Different multi-scale structural features of oat resistant starch prepared by ultrasound combined enzymatic hydrolysis affect its digestive properties

Assessing the impact of plasma-activated water-assisted heat-moisture treatment on the extrusion-recrystallization process of hausa potato starch

The study explored the plasma-activated water (PAW)-assisted heat-moisture treatment (HMT) on the structural, physico-chemical properties, and in vitro digestibility of extrusion-recrystallized starch. Native starch of hausa potatoes underwent modification through a dual process involving PAW-assisted HMT (PHMT) followed by extrusion-recrystallization (PERH) using a twin-screw extruder. The PHMT sample showed surface roughness and etching with a significantly greater (p ≤ 0.05) RC (20.12 %) and ΔH (5.86 J/g) compared to DHMT. In contrast, PERH-induced structural damage, resulting in an irregular block structure, and altered the crystalline pattern from A to B + V-type characterized by peaks at 17.04°, 19.74°, 22°, and 23.94°. DSC analysis showed two endothermic peaks in all the extrusion-recrystallized samples, having the initial peak attributed to the melting of structured amylopectin chains and the second one linked to the melting of complexes formed during retrogradation. Dual-modified samples displayed notably increased transition temperatures (To1 74.54 and 74.17 °C, To2 122.65 and 121.49 °C), along with increased RS content (43.76 %-45.30 %). This study envisages a novel approach for RS preparation and broadens the utilization of PAW in starch modification synergistically with environmentally friendly techniques.

Effects of different oil additives on water resistance of corn starch straws

To investigate the effect of oil additives on improving the water resistance of corn starch straws, corn oil (CO), soybean oil (SO), rapeseed oil (RO), peanut oil (PO), lard (LD) and coconut oil (CCO) were chosen and compared the structure and properties of starch straws with different oil additives. Corn starch straws (CS), and starch straws supplemented with CO, SO, RO, PO, LD and CCO were prepared by thermoplastic extrusion. The results showed that the incorporation of oils effectively enhanced the water resistance of starch straws such as water absorption, water solubility and water swelling performance. Meanwhile, the flexural strength of starch straws significantly increased. There was no significant linear relationship among starch chain length, oil unsaturation and straw performance. Among seven starch straws, S-SO had the strongest hydrogen bond interaction (3289 cm-1) and relaxation time (0.96 ms). The S-CO had the highest relative crystallinity (16.82 %) and degree of double helix (1.535), hence resulting in the lowest water absorption and solubility values, the highest flexural strength (23.43 MPa), the highest ΔT value (9.93 °C) and ΔH value (4.79 J/g). S-RO had the highest thermal transition temperatures.

Oat Dietary Fiber Delays the Progression of Chronic Kidney Disease in Mice by Modulating the Gut Microbiota and Reducing Uremic Toxin Levels

Chronic kidney disease (CKD) has emerged as a significant public health concern. In this article, we investigated the mechanism of oat dietary fiber in regulating CKD. Our findings indicated that the gut microbiota of CKD patients promoted gut microbiota dysbiosis and kidney injury in CKD mice. Intervention with oat-resistant starch prepared by ultrasonic combined enzymatic hydrolysis (ORSU) and oat β-glucan with a molecular weight of 5 × 104 Da (OBGM) elevated the levels of short-chain fatty acids (SCFAs) and regulated gut dysbiosis in the gut-humanized CKD mice. ORSU and OBGM also reduced CKD-related uremic toxins such as creatinine, indoxyl sulfate (IS), and p-cresol sulfate (PCS) levels; reinforced the intestinal barrier function of the gut-humanized CKD mice; and mitigated renal inflammation and fibrosis via the NF-κB/TGF-β pathway. Therefore, ORSU and OBGM might delay the progression of CKD by modulating the gut microbiota to reduce uremic toxins levels. Our results explain the mechanism of oat dietary fiber aimed at mitigating CKD.

Rheological, thermal, and in vitro starch digestibility properties of oat starch-lipid complexes

The influence of oat lipids on the structural, thermal, rheological, and in vitro digestibility properties of oat starch under heat processing conditions was investigated. X-ray diffraction, fourier infrared spectroscopy, and differential scanning calorimetry revealed the formation of a V-shaped crystal structure between starch and lipid, resulting in enhanced orderliness and enthalpy. Oat lipids decreased the final viscosity and gel strength of oat starch while weakening the trend towards gel network formation. Additionally, oat lipids exhibited enhanced resistance to starch hydrolase, leading to elevated contents of slowly digestible starch and resistant starch. Consequently, this leads to an augmentation in the rate constants for the rapid digestion fraction (k1) and the slow digestion fraction (k2). When the lipid content reached 7.50 %, a significant increase of 42.20 % was observed in the maximum digestibility of slow digestion fraction (C∞2), while a notable decrease of 44.06 % was noted in the maximum digestibility of rapid digestion fraction (C∞1). The correlation analysis revealed that lipid content, final viscosity, and enthalpy exerted significant influences on in vitro starch digestion. These results demonstrate the substantial impact of lipid content on oat starch structure, subsequently affecting its thermal, rheological, and digestive properties.

The properties of the rice resistant starch processing and its application in skimmed yogurt

Extrusion is typically employed to prepare resistant starch (RS). However, the process is complicated. In this study, the effects of twin-screw extrusion on the crystallinity, thermal properties, and functional properties of starch formed in different extrusion zones were investigated. The effects of this process on the rheological properties and microstructure of RS-added skimmed yogurt were also studied. According to the results, the RS content increased from 7.40 % in the raw material to 33.79 % in the extrudate. The A-type crystal structure of the starch was not observed. The dissociation temperature of the extruded starch ranged from 87.76 °C to 100.94 °C. The glycemic index (GI) of skimmed yogurt fortified with 0.4 % RS was 48.7, and the viscosity was also improved. The microstructure exhibited a uniform network of the starch-protein structure. The findings may serve as a theoretical basis for the application of RS in the food industry.

Physicochemical properties of a novel chestnut porous starch nanoparticle

A novel chestnut porous starch nanoparticle (PSNP) was successfully synthesized, combining the properties of starch nanoparticle (SNP) and porous starch. The SNP obtained through ultrasonic and acid hydrolysis, exhibited a smaller particle size (173.9 nm) and a higher specific surface area (SSA) compared to native starch. After the synergistic hydrolysis by α-amylase and glucoamylase, the porous structure appeared on the surface of SNP. The prepared PSNP had a size of 286.3 nm and the highest SSA. In the adsorption experiments, PSNP showed higher capacities for adsorbing water, oil and methylene blue (MB) compared to other samples. The acid and enzymatic treatments resulted in a decrease in the levels of total starch content and amylose ratio. Furthermore, the treatments increased the levels of relative crystallinity (RC) and solubility, while decreasing the short-range ordered structure and swelling ratio at high temperatures. It was observed that the SSA of starch granules positively correlated with the MB and water adsorption capacity (WAC), solubility, and RC. These findings highlight the potential of the novel PSNP as an efficient adsorbent for bioactive substances and dyes.

Improvement of in vitro digestibility and thermostability of debranched waxy maize starch by sequential ethanol fractionation

This study aimed to improve the in vitro digestibility and thermostability of debranched waxy maize starch (DWMS) by sequential fractionation. Waxy maize starch was debranched by pullulanase, followed by sequential precipitation through controlling the ratio of starch supernatants to ethanol at 1:0.5, 1:1, and 1:1.5 (v/v). Subsequently the structural, thermal, in vitro digestive properties of DWMS were investigated. In vitro digestion results showed that the secondary ethanol fractionation of 1:1 on the basis of the initial fractionation (1:0.5) induced a significant higher amount of slowly digestive starch (SDS, 30.0 %) and resistant starch (RS, 58.6 %) amongst all three fractions, along with the highest peak temperature (Tp, 106.4 °C) and the highest decomposition value (Td, 310.0 °C) in calorimetric (DSC) and thermogravimetry (TGA) measurements. Chain length distribution, surface morphology, and laser confocal micro-Raman spectroscopy (LCM-Raman) analyses revealed that medium (degree of polymerization, DP 13- 36) and long chains (DP ≥37) respectively constituting 72.0 % and 10.2 % of DWMS resulted in the formation of spheroidal crystallites with higher homogeneity and more ordered short-range structures. Overall, this work confirmed that ethanol fractionation is an efficient method for improving the in vitro digestibility and heat stability of waxy maize starch.