Introduction of chlorogenic acid during extrusion affects the physicochemical properties and enzymatic hydrolysis of rice flour

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.

Prebiotic properties of extruded maize starch-caffeic acid complexes: A study from the small intestine to colon in vitro

Recent studies show that starch-polyphenols complexes exert positive effects on gut health, but the probiotic effects of maize starch-caffeic complexes remain underexplored. Therefore, this study aimed to investigate the probiotic effect of maize starch-caffeic complexes from the small intestine to the colon. First, maize starch was extruded with caffeic acid and subjected to in vitro digestion, and the undigested parts were fermented in vitro, and the structural characteristics, short chain fatty acids (SCFAs) and microbiota communities were investigated. Results showed that caffeic acid reduced the long/short-range order of maize starch after extrusion, significantly increasing resistant starch to 30.35 ± 2.36 %. In vitro fermentation indicated that microbiota utilized the amorphous area of the residues first, promoting SCFAs production and the growth of Bifidobacterium and Lactococcus genus. Overall, the probiotic properties of extruded maize starch-caffeic acid complexes suggest they could serve as a functional food for health benefits.

Different effects of polyphenols on hydration, pasting and rheological properties of rice starch under extrusion condition: From the alterations in starch structure

Effects of polyphenols including caffeic acid (CA), ferulic acid (FA), epigallocatechin gallate (EG), tannic acid (TA) and resveratrol (R) on physicochemical and structural properties of rice starch (RS) under the extrusion condition were investigated. Extrusion altered the hydration, pasting and rheological properties of rice starch. Adding FA exhibited the best improvement effect on hydration properties of extruded rice starch (E-RS). All polyphenols possessed different inhibitory effects on short-term retrogradation of E-RS following the order of TA > EG > CA > FA > R. The FA and CA enhanced the viscoelasticity of E-RS, whereas the other polyphenols had opposite influences. Polyphenols mainly interacted with starch via hydrogen bonds, which transformed the crystalline structure to V-type and increased the molecular weight of E-RS. Above different effects were due to polyphenols exhibited varied microstructure and phenolic hydroxyl group content. These findings provided valuable information for preparing extruded starchy foods rich in polyphenols.

Effects of chlorogenic acid on the physicochemical properties, 3D printing characteristics, and anti-digestive properties of sweet potato starch

This study investigated the effects of chlorogenic acid (CA) with different levels (0.5 %-2.0 %) on the printing accuracy, micro-structure, rheological properties, thermodynamic properties, texture, digestion characteristics, and other indicators of sweet potato starch (SPS). Results showed that the printed SPS products with 0.5 % CA exhibited the best structural recovery properties and printing accuracy, with a thixotropic recovery rate of 98.37 %. The addition of CA significantly increased the gelatinization enthalpy of SPS and free water content. The SPS gel with 2.0 % CA exhibited the poorest water-binding ability with free water content of 3.49 %. SPS with higher levels of CA displayed less lamellar structure denser network structure, and more thickened pore walls. The printed SPS product with 2.0 % CA had the lowest hardness (173.64 g), elasticity (0.74), adhesiveness (89.24), and chewiness (65.93). The content of double helix structure in SPS with 0.5 %-1.5 % CA was significantly lower than that in the SPS without CA. All the addition proportions of CA significantly increased the relative crystallinity of SPS, and the SPS with 2 % CA had the highest relative crystallinity (19.96 %). Additionally, CA significantly enhanced the antioxidant ability of printed SPS products. All the levels of CA significantly reduced the RDS content and increased the RS content in the printed SPS products. The RS content in SPS with 2.0 % CA increased by 25.44 %, compared with SPS alone. Therefore, this study provides a theoretical basis for the development of polyphenol-enriched 3D-printed SPS diets for the populations with hyperglycemia and obesity.

Mechanism of hydrocolloids effect on buckwheat starch gels from interaction and structural perspectives: A comparative study

Controlling the digestibility and gel properties of Tartary buckwheat starch (TBS) has become a central issue for functional foods. The effects of hydroxypropyl methylcellulose (HPMC), guar gum (GG) and Konjac glucomannan (KGM) on TBS from the interaction and structural perspectives were studied. Three hydrocolloids increased the peak, trough and final viscosity of TBS in a concentration-dependent manner. Dynamic frequency sweeps and flow state tests indicated that the TBS-hydrocolloid systems exhibited gel-like behaviour, and TBS-HPMC was more thixotropic than the other systems. The addition of hydrocolloids significantly enhanced the hardness and chewiness of the TBS gels. The structural analyses revealed that hydrocolloids did not affect the functional groups or crystalline structure of TBS, but did improve the orderliness of the systems. The interaction mechanism confirmed that hydrogen bonds and electrostatic forces are the main forces in the formation of HPMC and TBS-KGM gels; while hydrogen bonds are dominant in TBS-GG gels. Moreover, HPMC, GG and KGM can each delay starch hydrolysis to some extent, with a hydrolysis rate varying from 78.66 % ± 2.81 % to 44.8 % ± 0.35 % at three addition levels. The results can provide both theoretical and practical insights into the glycaemic control of starch and TBS-based jelly foods production.

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.

Promoting starch interaction with genistein to slow starch digestion using an antisolvent method

Genistein could interact with starch to slow starch digestion by forming starch-genistein complexes. However, genistein had low solubility in water, which hindered the interaction with starch and therefore the formation of the complexes. This study presented a pathway to promote the formation of starch-genistein complexes using an antisolvent method in two steps: (i) adding ethanol to the solution containing starch and genistein to increase genistein solubility, and (ii) evaporating ethanol from the solution to promote genistein interaction with starch. The complexes prepared using this antisolvent method had higher crystallinity (9.45 %), complex index (18.17 %), and higher content of resistant starch (RS) (19.04 %) compared to samples prepared in pure water or ethanol-containing aqueous solution without ethanol evaporation treatment (these samples showed crystallinity of 6.97 %-8.00 %, complex index of 9.09 %-11.4 2%, and RS of 4.45 %-14.38 %). Molecular dynamic simulation results confirmed that the changes in solution polarity significantly determined the formation of starch-genistein complexes. Findings offered a feasible pathway to efficiently promote starch interaction with genistein and in turn mitigate starch digestibility.

Synergistic impact of ultrasound-high pressure homogenization on the formation, structural properties, and slow digestion of the starch-phenolic acid complex

The modification of starch digestibility can be achieved through the formation of complexes with polyphenols. We studied the combined impacts of ultrasound and high-pressure homogenization (UT-HPH) on the structure and in vitro digestibility of rice starch-chlorogenic acid complexes. The development of V-type complexes was supported by our findings, which also showed that synergistic UT-HPH therapy exhibited the highest absorbance value for the complexing index (0.882). Significant alterations in digestibility were also observed in the complexes, with the content of RDS decreasing from 49.27% to 27.06%, the content of slowly SDS increasing from 25.69% to 35.35%, and the percentage of RS increasing from 25.05% to 37.59%. Furthermore, a high positive correlation was found by applying the Pearson correlation coefficient in our research between RS, weight, PSD, and CI. This study presents a sustainable processing approach for utilizing chlorogenic acid in starch-rich food systems.

A comparative study on the gel and structural characteristics of starch from three rice varieties when combined with Mesona chinensis polysaccharides

Mesona chinensis polysaccharide (MCP) has excellent gel-forming characteristic, previous studies showed that MCP could affect the gelling and structural properties of rice starch, but the effect of MCP on rice starch from different types is not clarified. In this study, the effects of MCP on the pasting, rheological, and structural characteristics of glutinous rice starch (GRS), japonica rice starch (JRS), and indica rice starch (IRS) were investigated. The results showed that GRS-MCP has the best viscosity, its peak and final viscosities are higher than JRS-MCP and IRS-MCP. The gel network structure was enhanced by MCP in the order of IRS > JRS > GRS, which was reflected by greater elasticity, higher gel strength and hardness, and less free water in JRS-MCP and IRS-MCP. MCP also enhanced the ordered structure and thermal stability of the three starch gels, which is conducive to their application in the market. These findings provide new theoretical insights to produce rice starch-based foods.

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.

Two-step modification of pullulanase and transglucosidase: A novel way to improve the gel strength and reduce the digestibility of rice starch

The multiscale structure, gel strength and digestibility of rice starch modified by the two-step modification of pullulanase (PUL) pretreatment and transglucosidase (TG) treatment for 6, 12, 18 and 24 h were investigated. The debranching hydrolysis of PUL produced some linear chains, which rearranged to form stable crystalline structures, reducing the digestible starch content, but weakening the gel strength. TG treatment connected some short chains to longer linear chains via α-1,6-glycosidic bonds, generating the structures of linear chain with fewer branches. The short branches promoted the interaction between starch molecules to form a more compact three-dimensional gel network structure, showing higher hardness and springiness. Moreover, these chains could form more stable crystals, reducing the digestible starch content, and the increase of branching degree inhibited digestive enzyme hydrolysis, reducing the digestion rate. The multiscale structure of starch tended to stabilize after TG treatment for 18 h, which could form a gel with stronger strength and lower digestibility than native starch gel. Therefore, the two-step modification of PUL and TG was an effective way to change the structure of rice starch to improve the gel strength and reduce the digestibility.

Effect of different screw speeds on the structure and properties of starch straws

To illustrate the action mechanism of screw speed on the performance of starch-based straws during the extrusion process, starch-based straws at different screw speeds were prepared using a twin-screw extruder and the structures and characteristics were compared. The results indicated that as screw speeds improved from 3 Hz to 13 Hz, the A chain of amylopectin increased from 25.47 % to 28.87 %, and the B3 chain decreased from 6.34 % to 3.47 %. The absorption peak of hydroxyl group shifted from 3296 cm-1 to 3280 cm-1. The relative crystallinity reduced from 13.49 % to 9.89 % and the gelatinization enthalpy decreased from 3.5 J/g to 0.2 J/g. The performance of starch straws did not increase linearly with increasing screw speeds. The starch straw produced at screw speed of 7 Hz had the largest amylose content, the highest gelatinization temperature, the minimum bending strength, and the lowest water absorption rate in hot water (80 °C). Screw speed had a remarkable impact on the mechanical strength, toughness and hydrophobicity of starch-based straws. This study revealed the mechanism of screw speed on the mechanical strength and water resistance of starch straws in the thermoplastic extrusion process and created the theoretical basis for the industrial production of starch-based straws.

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.

Pesticides in rice-based products commercialised in Argentina

People with coeliac disease have a limited diet. Therefore, rice-based products are an ideal alternative. Highlighting this import item, an analytical methodology was validated to determine pesticides in rice-based product samples. The precision was satisfactory for all pesticides since the RSD did not exceed 13% in any case. Regarding recovery, the method had values close to 100%. The limit of quantification was established at 10 µg/kg and the expanded uncertainty was less than 20%. After validation, 80 samples of toasts and rice crackers were analysed. All samples were compliant with the national regulations for dichlorvos and tebuconazole. The pesticide that was present in the highest number of samples was pirimiphos - methyl, but all below the maximum residue limit. From all samples analysed, 38 were positive for at least one pesticide and only one contained four pesticides simultaneously: deltamethrin, pirimiphos-methyl, kresoxim-methyl and epoxiconazole.

Insights into Recent Updates on Factors and Technologies That Modulate the Glycemic Index of Rice and Its Products

Rice is a staple food and energy source for half the world's population. Due to its quick digestion and absorption in the gastrointestinal tract, rice is typically regarded as having a high or medium-high glycemic index (GI); however, this can vary depending on the variety, nutrient compositions, processing, and accompanying factors. This report included a table of the glycemic index for rice and rice products in different countries, which could give an overview and fundamental information on the recent GI of different rice varieties. In addition, latest updates about the mechanism effects of rice nutritional profiles and processing techniques on GI were also provided and discussed. The influence of state-of-the-art GI regulation methods was also evaluated. Furthermore, the effectiveness and efficiency of applied technologies were also given. Furthermore, this review offered some aspects about the potential nutraceutical application of rice that food scientists, producers, or consumers might consider. Diverse types of rice are grown under various conditions that could affect the GI of the product. The instinct nutrients in rice could show different effects on the digestion rate of its product. It also revealed that the rice product's digestibility is process-dependent. The postprandial glucose response of the rice products could be changed by modifying processing techniques, which might produce the new less-digestive compound or the inhibition factor in the starch hydrolysis process. Because of the significant importance of rice, this paper also concluded the challenges, as well as some important aspects for future research.

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.

Changes in physiochemical properties and in vitro digestion of corn starch prepared with heat-moisture treatment

To investigate the effect of heat-moisture treatment (HMT) on the physiochemical properties and in vitro digestibility of corn starch, the pasting behavior, viscoelasticity, thermal properties, long/short range structure, morphology and in vitro digestion of corn starch treated with different HMT conditions (HMT-20, 25, 30, 35 and 40 %) were characterized. Results indicated that after HMT, the pasting and disintegration behaviors of corn starch were affected and correlated with the moisture content. The dynamic viscoelasticity of corn starch was changed, and when glassy conditions were reached, the elastic properties decreased with increasing moisture while the viscous properties increased, especially for the HMT-40 %. The thermal stability of starch was improved by HMT, although the enthalpy of pasting (ΔH) was reduced. Additionally, the HMT processing also promoted the conversion of RDS to SDS and/or RS (SDS and RS increased to 39.80 % and 31.68 % for HMT-40 %, respectively), which might attribute to the rearrangement of free starch molecules. The present work provides a potential approach to make functional starches with healthy properties.

Effects of ultrasound-induced V-type rice starch-tannic acid interactions on starch in vitro digestion and multiscale structural properties

V-type starch-polyphenol complexes, known for their improved physicochemical properties compared to native starch, are challenging to form efficiently. In this study, the effects of tannic acid (TA) interaction with native rice starch (NS) on digestion and physicochemical properties were investigated using non-thermal ultrasound treatment (UT). Results showed the highest complexing index for NSTA-UT3 (∼ 0.882) compared to NSTA-PM (∼0.618). NSTA-UT complexes reflected the V6I-type complex having six anhydrous glucose per unit per turn with peaks at 2θ = 7°, 13°, and 20°. The maxima of the absorption for iodine binding were suppressed by the formation of V-type complexes depending on the concentration of TA in the complex. Furthermore, rheology and particle size distributions were also affected by TA introduction under ultrasound, as revealed by SEM. XRD, FT-IR, and TGA analyses confirmed V-type complex formation for NSTA-UT samples, with improved thermal stability and increased short-range ordered structure. Ultrasound-induced addition of TA also decreased the hydrolysis rate and increased resistant starch (RS) concentration. Overall, ultrasound processing promoted the formation of V-type NSTA complexes, suggesting that tannic acid could be utilized for the production of anti-digestion starchy foods in the future.

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.

Microstructural, physicochemical properties and starch digestibility of brown rice flour treated with extrusion and heat moisture

Effects of heat moisture treatment (HMT), extrusion treatment (ET), and the combination treatment (HMT-ET) on microstructural, physicochemical properties, and starch digestibility of brown rice flour (BRF) were investigated. With a rise in resistant starch (RS), melting temperature, and a decrease in swelling capacity (SC), peak viscosity, and apparent amylose content (AAC), the HMT-ET BRF showed a significant lower expected glycemic index (eGI) than HMT and ET. XRD and FTIR results showed ET, HMT-ET caused the transition of starch crystals from amorphous to crystalline region, suggesting the formation of the starch-lipid complex. The analysis of DSC and RVA proved HMT-ET flours induced starch gelatinization and inhibited the starch retrogradation of BRF compared with the other three flours. Correlation analysis suggested that the combined effect of HMT and ET was response for the changes in physicochemical properties and reduction of in vitro starch digestibility. Overall, the BRF after HMT-ET with improved physicochemical properties and starch digestibility could be better utilized as a good substitute for carbohydrate sources.

Understanding effects of glutelin on physicochemical and structural properties of extruded starch and the underlying mechanism

This work studied effects of different amounts of rice glutelin (RG) on physicochemical and structural properties of extruded rice starch (ERS) and explored the underlying mechanism of interaction between rice starch and RG upon extrusion processing. The results showed that the addition of RG altered the pasting properties, improved the viscoelastic, and increased the water mobility of ERS. The weight loss of ERS decreased from 71.40 % to 62.61 %, while the degradation temperature increased from 290.48 °C to 296.25 °C as the RG content increased from 0 % to 12 %. The complex index of extruded starch-glutelin complexes significantly elevated from 10.40 % to 35.81 % when RG content increased from 6 % to 12 %. Fourier-transform infrared spectra confirmed that RG interacted with starch via Maillard reactions, and the binding strength between RG and starch was enhanced at a higher RG content. Furthermore, results of rheological property and chemical interactions demonstrated that hydrogen bonding, hydrophobic, and electrostatic interaction were formed between RG and starch during extrusion. In summary, the obtained results of this study can further enrich the theory of starch-protein interactions and show the possibility of RG applied in the extruded starchy foods.

Effects of rice protein, soy isolate protein, and whey concentrate protein on the digestibility and physicochemical properties of extruded rice starch

Protein, as the second major component in starchy foods, is crucial for its influence on the physicochemical properties and digestibility of starch. However, the effect of different sources of protein on starch digestibility is still unclear. In this paper, the effects of different sources of proteins (rice protein: RP, soybean isolate protein: SPI, and whey concentrate protein: WPC) on structural features, digestibility, and enzyme activity of extruded rice starch were investigated. The addition of all three proteins reduced the starch digestibility of extrudates. Native SPI and WPC suppressed amyloglucosidase activity, and all three proteins exhibited stronger amyloglucosidase inhibition when hydrolyzed. The rheological properties and Fourier transform infrared spectroscopy results revealed the exogenous proteins and starch interacted through non-covalent bonds and improved the ordered structures in the extrudates. The extrusion process also facilitated the formation of a V-type structure. The sum of SDS and RS content of extrudates was negatively correlated with the content of leached amylose and positively correlated with the ratio of 1047/1022 cm^-1 . These findings suggest that the inclusion of exogenous proteins during extrusion can affect starch digestibility through mechanisms such as the interaction with starch molecules, as well as the inhibition of amylase activity. PRACTICAL APPLICATION: This result indicated that the addition of protein during extrusion not only increased the nutritional value of the extrudate, but also decreased the starch digestibility. Extrusion technology can efficiently produce extruded products with protein, expanding further applications of protein in food and providing new healthy staple food options for special populations, such as diabetic and overweight people.

Effect of Maltodextrin on the Physicochemical Properties and Cooking Performance of Sweet Potato Starch Noodles

Maltodextrin (MD), the hydrolyzed starch product, is a promising alternative ingredient to improve the quality of starch-based foods. The effects of MD on the physicochemical, microstructural, and cooking properties of sweet potato starch (SPS) noodles, as well as the mechanism of SPS-MD interactions, are discussed. Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) results indicated that MD at a suitable concentration can improve the ordered structure of SPS-MD gels. The cooking loss showed lower values of 1.47−2.16% at 0.5−2.0 wt% MD. For the texture properties, an increase in hardness and chewiness occurred at first with the addition of MD, followed by a decreasing trend, showing a maximum value at 2.0 wt% of MD. The pasting and thermal results verified the increased stability of the starch granules with MD < 3 wt%. Additionally, SPS formed a solid-like gel with MD, and the main interaction forces between SPS and MD were hydrogen bonding. The scanning electron microscopy results revealed that the higher concentrations of MD (>3 wt%) loosened the gel structure and markedly increased the pore size. These results help us to better understand the interaction mechanism of the SPS-MD complex and facilitate the development of SPS-based gel products.

Efficient Retention and Complexation of Exogenous Ferulic Acid in Starch: Could Controllable Bioextrusion Be the Answer?

The starch-phenolics complexes are widely fabricated as functional foods but with low phenolics retention limited by traditional liquid reaction and washing systems. In this study, ferulic acid (FA, 5%) was exogenously used in the crystalline form, and it reacted with starch in a high-solid extrusion environment, which was simultaneously controlled by thermostable α-amylase (0-252 U/g). Moderate enzymolysis (21 or 63 U/g) decreased the degree of the starch double helix and significantly increased the FA retention rate (>80%) with good melting and distribution. Although there were no significantly strong chemical bonds (with only 0.17-2.39% FA bound to starch hydrolysate), the noncovalent interactions, mainly hydrogen bonds, van der Waals forces, and electrostatic interactions, were determined by ¹H NMR and molecular dynamics simulation analyses. The phased release of total FA (>50% in the stomach and ∼100% in the intestines) from bioextrudate under in vitro digestion conditions was promoted, which gives a perspective for handing large loads of FA and other phenolics based on starch carrier.

Polyphenol-Modified Starches and Their Applications in the Food Industry: Recent Updates and Future Directions

Health problems associated with excess calories, such as diabetes and obesity, have become serious public issues worldwide. Innovative methods are needed to reduce food caloric impact without negatively affecting sensory properties. The interaction between starch and phenolic compounds has presented a positive impact on health and has been applied to various aspects of food. In particular, an interaction between polyphenols and starch is widely found in food systems and may endow foods with several unique properties and functional effects. This review summarizes knowledge of the interaction between polyphenols and starch accumulated over the past decade. It discusses changes in the physicochemical properties, in vitro digestibility, prebiotic properties, and antioxidant activity of the starch-polyphenol complex. It also reviews innovative methods of obtaining the complexes and their applications in the food industry. For a brief description, phenolic compounds interact with starch through covalent or non-covalent bonds. The smoothness of starch granules disappears after complexation, while the crystalline structure either remains unchanged or forms a new structure and/or V-type complex. Polyphenols influence starch swelling power, solubility, pasting, and thermal properties; however, research remains limited regarding their effects on oil absorption and freeze-thaw stability. The interaction between starch and polyphenolic compounds could promote health and nutritional value by reducing starch digestion rate and enhancing bioavailability; as such, this review might provide a theoretical basis for the development of novel functional foods for the prevention and control of hyperglycemia. Further establishing a comprehensive understanding of starch-polyphenol complexes could improve their application in the food industry.

Modifying the rheological properties, in vitro digestion, and structure of rice starch by extrusion assisted addition with bamboo shoot dietary fiber

This paper investigated the effect of extrusion treatment on the rheological properties, in vitro digestibility, and multi-structure of starch with or without bamboo shoot dietary fiber (BSDF). The viscoelasticity and thixotropy decreased after extrusion treatment, however, they increased after BSDF addition, and decreased with increasing BSDF content. The starch granules became smooth and formed big lumps after extrusion treatment. The dense lumps became loose after the addition of BSDF. Extrusion treatment changed the movement and arrangement of starch chains and thus the relative crystallinity and branching degree decreased by 92.6% and 40.9%, respectively. The disruption of starch further increased rapid digestion starch (RDS) content by 10%. The decreased disruption of starch granules and increased entanglement between BSDF and starch decreased the RDS content. The addition of BSDF is a novelty method to enhance the nutritional properties and control the physicochemical properties of extruded starchy foods.

Effects of carboxymethyl chitosan on physicochemical, rheological properties and in vitro digestibility of yam starch

The effects of carboxymethyl chitosan (CMCS) on the pasting, rheological, and physical properties of yam starch (YS) were investigated. Different concentrations of CMCS were added to the YS, followed by heating paste treatment at 95 °C. Then the blends were subjected to the determination of physicochemical, rheological properties and in vitro digestibility. Our results showed that CMCS reduced the paste viscosity of YS and the addition of CMCS did not effectively inhibit the movement of water molecules. Rheological measurements results showed that YS-CMCS blends exhibited shear thinning behavior. Furthermore, because of the presence of amylose inhibited the swelling of the starch and leaching of amylose, the addition of CMCS had no significant difference between solubility and swelling power of YS.

Enhanced Resistance to Amylolysis in Rice Kernels through Interaction with Chlorogenic Acid

In this study, rice-phenolic acid complexes were prepared by processing rice kernels in chlorogenic acid (CGA) solutions of different concentrations, followed by heating at different adsorption times. An adsorption treatment of 80 °C for 3 h effectively enhanced the complexation of rice samples with CGA (3.86 mg/g) and imparted antioxidant capacities to the complex. An apparent interaction between CGA and rice starch molecules was suggested by electrospray ionization mass spectrometry analysis. Our results revealed that rice samples were functionalized with CGA by modifying their physicochemical properties by increasing swelling ability (9.1%) and breakdown value (24.7%), and retarding retrogradation (−9.8%). The complexation of rice with a high dose of CGA could significantly reduce in vitro and in vivo starch digestibility by 41.9% and 23.0%, respectively, relative to control. This treatment is considered a potential way to confer rice with an increased resistance to digestion, along with desirable pasting properties.