柑桔加工下脚料提取类胡萝卜素、橙皮苷、果胶和柠檬苦素

介绍了从柑桔加工下脚料提取类胡萝卜素、橙皮苷、果胶和柠檬苦素类产品的工艺方法 ,并简述了这些产品在医药、食品、日化等方面的应用     

多孔梯度金属膜在果汁生产中的应用探索

简要叙述膜的发展现状及在果汁中的应用情况,利用多孔梯度金属膜进行苹果汁酶解前的淀粉和果胶过滤试验、果汁澄清通量试验和浓缩汁的巴氏杀菌试验。结果表明:酶解前的果汁经95℃左右的活化处理,利用多孔梯度金属膜在酶解前进行果汁微滤试验后,淀粉和果胶检验均为阴性,表明果汁中淀粉和果胶,经多孔梯度金属膜过滤即可分离除去,不需要淀粉酶和果胶酶的分解,节约大量的酶费用。在巴氏杀菌工段用了多通道的多孔梯度金属膜过滤后巴氏滤液,经检验不能降低后巴氏杀菌的浊度和隔除耐热菌,进行超滤试验发现滤液指标与陶瓷膜过滤还有一定距离。     

杀青条件对酶法提取南瓜果胶影响的研究

探讨了对纤维素酶法提取南瓜果胶效果有影响的两个杀青条件———温度和时间,并研究了优化工艺条件的放大过程。结果表明:杀青温度为85℃,杀青时间为20 min为最佳提取工艺,提取得率为14.3%。在放大15倍的实验中,提取得率为21.4%,这可能是由于放大实验中的测量误差减少所致。实验所得到的最佳果胶提取条件可以为综合利用南瓜提供一定的实验依据。     

微波辅助提取胡萝卜中果胶的工艺研究

采用微波辐射的方法提取胡萝卜中的果胶.实验考察了微波辐射时间、微波火力、草酸铵浓度、料液比及醇析中乙醇浓度对提取率的影响.实验确定微波条件下提取果胶的最佳工艺条件是:微波辐射时间2min,微波火力为中火,草酸铵浓度4g·L-1,料液比1:15 (g:mL),醇析中乙醇的浓度是70％,提取率可达6.907％.     

内源果胶酯酶制备低甲氧基果胶的研究

以新鲜橙皮为原料，在盐酸水解乙醇沉淀提取果胶之前，激活并利用果皮中固有的果胶酯酶进行果胶的酶法脱酯，制备低甲氧基果胶，以产品的甲氧基含量和果胶得率为指标，确定最佳工艺条件。结果表明新鲜橙皮内源酶法制备低甲氧基果胶的最佳工艺条件为：加入果皮浆液量0．15％的内源性果胶酯酶激活剂碳酸钠，控制温度45℃，pH值8．0进行脱酯，时间60min；果胶提取温度90％，时间60min，pH值2．0；在此条件下制备的果胶甲氧基含量为5．93％，符合低甲氧基果胶标准，果胶得率为2．46％。     

薛荔籽果胶对去势雌性大鼠矿物质吸收的影响

目的:探讨薛荔籽果胶对去势雌性大鼠矿物质吸收的影响。方法:将30只SD成年雌鼠随机分为5组。4组大鼠做双侧卵巢切除手术,一周后分为空白组和薛荔籽果胶高、中、低剂量组;用伪切除同龄大鼠作对照(Sham组)。喂养4周后解剖,测定盲肠内容物pH值、短链脂肪酸、骨钙、骨磷含量及矿物质元素的表观吸收等指标。结果:去势雌性大鼠对钙、镁、磷、锌和铁元素的表观吸收率及骨钙和骨磷含量显著低于正常大鼠(P<0.05)。薛荔籽果胶能显著增加去势雌性大鼠短链脂肪酸含量和盲肠面积(P<0.05),降低盲肠pH值,并且在一定程度上抑制钙、镁、磷、锌和铁元素的表观吸收率。结论:薛荔籽果胶能降低去势雌性大鼠矿物质的表观吸收率。     

柚皮中黄酮和果胶联产工艺的研究

柚皮中黄酮和果胶的联产工艺研究,对提高柚皮的综合利用率、降低生产成本、提高附加经济价值和企业经济效益具有积极作用。实验就黄酮提取和果胶提取分别作L9(34)和L16(44)正交优化试验,工艺实验表明,提取黄酮的较佳工艺条件是:85%的乙醇,固液比1∶15、温度85℃、时间1h,黄酮提取后的柚皮渣中提取果胶的较佳工艺条件是:温度100℃、pH1.5、固液比1∶16、时间1.5h。50g柚皮中可提取粗黄酮13.5g,其滤渣中可得果胶4.36g,纯度为89.31%。     

Effect of Phenolic Acid on Antioxidant Activity of Wine and Inhibition of Pectin Methyl Esterase

Antioxidant activity, malolactic fermentation and sensory evaluation of the grape must after fermentation in the presence of gallic acid and coumaric acid, as well as the inhibitory mechanism of gallic acid and coumaric acid on pectin methyl esterase (PME), were investigated. The content of malic acid and lactic acid increased 40.4% and 36.9% compared to the control when commercial pectic enzyme (CPE) was used. The increase in malic acid content was enhanced by 64.8% and 83.4%, compared to the control in the presence of CPE + Gallic acid and CPE + Coumaric acid respectively. Ferric reducing/antioxidant power (FRAP) increased in the samples with added CPE. In addition to an increase in the FRAP, antioxidant capacity was enhanced in the CPE + Gallic acid and CPE + Coumaric acid samples. No significant differences were found in the content of total anthocyanin and in the value of sensory characteristics. The content of total flavanols increased significantly in the samples with added CPE. Lineweaver‐Burk plots of PME, with gallic acid or coumaric acid, indicated that gallic acid and coumaric acid were mixed inhibitors of PME.     

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.     

Optimisation of acid extraction of pectin from sweet potato residues by response surface methodology and its antiproliferation effect on cancer cells

The response surface methodology was employed to study the acid extraction of pectin from sweet potato residues. The effects of extraction temperature, extraction time, solution pH and liquid/solid ratio on yield and galacturonic acid content of pectin were investigated. Experimental data were fitted to quadratic polynomial models and analysed using appropriate statistical methods. The determined optimum conditions were extraction temperature 93 °C, extraction time 2.2 h, solution pH 1.7 and liquid/solid ratio (v/w) 30:1. Under these conditions, the experimental extraction yield and galacturonic acid content of pectin were 5.09% and 70.03% (w/w), which were in good agreement with predicted values, 5.08% and 69.40%, respectively. In addition, sweet potato pectin exhibited remarkable antiproliferation effects on human colon cancer cells HT‐29 and human breast cancer cells Bcap‐37 by 46.64% and 42.64% at 1.00 mg mL^?1 separately, indicating that it could potentially be used as a natural supplement in functional foods.