Henan University of Technology

About: Henan University of Technology is a education organization based out in Zhengzhou, China. It is known for research contribution in the topics: Catalysis & Chemistry. The organization has 7648 authors who have published 6503 publications receiving 73067 citations. The organization is also known as: Hénán Gōngyè Dàxué.

Heating effect on the DSC melting curve of flaxseed oil

Abstract: Flaxseed oil is rich in the alpha-linolenic acid. The effect of heating on the thermal properties of flaxseed oil extracted from flax seeds has been investigated. The flaxseed oils were heated at a certain temperature (75, 105, and 135 °C, respectively) for 48 h. The melting curve (from −75 to 100 °C) of flaxseed oil was determined by differential scanning calorimetry (DSC) at intervals of 4 h. Three DSC parameters of exothermic event and endothermic event, namely, peak temperature (Tpeak), enthalpy, and temperature range were determined. The initial flaxseed oil exhibited an exothermic peak, two endothermic peaks, and two endothermic shoulders between −68 and −5 °C in the melting profile. Heating temperature had a significant influence on the oxidative deterioration of flaxseed oil. The melting curve and parameters of flaxseed oil were almost not changed when flaxseed oil was heated at 75 °C. However, the endothermic peaks of melting curve decreased dramatically with the increasing of heating time when heating temperature was above 105 °C. There is almost no change of melting heat flow of flaxseed oil when heating time exceeded 32 h at 135 °C. The preliminary results suggest that the DSC melting profile can be used as a fast and direct way to assess the deterioration degree of flaxseed oil.

Chemical composition, angiotensin-converting enzyme-inhibitory activity and antioxidant activities of few-flower wild rice (Zizania latifolia Turcz.).

Abstract: BACKGROUND: The chemical compositions of the stem and leaf sheath of few-flower wild rice were analysed. In addition, their extracts were evaluated for diphenylpicrylhydrazyl (DPPH) free radical-scavenging activity, ferric-reducing antioxidant power and angiotensin-converting enzyme (ACE)-inhibitory activity, since these are important properties of sources of nutraceuticals or functional foods. RESULTS: The stems contained more ascorbic acid (0.06 g kg−1 fresh weight), protein (28.18 g kg−1 dry weight (DW)), reducing sugars (308.54 g kg−1 DW), water-soluble pectin (20.63 g kg−1 DW), Na2CO3-soluble pectin (44.14 g kg−1 DW), K (8 g kg−1 dry matter (DM), S (6 g kg−1 DM) and P (5 g kg−1 DM) but less starch, total dietary fibre, Si, Na and Ca than the leaf sheaths. The DPPH free radical-scavenging IC50 values of the stem and leaf sheath extracts were 19.28 and 21.22 mg mL−1 respectively. In addition, the ACE-inhibitory IC50 value of the stem extracts was 38.54 mg mL−1. CONCLUSION: Both the stem and leaf sheath extracts exhibited good antioxidant properties, while good ACE-inhibitory activity was detected only in the phosphate buffer solution extracts of the stem. Few-flower wild rice could be processed into formula feeds for fish, poultry, etc. or functional foods for persons with high blood pressure. Copyright © 2011 Society of Chemical Industry

Structural Characterization of Lignin in Fruits and Stalks of Chinese Quince

Abstract: Chinese quince (Chaenomeles sinensis) is used in food and pharmaceutical products, but it is seldom eaten as a raw fruit due to its astringent, woody flesh The structural characterization of lignin fractions from Chinese quince was very important to investigate the structure-activity relationships of lignin In this investigation, to characterize the structure of lignin in Chinese quince fruits, the milled wood lignin sample was isolated from the fruits (FMWL) and the chemical structure of FMWL was investigated by sugar analysis, FT-IR, GPC, pyrolysis-GC/MS analysis, UV spectra analysis, thermogravimetric analysis (TGA), and advanced NMR spectroscopic techniques In addition, the lignin fraction from the stalk of Chinese quince (SMWL) was also prepared for comparison to obtained more information of lignin structure in the fruits The results showed that the two lignin fractions isolated from fruit and stalk of Chinese quince exhibited different structural features The two MWL samples were mainly composed of β-O-4 ether bonds, β-5 and β-β′ carbon-carbon linkages in the lignin structural units Compared to the SMWL, the FMWL fraction had the higher S/G ratio and more carbohydrates linkages The predominant carbohydrates associated with FMWL and SMWL fractions were glucans-type hemicelluloses and xylan-type hemicelluloses, respectively Understanding the structure of lignin could give insight into the properties of the lignin and enable the food processing industry to separate lignin more efficiently

Transition-metal free C3-amidation of quinoxalin-2(1H)-ones using Selectfluor as a mild oxidant.

Abstract: A practical and efficient synthetic route to construct a variety of 3-amidated quinoxalin-2(1H)-ones was developed via transition-metal free direct oxidative amidation of quinoxalin-2(1H)-ones with amidates using Selectfluor reagent as a mild oxidant. This protocol features mild reaction conditions, operational simplicity, broad substrate scope, and good to excellent yields.