Slow digestion property of octenyl succinic anhydride modified waxy maize starch in the presence of tea polyphenols

Effects of different adzuki bean flour additions on structural and functional characteristics of extruded buckwheat noodles

BACKGROUND

Understanding the effects of different additions of adzuki bean flour (ABF) on structural and functional characteristics of extruded buckwheat noodles is important in developing high-quality starchy foods with desirable glycemic indexes. This study explored how varying amounts of ABF in extruded buckwheat noodles influenced their structural and functional characteristics.

RESULTS

The findings indicated that adding ABF substantially boosted the levels of protein and flavonoids, while decreasing the content of fat and starch. Adding ABF to the noodles extended the optimum cooking time and led to a reduction in both the stickiness of the cooked noodles and the pore size of the starch gel structure, compared with pure buckwheat noodles. Fourier transform infrared spectroscopy indicated that R1047/1022 increased with the content of ABF increased, while R1022/995 decreased. X-ray diffraction showed that the relative crystallinity of buckwheat noodles was enhanced with increasing ABF amount. Adding ABF notably significantly decreased the estimated glycemic index. The buckwheat noodles extruded with 20% ABF addition demonstrated notably stronger α-glucosidase inhibitory effects than those extruded with no ABF addition.

CONCLUSION

The present study demonstrates that the additions of ABF improved the structure and hypoglycemic activity of extruded buckwheat noodles while decreasing starch digestibility, and the optimal value was reached at an ABF addition of 20%. The study might fill gaps in starch noodle research and provide a new strategy for the development of functional food in the food industry. © 2024 Society of Chemical Industry.

Microencapsulation of green tea polyphenols: Utilizing oat oil and starch-based double emulsions for improved delivery

The stability and bioavailability of green tea polyphenols, crucial for their health benefits, are compromised by environmental sensitivity, limiting their use in functional foods and supplements. This study introduces a novel water-in-oil-in-water double emulsion technique with microwave-assisted extraction, significantly enhancing the stability and bioavailability of these compounds. The primary objective of this study was to assess the effectiveness of several encapsulating agents, such as gum Arabic as control and native and modified starches, in improving encapsulated substances' stability and release control. Native and modified starches were chosen for their outstanding film-forming properties, improving encapsulation efficiency and protecting bioactive compounds from oxidative degradation. The combination of maltodextrin and tapioca starch improved phenolic content retention, giving 46.25 ± 2.63 mg/g in tapioca starch microcapsules (GTTA) and 41.73 ± 3.24 mg/g in gum arabic microcapsules (GTGA). Besides the control, modified starches also had the most potent antioxidant activity, with a 45 % inhibition (inh%) in the DPPH analysis. Oat oil was utilized for its superior viscosity and nutritional profile, boosting emulsion stability and providing the integrity of the encapsulated polyphenols, as indicated by the microcapsules' narrow span index (1.30 ± 0.002). The microcapsules' thermal behavior and structural integrity were confirmed using advanced methods such as Differential Scanning Calorimetry (DSC) and Fourier-Transform Infrared Spectroscopy (FT-IR). This study highlights the critical role of choosing appropriate wall materials and extraction techniques. It sets a new standard for microencapsulation applications in the food industry, paving the way for future innovations.

The interaction and physicochemical properties of the starch-polyphenol complex: Polymeric proanthocyanidins and maize starch with different amylose/amylopectin ratios

This study investigated the impact of polymeric proanthocyanidins (PPC) on the physicochemical characteristics of maize starch with varying amylose content, and their potential interaction mechanism. PPC with a lower content (1 %) reduced the viscoelasticity of the high amylose maize starch (HAM) system, inhibited amylose rearrangement, and enhanced its fluidity. However, excessive PPC restrained the interaction between PPC and amylose. In contrast to HAM, PPC improved the gelation ability of waxy maize starch (WAM) as PPC concentration was raised. PPC suppressed the recrystallization of starch during storage, and PPC had a superior inhibition influence on the retrogradation of WAM in comparison to HAM. This indicated that amylopectin was more likely to interact with PPC than amylose. Hydrogen bonds were the main driving force between PPC and starch chains, which was clarified by Fourier transform-infrared, nuclear magnetic resonance, X-ray diffraction, iodine bonding reaction, and dynamic light scattering data. Additionally, the mechanism of interaction between PPC and the two starch components may be similar, and variance in physicochemical attributes can be primarily credited to the percentage of amylose to amylopectin in starch.

Effects of different content of EGCG or caffeic acid addition on the structure, cooking, antioxidant characteristics and in vitro starch digestibility of extruded buckwheat noodles

The effects of different types and content of polyphenol addition on the structure, cooking, antioxidant characteristics and in vitro starch digestibility of extruded buckwheat noodles were investigated in this study. The result showed epigallocatechin-3-gallate (EGCG) was more easily combined with starch to form complex than caffeic acid, and amylose tended to be combined with polyphenols to form more complex. Amylose had a protective effect on polyphenols during extrusion process, which led to a significant increase of polyphenol content and antioxidant activity of extruded noodles. The addition of polyphenol and high amylose corn starch (HACS) improved the cooking quality of extruded buckwheat noodles. The extruded buckwheat noodles with 20 % HACS and 1 % EGCG had the lowest cooking loss of 6.08 %. The addition of EGCG and HACS increased the content of resistant starch and reduced predicted glycemic index (pGI). The noodles with 20 % HACS and 3 % EGCG had the lowest pGI (63.38) and the highest resistant starch (RS) content (61.60 %). This study provides a theoretical basis for the development of low pGI extruded buckwheat noodles.

A review of green methods used in starch-polyphenol interactions: physicochemical and digestion aspects

The interactions of starch with lipids, proteins, and other major food components during food processing are inevitable. These interactions could result in the formation of V-type or non-V-type complexes of starch. The starch-lipid complexes have been intensively studied for over five decades, however, the complexes of starch and polyphenols are relatively less studied and are the subject of recent interest. The interactions of starch with polyphenols can affect the physicochemical properties and its digestibility. The literature has highlighted several green methods such as ultrasound, microwave, high pressure, extrusion, ball-milling, cold plasma etc., to assist interactions of starch with polyphenols. However, comprehensive information on green methods to induce starch-polyphenol interactions is still scarce. Therefore, in light of the importance and potential of starch-polyphenol complexes in developing functional foods with low digestion, this review has summarized the novel green methods employed in interactions of starch with flavonoids, phenolic acids and tannins. It has been speculated that flavonoids, phenolic acids, and tannins, among other types of polyphenols, may have anti-digestive activities and are also revealed for their interaction with starch to form either an inclusion or non-inclusion complex. Further information on the effects of these interactions on physicochemical parameters to understand the chemistry and structure of the complexes is also provided.

Complexation of starch and phenolic compounds during food processing and impacts on the release of phenolic compounds

Phenolic compounds can form complexes with starch during food processing, which can modulate the release of phenolic compounds in the gastrointestinal tract and regulate the bioaccessibility of phenolic compounds. The starch-phenolic complexation is determined by the structure of starch, phenolic compounds, and the food processing conditions. In this review, the complexation between starch and phenolic compounds during (hydro)thermal and nonthermal processing is reviewed. A hypothesis on the complexation kinetics is developed to elucidate the mechanism of complexation between starch and phenolic compounds considering the reaction time and the processing conditions. The subsequent effects of complexation on the physicochemical properties of starch, including gelatinization, retrogradation, and digestion, are critically articulated. Further, the release of phenolic substances and the bioaccessibility of different types of starch-phenolics complexes are discussed. The review emphasizes that the processing-induced structural changes of starch are the major determinant modulating the extent and manner of complexation with phenolic compounds. The controlled release of complexes formed between phenolic compounds and starch in the digestive tracts can modify the functionality of starch-based foods and, thus, can be used for both the modulation of glycemic response and the targeted delivery of phenolic compounds.

Molecular interactions between apigenin and starch with different amylose/amylopectin ratios revealed by X-ray diffraction, FT-IR and solid-state NMR

Starch can readily form complexes with polyphenols. However, its two components, namely amylose and amylopectin, differ significantly in their ability to complex with phenolic compounds. Given that the mechanism of their interaction is still poorly studied, this work investigated intermolecular interactions between apigenin and starch with different amylose/amylopectin ratios using ¹H NMR, FT-IR, XRD, DSC and solid-state NMR. Results showed that corn starch with high amylose/amylopectin ratios had a better complexing ability and higher complexing index with apigenin than amylopectin. Besides, solid-state NMR suggested that the molecular mechanism behind the strong intermolecular interactions between corn starch and apigenin involved hydrogen bonds. Furthermore, the detailed binding sites of hydrogen bonds, that linked by hydroxyl-starch and phenyl-apigenin were also confirmed by ¹H¹³C heteronuclear correlation (HETCOR) spectra. This study revealed the molecular mechanism on amylose/amylopectin complexing with apigenin and provides a theoretical basis for further developing polyphenols in starchy food.

Bioaccessibility and Bioavailability of Diet Polyphenols and Their Modulation of Gut Microbiota

It is generally accepted that diet-derived polyphenols are bioactive compounds with several potentially beneficial effects on human health. In general, polyphenols have several chemical structures, and the most representative are flavonoids, phenolic acids, and stilbenes. It should be noted that the beneficial effects of polyphenols are closely related to their bioavailability and bioaccessibility, as many of them are rapidly metabolized after administration. Polyphenols-with a protective effect on the gastrointestinal tract-promote the maintenance of the eubiosis of the intestinal microbiota with protective effects against gastric and colon cancers. Thus, the benefits obtained from dietary supplementation of polyphenols would seem to be mediated by the gut microbiota. Taken at certain concentrations, polyphenols have been shown to positively modulate the bacterial component, increasing Lactiplantibacillus spp. and Bifidobacterium spp. involved in the protection of the intestinal barrier and decreasing Clostridium and Fusobacterium, which are negatively associated with human well-being. Based on the diet-microbiota-health axis, this review aims to describe the latest knowledge on the action of dietary polyphenols on human health through the activity of the gut microbiota and discusses micro-encapsulation of polyphenols as a strategy to improve the microbiota.

Preparation and Physico-Chemical Characterization of OSA-Modified Starches from Different Botanical Origins and Study on the Properties of Pickering Emulsions Stabilized by These Starches

Native starch (NS) from different botanical origins (native rice/tapioca/oat starch, NRS/NTS/NOS) were hydrophobically modified by octenyl succinic anhydride (OSA), and the octenyl succinic (OS) groups were successfully introduced in the starch molecules which obtained OS-starch (OSRS, OSTS and OSOS) with different levels of modification (0.5%, 1.0%, 1.5%, 2.0%, 2.5%, 3.0%) and degree of substitution (DS). The structural properties of the OS-starch, such as granule size, crystal, wettability and morphology were studied, and the OS-starch was used as particulate stabilizers to produce oil-in-water (O/W) Pickering emulsions. The emulsion index, droplet size distribution and microstructures of Pickering emulsions produced by different OS-starches were compared. OSA modification had almost no effect on the morphology or crystal structure types of three kinds of NS and OS-starch but markedly increased the contact angle and particle size distribution of OSRS, OSTS and OSOS. Esterification reaction of OSA and starch mainly occurred in amorphous regions of starch, and the OSA significantly improved the emulsifying capacity of OSRS, OSTS and OSOS granules and thus stabilized emulsions formed at higher levels (2.5% and 3.0%) of modification of OS-Starch exhibited better stability; the ability of OS-starch to stabilize Pickering emulsion was 3.0% OSRS > 3.0% OSOS > 3.0% OSTS, respectively. Observation and structural properties analysis of OS-starch granules and Pickering emulsion droplets showed that the number and thickness of the starch granules on the oil-water interface of the emulsion droplets increased with improvement of the OSA modification level, and an aggregation state was formed between the OS-starch granules, which was also enhanced with the OSA modification levels. These were all necessary for the Pickering emulsion stabilized by starch granules to remain in a steady state.

Recent advances of octenyl succinic anhydride modified polysaccharides as wall materials for nano-encapsulation of hydrophobic bioactive compounds

Polysaccharides can be esterified with octenyl succinic anhydride (OSA) to form derivatives with amphiphilic properties. The general preparation methods of OSA-polysaccharides are described, especially the aqueous method. The new hydrophobic groups introduced result in OSA-polysaccharides showing higher interfacial properties, better emulsifying stability, higher viscosity, and lower digestibility. There have been advances in the development of OSA-polysaccharides-based nano-encapsulation systems for hydrophobic bioactive compounds in recent years. Nano-encapsulation systems are formed through nanoemulsions, nanocapsules, nanoparticles, micelles, vesicles, molecular inclusion complexes, and so on. This review aims to describe the preparation methods, the structure characterizations, and the physicochemical properties of OSA-polysaccharides as encapsulating agents. In addition, the focus is on the different nano-encapsulation systems based on OSA-polysaccharides as wall materials. Future perspectives will concern OSA-polysaccharides-based nano-encapsulation systems with optimized functional properties for providing higher bioavailability and targeted delivery of various hydrophobic bioactive compounds. © 2022 Society of Chemical Industry.

Short-Clustered Maltodextrin Activates Ileal Glucose-Sensing and Induces Glucagon-like Peptide 1 Secretion to Ameliorate Glucose Homeostasis in Type 2 Diabetic Mice

Reconstructing molecular structure is an effective approach to attenuating glycemic response to starch. Previously, we rearranged α-1,4 and α-1,6-glycosidic bonds in starch molecules to produce short-clustered maltodextrin (SCMD). The present study revealed that SCMD slowly released glucose until the distal ileum. The activated ileal glucose-sensing enabled SCMD to be a potent inducer for glucagon-like peptide-1 (GLP-1). Furthermore, SCMD was found feasible to serve as the dominant dietary carbohydrate to rescue mice from diabetes. Interestingly, a mixture of normal maltodextrin and resistant dextrin (MD+RD), although it caused an attenuated glycemic response similar to that of SCMD, failed to ameliorate glucose homeostasis because it hardly induced GLP-1 secretion. The serum GLP-1 levels seen in MD+RD-fed mice (5.25 ± 1.51 pmol/L) were significantly lower than those seen in SCMD-fed mice (8.25 ± 2.01 pmol/L, p < 0.05). Further investigation revealed that the beneficial effects of SCMD could be abolished by a GLP-1 receptor (GLP-1R) antagonist. These results identify GLP-1R signaling as a critical contributor to SCMD-exerted health benefits and highlight the role of ileal glucose-sensing in designing dietary carbohydrates.

Lipase-polydopamine magnetic hydrogel microspheres for the synthesis of octenyl succinic anhydride starch

Octenyl succinic anhydride (OSA) starch is an important edible additive in the food field, and its synthesis method has attracted much attention. Lipase as a biocatalyst can improve the synthesis efficiency of OSA starch, and significantly inhibit the occurrence of side reactions. However, free lipase has not been widely applied in the synthesis of OSA starch due to the difficulty of separation from starch and poor reusability. In this work, a promising strategy for the synthesis of OSA starch catalyzed by lipase immobilized on polydopamine magnetic hydrogel microspheres (PMHM) is reported. The prepared lipase-polydopamine magnetic hydrogel microspheres (L-PMHM) can be uniformly dispersed in starch slurry, which is conducive to the full contact between lipase and starch. L-PMHM (Km =2.6276 μmol/mL) exhibits better affinity to the substrate than free lipase (Km = 3.4301 μmol/mL). Compared with the OSA starch catalyzed by free lipase (DS = 0.0176), the degree of substitution of OSA starch catalyzed by L-PMHM is up to 0.0277 in a short reaction time. In cyclic catalysis, L-PHMM can remain about 48 % of their original activity after 20 reuses and can be quickly separated from the product. These results suggest that L-PMHM has great potential as a biocatalyst for the efficient synthesis of OSA starch.

Slow digestion-oriented dietary strategy to sustain the secretion of GLP-1 for improved glucose homeostasis

Dysregulated glucose metabolism is associated with many chronic diseases such as obesity and type 2 diabetes mellitus (T2DM), and strategies to restore and maintain glucose homeostasis are essential to health. The incretin hormone of glucagon-like peptide-1 (GLP-1) is known to play a critical role in regulating glucose homeostasis and dietary nutrients are the primary stimuli to the release of intestinal GLP-1. However, the GLP-1 producing enteroendocrine L-cells are mainly distributed in the distal region of the gastrointestinal tract where there are almost no nutrients to stimulate the secretion of GLP-1 under normal situations. Thus, a dietary strategy to sustain the release of GLP-1 was proposed, and the slow digestion property and dipeptidyl peptidase IV (DPP-IV) inhibitory activity of food components, approaches to reduce the rate of food digestion, and mechanisms to sustain the release of GLP-1 were reviewed. A slow digestion-oriented dietary approach through encapsulation of nutrients, incorporation of viscous dietary fibers, and enzyme inhibitors of phytochemicals in a designed whole food matrix will be implemented to efficiently reduce the digestion rate of food nutrients, potentiate their distal deposition and a sustained secretion of GLP-1, which will be beneficial to improved glucose homeostasis and health.

Two 1,4-α-glucan branching enzymes successively rearrange glycosidic bonds: A novel synergistic approach for reducing starch digestibility

Enzymatically rearranging α-1,4 and α-1,6 glycosidic bonds in starch is a green approach to regulating its digestibility. A two-step modification process successively catalyzed by 1,4-α-glucan branching enzymes (GBEs) from Rhodothermus obamensi STB05 (Ro-GBE) and Geobacillus thermoglucosidans STB02 (Gt-GBE) was investigated as a strategy to reduce the digestibility of corn starch. This dual GBE modification process caused a reduction of 25.8 % in rapidly digestible starch fraction in corn starch, which were more effective than single GBE-catalyzed modification with the same duration. Structural analysis indicated that the dual GBE modified product contained higher branching density, more abundant short branches, and shorter external chains than those in single GBE-modified product. These results demonstrated that a moderate Ro-GBE treatment prior to starch gelatinization caused several suitable alterations in starch molecules, which promoted the transglycosylation efficiency of the following Gt-GBE treatment. This dual GBE-catalyzed modification process offered an efficient strategy for regulating starch digestibility.

Study on the structure and digestibility of high amylose Tartary buckwheat (Fagopyrum tataricum Gaertn.) starch-flavonoid prepared by different methods

Tartary buckwheat (Fagopyrum tataricum Gaertn.) is the only food rich in flavonoid bioactive substances in grains. Studies have shown that flavonoids interaction with amylose has an important impact on the physical and chemical properties and structure of starch. In this study, Tartary buckwheat was used as a raw material. It was then threshed with pullulanase, and a high amylose Tartary buckwheat starch flavonoid complex (HBS/BF) was prepared by physical mixing (PM), water bath treatment (WT), acid-base precipitation (AP), microwave treatment (MT), and ultrasonic treatment (UT); the physical and chemical properties were then evaluated. The results show that HBS/BF-UT and HBS/BF-MT have a higher iodine binding rate than HBS/BF-PM; X-ray diffraction results show that HBS/BF-AP has a V-type crystal form, but the relative crystallinity was reduced. Fourier infrared spectroscopy showed that there is no new covalent bond between Tartary buckwheat starch and flavonoids. In vitro digestion showed that adding flavonoid significantly increased the digestibility of Tartary buckwheat starch. PRACTICAL APPLICATION: These results will provide a theoretical basis for further starch anti-digestion mechanisms and the preparation of resistant starch. These steps will provide insights into the application of Tartary buckwheat starch and flavonoids in the food industry.

Food Matrix Effects for Modulating Starch Bioavailability

As the prevalence of obesity and diabetes has continued to increase rapidly in recent years, dietary approaches to regulating glucose homeostasis have gained more attention. Starch is the major source of glucose in the human diet and can have diverse effects, depending on its rate and extent of digestion in the small intestine, on postprandial glycemic response, which over time is associated with blood glucose abnormalities, insulin sensitivity, and even appetitive response and food intake. The classification of starch bioavailability into rapidly digestible starch, slowly digestible starch, and resistant starch highlights the nutritional values of different starches. As starch is the main structure-building macroconstituent of foods, its bioavailability can be manipulated by selection of food matrices with varying degrees of susceptibility to amylolysis and food processing to retain or develop new matrices. In this review, the food factors that may modulate starch bioavailability, with a focus on food matrices, are assessed for a better understanding of their potential contribution to human health. Aspects affecting starch nutritional properties as well as production strategies for healthy foods are also reviewed, e.g., starch characteristics (different type, structure, and modification), food physical properties (food form, viscosity, and integrity), food matrix interactions (lipid, protein, nonstarch polysaccharide, phytochemicals, organic acid, and enzyme inhibitor), and food processing (milling, cooking, and storage).

Synergistic effects of amorphous OSA-modified starch, unsaturated lipid-carrier, and sonocavitation treatment in fabricating of Lavandula angustifolia essential oil nanoparticles

This investigation aims to evaluate the synergistic effects of amorphous OSA-modified starch, unsaturated lipid-carrier (RBD-SFO), and high-energy microfluidization in synergy with the ultrasonic techniques in fabricating of Lavandula angustifolia essential oil (LAF-EO) nanoparticle. GC-MS and SEM techniques were employed to investigate the LAF-EO isolation method used. DLS analysis was employed along with CLSM and TEM techniques to investigate the physicochemical properties of nanoemulsion formulation (NE) matrices. The NE achieved the optimal spherical and size distributions of droplets (125.7 nm), Poly Dispersity Index (PdI) (0.183), and ζ-potential (-40.3 mV) when the contents of the formulation matrix were as follows: OSA-MS (2%), LAF-EO (1%), RBD-SFO (1%), and Tween-80 (1%). The findings of this work provide a new concept about the synergistic effects of amorphous OSA-modified starch and unsaturated lipid carrier as safe-grade macromolecules in the fabricating of LAF-EO nanoparticles. Besides, the application of the ultrasound cavitation phenomenon has been shown to have effective effect in reducing the droplet hydrodynamic diameter along with enhancing the distribution (PdI) and electrokinetic potential of the LAF-EO nanoparticles.

Dietary polyphenols modulate starch digestion and glycaemic level: a review

Polyphenols, as one group of secondary metabolite, are widely distributed in plants and have been reported to show various bioactivities in recent year. Starch digestion not only is related with food industrial applications such as brewing but also plays an important role in postprandial blood glucose level, and therefore insulin resistance. Many studies have shown that dietary phenolic extracts and pure polyphenols can retard starch digestion in vitro, and the retarding effect depends on the phenolic composition and molecular structure. Besides, dietary polyphenols have also been reported to alleviate elevation of blood glucose level after meal, indicating the inhibition of starch digestion in vivo. This review aims to analyze how dietary polyphenols affect starch digestion both in vitro and in vivo. We can conclude that the retarded starch digestion in vitro by polyphenols results from inhibition of key digestive enzymes, including α-amylase and α-glucosidase, as well as from interactions between polyphenols and starch. The alleviation of postprandial hyperglycemia by polyphenols might be caused by both the inhibited starch digestion in vivo and the influenced glucose transport. Therefore, phenolic extracts or pure polyphenols may be alternatives for preventing and treating type II diabetes disease.

Properties and Digestibility of Octenyl Succinic Anhydride-Modified Japonica-Type Waxy and Non-Waxy Rice Starches

Waxy and non-waxy rice starches from japonica type Korean rice varieties were esterified with different levels of octenyl succinic anhydride (OSA), and the molecular structure of amylopectin (AP), digestibility, and emulsion stability were investigated. As OSA levels increased, the degree of substitution, granule size, peak and final viscosities, emulsion stability, and short chain of AP increased. However, the gelatinization temperature and enthalpy, and digestibility decreased. All OSA esterified starches showed a new band at 1723 cm-1, but maintained A-type crystallinity. The DP6-12 of AP in waxy rice starch (WRS) was higher than that in non-waxy rice starch (NRS) with increasing OSA levels. Because the amylose and long chain of AP accessed easily with OSA groups, the digestibility of NRS was lower than that of WRS. The emulsion stability was higher in WRS than in NRS. From the above results, it is suggested that amylose should have a higher affinity with OSA esterification than AP and that the emulsion stability should increase in WRS, but the digestibility should decrease in NRS after OSA modification.

Joint Effects of Granule Size and Degree of Substitution on Octenylsuccinated Sweet Potato Starch Granules As Pickering Emulsion Stabilizers

The granules of sweet potato starch were size fractionated into three portions with significantly different median diameters ( D₅₀) of 6.67 (small-sized), 11.54 (medium-sized), and 16.96 μm (large-sized), respectively. Each portion was hydrophobized at the mass-based degrees of substitution (DS_m) of approximately 0.0095 (low), 0.0160 (medium), and 0.0230 (high). The Pickering emulsion-stabilizing capacities of modified granules were tested, and the resultant emulsions were characterized. The joint effects of granule size and DS_m on emulsifying capacity (EC) were investigated by response surface methodology. For small-, medium-, and large-sized fractions, their highest emulsifying capacities are comparable but, respectively, encountered at high (0.0225), medium (0.0158), and low (0.0095) DS_m levels. The emulsion droplet size increased with granule size, and the number of freely scattered granules in emulsions decreased with DS_m. In addition, the term of surface density of the octenyl succinic group (SD_-OSG) was first proposed for modified starch granules, and it was proved better than DS_m in interpreting the emulsifying capacities of starch granules with varying sizes. The present results implied that, as the particulate stabilizers, the optimal DS_m of modified starch granules is size specific.

The nutritional property of endosperm starch and its contribution to the health benefits of whole grain foods

Purported health benefits of whole grain foods in lowering risk of obesity, type 2 diabetes, cardiovascular disease, and cancer are supported by epidemiological studies and scientific researches. Bioactive components including dietary fibers, phytochemicals, and various micronutrients present in the bran and germ are commonly considered as the basis for such benefits. Endosperm starch, as the major constituent of whole grains providing glucose to the body, has been less investigated regarding its nutritional property and contribution to the value of whole grain foods. Nutritional quality of starch is associated with its rate of digestion and glucose absorption. In whole grain foods, starch digestion and glucose delivery may vary depending on the form in which the food is delivered, some with starch being rapidly and others slowly digested. Furthermore, there are other inherent factors in whole grain products, such as phenolic compounds and dietary fibers, that may moderate glycemic profiles. A good understanding of the nutritional properties of whole grain starch is important to the development of food processing technologies to maximize their health benefits.