Hongtao Du,Juncheng Chen,Shan Tian,Hongling Gu,Na Li,Yao Sun,Jiajia Ru,Junru Wang
In this research, extraction optimization, preliminary characterization and immunological activities in vitro of polysaccharides from Elaeagnus angustifolia L. pulp were investigated. A response surface methodology (RSM) with a Box-Behnken design (BBD) was used to optimize the extraction process. The maximum EAP yield was 9.82 ± 0.38%, which is in good agreement with the predicted value (9.93 ± 0.24%). Two homogeneous polysaccharides, EAP-1a and EAP-1b with molecular weights of 8.70 kDa and 4.39 kDa respectively, were prepared by DEAE-52 cellulose and Sephadex G-100 columns and characterized by HPLC, HPGPC, and FT-IR. Three polysaccharides (EAP, EAP-1a and EAP-1b) could stimulate macrophages to release NO and enhance phagocytic activities of RAW 264.7 cells in dose-dependent manner. Moreover, there was no significant difference between crude EAP group (400 μg/mL) and positive control group (LPS) in effects on macrophages. The results implied that EAP had the potential to be developed as natural medicines or health foods .
A novel and economical approach was proposed for synthesizing the β-cyclodextrin (β-CD) embellished ginkgo nut-derived porous carbon (GNDPC) with three-dimensional (3D) interconnected honeycomb-like morphology, which was employed to decorate the glassy carbon electrode (GCE) for the construction of methyl parathion (MP) electrochemical sensor (GNDPC@β-CD/GCE) for the first time. GNDPC with higher surface area possessed good adsorptive capacity and superior conductive property because of 3D interconnected honeycomb-like porous carbon network. β-CD improved the dispersibility of GNDPC and enhanced the molecular recognition and accumulation capability of GNDPC towards MP. The synergetic cooperation of β-CD and GNDPC realized the ultrasensitive detection property of MP (Limit of detection: 4.52 nM; Concentration: 0.005–15 μM). The constructed GNDPC@ β-CD/GCE displayed good MP determination feasibility in apple and pear juices (Recovery rate: 95.8–100.1%; Relative standard deviation: 2.12–4.17). This work exhibits a novel approach for the sensitive determination of MP in foods.
Lactobacillus curieae CCTCC M2011381 is a novel strain isolated from stinky tofu brine. In order to evaluate the potential of the strain in fermenting plant foodstuff and possible bioactivity produced in fermentation, the growth of the strain in soymilk, soy protein isolate and ginkgo nut beverages was studied firstly. Cell counts of the strain could increase 4 log CFU/mL after 20 h of growth in all materials. The scavenging ratio of diphenyl picryl hydrazinyl radical was improved by the fermentation due to total flavonoids content increase, peptides formation, and efficient transformation of soy isoflavone glycoside to aglycone. Meanwhile, the fermentation significantly enhanced the inhibitions of 3-hydroxy-3-methylglutaryl-coenzyme A reductase of all the three materials. The highest inhibition of 67.2% was achieved by the fermented ginkgo nut beverage. The fermentation also significantly raise the inhibition of angiotensin I converting enzyme of soy protein isolate and ginkgo nut beverages. Finally, the strain was verified survival in mice gastrointestinal tract within all the fermented matrices. The highest cell count, 5.14 log CFU/g faeces, was detected at 5 d after the gavage of fermented soy protein isolate beverage. Accordingly, L. curieae has the prospect as the starter culture in fermentation of plant foodstuff.