•Addition of sugars increased pasting temperature of sweet potato starch (SPS).•Addition of sugars decreased peak, trough, final viscosities, and setback value of SPS.•Addition of sugars increased gelatinization temperature and enthalpy of SPS-sugar mixtures.•Sugars addition increased yield stress and consistency coefficient of SPS-sugar mixture.•Addition of sugars promoted liquid-like characteristics of SPS-sugar mixed pastes.Effects of sucrose, raffinose and stachyose on pasting, thermal, and rheological properties of sweet potato starch (SPS) were investigated. The results indicated that pasting temperature of SPS increased with increasing sugar concentration in the order of stachyose > raffinose > sucrose. Addition of sugars significantly decreased the peak, trough, and final viscosities as well as setback value. The gelatinization temperatures of SPS-sugar mixtures markedly increased with increasing sugar concentration in the order of stachyose > raffinose = sucrose, gelatinization enthalpy also increased when sugar was added at high concentration compared with native starch. The addition of sugars increased the yield stress and consistency coefficient of SPS-sugar mixed pastes. The SPS-sugar mixed pastes exhibited a pseudoplastic and shear-thinning behavior under yield stress condition. Moreover, storage moduli (G′) of SPS-sugar mixed pastes decreased with addition of sugars. This study also showed that addition of sugars promoted liquid-like characteristics of SPS-sugar mixed pastes.

•Waxy wheat starch treated with HHP of 600 MPa had the maximum SDS content of 31.12%.•HHPR treatment decreased gelatinization temperatures of waxy wheat starch.•HHPR treatment decreased gelatinization enthalpy of waxy wheat starch.•HHPR treatment decreased relative crystallinity and peak viscosity of waxy wheat starch.•HHPR treatment destroyed the structure of waxy wheat starch granules.In this study, the effects of high hydrostatic pressure and retrogradation (HHPR) treatments on in vitro digestibility, structural and physicochemical properties of waxy wheat starch were investigated. The waxy wheat starch slurries (10%, w/v) were treated with high hydrostatic pressures of 300, 400, 500, 600 MPa at 20 °C for 30 min, respectively, and then retrograded at 4 °C for 4 d. The results indicated that the content of slowly digestible starch (SDS) in HHPR-treated starch samples increased with increasing pressure level, and it reached the maximum (31.12%) at 600 MPa. HHPR treatment decreased the gelatinization temperatures, the gelatinization enthalpy, the relative crystallinity and the peak viscosity of the starch samples. Moreover, HHPR treatment destroyed the surface and interior structures of starch granules. These results suggest that the in vitro digestibility, physicochemical, and structural properties of waxy wheat starch are effectively modified by HHPR.

•Microwave-assisted extraction technology of OFPP was optimized by RSM.•OFPP obtained by HWE exhibited a lower viscosity compared with that by MAE.•There were strong interactions between calcium ion and OFPP.In this study, response surface methodology (RSM) was employed to optimize microwave-assisted extraction (MAE) technology of mucilage polysaccharide from the peel of Opuntia dillenii haw. fruits (OFPP), and the physicochemical characteristics of OFPP were also investigated. The three parameters were the ratio of water to raw material (30–40 ml/g), microwave power (300–400 W) and extraction time (120–180 s). The results indicated that the yield of OFPP was 15.62 ± 0.37% under the optimum extraction conditions. Compared with MAE, the OFPP yield by hot water extraction (HWE) was 13.36 ± 0.71%. In addition, the rheological properties of OFPP were also explored. The OFPP obtained by HWE exhibited a lower viscosity compared with that by MAE. The FT-IR spectra analysis, scanning electron microscopy (SEM) observation and thermogravimetric analysis (TGA) revealed that there were strong interactions between Ca2+ and OFPP, which resulted in the high viscosity, different microstructure and thermal stability of OFPP.

Neuroinflammation has been reported to be involved in the pathogenesis of Parkinson’s disease (PD). Inhibition of microglia-mediated neuroinflammation might be a potential strategy for PD treatment. Biochanin A, is an O-methylated isoflavone, classified as a kind of phytoestrogens due to its chemical structure that is similar to mammalian estrogens. It has been found to possess antifibrotic, antiapoptotic, and antioxidant effects. In the present study, we investigated the neuroprotective effects of biochanin A on lipopolysaccharide (LPS)-induced dopaminergic neurons damage both in vivo and in vitro and the related molecular mechanisms. The results showed that biochanin A treatment for 21 days significantly attenuated the behavioral dysfunction of PD rats, prevented dopaminergic neurons damage, and inhibited activation of microglia in the LPS-induced PD rats. Furthermore, biochanin A decreased the levels of interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) in the serum, and inhibited the phosphorylation of ERK, JNK, p38 in the substantia nigra of PD rats. In vitro test, biochanin A also inhibited primary microglial activation and protected dopaminergic neurons, decreased the content of nitric oxide, IL-1β, and TNF-α in supernatants, and inhibited the reactive oxygen species production. Taken together, these results suggest that biochanin A exerts protective effects on LPS-induced PD rats, and the mechanisms may be associated with the inhibition of inflammatory response and the MAPK signaling pathway.

•IR-4/25 treatment significantly increased the yield of SDS in waxy wheat starch.•IR-4/25-treated waxy wheat starch sample had a relatively low value of ΔH.•CR-25- and IR-25-treated starch samples exhibited a mixed A + B type pattern.•IR-treated starch samples had a higher pasting temperature than CR-treated samples.The effects of continuous retrogradation (CR) and intermittent retrogradation (IR) treatments under 4 °C and 25 °C or temperature-cycled condition of 4/25 °C on the digestibility and structural properties of waxy wheat starch were investigated. The results indicated that IR treatment under temperature cycles of 4/25 °C (IR-4/25) was more beneficial to the formation of slowly digestible starch (SDS, 42.24%). Moreover, the gelatinisation enthalpy of IR-4/25-treated starch sample was lower than that of CR-4/25-treated sample. Variation in infrared absorbance ratio of 1047 cm−1/1022 cm−1 of IR-treated starch samples was consistent with relative crystallinity. Through retrogradation treatment under 4/25 °C or 4 °C, starch samples exhibited X-ray diffraction pattern of B-type, while CR-25 and IR-25-treated samples showed a mixed A + B type pattern. Besides, the swelling power of CR-4/25-treated starch sample was higher than that of IR-4/25-treated sample. The pasting temperatures of IR-treated starch samples were higher than those of the CR-treated samples.

•A novel polysaccharide fraction is isolated from the bulbs of Lilium lancifolium Thunb.•The structural characterisation of LP2-1 was studied.•The physicochemical properties including rheology of LP2-1 were investigated.•In vitro antioxidant activities of LP2-1 were determined.A novel polysaccharide fraction (LP2-1) was isolated and purified from the edible bulbs of Lilium lancifolium Thunb. by DEAE cellulose chromatography and Sephacryl S-400 size-exclusion chromatography. The structural characterisation, physicochemical properties and antioxidant activity of LP2-1 were investigated. The results showed that LP2-1 had an average molecular weight of approximately 8.52 × 103 kDa and was mainly composed of l-rhamnopyranose, d-arabinofuranose, d-glucopyranose and d-galactopyranose in the molar ratio of 1.88:2.13:1.00:2.50, and major functional groups of LP2-1 were COO and OH. The viscoelastic properties of LP2-1 systems exhibited a gel-like behaviour, with storage modulus higher than loss modulus, and both moduli increased with increasing Ca2+ concentration. In addition, LP2-1 had DPPH and hydroxyl radicals scavenging activities, and also had the strong reducing power and chelating activity on ferrous ion. These results suggest that LP2-1 has good antioxidant activity and can be used in food industry.

•Citric acid esterification can increase the SDS and RS contents of cassava starch.•Citric acid esterification does not change the crystalline pattern of cassava starch.•Citric acid esterification can improve the freeze-thaw stability of cassava starch.•Citric acid esterification changes the thermal properties of cassava starch.In this study, citric acid was used to react with cassava starch in order to compare the digestibility, structural and physicochemical properties of citrate starch samples. The results indicated that citric acid esterification treatment significantly increased the content of resistant starch (RS) in starch samples. The swelling power and solubility of citrate starch samples were lower than those of native starch. Compared with native starch, a new peak at 1724 cm−1 was appeared in all citrate starch samples, and crystalline peaks of all starch citrates became much smaller or even disappeared. Differential scanning calorimetry results indicated that the endothermic peak of citrate starches gradually shrank or even disappeared. Moreover, the citrate starch gels exhibited better freeze–thaw stability. These results suggested that citric acid esterification induced structural changes in cassava starch significantly affected its digestibility and it could be a potential method for the preparation of RS with thermal stability.

•A novel polysaccharide fraction is isolated from the fruits of Opuntia dillenii Haw.•ODFP can decrease blood glucose level of STZ-induced diabetic rats.•ODFP can decrease lipid peroxidation level of STZ-induced diabetic rats.•ODFP can increase antioxidant enzyme activity in serum and tissues of diabetic rats.•ODFP can restore pancreatic islet structure integrity of STZ-induced diabetic rats.In this study, a novel water-soluble polysaccharide fraction with molecular weight of 6479.1 kDa was isolated from the fruits of Opuntia dillenii Haw., which consisted of rhamnose, xylose, mannose and glucose in the molar ratio of 14.99:1.14:1.00:6.47. The protective effect of O. dillenii Haw. fruits polysaccharide (ODFP) against oxidative damage in streptozotocin (STZ)-induced diabetic rats was investigated. The results showed that oral administration of ODFP significantly decreased food intake, water intake, urine production, organ weights and blood glucose level, and increased body weight in STZ-induced diabetic rats. ODFP also significantly increased the activities of SOD, GPx and CAT, and decreased malondialdehyde level in serum, liver, kidney, and pancreas in STZ-induced diabetic rats. Moreover, histopathological examination showed that ODFP could markedly improve the structure integrity of pancreatic islet tissue in STZ-induced diabetic rats. These results suggest that ODFP have hypoglycemic and antioxidant properties and can protect rats from STZ-induced oxidative damage.

•D-HMT starch showed a considerable SDS content of 31.60%.•DT and D-HMT decreased the ratio of SF of DP < 13 to LF of DP ⩾ 13.•DT and D-HMT decreased the molecular weight of starch samples.•Crystalline pattern of D-HMT starch was altered from Ca to A type compared with DT.•Relative crystallinity of D-HMT starch was significantly increased compared with DT.The effects of debranching treatment (DT) and debranching-heat-moisture treatment (D-HMT) on the structural characteristics and in vitro digestibility of sweet potato starch were investigated. The results indicated that DT and D-HMT decreased the percentage of starch fraction with degree of polymerization (DP) ⩽ 13, increased the percentages of the other fractions, and decreased the molecular weight of starch sample. The D-HMT starch showed a considerable SDS content of 31.60%. Compared with the DT starch sample, the To, Tp, Tc, Tc − To and ΔH of D-HMT starch samples for the second endothermal were increased significantly, crystalline pattern was altered from Ca to A type, the surface became more smooth. The pasting temperatures of DT and D-HMT starch samples were higher while the peak viscosities, breakdown and setback values were lower than that of native starch. These results suggested that structural changes of sweet potato starch by D-HMT significantly affected the digestibility.

•RR-2 treatment increases the yield of SDS in waxy potato starch.•RR-2 treatment decreases ΔH and Tc − To of waxy potato starch.•RR treatment alters crystalline type of waxy potato starch from B-type to C-type.•RR-2 treatment decreases relative crystallinity of waxy potato starch.•RR treatment can change the morphology of waxy potato starch.The effects of repeated retrogradation (RR) treatment on the structural characteristics and in vitro digestibility of waxy potato starch were investigated. The cycling times of RR ranging from 1 to 5 were designated as RR-1, RR-2, RR-3, RR-4, and RR-5, respectively. A maximum SDS content (40.41%) was obtained by RR-2 treatment with the time interval of 48 h. RR-2-treated starch product exhibited a narrower melting temperature range, a higher onset temperature and a lower melting enthalpy compared with RR-1 treatment. Compared with native starch, X-ray diffraction patterns of treated starches were altered from B-type to C-type. The variation in relative crystallinity of RR-treated starch products was consistent with that in melting enthalpy. Moreover, compared with RR-1-treated starch, a large number of cavities were observed on the surface of RR-2-treated starch product with a time interval of 48 h, whereas more smooth regions were found on the surface of RR-5-treated starch product. This study suggested that structural changes of waxy potato starch treated with different cycling times of RR significantly affected the digestibility.

•DR treatment increases the yield of SDS in waxy wheat starch.•DR treatment decreases ΔH and Tc – To of waxy wheat starch.•DR treatment alters crystalline type of waxy wheat starch from A-type to B-type.•DR treatment decreases relative crystallinity of waxy wheat starch.•DR treatment can change the morphology of waxy wheat starch.The effects of single-retrogradation (SR), dual-retrogradation (DR) and triple-retrogradation (TR) treatments on in vitro digestibility and structural characteristics of waxy wheat starch were investigated. The yield of slowly digestible starch in a DR-treated starch with retrogradation time interval of 48 h reached a maximum of 44.41%. The gelatinization temperature range and gelatinization enthalpy of DR-treated starch samples were the lowest. Moreover, compared with native starch, X-ray diffraction patterns of treated starches were altered from A-type to B-type and relative crystallinity was significantly decreased, which was responsible for the interaction between amylose–amylose and/or amylose–amylopectin chains that may generate more imperfect structures. Scanning electron micrographs revealed that compared with SR-treated and TR-treated starches, the surface of DR-treated starch with a retrogradation time interval of 48 h exhibited a net-like structure with numerous cavities. These results suggest that structural changes of waxy wheat starch by cycled retrogradation treatment significantly affect digestibility, and DR treatment can be used for preparing SDS product.

•The formation and distribution of microgel-lysozyme complexes were estimated.•The structure of lysozyme in the complexes was evaluated by FT-IR and Raman spectra.•In vitro release of lysozyme from the complexes has been investigated.•The structure of lysozyme released from stomach fluid was identified by CD.The formation and distribution of microgel-lysozyme complexes were identified by confocal laser scanning microscope (CLSM). The structure of lysozyme in the microgel was investigated by Fourier transform infrared (FT-IR) spectroscopy and Raman spectra. In vitro release of lysozyme from the microgel-lysozyme complexes was estimated. The structure of lysozyme released from stomach juice was further evaluated by circular dichroism (CD). The CLSM images showed that microgel-lysozyme complexes was formed and the lysozyme distributed quite homogeneously over the microgel particles. The FT-IR and Raman spectra indicated that lysozyme secondary structure maintained unchanged in the microgels. The microgels could be used as a carrier system to guard against the early release of lysozyme and protect lysozyme in the stomach and deliver targeted object to the intestine, as confirmed by the results of in vitro release and CD. This carboxymethyl starch-based microgel had potential as a specific delivery system for gastrointestinal environment.

•OSCS with different degree of substitution were synthesized.•The structural properties of OSCS were characterized by FT-IR, XRD, and SEM.•The gelatinization characteristics of starch samples were determined by DSC.•In vitro digestibility of OSCS was also measured.The octenylsuccinylated cassava starch (OSCS) samples with a degree of substitution (DS) in the range of 0.008 to 0.035 were prepared in this study. The structural, physicochemical, and in vitro digestibility properties of OS-starch samples were investigated. Intensities of characteristic peaks at 1724 cm−1 and 1572 cm−1 increased with increasing DS, which confirmed successful introduction of ester carbonyl groups into starch molecules. The esterification occurred primarily in the amorphous regions and surface of starch granule, and the crystalline pattern did not change. SEM results revealed that the modification had slight effects on the morphological structure of native starch. Differential scanning calorimetry (DSC) thermograms of OS-starch samples showed lower onset temperature, peak temperature, conclusion temperature, and endothermic energy than their native counterpart. This study also showed that esterification with OSA was an effective method for increasing slowly digestible starch and resistant starch contents in starch samples.