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Snake gourd is a seasonal vegetable with a high water content and medicinal value, but the short harvest period limits the large-scale application of snake gourd. Therefore, the effects of freeze–thaw pretreatment (FT) combined with hot air (HD) on the drying characteristics, active ingredients and bioactivities of snake gourd were investigated. The results showed that FT pretreatment reduced browning and shortened the drying time by 44%; the Page model was the best fit for describing the drying process. The polysaccharide contents (21.70% in alcoholic extract (TG1) and 44.34% in water extract (TG2)) and total phenol contents (1.81% in TG1 and 0.88% in TG2) of snake gourd pretreated by FT-HD were higher than those of snake gourd pretreated by the corresponding HD treatment. The FT pretreatment decreased the molecular weight of snake gourd polysaccharides and increased the molar ratio of glucose. The extracts pretreated by FT-HD showed greater chemical, cellular antioxidant capacity and α-amylase and α-glucosidase inhibition than those pretreated by HD. FT-HD can be recommended for achieving a short drying time and high quality of snake gourd and can be used for the drying of other fruits and vegetables. [ABSTRACT FROM AUTHOR]

Byline: Weiwei. Feng, Qian. Li, Wei. Wang, Ting. Zhao, Yun. Feng, Fang. Li, Guanghua. Mao, Yao. Chen, Yangyang. Ding, Liuqing. Yang, Xiangyang. Wu OBJECTIVES: In our preliminary study, chromium malate [...]

Our previous study revealed that the antioxidant activity of polysaccharide (coded as FGFP) extracted from Grifola frondosa by enzymolysis treatment was significantly superior than that (coded as GFP) extracted by boiling-water. In this study, one purified polysaccharide fractions (coded as FGFP-11) was obtained from FGFP by purified using DEAE-52 column and Sephacryl S-500HR column. Results indicated that FGFP-11 with MW of 59.82 kDa consisted of mannose, glucose and galactose with a molar ratio of 1.00:16.36:5.25. Fourier Transform Infrared Spectroscopy (FTIR spectrum) of FGFP-11 was similar with that of polysaccharide extracted by boiling-water from Grifola frondosa. These indicated the enzymolysis did not destroy the polysaccharide structure. NMR spectrum showed that FGFP-11 possess α-(1→6) glycosidic bond and α-(1→3) glycosidic bond configuration. The experiment of Congo red also revealed that FGFP-11 had triple helix stereo-configuration. Moreover, the antioxidant activities of FGFP-11 were improved compared with that of GFP, especially in scavenging of hydroxyl radical and diphenyl picryl hydrazinyl (DPPH) radical. [ABSTRACT FROM AUTHOR]

Previous study has revealed that chromium malate could improve insulin resistance and the regulation of fasting blood glucose in type 2 diabetic rats. This study was designed to investigate the effect of chromium malate on hypoglycemic and improve insulin resistance activities in 3T3-L1 adipocytes with insulin resistance and investigate the acting mechanism. The result indicated that chromium malate exhibited direct hypoglycemic activity in vitro . Compared with the model group, chromium malate could significantly promote the expression levels of GLUT-4, Akt, Irs-1, PPARγ, PI3K and p38-MAPK and their mRNA, increase p -AKT/AKT level, AKT and AMPKβ1 phosphorylation and reduce Irs-1 phosphorylation and p -Irs-1/Irs-1 level in 3T3-L1 adipocytes ( p < 0.05). Chromium malate is more effective in regulating the proteins and mRNA expressions than those of chromium trichloride and chromium picolinate. Compared to the model group, pretreatment with the specific p38-MAPK inhibitor completely inhibited the GLUT-4 and Irs-1 proteins and mRNA expressions induced by the chromium malate. In conclusion, chromium malate had a beneficial influence on improvement of controlling glucose levels and insulin resistance in 3T3-L1 adipocytes with insulin resistance by regulating proteins productions and genes expressions in glucose uptake and insulin sensitivity signaling pathways., Competing Interests: No., (This journal is © The Royal Society of Chemistry.)

Background: This research is among the few that has been conducted on the feasibility of subcritical water extraction (SWE) as a rapid and efficient extraction tool for polysaccharides., Objective: The aim of the study was to extractand optimize the parameter conditions of SWE of polysaccharides from Grifola frondosa using response surface methodology., Materials and Methods: In the study, SWEwas applied to extractbioactive compounds from G. frondosa. A preliminary analysis was made on the physical properties and content determination of extracts using SWE and hot water extraction (HWE). Analysis of the sample residues and antioxidant activities of the polysaccharides extracted by SWE and HWE were then evaluated., Results: THE OPTIMAL EXTRACTION CONDITIONS INCLUDE: extraction temperature of 210°C, extraction time of 43.65 min and the ratio of water to raw material of 26.15:1. Under these optimal conditions, the experimental yield of the polysaccharides (25.1 ± 0.3%) corresponded with the mean value predicted by the model and two times more than the mean value obtained by the traditional HWE. The antioxidant activities of polysaccharides extracted by SWE were generally higher than those extracted by HWE. From the study, the SWE technology could be a time-saving, high yield, and bioactive technique for production of polysaccharides.