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The aim of this study was to investigate and compare the structural and physicochemical properties of native Banxia starch (BXS) and autoclaving-cooling treated Banxia starch (CTBXS) and its related impacts on production of short chain fatty acids (SCFAs) and human gut microbiota by in vitro fecal fermentation. BXS had semicircle to spherical granules, whereas CTBXS exhibited block-shape. According to XRD and TGA, BXS had a C-type crystalline pattern, while CTBXS had a B-type crystalline pattern. CTBXS had better thermal stability than BXS. In addition, BXS exhibited significantly higher solubility and swelling power than CTBXS, and CTBXS had higher content of SDS than BXS. Moreover, BXS and CTBXS could change the composition and abundance of gut microbiota, could also promote the production of SCFAs. This study is beneficial to well understand the in vitro digestion and fecal fermentation behaviors of BXS and CTBXS, and can be developed as a potential functional food with the aim of improving colonic health., (Copyright © 2021. Published by Elsevier B.V.)

The effects of five different drying processes, air drying (AD), sulphur fumigation drying (SFD), hot air drying (HAD), freeze drying (FD) and microwave drying (MWD) for yams in terms of starch-related properties and antioxidant activity were studied. From the results of scanning electron microscopy (SEM), polarized optical microscopy (POM), X-ray diffraction (XRD), and Fourier transform infrared (FT-IR), the MWD sample was found to contain gelatinized starch granules. The FD yam had more slow digestible (SDS) and resistant starches (RS) compared with those processed with other modern drying methods. The bioactive components and the reducing power of the dried yams, were lower than those of fresh yam. When five dried samples were compared by principal component analysis, the HAD and SFD samples were observed to have the highest comprehensive principal component values. Based on our results, HAD would be a better method for yam drying than the more traditional SFD., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

To find new starch sources with particular characteristics, five untraditional starches from zingiberaceae plants were studied about their physicochemical properties, digestibility and anticonstipation activity and compared with starches from traditional sources (potato and corn). All the five starches presented the shape of triangular, with visible thin sheet, which were significantly different from conventional sources. The crystal type of these five starches was B-type pattern. Swelling power at 75 °C was negatively correlated with crystallinity. There was no significant difference in amylose content between starches from rhizome and tuber of Curcuma phaeocaulis Val., while they displayed significant variability in RS content. Starches from rhizome of Curcuma kwangsiensis, Curcuma wenyujin, Curcuma phaeocaulis Val. and Curcuma longa L. possessed much higher resistant starch content (range from 87.06% to 95.40%) and could better prevent constipation than potato and corn starches, which made them potential for managing diabetes and improving defecation conditions. [ABSTRACT FROM AUTHOR]

Four methods were applied to dry yam slices, and then, starches were isolated from dried yam slices. Starch isolated from fresh yam was as the study control, and physicochemical properties and in vitro digestibility of starches were studied. The results showed that the amylose content ranged from 12.62% to 28.25%, water-binding capacity (WBC) from 111.67% to 262.88%, paste clarity from 2.1% to 6.23%, resistant starch (RS) from 66.60% to 88.49% and crystallinity from 11.27% to 25.52%. Compared with the control starch, hot air-drying at 60 °C significantly decreased amylose content, paste clarity, RS and crystallinity, while increasing the WBC. Low levels of rapidly digestible starch and glucose and high RS levels were found in the starch from freeze-drying yam. Digestibility of the starches was significantly correlated with amylose content, WBC, paste clarity and swelling power. The starch samples were divided into three groups by principal component analysis (PCA). [ABSTRACT FROM AUTHOR]

Abstract: The effect of alkali-treatment for 0, 15, and 30 days at 35 °C on amylose content, morphological properties, crystalline properties, swelling power, solubility, absorbance spectra and in vitro digestibility of starches from Dioscorea zingiberensis, Dioscorea persimilis and Dioscorea opposita were investigated. The amylose content of all the three starches decreased after 15 days of alkaline treatment and then increased after 30 days of alkaline treatment. There were similar changes in relative crystallinity for D. zingiberensis and D. persimilis starches. It was observed that the three starches displayed a reduction trend in swelling power with a significant increase in solubility. Adhesion among some of the starch granules was observed after alkali-treatment for 30 days in D. zingiberensis and D. opposita starches, while D. persimilis starch showed some hollows on the granule surface. The rise in the absorbance ratio of 1047/1035 and 1047/1022 cm−1 from FT-IR was observed during alkali-treatment for D. persimilis and D. opposita starches. Alkali-treatment elevated the in vitro digestibility with resistant starch values climbing up from 50.16% to 64.95% and from 66.14% to 70.74% for D. zingiberensis and D. persimilis starches, respectively, but there was no significant change in resistant starch value for D. opposita starch. [Copyright &y& Elsevier]

Abstract: Physicochemical properties (paste clarity, water-binding capacity, swelling power, solubility and thermal properties) and in vitro digestion of starches isolated from ten different Dioscorea plants were investigated. Moisture content ranged from 7.52% to 15.75% and protein content varied between 0.010% and 0.028%. All of the starches gave a typical C-type X-ray diffraction pattern except D.BY (CA-type pattern) and Dioscorea persimilis (B-type pattern) starches. The relative crystallinity of them varied from 12.02% to 51.68%. The starches displayed significant variability in thermal transition temperatures and susceptibility to in vitro digestion, and varied in rapidly digestible starch (RDS), slowly digestible starch (SDS), resistant starch (RS) contents, hydrolysis index (HI) and glycemic index (GI). The ten Dioscorea starch samples can be classified into two major clusters by hierarchical cluster analysis: one cluster with more D.PP, D.BY and D.RC, and another cluster with D. XM, D.M-1, D.M-2, D.TG, D.H, D.CJ and D.J. [Copyright &y& Elsevier]

Different sources of Dioscorea nipponica Makino. were collected from different regions, Funiu, Qingyuan, and Yichun. Starches isolated from the three sources were studied regarding their morphological, physicochemical, and thermal properties. Funiu and Qingyuan starches have larger granules than Yichun starch. The swelling power (85-95°C), solubility (85-95°C), amylose leaching, moisture content, protein content, and starch content were found to be higher compared to the Yichun starch. However, the Yichun starch displayed much higher gelatinization temperatures and enthalpy of gelatinization (Δ Hgel) (1.69 J/g), meanwhile Funiu starch presented the lowest values (0.55 J/g). To, Tp, and Tc values varied from 68.41 to 71.96°C, 73.83 to 77.76°C, and 78.92 to 82.52°C, respectively. Funiu starch with higher digestibility was more susceptible to in vitro starch digestibility than Qingyuan and Yichun starches after 40-180 min, which provided more information about the starch nutritional component. [ABSTRACT FROM AUTHOR]

Traditional Chinese medicines (TCMs), Paeonia suffruticosa Andr. (PSA), Paeonia lactiflora Pall. (PLP), and Curcuma phaeocaulis Val. (CPV) all contained abundant starch in tubers, which have usually been discard as waste in the pharmaceutical industry. In this paper, the intrinsic properties of three TCM starches were studied and the structure-property relationships were analyzed, on the purpose of exploring new starch resource for food and non-food industries. PSA starch with the highest amylose (AM) content showed the lowest water binding capacity (WBC), while the CPV starch showed the contrary. Moreover, the starches differed in granule shape and size. The PSA and PLP starches had larger spherical or elliptic granules, whereas CPV starch possessed the smallest granules in large number among the three starches. PSA starch displayed the typical C-type diffraction pattern, while the PLP and CPV starches were classified as A-type pattern. The degrees of crystallinity of the three TCM starches were about 22.8, 16.6, and 24.2%, respectively. The starch separated from CPV indicated the highest transition temperatures ( To, Tp, and Tc) and gelatinization temperature range ( R) value with lowest peak height indices (PHI), whereas PLP starch showed the lowest transition temperatures and enthalpy of gelatinization (Δ Hgel). [ABSTRACT FROM AUTHOR]

The effect of sulfur fumigation and freeze-drying on the physicochemical and functional properties of Dioscorea opposita Thunb. starch was investigated. Freeze-drying markedly decreased the AM content of starch from 16.68 to 8.59%. Both sulfur fumigation and freeze-drying decreased the protein content but obviously increased the water absorption capacity and swelling power. Sulfur fumigation significantly increased the solubility of starch. Retrogradation tests showed that Chinese yam starch had a poor stability of retrogradation in water, salty, sugar, and acidic medium, but a good stability in alkaline medium. SEM analysis showed that different drying methods had minor effects on the morphological properties of D. opposita cv. Ma starch. Although the pattern of D. opposita cv. Ma starch was C-type and was not affected by drying methods, sulfur-fumigation, and freeze-drying increased the crystalline degree of starches from 23.24 to 25.16% and 34.40%, respectively. A minor difference was found in the Fourier transform infrared spectra of native and treatment starches. After sulfur fumigation and freeze-drying, the peak gelatinization temperatures increased from 71.03 to 76.03°C and 83.07°C, respectively, whereas the gelatinization enthalpy and gelatinization range decreased. [ABSTRACT FROM AUTHOR]

Abstract: The physicochemical, morphological and crystal structure characterization of the starches separated from rhizomes of Dioscorea opposita Thunb. Dioscorea alata Linn., Dioscorea nipponica Makino, Dioscorea bulbifera Linn. and Dioscorea septemloba Thunb. were studied and compared. Amylose content varied between 13.58% and 20.05%. Water-binding capacity, swelling power, solubility and total starch content of starches differed significantly. Scanning electron micrographs revealed that the surface was smooth or rough, the granules were oval to spherical and the size was obviously different. D. nipponica displayed A-type pattern. D. opposita D. alata, D. septemloba and D. bulbifera starches all exhibited C-type crystal. While the crystallinity degree of the starches separated from the five species were about 33.90%, 37.63%, 43.11%, 32.06% and 53.35%, respectively. The gelatinization transition temperatures (T o, T p and T c) and enthalpy of gelatinization (ΔH gel) and peak height index (PHI) were determined. D. OT, D. AL and D. BL starches showed the higher enthalpy of gelatinization. Pasting viscosity of D. OT and D. BL starches were much higher than others. The five plants could be separated into two groups: D. OT, D. AL and D. BL; D. ST and D. NM. [Copyright &y& Elsevier]

The starches studied from the nine Fritillaria species had differently shaped and sized granules but all of them showed the presence of smooth, round, or elliptic-shaped, indicating that the isolation process did not destroyed the starch granules. The nine Fritillaria starches presented different AM content, moisture content, ash content, particle size, swelling power, solubility, water absorption capacity and light transmittance. The starches isolated from Chuan-Beimu species exhibited a higher amount of crude protein content and lower amount of AM than other the groups, which had lower swelling power, higher solubility and light transmittance. All the nine Fritillaria starches had an XRD pattern of the B-type. In addition, F. hupehensis, F. walujewii and F. ussuriensis starches with fairly large-sized or irregular granules had higher Tp and Δ Hgel values than that isolated from the four Chuan-Beimu species. The results obtained yielded information about the possible behavior of these starches when being used in certain applications. Cluster analysis results showed that this classification method based on macromolecule chemical compounds (starch) is original and credible in the quality control of various Beimu. In addition, it provided more information to the authentication systematics taxonomy methods including morphological, histological and molecular biological techniques of Fritillaria species. [ABSTRACT FROM AUTHOR]

The physico-chemical, morphological, thermal, and crystal properties of the starches separated from three different rhizomes of Dioscorea bulbifera Linn. (D.BLH, Hubei; D.BLG1, Guangxitianlin; D.BLG2, Guangxiyulin) were studied and compared. A light microscopic technique was applied in order to quantify the integrity and shape of the starch granules after isolation. Amylose contents of different cultivars were in the range of 12.18-14.34%. Moisture content, ash content, swelling power, solubility, water-binding capacity, and protein content of starches also differed significantly. The three different D. bulbifera starches all showed a typical C-type pattern with crystallinity 45.36, 27.10, and 53.04%, corresponding to D.BLH, D.BLG1, and D.BLG2, respectively. The starch separated from the three starches above showed gelatinization range of 10.09, 11.55, and 7.26°C, corresponding to D.BLH, D.BLG1, and D.BLG2. The enthalpy of gelatinization (Δ Hgel) ranged from 1.28 to 3.11 J/g. Correlation analysis displayed that amylose content and relative crystallinity values were important in determining thermal starches. [ABSTRACT FROM AUTHOR]

Abstract: Comparative studies on glucoamylase hydrolysis of A-type Zea mays L., B-type F. ussuriensis Maxim., and C-type Dioscorea opposita Thunb. were carried out by scanning electron microscope (SEM), X-ray diffractometer (XRD), Fourier transform infrared (FT-IR) spectra and differential scanning calorimetry (DSC). Maize, Fritillaria, Dioscorea starches were hydrolyzed with glucoamylase for 2, 4, 8, 12 and 24h, respectively. The SEM and XRD results revealed that A-type, B-type starch and C-type starch displayed different hydrolysis mechanisms. A-type starch was digested with enzyme penetrating into starch granules through natural pores on the surface and disrupted the interior of the starch granules. The glucoamylase worked by attacking the surface of B-type starch and forming cracks. When endo-corrosion occurred, the internal part of the granule was corroded through small cracks. However, the glucoamylase primarily attacked the interior of the C-type starch granules and then the exterior of starch granules. FT-IR confirmed that the amorphous regions in the starch granules are firstly hydrolyzed and could be hydrolyzed completely as long as the hydrolysis time is sufficient. The transition temperatures and enthalpy of gelatinization (ΔH gel) were determined using DSC. According to the gelatinization parameters, it could be further proved amorphous and crystalline structures were hydrolyzed. [ABSTRACT FROM AUTHOR]

Abstract: The starches separated from five different medicinal plants-Fritillaria (Fritillaria thunbergii Miq., Fritillaria ussurensis Maxim., Fritillaria pallidifloca Schrenk, Fritillaria cirrhosa D. Don and F. hupehensis Hsiao et K.C. Hsia) were investigated for morphological, thermal, crystal, swelling power, solubility and water-binding capacity properties. The thunbergii F. and ussurensis F. starches had a granule size ranging between 5 and 30μm and the shape of the granules was oval and elliptic, while the other Fritillaria starches had the granule size from 5 to 40μm and the granule shape varied from oval to irregular or cuboidal. The transition temperatures and enthalpy of gelatinization (ΔH gel) were determined using differential scanning calorimetry (DSC). Cirrhosa F. starch showed the highest ΔH gel values (9.18J/g) while hupehensis F. starch showed the lowest values (5.90J/g). All Fritillaria starches showed a typical B-type pattern with the degree of crystallinity of between 43.8% and 52.3%. Cirrhosa F. starch had the highest swelling power and the lowest solubility while the values for hupehensis F. starch were contrary. Hupehensis F. starch showed the highest water binding capacity and it was the lowest for pallidifloca F. starch. [Copyright &y& Elsevier]

Abstract: Fritillaria, an important medicinal plant, are widely utilized in the pharmaceutical industry. The bulbs of Fritillaria contain plenty of starches which have been ignored and wasted during the isolation and separation of the small-molecule bioactive ingredients. With the development of food and medicine industry, new starches with different properties have been paid more and more attention. The object of this work is to study the basic physicochemical properties of starch contained in the Fritillaria bulbs. The results revealed that the crystal type of the three Fritillaria starches was the characteristic B-type which was in agreement with the crystal type of potato starch. The results of scanning electron microscope showed that the size of the Fritillaria thunbergii and Fritillaria ussurensis starch granules ranged from 5 to 30μm, while the Fritillaria pallidifloca starch granules ranged from 5 to 40μm. The shape of the three Fritillaria starches was also different from each other. The starch separated from F. ussurensis showed the highest enthalpies of gelatinization (ΔH gel) and the lowest transition temperature (T o, T p, and T c), while the starch from F. thunbergii showed the highest transition temperature, peak height indices (PHI) and the lowest gelatinization temperature range (R). [Copyright &y& Elsevier]

Structural and functional properties of starches isolated from Ginkgo biloba L. (GBL), Angelica dahurica (Fisch. ex Hoffm.) Benth. et Hook. f. (ADB) and Bletilla sfriata (Thunb.) Reiehb. f. (BSR) have been studied using a range of characterization methods including amylose content, water-binding capacity, paste clarity, scanning electron microscopy (SEM) and light microscopy, X-ray diffraction (XRD), amylose leaching, differential scanning calorimetry (DSC) and in vitro digestion. Considerable differences in these properties were observed. Amylose content varied from 16.7% to 30.5%, while paste clarity was in the range of 8.03–25.3%. Moreover, the shape of starch granules varied from spherical, elliptical to irregular or polygonal with different sizes. ADB displayed a B-type pattern, while GBL and BSR showed a C-type pattern. In addition, amylose leaching (AML) varied linearly with temperature for BSR, while the AML of other samples increased gradually below 60 °C, but increased dramatically beyond 60 °C. The three starch samples had similar gelatinization temperature ranging from 63.0 to 76.7 °C, but showed lower enthalpy values (0.90–3.96 J/g) than most of conventional starch. GBL and ADB possessed much higher slowly digested starch (SDS) content in vitro digestion, which made them suitable candidates for dietary starch. [ABSTRACT FROM AUTHOR]

Abstract: The physico-chemical, morphological, thermal, and crystal properties of the starches separated from three different bulbs of Fritillaria cirrhosa (Song Beimu, Qing Beimu and Lu Beimu) were studied and compared. The starch separated from Song Beimu showed the highest transition temperatures (onset temperature (T o); peak temperature (T p); conclusion temperature (T c)), peak height indices (PHI), gelatinization temperature range (R) and enthalpies of gelatinization (ΔH gel). However, the starch separated from Qing Beimu had the lower transition temperature (T o, T p, and T c) and R values. Swelling power, solubility, amylose content and turbidity values were observed to be higher for Delavayi F. starch and it was lower for Przewalskii F. The mean particle diameter of starches from three different F. cirrhosa were 30.65μm, 28.43μm and 30.65μm for Qing Beimu, Song Beimu and Lu Beimu. The shape of starch granules varied from oval to irregular or cuboidal. The starch isolated from Lu Beimu had larger oval or round granules than the starches separated from the other two F. cirrhosa. The three different F. cirrhosa starches all showed a typical B-type pattern. The degree of crystallinity of three Fritillaria starches was about 42.6%, 38.4% and 47.5%, respectively, corresponding to Qing Beimu, Song Beimu and Lu Beimu. [Copyright &y& Elsevier]

Abstract The starch-palmitic acid complex was prepared by the reaction of different concentrations (0.1%–5.0%) of palmitic acid and yam starch. In order to find out the effects of concentration of palmitic acid on the properties of the complex, the physicochemical properties, morphological properties, freeze-thaw stability, antioxidant activity and bile acid binding capacity of complexes were studied. It was found that with the increase of palmitic acid concentration, the complex index of starch-fatty acid increased first and then decreased. When the concentration of palmitic acid was 2%, the complex index was the highest (26.39%). The crystal type has gradually changed from Ca type into mixtures of V-type pattern and B-type pattern when introduced palmitic acid. The water binding capacity, solubility, swelling power and paste clarity were decreased, while the content of resistant starch and freeze-thaw stability were obviously increased. Compared with the native starch, the antioxidant activity and bile acid binding capacity of the complex were significantly increased. All the result showed that the concentration of palmitic acid has a great influence on the physicochemical properties of modified starch and the starch-palmitic acid complexes have higher ability of controlling cholesterol and improving the anti-oxidant activity than native yam. Highlights • Different concentration of palmitic acid-yam starch complexes were prepared. • When the concentration of palmitic acid was 2%, the complex index was the highest. • The palmitic acid-yam starch complex exhibited significant antioxidant activity and bile acid binding capacity. • 2% should be the optimum concentration of palmitic acid combined with yam starch. [ABSTRACT FROM AUTHOR]

Physicochemical properties and gastroprotection of four types of resistant starch (RS) including native (RS2), retrograded (RS3), cross-linked with sodium trimetaphosphate/sodium tripolyphosphate (RS4) and complexed with palmitic acid (RS5) resistant starches were investigated and compared. After modification, there was no significant change in RS content in addition to the decline in the RS3. The crystal type of RS2 was B-type pattern. During modification, RS3 and RS5 lost their granular shape and crystalline structure collapsed, while RS4's granular structure was not destroyed and maintained the B-type crystalline pattern. In addition, gastroprotective effect of the four types of RS on gastric ulcer induced by ethanol in mice was investigated. Pretreatment with the four types of RS had an obvious gastroprotection compared to ethanol group that significantly attenuated the level of histopathological injury and ulcerative lesion index (ULI). Also, the excess malondialdehyde (MDA) and the reduced superoxide dismutase (SOD) induced by ethanol can be effectively inhibited. Furthermore, there were more SCFAs (short chain fatty acids) generated in colon with the four starches when compared with ethanol group. The results demonstrated that the four types of RS were proved to be effective on ethanol-induced gastric injure probably by ameliorating oxidative stress, generating more SCFAs and promoting gastric emptying. Of the four RS samples tested, the high dose groups of RS3 and RS5 showed the best activity. This study reported four kinds of gastro-protection starches and provided useful information for functional food and pharmaceutical industries. [ABSTRACT FROM AUTHOR]

The effects of blanching (in boiling water for 1min) and different hot air drying temperatures (40 °C, 60 °C and 80 °C) on the polyphenol oxidase (PPO), peroxidase (POD) and antioxidant activities, main bioactive components, as well as the starch-related physicochemical properties of yam flours were studied. The results of PPO and POD activities, and total flavone and total soluble polyphenol contents showed that blanching was effective to inhibiting enzymatic browning of yams, and the substrate of enzymatic browning reaction may be mainly flavonoid ingredients. The sample of H-40 had higher allantoin and total soluble polyphenol content, stronger DPPH scavenging activity and reducing power. From the results of scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared (FT-IR), the blanching yams was found contain partly gelatinized starch granules, and had lower crystallinity. The H-40 and H-80 samples had higher RS contents and lower GI values. Furthermore, the protein and soluble amylose contents, solubility and swelling power at 90 °C of the blanching yams were lower than those of the yams without blanching. We can effectively apply these flours in various products based on their characteristics. [ABSTRACT FROM AUTHOR]

Ten different Asian ginseng cultivars ( Panax ginseng) from China and Korea were characterized for their starch-related physicochemical and functional properties. American ginseng ( Panax quinquefolious) flour and starch were also assessed as contrast. All the ginseng samples were investigated for their morphological, crystalline, and thermal properties, as well as in vitro digestibility. American ginseng starch (A-S) showed characteristic peaks as B-type in X-ray diffraction. Furthermore, the hydrolysis index (HI) and glycemic index (GI) were valued by in vitro digestion. American ginseng starch with high HI (111.94) and GI (101.17) has potential application in healthy energy-giving food products. According to statistics by principal component analysis (PCA) and cluster analysis, two different samples from Chinese ginseng were potential to be new cultivated varieties, for being different with 'Da di' (a stable variety). The starch-related properties of ginseng flours were investigated and used as reference for breeding of cultivated ginseng for the first time. [ABSTRACT FROM AUTHOR]

Abstract: The objective of current work is to investigate the intensification of starch towards acetylation by acetic anhydride after ultrasound treatment. Native dioscorea starch (NDS) slurry was ultrasonically treated to produce ultrasound-treated dioscorea starch (UTDS). The effects of ultrasound-treated conditions of NDS on degree of substitution (DS) of ultrasound-treated dioscorea starch acetate (UTDSA) were examined. The influences of different acetylation conditions such as reaction time, reaction temperature and the molar ratios of H2SO4 to starch on the DS of starch acetate (SA) were also investigated by comparing the DS of UTDSA with NDSA''s. The results demonstrate that a higher DS value is always observed for the acetylation of UTDS sample under the same reaction conditions. Moreover, using UTDS or NDS as material, the SAs with same DS value (0.55 and 1.75) were synthesized, and their chemical structure, crystalline structure, thermal stability, and morphological properties were characterized by the Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM) techniques. [Copyright &y& Elsevier]

Abstract: The objective of this study was to prepare and characterize solid complex of starch with quercetin. Starches with different content of quercetin were prepared and their formation was confirmed by the presence of the carbonyl signal around 1662 cm−1 in the FT-IR spectra. Scanning electron microscopy (SEM) suggested most of the starch granules disintegrated with many visible fragments along with increasing quercetin content in the binary mixtures. X-ray diffraction (XRD) of quercetin–starch complexes revealed that the crystal structure of native starch was disappeared and new crystalline regions were formed. The thermal behavior of quercetin–starch was investigated using thermogravimetric analyses (TGA) and differential scanning calorimetry (DSC). It was observed that the mass loss and thermal stability of complexes depend on the content of quercetin in the complexes. There were obvious differences between pregelatinized starch and quercetin–starch complexes in digestion rate. The digestion rate was drastically reduced as the quercetin was blended. The digestion rate was steady at about 37.3% for pregelatinized starch and 10.1% for quercetin–starch complex (2.5 g/100 g) after incubating 2 h. The residual starch of quercetin–starch complexes can be thought as resistant starch, the amounts of resistant starch were sharply increased in comparison with the pregelatinized starch. [ABSTRACT FROM AUTHOR]

Abstract: Dialdehyde yam starches (DASs) are prepared and characterized. Compared with native starch, viscosity average molecular weight of DASs decreases, and the extent of degradation depends on content of the aldehyde groups. Fourier transform infrared (FT-IR) spectra confirm that the characteristic peak for Ct 1732cm−1 is enhanced with the increasing of content of the aldehyde groups. Scanning electron microscopy (SEM) micrographs show that the surface of starch granules becomes wrinkled. X-ray diffraction (XRD) patterns clearly indicate that their crystallinity decreases with the increasing content of the aldehyde groups before they become amorphous at higher oxidation states. The experimental results of thermogravimetric analysis (TGA) show that DASs have poor stability as compared to native starch. With the increase in content of the aldehyde groups, the thermal stability of DAS declines gradually. According to the results of differential scanning calorimetry (DSC), gelatinization temperature (T o and T p) of DASs are increased, whereas the gelatinization enthalpy decreased. [ABSTRACT FROM AUTHOR]

Abstract: Yellow ginger starch acetates with different degrees of substitution (DS) were prepared by reacting native starch with glacial acetic acid/acetic anhydride using sulfuric acid as catalyst. X-ray diffraction (XRD) of acetylated starch revealed that the crystal structure of native starch was disappeared and new crystalline regions were formed. Their formation was confirmed by the presence of the carbonyl signal around 1750cm−1, as well as the reduced hydroxyl groups, in the Fourier transform infrared spectroscopy (FT-IR). The scanning electron microscopy (SEM) suggested most of the starch granules disintegrated with many visible fragments along with the increasing DS. The thermal behavior of the native starch and starch acetate were investigated using thermogravimetric analysis (TGA) and differential thermal analysis (DTA), it was observed that the thermal stability of acetylated starch depends on the degree of substitution. Thermal stability of high DS acetylated starch is much better than that of the original starch when DS reached to 2.67. [Copyright &y& Elsevier]