Isolation and evaluation of the antioxidant activity of phenolic constituents of the Garcinia brasiliensis epicarp

A new glycosylated biflavonone, morelloflavone-4′″-O-β-d-glycosyl, and the known compounds 1,3,6,7-tetrahydroxyxanthone, morelloflavone (fukugetin) and morelloflavone-7″-O-β-d-glycosyl (fukugeside) were isolated from the epicarp of Garcinia brasiliensis collected in Brazil. The structures of these compounds were established using ¹H and ¹³C NMR, COSY, gHMQC and gHMBC spectroscopy. The compounds exhibited antioxidant activity. The greatest potency was displayed by morelloflavone (2), with IC₅₀ = 49.5 mM against DPPH and absorbance of 0.583 at 400 μg/mL for the reduction of Fe³⁺. The weakest potency was displayed by 1,3,6,7-tetrahydroxyxanthone (1), with IC₅₀ = 148 mM against DPPH and absorbance of 0.194 at 400 μg/mL for the reduction of Fe³⁺.     

Lotus seed epicarp extract as potential antioxidant and anti-obesity additive in Chinese Cantonese Sausage

The antioxidative activities of a lotus seed epicarp extract in different concentrations (6.25, 12.5, 25, 50 and 100 μg.mL^− 1) in pork homogenates representative of Chinese Cantonese Sausage were evaluated using three methods: thiobarbituric acid-reactive substances (TBARS) values, peroxide values (POVs) and acid values (AVs). Also the cytotoxic and anti-obesity effects of the lotus seed epicarp extracts were evaluated using an in vitro 3T3-L1 preadipocyte cell model. Results showed that the lotus seed epicarp extracts were non-toxic and effective in inhibiting preadipocyte differentiation. Supplementation of pork homogenate with lotus seed epicarp extracts was effective in retarding lipid oxidation. Moreover, the antioxidative and preadipocyte differentiation inhibition effects of the lotus seed epicarp extracts were dose-dependent. Thus, the lotus seed epicarp extract might be a good candidate as an antioxidant and anti-obesity natural additive in Chinese Cantonese Sausage.     

Variations in proanthocyanidins of japanese-type plums during maturation and storage

Proanthocyanidins in epicarp and mesocarp tissue of dark-red-fleshed (Rubysweet) and yellow-fleshed (Byrongold) plums remained unchanged during the third stage of fruit development and storage of green and midripe fruit for 6 days at 18 °C, 80% RH. Differences were significant by cultivar and tissue type. Red-fleshed plums and epicarps of both cultivars contained greater quantities of proanthocyanidins. Degree of polymerization, indicated by vanillin/proanthocyanidin ratios, did not increase in either cultivar with maturity or storage time.     

莲子皮渣中酚类物质的提取优化及抗氧化活性评价

本文以莲子加工副产物-莲子皮渣为实验材料,在单因素实验的基础上,以总酚、总原花色素、DPPH·+清除能力为响应值,通过响应面设计优化莲子皮渣活性成分超声辅助提取条件,建立二次响应面回归模型,模型均显著且拟合性好。最优提取工艺为:丙酮浓度70%,料液比1:25.5 g/mL,提取时间1.6 h,提取温度50℃。该提取条件下,里叶白莲莲子皮渣提取物总酚、总原花色素、DPPH·+清除能力分别为194.54±3.63 mg GAE/g DW,243.15±2.88 mg CE/g DW,238.53±3.07 mg AAE/g DW,与预测值相符,证明实验建立的响应面模型可用于莲子皮渣中总酚、总原花色素、DPPH·+清除能力实验结果预测。对不同品种莲子皮渣植物化学素含量及体外抗氧化活性进行测定,发现莲子皮渣均富含多酚、类黄酮、原花色素、三萜等生物活性物质,且具有较高体外抗氧化活性。研究表明莲子皮渣富含生物活性成分,具有开发利用的巨大潜在价值。     

山核桃等3种果蓬化学成分分析和利用评价的研究

以机制炭致密成型常用原料杉木屑、松木屑为对照,对比分析了山核桃、板栗、油茶3种果蓬的灰分、抽出物、纤维素、木质素等9种化学成分,结果表明:山核桃果蓬的灰分为12.23%;从抽出物对比来看,山核桃、板栗和油茶果蓬的冷水抽出物、热水抽出物、1%NaOH抽出物均大于杉木屑和松木屑,说明果蓬类原料比杉木屑、松木屑含有更多的低分子多聚戊糖和低分子木质素;纤维素和木质素含量低、灰分含量高也限制了果蓬类原料大量替代木屑制备机制炭。