Microencapsulation of bioactive compounds from mulberry (Morus alba L.) leaf extracts by protein–polysaccharide interactions

Mulberry leaf extracts were generated using four concentrations of ethanol (50%, 60%, 70%, and 95% v/v). A 60% ethanolic mulberry leaf extract (60E) yielded a high total phenolic content (TPC) and antioxidant activity using 1, 1‐diphenyl‐2‐picrylhydrazyl (DPPH) radical scavenging and a ferric reducing antioxidant power (FRAP) assay. Coating materials were derived using a combination of soy protein isolates (SPI) and low methoxyl (LM) pectin in a 1:1 ratio. The effect of various parameters on microencapsulation, such as pH (3.5, 4.0, and 4.5) and the concentration of coating materials (2.5, 5.0 and 7.5% w/v), was studied. Microcapsules produced using 60E as a core material at pH 4.0 with 7.5% of coating material showed a high encapsulation yield, encapsulation efficiency, TPC and antioxidant activity.     

Effects of hydrogen sulphide on quality and antioxidant capacity of mulberry fruit

Here we investigated the effect of hydrogen sulphide (H₂S) on postharvest quality of mulberry fruit and possible underlying mechanisms. Endogenous H₂S content first increased after harvest and then decreased sharply with the process of ripening and senescence. A fumigation with H₂S released from 0.8 mm NaHS solution could significantly enhance the endogenous H₂S content by increasing the activities of D‐cysteine desulfhydrase and L‐cysteine desulfhydrase. NaHS could significantly slow down the ripening rate of mulberry fruit and reduce the respiratory intensity and anthocyanin content. Moreover, H₂S fumigation was able to obviously delay or slow down the decreases in soluble protein, titratable acidity and ascorbate contents. Further results showed that activities of representative antioxidant enzymes in H₂S‐treated sample were higher than those of control samples during storage, resulting in a decrease in superoxide anion production. Together, these results clearly indicate that H₂S fumigation has a potential role in the preservation of mulberries.     

桑椹天然植物染料的稳定性能

研究了桑椹天然植物染料在不同条件下的稳定性能.通过测试染液可见吸收光谱来探讨酸碱、温度、光照以及金属离子对桑椹天然植物染液的影响.结果显示:桑椹天然植物染液可见吸收光谱在紫外区域出现新的吸收峰且峰形尖锐,随pH提高而出现吸收峰红移现象(逐渐减弱并消失),染料适合在酸性浴(pH≤4)或碱性浴(pH≥8)中染色;在80℃以下稳定性良好,但耐光性较差,长时间的光照使染液色泽灰暗,鲜艳度下降:Al<'3+>使染液表现出明显的增色效应和轻微的吸收峰红移现象,Mg<'2+>对染液颜色影响很小、Cu<'2+>有轻微增色效应,加入Fe<'3+>染液吸收峰红移(逐渐减弱消失并在紫外光区域出现末端吸收效应).     

A simple preparative method for isolation and purification of polysaccharides from mulberry (Morus alba L.) leaves

An effective method for preparative extraction and purification of the polysaccharides from mulberry leaves was studied. Orthogonal experiment was carried out to get the optimal conditions (T = 70 °C, pH = 6, t = 60 min, D = 0.4 g g^?1 material) of activated carbon decolorisation. The staged, isocratic and multiple ethanol precipitation procedures were also investigated. Through the activated carbon decolorisation and 20% ethanol precipitation procedure, the polysaccharides yield reached 2.91%, and the content of neutral sugar and uronic acid were improved to 21.87% and 57.43% respectively. This process was superior to the macroporous resin adsorption and gel permeation chromatography (GPC) methods. The structure analysis indicated that the purified mulberry leaves polysaccharide (MLP) was composed of Man, GalA and Rha in the ratio of 1.0:7.2:20.0. The molecular weight measured using GPC was approximately 557 062 D. The IR and ¹H NMR spectra indicated that the MLP was mainly pectin, which was classified as high‐methoxyl pectin.     

竹/丝交织物设计与性能测试

从充分发挥纤维的性能优势及获得优异的织物服用性能出发,重点对纱线、织物结构及性能进行设计,选择桑蚕丝做经纱、竹浆纤维做纬纱,生产平纹、1/3破斜纹、5/3经面缎纹织物,并与纯桑蚕丝、纯竹浆纤维织物进行性能测试比较,可知竹/丝交织物的性能得到了一定程度的改善.     

Sex phermone components of mulberry looper,Hemerophila atrilineata butler (lepidoptera: Geometridae)

(6Z-9S, 10R)-Epoxy-octadecene (SR-1) and (3Z, 6Z-9S, 10R)-epoxy-octadecadiene (SR-2) are sex pheromone components of the mulberry looper (MBL),Hemerophila atrilineata Butler. Compounds extracted from female MBL pheromone glands were identified by coupled gas chromatographic-electroantennographic detection (GC-EAD) and GC-mass spectrometry. In field experiments in China,SR-2,RS-2, or both combined were hardly attractive, butSR-2 in combination withSR-1 attracted significant numbers of MBL males. Synergistic behavioral activity ofSR-1 plusSR-2, but not of corresponding antipode mixtures, indicates enantiospecificity of MBL pheromone communication. Because blends of racemic and enantiospecific (SR)1 plus2 were similarly attractive, racemic1 plus2 may have potential for mass trapping or confusion of MBL males in commercial mulberry plantations.