 d) and long-term (21 d) retrogradation. Removal of internal lipids decreased the degree of retrogradation in PA-starch complexes after 1 d and 21 d retrogradation. The relative crystallinity (RC) of PA-NMS, PA-HMS56 and PA-HMS72 without internal lipid complexes after short-term retrogradation decreased by 5.46 %, 6.47 % and 7.52 % when the addition of PA was 10 %, respectively, compared with corresponding samples without PA. Compared with PA-native starch complexes, PA-starch without internal lipids complexes had lower correlation length (ξ) and tended to form smaller polymeric assemblies suggesting that the size of aggregates growing within gels was decreased because more PA molecules impeded the reformation of ordered starch structures. Removal of internal lipids exposed hydrogen bonds and the cavities of amylose, promoting the interaction between PA and amylose and more formation of PA-amylose complexes, which in turn reduced amylose available for crystal nucleus formation delaying retrogradation. Overall, retrogradation could further slow down by PA after internal lipid removal, which provided a new perspective for enhancing the modification effect of PA on starch.

Research progress on the regulation of starch-polyphenol interactions in food processing

Starch is a fundamental material in the food industry. However, the inherent structural constraints of starch impose limitations on its physicochemical properties, including thermal instability, viscosity, and retrogradation. To address these obstacles, polyphenols are extensively employed for starch modification owing to their distinctive structural characteristics and potent antioxidant capabilities. Interaction between the hydroxyl groups of polyphenols and starch results in the formation of inclusion or non-inclusion complexes, thereby inducing alterations in the multiscale structure of starch. These modifications lead to changes in the physicochemical properties of starch, while simultaneously enhancing its nutritional value. Recent studies have demonstrated that both thermal and non-thermal processing exert a significant influence on the formation of starch-polyphenol complexes. This review meticulously analyzes the techniques facilitating complex formation, elucidating the critical factors that dictate this process. Of noteworthy importance is the observation that thermal processing significantly boosts these interactions, whereas non-thermal processing enables more precise modifications. Thus, a profound comprehension and precise regulation of the production of starch-polyphenol complexes are imperative for optimizing their application in various starch-based food products. This in-depth study is dedicated to providing a valuable pathway for enhancing the quality of starchy foods through the strategic integration of suitable processing technologies.

Rheological properties, multiscale structure, and in vitro digestibility of a maize starch-konjac glucomannan-bamboo leaf flavonoid complex modified by dynamic high-pressure microfluidization

The effects of dynamic high-pressure microfluidization (DHPM) treatment on the rheological properties, multiscale structure and in vitro digestibility of complex of maize starch (MS), konjac glucomannan (KGM), and bamboo leaf flavonoids (BLFs) were investigated. Compared with MS, the MS-KGM-BLF complex exhibited reduced viscosity and crystallinity, along with increased lamellar thickness to 10.26 nm. MS-KGM-BLF complex had lower viscosity after DHPM treatment. The highest ordered structure and crystallinity were observed at 50 MPa, with the α value increasing from 3.40 to 3.59 and the d value decreasing from 10.26 to 9.81 nm. However, higher DHPM pressures resulted in a decrease in the α value and an increase in the d value. The highest gelatinization enthalpy and resistant starch content were achieved at 100 MPa DHPM, while the fractal structure shifted from surface fractal to mass fractal at 150 MPa. This study presents an innovative method for enhancing the properties of MS.

Understanding the multiscale structure and in vitro digestibility changes of corn starch-ferulic acid complexes induced by high hydrostatic pressure

High hydrostatic pressure (HHP) was used to synthesize corn starch (CS) and ferulic acid (FA) complex (CS-FA). Its effects on the structure of the complex at multiple scales and its digestibility were examined. The results demonstrated that HHP significantly influenced the digestibility of the CS-FA complex, decreasing the content of rapidly digestible starch (RDS) while increasing slowly digestible starch (SDS) and resistant starch (RS). Notably, the combined SDS and RS content in the HHP-treated CS-FA complex with 2.0 % FA addition (38.13 %) was significantly higher (p < 0.05) than those in the CS-FA complex without HHP treatment (29.21 %) and pure CS (21.72 %). The results indicated that HHP treatment reduced the enthalpy change (ΔH), number of short-range order structures, and relative crystallinity (RC) while increasing the average particle size of these CS-FA complexes. This treatment also increased the proportion of amorphous starch regions and the degree of agglomeration between the starch and FA. HHP treatment-induced CS-FA complexes exhibited a denser fractal structure and higher short-range order, affecting the interaction sites between the starch and digestive enzymes. These findings suggest the potential application of HHP treatment and FA in modulating the postprandial glycemic response to starchy food.

Effect of adding various supplements on physicochemical properties and starch digestibility of cooked rice

This study investigated the physicochemical modifications of cooked rice caused by adding various supplements (rapeseed oil, dried wasabi powder, and dried chili pepper powder). The physicochemical and digestive properties of treated cooked rice were analyzed using multiple techniques to determine the impact of supplements on the rice quality, including its starch digestibility. All samples with added supplements showed an increase in surface firmness (0.77-0.95 kg·m/s2 (N)) and a decrease in thickness (2.23-2.35 mm) and surface adhesiveness (1.43-7.22 J/m3). Compared to the control group, two absorption peaks at 2856 and 1748 cm-1 and new signals at 1683 and 1435 cm-1 appeared in the Fourier transform infrared (FTIR) spectroscopy. Analysis of FTIR results revealed that the interaction force was mainly through noncovalent interactions. Moreover, adding supplements increased the resistant starch (RS) levels in all samples. Scanning electron microscopy (SEM) suggested that oil-enriched phases, proteins, and polyphenols could cause large agglomeration and loose gel structure. These results suggested the formation of amylose-guest molecule complexes, which may influence starch functionality. Our work could provide insight into the starch-supplement interactions and the key factors affecting starch digestibility.

Potential Antidiabetic, Antioxidative and Antiproliferative Properties of Functional Wheat Flour Muffins Enriched with White Clover Flowers (Trifolium repens L.)

The aim of the study was to evaluate the functional properties of muffins fortified with white clover flowers (Trifolium repens L.), which were added to the dough in the following amounts: (i) 0% (control); (ii) 2.5%; (iii) 5.5%; (iv) 7.5%; and (v) 10%. The organoleptic properties were assessed by a panel of consumers. Additionally, the following parameters were also tested: basic chemical composition, total polyphenols, the antioxidant activity together with antiproliferative effects on the A375 melanoma cell line, starch nutritional fractions and the in vitro glycemic index. As a result, replacing wheat flour with white clover flour significantly affected the color, aroma and taste of the muffins. The content of proteins, fats, total ash, dietary fiber, resistant starch (RS), slowly digestible starch (SDS),total polyphenols and antioxidant activity increased statistically significantly with the elevated amount of white clover flour added to the dough. At the same time, the content of free glucose (FG), rapidly available glucose (RAG) and rapidly digestible starch (RDS), the value of the in vitro glycemic index and the viability of melanoma cancer cells decreased significantly. The muffins enriched with white clover flowers might constitute an interesting proposition and extension of the existing assortment of confectionery products.

Effects of varied preparation processes on polyphenol-rice starch complexes, in vitro starch digestion, and polyphenols release

This study synthesized composite samples incorporating four representative polyphenolic structures, gallic acid (GA), quercetin (QC), resveratrol (RES), and magnolol (MN), with rice starch using various preparation processes, including the addition of polyphenols and alteration of temperature and pH, via co-gelatinization. Subsequently, the complexation rates, starch digestion properties, and polyphenol release during in vitro digestion were examined. The results indicated that both the preparation process and structural variations of polyphenols affected starch digestion and polyphenol release by modulating the complexation. All polyphenols displayed inhibitory effects on rice starch digestion, with GA being the most efficient polyphenol. Additionally, rice starch exhibited a protective effect against RES during in vitro digestion, as rice starch-coated RES reduced the damage from stomach acids. Overall, these findings may help optimize the processing conditions for the synthesis of polyphenol-rice starch-based food products.

Physiological potential of different Sorghum bicolor varieties depending on their bioactive characteristics and antioxidant potential as well as different extraction methods

A comprehensive study of sorghum bran and flour was performed to explore the secondary metabolite profiles of differently coloured genotypes and to evaluate the variability in the antioxidant properties based on differences in polarity and solubility. This research included one red variety and one white variety. Among the samples, the red variety contained significantly greater amounts of secondary metabolites than did the white variety, with total polyphenol contents of 808.04 ± 63.89 mg.100 g-1 and 81.56 ± 3.87 mg.100 g-1, respectively. High-molecular-weight condensed tannin-type flavonoid extracts with high antioxidant activity were obtained by using relatively low-polarity acetone-water solvents, which was reflected by the measured antioxidant values. Among the methods used, the electron-donating Trolox equivalent antioxidant assay provided the highest antioxidant capacity, with values ranging from 118.5 to 182.6 μmol g-1 in the case of the red variety, in accordance with the electron donor properties of condensed tannins. Key secondary metabolites were identified using MS techniques and quantified using HPLC. Catechin and procyanidin B1 were found in the red variety at concentrations of 3.20 and 96.11 mg.100 g-1, respectively, while the concentrations in the white variety were under the limit of detection. All four tocopherols were found in sorghum, with the red variety containing a higher amount than the white variety, but the vitamin B complex concentrations were higher in the white variety. Overall, the red sorghum variety proved to be a better source of secondary metabolites with potential health benefits and could be used as a nutrient-rich food source.

High-Resistant Starch Based on Amylopectin Cluster via Extrusion: From the Perspective of Chain-Length Distribution and Structural Formation

Resistant starch (RS) has the advantage of reshaping gut microbiota for human metabolism and health, like glycemic control, weight loss, etc. Among them, RS3 prepared from pure starch is green and safe, but it is hard to achieve structural control. Here, we regulate the crystal structure of starch with different chain-length distributions (CLDs) via extrusion at low/high shearing levels. The change in CLDs in extruded starch was obtained, and their effects on the fine structure (Dm, dBragg, dLorentz, degree of order and double helix, degree of crystal) of RS and its physicochemical properties were investigated by SAXS, FTIR, XRD and 13C NMR analyses. The results showed that the RS content under a 250 r/min extrusion condition was the highest at 61.52%. Furthermore, the crystalline system induced by high amylopectin (amylose ≤ 4.78%) and a small amount of amylose (amylose ≥ 27.97%) was favorable for obtaining a high content of RS3-modified products under the extruding environment. The control of the moderate proportion of the A chains (DP 6-12) in the starch matrix was beneficial to the formation of RS.

Structural, physicochemical, and digestive properties of enzymatic debranched rice starch modified by phenolic compounds with varying structures

The physicochemical properties of starch and phenolic acid (PA) complexes largely depend on the effect of non-covalent interactions on the microstructure of starch. However, whether there are differences and commonalities in the interactions between various types of PAs and starch remains unclear. The physicochemical properties and digestive characteristics of the complexes were investigated by pre-gelatinization of 16 structurally different PAs and pullulanase-modified rice starches screened. FT-IR and XRD results revealed that PA complexed with debranched rice starch (DRS) through hydrogen bonding and hydrophobic interaction. Benzoic/phenylacetic acid with polyhydroxy groups could enter the helical cavities of the starch chains to promote the formation of V-shaped crystals, and cinnamic acid with p-hydroxyl structure acted between starch chains in a bridging manner, both of which increased the relative crystallinity of DRS, with DRS-ellagic acid increasing to 20.03 %. The digestion and hydrolysis results indicated that the acidification and methoxylation of PA synergistically decreased the enzyme activity leading to a decrease in the digestibility of the complexes, and the resistant starch content of the DRS-vanillic acid complexes increased from 28.27 % to 71.67 %. Therefore, the selection of structurally appropriate PAs can be used for the targeted preparation of starch-based foods and materials.

Structural changes of rice starch-anthocyanins complexes (V-type) and its impact on gut microbiotas and potential metabolic pathways during in vitro fermentation

This study explored the differences in the in vitro fermentation properties of rice starch (RS) and rice starch-anthocyanins complexes (RS-A). Structural characterization suggested that RS and RS-A complexes showed a V-type crystalline structure. The degree of order (DO) and degree of double helix (DD) values of RS and RS-A complexes were enhanced after fermentation. Moreover, the RS-A complexes could improve the relative abundance of Bacteroidetes, Ruminococcaceae, and up-regulate gut microbiota diversity to maintain gut homeostasis. Relative abundance of potential metabolic pathways, such as energy metabolism, digestion system, and carbohydrate degradation overexpressed in the presence of RS-A complexes. The results demonstrated that the RS-A complexes had slower fermentation rates contributing to the transport of the formed short-chain fatty acid (SCFA) to the end of the colon and that the crystallinity might be a factor influencing the utilization of the starch matrix by the gut microbiota for SCFA formation.

Polyphenol recovery from sorghum bran waste by microwave assisted extraction: Structural transformations as affected by grain phenolic profile

Sorghum milling waste stream (bran), contains diverse phenolic compounds with bioactive properties. The study determined the potential of microwave assisted extraction (MAE) to recover the bran phenolic compounds. Red, white, and lemon-yellow pericarp sorghum brans were subjected to MAE and phenolic yield and structural transformation vs conventional extraction (control) assessed by UPLC-MS/MS, Folin-Ciocalteu and Trolox equivalent antioxidant capacity methods. Phenols yield increased from 3.7-20.3 to 12.6-75.5 mg/g, while antioxidants capacity increased average 3.3X in MAE extracts vs controls. Hydroxycinnamic acids increased most dramatically (3.0-32X) in MAE extracts (0.08-2.64 to 2.57-8.01 mg/g), largely driven by release of cell-wall derived feruloyl- and coumaroyl-arabinose. MAE hydrolyzed flavonoid glycosides into aglycones, and depolymerized condensed flavonoid heteropolymers into flavanones, flavanols and (deoxy)anthocyanidins. Thus, MAE dramatically enhances yield of valuable phenolics from sorghum bran waste, but also alters the phenolic profile in ways that may influence their chemical and biological properties.

Persimmon leaf polyphenols as potential ingredients for modulating starch digestibility: Effect of starch-polyphenol interaction

The interaction mode between persimmon leaf polyphenols (PLP) and corn starch with different amylose content and its effect on starch digestibility was studied. Results of iodine binding test, TGA, and DSC revealed that PLP interacted with starch and reduced the iodine binding capacity and thermal stability of starch. High amylopectin corn starch (HAPS) interacted with PLP mainly via hydrogen bonds, since the FT-IR of HAPS-PLP complex showed higher intensity at 3400 cm-1 and an obvious shift of 21 cm-1 to shorter wavelength, and the chemical shifts of protons in 1H NMR and the shift of C-6 peak in 13C NMR of HAPS moved to low field with the addition of PLP. Results of 1H NMR also showed the preferential formation of hydrogen bonds between PLP and OH-3 of HAPS. Different from HAPS, PLP formed V-type inclusion complex with high amylose corn starch (HAS) because XRD of HAS-PLP complex showed characteristic feature peaks of V-type inclusion complex and C-1 signal in 13C NMR of PLP-complexed HAS shifted to low field. Interaction with PLP reduced starch digestibility and HAS-PLP complex resulted in more resistant starch production than HAPS-PLP complex. To complex PLP with starch might be a potential way to prepare functional starch with slower digestion.

Interactions between corn starch and lingonberry polyphenols and their effects on starch digestion and glucose transport

This study investigated the interaction mechanism between corn starch (CS) and lingonberry polyphenols (LBP) during starch gelatinization, focusing on their effects on starch structure and physicochemical properties. Moreover, it explored the effect of this interaction on starch digestion and glucose transport. The results indicated that LBP interacted non-covalently with CS during starch gelatinization, disrupted the short-range ordered structure of starch, decreased gelatinization enthalpy of starch, and formed a dense network structure. Furthermore, the incorporation of LBP remarkably reduced the digestibility of CS. In particular, the addition of 10 % LBP decreased the terminal digestibility (C∞) from 77.87 % to 60.43 % and increased the amount of resistant starch (RS) by 21.63 %. LBP was found to inhibit α-amylase and α-glucosidase in a mixed manner. Additionally, LBP inhibited glucose transport in Caco-2 cells following starch digestion. When 10 % LBP was added, there was a 34.17 % decrease in glucose transport compared with starch digestion without LBP. This study helps establish the foundation for the development of LBP-containing starch or starch-based healthy foods and provides new insights into the mechanism by which LBP lowers blood glucose.

Structural characteristics and in vitro starch digestibility of oil-modified cooked rice with varied addition manipulations

Lipid has crucial applications in improving the quality of starchy products during heat processing. Herein, the influence of lipid modification and thermal treatment on the physicochemical properties and starch digestibility of cooked rice prepared with varied addition manipulations was investigated. Rice bran oil (RO) and medium chain triglyceride oil (MO) manipulations were performed either before (BC) or after cooking (AC). GC-MS was applied to determine the fatty acid profiles. Nutritional quality was analyzed by quantifying total phenolics, atherogenic, and thrombogenic indices. All complexes exhibited higher surface firmness, a soft core, and less adhesive. FTIR spectrum demonstrated that the guest component affected some of the dense structural attributes of V-amylose. The kinetic constant was in the range between 0.47 and 0.86 min-1 wherein before mode presented a higher value. The lowest glucose release was observed in the RO_BC sample, whereas the highest complexing index was observed in the RO_AC sample, indicating that the dense molecular configuration of complexes that could resist enzymatic digestion was more critical than the quantity of complex formation. Despite the damage caused by mass and heat transfer, physical barrier, intact granule forms, and strengthened dense structure were the central contributors affecting the digestion characteristics of lipid-starch complexes.

Formation and Application of Starch-Polyphenol Complexes: Influencing Factors and Rapid Screening Based on Chemometrics

Understanding the nuanced interplay between plant polyphenols and starch could have significant implications. For example, it could lead to the development of tailor-made starches for specific applications, from bakinag and brewing to pharmaceuticals and bioplastics. In addition, this knowledge could contribute to the formulation of functional foods with lower glycemic indexes or improved nutrient delivery. Variations in the complexes can be attributed to differences in molecular weight, structure, and even the content of the polyphenols. In addition, the unique structural characteristics of starches, such as amylose/amylopectin ratio and crystalline density, also contribute to the observed effects. Processing conditions and methods will always alter the formation of complexes. As the type of starch/polyphenol can have a significant impact on the formation of the complex, the selection of suitable botanical sources of starch/polyphenols has become a focus. Spectroscopy coupled with chemometrics is a convenient and accurate method for rapidly identifying starches/polyphenols and screening for the desired botanical source. Understanding these relationships is crucial for optimizing starch-based systems in various applications, from food technology to pharmaceutical formulations.

Preparation of catechin-starch nanoparticles composites and its application as a Pickering emulsion stabilizer

Starch is a biopolymer commonly used for nanoparticle synthesis. Starch nanoparticles (SNPs) have potential as encapsulation agents and Pickering emulsion stabilizers. Here, we prepared SNPs by dry heating under mildly acidic conditions to encapsulate catechin. Catechin (30 mg) and SNPs (50-150 mg) were dispersed in distilled water and freeze-dried to prepare catechin-SNP composites. Isothermal titration calorimetry and Fourier-transform infrared spectroscopy revealed that the binding of catechin to SNP may involve spontaneous hydrogen bonding and hydrophobic interactions. SNPs exhibited encapsulation efficiency for catechin, with 100 % catechin retention when 150 mg of SNP was used to prepare the composites. The catechin-SNP composites had a particle size of 54.2-74.9 nm. X-ray diffraction analysis revealed the formation of small amounts of inclusion complexes in catechin-SNP composites. As the amount of SNPs added for encapsulation increased, the catechin encapsulated in the SNP composites exhibited higher water solubility and UV stability than the pure catechin. The catechin-SNP composite with 150 mg of catechin exhibited the highest contact angle (51.37°) and formed a stable emulsion without notable droplet size changes. Therefore, catechin-SNP composites improved the encapsulation efficiency, water-solubility, stability of catechins, and Pickering emulsion stability.

Optimization of ultrasonic conditions for improving the characteristics of corn starch-glycyrrhiza polysaccharide composite to prepare enhanced quality lycopene inclusion complex

In this study, based on response surface optimization of ultrasound pre-treatment conditions for encapsulating lycopene, the corn starch-glycyrrhiza polysaccharide composite (US-CS-GP) was used to prepare a novel lycopene inclusion complex (US-CS-GP-Lyc). Ultrasound treatment (575 W, 25 kHz) at 35 °C for 25 min significantly enhanced the rheological and starch properties of US-CS-GP, facilitating the preparation of US-CS-GP-Lyc with an encapsulation efficiency of 76.12 ± 1.76 %. In addition, the crystalline structure, thermal properties, and microstructure of the obtained lycopene inclusion complex were significantly improved and showed excellent antioxidant activity and storage stability. The US-CS-GP-Lyc exhibited a V-type crystal structure, enhanced lycopene loading capacity, and reduced crystalline regions due to increased amorphous regions, as well as superior thermal properties, including a lower maximum thermal decomposition rate and a higher maximum decomposition temperature. Furthermore, its smooth surface with dense pores provides enhanced space and protection for lycopene loading. Moreover, the US-CS-GP-Lyc displayed the highest DPPH scavenging rate (92.20 %) and enhanced stability under light and prolonged storage. These findings indicate that ultrasonic pretreatment can boost electrostatic forces and hydrogen bonding between corn starch and glycyrrhiza polysaccharide, enhance composite properties, and improve lycopene encapsulation, which may provide a scientific basis for the application of ultrasound technology in the refined processing of starch-polysaccharides composite products.

Insights into formation and stability mechanism of V7-type short amylose-resveratrol complex using molecular dynamics simulation and molecular docking

Pre-formed V-type amylose as a kind of wall material has been reported to carry polyphenols, while the interaction mechanism between V-type amylose and polyphenol is still elusive. In this work, the formation and stability mechanism of a V7-type short amylose-resveratrol complex was investigated via isothermal titration calorimetry, molecular dynamics, and molecular docking. The results presented that two stoichiometric ratios of resveratrol to short amylose were calculated to 0.120 and 0.800, and the corresponding main driving force was hydrogen bonding and hydrophobic interaction, respectively. The folding and unfolding conformation of V7-type short amylose chains appeared alternately during the simulation. Resveratrol tended to be bound in the short amylose helix between 40 ns and 80 ns to form a more stable complex. Hydrogen bonds between resveratrol molecule and O6 at the 22nd glucose molecule/O2 at the 24th glucose molecules and hydrophobic interaction between resveratrol molecule and glucose molecules (19th, 20th, 21st and 23rd) could be found.

Effects of purple potato anthocyanins on the in vitro digestive properties of starches of different crystalline types

This study explored the potential of purple potato anthocyanins (PPAs) in regulating the digestive properties of starches of various crystalline types. In vitro digestion experiments indicated that PPAs inhibit the hydrolysis of rice starch (A-type) better than that of garden pea starch (C-type) and potato starch (B-type). Further structural assessment of different PPA-starch systems showed that PPAs and starch likely interact through non-covalent bonds, resulting in structural changes. Microstructural changes observed in the starches were consistent with the in vitro digestion results, and the chain length and proportions of short/long chains in amylopectin molecules affected the binding strengths and interaction modes between PPAs and starch. Hence, the three starches differed in their PPA loading efficiency and digestibility. These discoveries contribute to a deeper understanding of the mechanisms underlying the inhibition of starch digestibility by PPAs. They can aid the formulation of value-added products and low-glycemic-index foods.