Characteristics of Citrate-Esterified Starch and Enzymatically Debranched Starch and Their Effects on Diabetic Mice.

Chickpea has significant benefits as an adjuvant treatment for type 2 diabetes mellitus (T2DM). The properties of chickpea resistant starches (RSs) and their abilities to reduce T2DM symptoms and control intestinal flora were investigated. The RS content in citrate-esterified starch (CCS; 74.18%) was greater than that in pullulanase-modified starch (enzymatically debranched starch (EDS); 38.87%). Compared with those of native chickpea starch, there were noticeable changes in the granular structure and morphology of the two modified starches. The CCS showed surface cracking and aggregation. The EDS particles exhibited irregular layered structures. The expansion force of the modified starches decreased. The CCS and EDS could successfully lower blood glucose, regulate lipid metabolism, lower the levels of total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C), reduce the expressions of interleukin-6 (IL-6) and interleuki n-10 (IL-10), and decrease diabetes-related liver damage. Moreover, the CCS and EDS altered the intestinal flora makeup in mice with T2DM. The abundance of Bacteroidota increased. Both types of chickpea RSs exhibited significant hypoglycaemic and hypolipidaemic effects, contributing to the reduction in inflammatory levels and the improvement in gut microbiota balance.

Detection of Soybean-Derived Components in Dairy Products Using Proofreading Enzyme-Mediated Probe Cleavage Coupled with Ladder-Shape Melting Temperature Isothermal Amplification (Proofman-LMTIA).

Food adulteration is a serious problem all over the world. Establishing an accurate, sensitive and fast detection method is an important part of identifying food adulteration. Herein, a sequence-specific ladder-shape melting temperature isothermal amplification (LMTIA) assay was reported to detect soybean-derived components using proofreading enzyme-mediated probe cleavage (named Proofman), which could realize real-time and visual detection without uncapping. The results showed that, under the optimal temperature of 57 °C, the established Proofman-LMTIA method for the detection of soybean-derived components in dairy products was sensitive to 1 pg/µL, with strong specificity, and could distinguish soybean genes from those of beef, mutton, sunflower, corn, walnut, etc. The established Proofman-LMTIA detection method was applied to the detection of actual samples of cow milk and goat milk. The results showed that the method was accurate, stable and reliable, and the detection results were not affected by a complex matrix without false positives or false negatives. It was proved that the method could be used for the detection and identification of soybean-derived components in actual dairy products samples.

Study on detection of soybean components in edible oil with ladder-shape melting temperature isothermal amplification (LMTIA) assay.

A ladder-shape melting temperature isothermal amplification (LMTIA) assay was established and used to detect soybean components in edible oils. LMTIA primers were designed with the sequence of the internal transcribed spacer (ITS) gene as the target, the reaction temperatures were optimized, the sensitivity was determined, and the suitability of the DNA extraction method for edible oil was assessed, with H2O and genomic DNA (gDNA) from corn, rapeseed, cottonseed, sesame, chili, chicken, pork, beef, and mutton as negative controls to test the false positives of the LMTIA assay. The established LMTIA assay gave a sensitivity of 1 pg at an optimal temperature of 57 °C. The Edible Oil DNA Extraction Kit was suitable for the LMTIA assay to detect soybean components in refined plant oil. No false positives occurred from all negative controls. This study successfully established the LMTIA assay for the detection of soybean ITS genes in edible oils, which could be used to detect soybean components in edible oils.

Coating function and stabilizing effects of surface layer protein from Lactobacillus acidophilus ATCC 4356 on liposomes.

Surface layer proteins (SLPs) are crystalline arrays in the outermost layer of cell envelope in many archaea and bacteria. SLPs subunits have the ability to reassemble on the surface of lipid layers. In this work, the SLP from Lactobacillus acidophilus ATCC 4356 was extracted and reassembled on the surface of positively charged liposomes composed of dipalmitoyl phosphatidylcholine, cholesterol and octadecylamine. Zeta potentials and particle size were determined to describe the adsorption process of SLP on liposomes. The liposomes completely coated with SLP were observed by transmission electron microscope. To investigate the stabilizing effects of SLP on liposomes, carboxyfluorescein (CF) was encapsulated and its leakage was determined as an evaluation index. The results showed that the L. acidophilus ATCC 4356 SLP significantly (P < 0.05) increased the stability of the liposomes in the course of thermal challenge. Furthermore, SLP was able to reduce the aggregation of liposomes in serum. Storage stability of liposomes was performed at 25 °C, 4 °C and -20 °C for 90 days. And the SLP-coated liposomes released less CF than the control liposomes during storage at the three evaluated temperatures. Our findings extended the application field of Lactobacillus SLPs and introduced a novel nanocarrier system with good chemical stability.

Disodium Guanylate Alleviates Acute Hepatic Injury Induced by Carbon Tetrachloride Via Antioxidative Stress and Antiapoptosis In Vivo and In Vitro.

Hepatic injury is one of the most common digestive system diseases worldwide in clinic. Guanylic acid or guanosine monophosphate (GMP) was an important component of nucleotides, which is mainly in the form of sodium salt (disodium guanylate, GMP-Na2 ). However, its effect on hepatic injury has not yet been investigated. This study is to investigate the protective effects of GMP-Na2 on acute hepatic injury induced by carbon tetrachloride (CCl4 ), and to explore its mechanism. The hepatic injury models of mice and HL-7702 cells were induced by CCl4 . The alanine transaminase (ALT), aspartate aminotransferase (AST), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), malondialdehyde (MDA), total antioxidant capacity (T-AOC) were determined by biochemical method. Hematoxylin-eosin staining were used to determine the morphological changes on liver tissue in mice. The mRNA and protein expressions of caspase-3, Bax, and Bcl-2 were detected by RT-PCR and Western blot analysis. Our results show that GMP-Na2 treatment significantly decreased the activities of ALT and AST, and the levels of MDA as well as increased the levels of SOD, GSH-Px, and T-AOC. Importantly, GMP-Na2 effectively enhanced the antiapoptosis function by upregulating Bcl-2 expression and downregulating caspase-3 and Bax expressions in vivo and in vitro. Moreover, the histopathological changes of liver tissue were obviously improved after GMP-Na2 treatment. These findings suggest that GMP-Na2 has protective effects on hepatic injury, and its mechanisms may be associated with antioxidative stress and antiapoptosis.

Evaluation of six white-rot fungal pretreatments on corn stover for the production of cellulolytic and ligninolytic enzymes, reducing sugars, and ethanol.

Fungal pretreatment on lignocellulosic biomass has the advantages of being eco-friendly, having low operating cost, and producing no inhibitor. In this study, six white-rot fungi (Trametes versicolor, Pleurotus ostreatus, Phanerochaete chrysosporium, Coriolopsis gallica, Pleurotus sajor-caju, Lentinula edodes) were applied to corn stover pretreatment. Biomass degradation, production of enzymes, reducing sugar via hydrolysis, and ethanol yield via yeast fermentation were quantified during 30 days cultivation, and samples were taken every 5 days. Among six fungi, the highest lignin degradation was 38.29% at 30 days for P. sajor-caju pretreatment, the highest sugar yield was 71.24%, and the highest ethanol yield was 0.124 g g-1 corn stover under P. sajor-caju pretreatment for 25 days. The highest activities of laccase and manganese peroxidase were 29.22 and 10.22 U g-1 dry biomass, respectively, under T. versicolor pretreatment at 25 days. The highest levels of enzyme, sugar, and ethanol production are comparable or higher than what has been reported in previous literature. P. sajor-caju is one of the most widely worldwide cultivated mushrooms. The findings in this study show the potential to incorporate P. sajor-caju mushroom cultivation into corn stover pretreatment to enhance the production of a suite of products such as enzymes, sugars, and ethanol.

High-activity production of xylanase by Pichia stipitis: Purification, characterization, kinetic evaluation and xylooligosaccharides production.

As an industrially important biological macromolecule, xylanase hydrolyzes xylan to produce xylooligosaccarides (XOS). XOS, with a degree of polymerization (DP) 2 to 4, are important prebiotics used as food ingredients. In this study, xylanase (5536 U/g substrate) was produced by Pichia stipitis using corncob and wheat bran mixture under solid state fermentation. Crude xylanase were purified and biochemically characterized. XOS hydrolyzed by crude and purified xylanases were quantified. Molecular weight of the purified enzyme was around 31.6 kDa on SDS-PAGE. Enzyme kinetics showed Km and Vmax values of 4.52 mg/mL and 9.17 µmol/min/mL, respectively. The optimal conditions were pH 6.0 and 50 °C. Xylanase was stable at pH 5-8 for 60 min by retaining 57% activity and at 50 °C for 80 min by retaining 65% activity. Cooper and potassium had no inhibitory effect on xylanase activity. Xylan hydrolysates produced by purified xylanase contained 92% XOS consisting of 14% xylotetroase (DP 4), 49% xylotriose (DP 3) and 29% xylobiose (DP 2). These findings indicate the potential of applying purified xylanase for industrial XOS production.

A novel, ultra-large xylanolytic complex (xylanosome) secreted by Streptomyces olivaceoviridis.

The production of a novel, very large xylanolytic complex (xylanosome) by Streptomyces olivaceoviridis E-86 is reported. The molecular weight was approx. 1200 kDa as determined by native gradient gel electrophoresis. Corncob xylan was the best inducer of xylanosome formation. The xylanosome was produced when the organism was grown for 5 d between pH 4.5-6 and at 27.5 to 35 degrees C.