玫瑰红景天醇提物不同溶剂萃取物的生物活性

以无水乙醇为溶剂,用索氏提取器对玫瑰红景天粉末进行回流提取,回收乙醇后将乙醇提取物分散和溶解在水相中,依次用环己烷、氯仿、乙酸乙酯、正丁醇分别萃取,得到不同溶剂萃取物。用比色法测定不同溶剂萃取物和水相物中总酚和总黄酮含量,DPPH·法、Fenton法、普鲁士蓝法评价其抗氧化活性以及测试最小抑菌浓度(MIC)和最小杀菌浓度(MBC)。结果表明,乙酸乙酯萃取物中总酚和总黄酮含量最高,分别为(469.32±1.15),(338.57±0.92)mg/g萃取物;不同萃取物和水相物对DPPH·、·OH有不同程度的清除作用且有还原能力,其中乙酸乙酯萃取物和正丁醇萃取物有相对较好的抗氧化活性;总酚和总黄酮含量与抗氧化活性呈显著相关性(P<0.05);对选用的9种菌株均有抑制和灭活作用,MBC值在0.28~16.94mg/mL,对金黄色葡萄球菌株灭活作用更为显著,其中氯仿萃取物和乙酸乙酯萃取物的抗菌效果相对较好。玫瑰红景天乙醇提取物的不同溶剂萃取物及水相物均有抗氧化活性和抗菌活性,有潜在的应用价值。     

一种制备超低盐、浅色、肉香型酵母提取物的工艺

鲜啤酒酵母在低温下清洗脱苦，并通过慢速冻结后解冻可获得一定程度的破壁作用，随后添加5％乙醇，采用超声波破壁处理，细胞内有46．3％的含氮物质溢出胞外。自溶前酵母浆葡萄糖含量达到1．49%(以鲜酵母计)，对自溶液色泽褐化加深有显著影响。采用酿酒活性干酵母发酵和葡萄糖氧化酶进行除糖前处理，对自溶酵母液色泽均有显著的保护作用，可获得淡黄色自溶液。发酵前处理对自溶液风味具有显著影响，抽提物为鸡肉香型，且氨基酸态氮含量达到5．12％(以干酵母计)。采用以上工艺可获得超低盐含量、色泽浅且为肉香型的酵母提取物制品。     

金莲花浸膏的热裂解行为及单料烟加香应用研究

在模拟卷烟点燃过程条件下对金莲花浸膏进行了热裂解,以气相色谱-质谱法测定其在不同温度（300、600、900 ℃）下的裂解产物,并进行单料烟加香研究。结果表明,在300、600、900 ℃的金莲花浸膏热解产物中分别鉴定出28、29和31种成分,裂解产物主要为酸类、酯类、醇类、酚类、醛类和酮类等对烟草香味有利的香味物质。金莲花浸膏具有改善和修饰单料烟吸味、丰满烟气、减轻刺激性的作用。     

仙人掌超氧化物歧化酶的制备研究

对500g仙人掌进行捣碎匀浆、硫酸铵分级沉淀浸提、离心、除杂蛋白、溶解等一系列处理后得到SOD(超氧化物歧化酶)粗酶液。所得粗酶液用聚酰胺(100目)层析柱层析实现纯化,再经过冷冻干燥即得到含有SOD的白色粉末。用联苯三酚法测定该白色粉末具有的酶活力。实验结果显示得到含有SOD的白色粉末酶活力为0.9590×104U/g粉末。影响酶活力大小的外界因素主要包括pH值、温度、抑制剂。结果显示在pH值为7.5～8.5时酶活力最大,稳定性也好。温度维持在25～30℃时酶活力最高。由于过氧化氢和氰化钾能使仙人掌SOD的酶活力显著下降,因而可以判断从仙人掌中提取到的SOD是Cu·Zn-SOD。     

藻类膳食纤维制备及功能进展

海洋藻类无需外源营养,通过光合作用即可生长,富含膳食纤维.本文综述了藻类膳食纤维的提取方法、生理功能和应用前景.藻类膳食纤维在降血糖、降血脂、抗氧化、改善肠道功能、增强免疫力方面的良好表现,使得其可以开发成多种功能食品.其良好的吸水性、吸油性、膨胀力使得藻类膳食纤维可以在面条、面包、可食用生物膜、食品添加剂方面有广泛的...     

Promising antifungal effect of some Euro-Asiatic plants against dangerous pathogenic and toxinogenic fungi

BACKGROUND: Increasing evidence of fungicide‐resistant toxinogenic and pathogenic fungal species is obvious. Looking for new possibilities of antifungal treatment or sources of antifungal substances is a major problem. Some medicinal plants exert strong antifungal properties and could be conveniently used as a promising alternative source for presently problematic antifungal treatment in many areas with respect to their natural origin. Methanol extracts of 46 medicinal plants from the Eurasian area were used in a screening assay for antifungal activity in this study. The growth inhibitory effect was tested against six significant pathogenic and toxinogenic fungal species: Fusarium oxysporum, F. verticillioides, Penicillium expansum, P. brevicompactum, Aspergillus flavus and A. fumigatus. RESULTS: For 14 plant species, the possibility of using them as natural fungicides was indicated. The extract from Grindelia camporum showed significant activity against all target fungal species. The most sensitive target fungus was the toxinogenic and human pathogenic species A. fumigatus. CONCLUSION: This study has identified 14 extracts of medicinal plants with a potential use as an antifungal treatment in various areas. One of them showed promising efficiency against all selected significant pathogenic and toxinogenic fungal species. Copyright © 2010 Society of Chemical Industry     

Anti‐influenza virus activity of extract of Japanese wasabi leaves discarded in summer

BACKGROUND: Japanese wasabi (Wasabia japonica) is now habitually used as a spice in some kinds of Japanese foods, and its pungent taste and flavor are preferred. Generally, rhizomes and winter leaves are used as a spice and for processed foods such as pickled wasabi. Since the leaf area of summer leaves is far greater than that of winter leaves, they are not used for food, and are discarded. Thus, we need to develop an effective use for summer leaves. We investigated anti‐influenza virus activity in these summer leaves as a new function. RESULTS: Seventy percent ethanol extracts of leaves harvested in July exhibited a high replication inhibition rate (98% or higher) in the type A strain (AH1N1, A/shimane/48/2002), its subtype (AH3N2, A/shimane/122/2002), and type B strain (B/shimane/2/2002). The extracts of summer leaves exhibited the same anti‐influenza virus activity as winter leaves, and showed a stronger activity than stems, roots, and rhizomes. CONCLUSION: A potent anti‐influenza virus activity was discovered in summer leaves of Japanese wasabi. The ethanol extracts inhibited influenza virus replication regardless of the hemagglutinin antigen type. Therefore, such extracts are expected to be a promising source of a novel anti‐influenza virus agent. Copyright © 2008 Society of Chemical Industry     

啤酒废酵母在酱油生产中的应用

现今我国已成为仅次于美国的第2大啤酒生产国。啤酒工业的迅速发展产生了大量啤酒废酵母泥。介绍了利用酵母水解技术与传统酿造工艺相结合生产出高级营养酱油的生产过程,此过程主要是通过添加木瓜蛋白酶来达到分解啤酒酵母的目的,同时利用固态低盐酿造工艺来生产生酱油,再经过适当的调配得到符合标准的优质酱油。用此工艺生产的酱油卫生质量指标符合国家有关标准,而且营养丰富,味道鲜美,具有良好的经济效益。     

骨素酶解工艺条件的响应面法优化

通过响应面法分析了木瓜蛋白酶酶解骨素的工艺条件,以水解度、鲜味、酸味、苦味为评价指标,建立了水解度与酶解温度、酶解时间、pH及酶用量之间的相关性模型,并对最优酶解工艺进行了优化,验证结果表面所得模型可用于预测不同酶解条件下骨素的水解度;优化结果显示,酶解温度60℃、酶解时间5 h、pH4、酶用量8 750 U/g时,木瓜蛋白酶酶解骨素的水解度最高,所得酶解液的鲜味强于酸味,无苦味。     

箭竹叶提取物的抗微生物作用

对箭竹叶提取物的抗菌作用进行了初步研究,结果表明:箭竹叶提取液对供试的几种主要危害食品卫生、安全和对临床医学以及生物材料等具有重要影响的金黄色葡萄球菌、表皮葡萄球菌、黑曲霉、酿酒酵母和大肠杆菌等均有抑制效果,以芦丁黄酮类物质计的箭竹叶提取物对各敏感供试菌的最低抑菌浓度分别是7.50、7.50、7.50、7.50和15.00mg/100ml。