柠檬苦素高效降解菌的分离筛选与鉴定

筛选出在酸性环境下高效降解柠檬苦素的菌株,扩展了生物法消除柑橘果汁中的苦味物质的应用领域。从新鲜醋醅中粗筛并分离出以柠檬苦素为唯一碳源的8株菌,其相应的柠檬苦素降解率均达70%以上,其中6、7、8号菌的柠檬苦素降解率较高,分别为95.14%、98.21%和94.31%。比较3株高效降解菌的胞外蛋白、胞内蛋白和菌液的柠檬苦素降解能力,3株菌中具有降解柠檬苦素的活性蛋白酶主要分布在细胞外,属于胞外蛋白酶,胞内蛋白对柠檬苦素几乎无降解作用,其中6号菌株胞外酶的柠檬苦素降解活性最强,柠檬苦素降解率为45.57%。形态学观察及分子生物学鉴定6、7、8号菌均属于拉乌尔菌属(Raoultella sp.)。菌株6具有高效降解柠檬苦素能力,能够成为今后降解柠檬苦素微生物源的优势菌种。     

添加剂柠檬苦素诞生

柠檬苦素及其类似物在柑橘属中含量丰富 ,主要存在于柑橘类果实的核、内果皮和囊衣等部位 ,含量在 1%左右 ,迄今在柑橘属中已分离出 3 6种柠檬苦素类似物和 17种葡萄糖配糖体。目前 ,美国、日本已取得采用柠檬苦素类似物制作药物、功能性保健食品和饮料的专利。随着对柑橘柠檬苦素类似物生理活性的阐明 ,国外对柠檬苦素类化合物的大规模的提取分离以及作为功能性食品添加剂的应用研究已有成功先例。中国食品发酵工业研究院刘凌博士表示 ,在不远的将来 ,柠檬苦素类似物将作为功能性食品添加剂或抗癌药物而商业化。添加剂柠檬苦素诞生…     

柑橘中类柠檬苦素的提取、分离纯化及检测技术研究进展

柑橘是世界第一大类水果，每年有大量的柑橘加工副产品产生，这些副产品中含有丰富的类柠檬苦素化合物，具有抗肿瘤、抗炎、抗病毒等多种生理作用，已被应用于食品、医药和农业等领域。开发高效的类柠檬苦素提取、分离纯化技术，研发快速的类柠檬苦素分析检测方法，有着重要的理论和实践价值。本文介绍了柑橘中类柠檬苦素结构特征及含量，重点综述了类柠檬苦素的提取、分离纯化及检测技术。总结发现新兴技术如超声辅助、超临界流体提取类柠檬苦素的提取效率较好，联合应用大孔树脂吸附、高速逆流色谱、制备型高效液相色谱法分离效果好。在检测技术方面，液相色谱是柑橘中类柠檬苦素使用最广泛的分析方法，可以准确检测出柑橘中所含类柠檬苦素的种类和含量，但高效、绿色、快速的前处理技术和便捷、高通量的检测技术还有待开发。本文为柑橘中类柠檬苦素的深入研究和综合开发利用提供参考,为促进柑橘副产物资源的利用提供依据。     

柑橘柠檬苦素大孔树脂分离纯化方法

以柑橘柠檬苦素为考察指标,研究大孔树脂分离纯化柠檬苦素的工艺条件。结果表明,D101大孔树脂对柑橘柠檬苦素有较好的吸附分离性能,是分离纯化柑橘柠檬苦素的适宜大孔树脂;D101大孔树脂分离纯化柑橘柠檬苦素的最佳工艺条件为：上样流速1 mL/min、上样质量浓度0.5 mg/mL、用 pH 6、80%的乙醇溶液作洗脱剂、洗脱流速2 mL/min。通过树脂回收重复使用,发现D101树脂通过再生处理后,其吸附性能未有明显降低,可以重复使用。采用上述方法得到D101大孔树脂对柠檬苦素的吸附率为88.53%,解吸率为93.47%,得率为82.75%。高效液相色谱检测可知,柠檬苦素的含量达到了92.79%。     

柑橘类的功能性成分研究概况

概述了柑橘类的功能性成分,包括类黄酮类、类柠檬苦素类、胡萝卜素类以及其它一些生理活性物质。其中,类黄酮类和类柠檬苦素类是柑橘中的最主要生理活性成分。     

柑橘活性成分检测技术研究进展

柑橘中富含类黄酮、类柠檬苦素、类胡萝卜素、酚酸等多种生理活性成分,在功能食品和药品开发方面具有广阔的应用前景。文中综述了近年来柑橘中主要活性成分的分离及检测技术进展,着重介绍了高效液相色谱在柑橘活性成分检测中的应用。     

响应面法优化柑橘皮柠檬苦素提取工艺

为优化柑橘皮中柠檬苦素的提取工艺,在单因素试验基础上,采用响应面分析法研究了提取时间、提取温度和液料比对柑橘皮柠檬苦素得率的影响,建立具有良好预测性能的数学模型,通过响应面分析法确定柑橘皮中柠檬苦素最优提取工艺条件。试验结果表明,提取温度和液料比对柑橘皮柠檬苦素得率的影响显著,最优提取条件为:提取时间20h,提取温度为51.5℃和液料比为96∶3(mL/g)。     

柑橘皮渣提取液中类黄酮与柠檬苦素分离工艺

柑橘皮渣提取液富含类黄酮与柠檬苦素,利用萃取与大孔树脂处理柑橘皮渣提取液分离2种物质。选择了4种萃取剂和7种大孔树脂,在萃取剂种类、萃取时间、溶液比例、大孔树脂吸咐率与解吸率方面对二者分离效果优劣进行比较,结果综合比较提取液经二氯甲烷与大孔树脂HPD100型处理后可良好分离类黄酮与柠檬苦素。柑橘皮渣提取液与二氯甲烷以1:1(mL/mL)的比例混合,萃取30min后,柠檬苦素全部转移至二氯甲烷有机相,二氯甲烷挥发完可得杂质较少的柠檬苦素类似物粗品,水相中的类黄酮未有损失,加入HPD100型吸咐分离水相中的类黄酮,其吸附率可达83.5%,解析率92.2%。柠檬苦素的大孔树脂纯化试验结果表明,大孔树脂纯化后与萃取后的柠檬苦素纯度无明显变化,同时会损失一部分目标物,所以大孔树脂不宜用在柠檬苦素的进一步纯化工艺。     

天然低共熔溶剂提取柑橘籽类柠檬苦素的工艺优化

为建立柑橘籽中柠檬苦素类化合物的绿色环保提取方法,该研究制备了13种天然低共熔溶剂,并对其理化性质进行了测定。采用超声辅助提取法从柑橘籽中提取柠檬苦素类化合物,并应用超高效液相色谱检测3种主要的柠檬苦素类化合物(柠檬苦素、诺米林和黄柏酮)。与传统乙醇溶剂(体积分数80%)相比,由氯化胆碱和甲酸(物质的量之比1∶4)组成的天然低共熔溶剂具有较好的提取效率。在此基础上,采用响应面法对含水量、液固比、提取温度和提取时间进行优化。结果显示,含水量12%(体积分数)、液固比10∶1(mL∶g)、提取温度60℃、提取时间34 min为最佳提取工艺,类柠檬苦素得率为13.87 mg/g。该研究表明,制备的天然低共熔溶剂可以作为从柑橘籽中提取类柠檬苦素的替代溶剂,为进一步应用天然低共熔溶剂从天然产物中提取生物活性物质提供参考。     

柑橘籽中柠檬苦素及类似物的生物活性研究进展

柠檬苦素类化合物是一类含有呋喃环并且高度氧化的四环三萜类植物次生代谢产物,具有显著的抗癌、抗病毒、抗氧化、抗微生物、昆虫拒食、抗炎镇痛和防治动脉粥样硬化等多种生物活性。柠檬苦素类化合物主要存在于芸香科和楝科植物中,在柑橘籽中的含量尤为丰富。该文综述了柑橘籽中柠檬苦素类化合物的种类、结构及其生物合成途径以及近年来国内外对柠檬苦素及类似物的生物活性的研究进展,并对其在食品工业、农业、医药和畜牧业中的应用等方面进行了概述。     

山茱萸果肉抑菌物质的提取及抑菌作用研究

以自来水作溶剂,对山茱萸果肉抑菌物质的提取条件进行了研究,得到了最佳提取条件为A3B2C1。将该物质对几种常见的食品微生物进行抑菌活性试验,发现其对细菌的抑制效果明显,但对霉菌和酵母效果一般;最低抑菌浓度(Mic)试验表明,该物质Mic为50%;此外,该物质抑菌pH范围为3~5、且热稳定性好。     

低糖果脯水分活性对保质期影响的研究

低糖果脯的保质期缩短是制约其发展的重要因素之一。本研究探讨了水分、糖分、亲水性物质对低糖果脯水分活性(Aw)的影响,明确(Aw)同保质期的关系。结果表明,亲水性物质降低Aw至0.65时,保质期达10个月以上。     

果汁中酚类物质的研究新思路

果汁中酚类物质与褐变、后混浊等技术难题密切相关,直接影响产品的色泽、风味和状态。但酚类物质对果汁特殊收敛口味很有贡献,且许多种类对人体有重要保健功能。论述了果汁中酚类物质的研究新思路,通过对果汁加工过程中酚类物质的形态和在各加工单元操作中变化规律的研究,探索其调控途径,为既消除果汁褐变和后混浊,又最大限度地保留果汁中酚类物质的功能成分提供科学依据。     

中草药提取液与淀粉复合膜在晚大新高梨的应用研究

为探讨中草药提取物与淀粉复合膜对晚大新高梨贮藏效果的影响,采用菌丝生长速率法探讨中草药提取物对引起梨轮纹病和梨黑星病两种贮藏病害病原菌的抑制作用,并探讨中草药提取液与淀粉复合膜对晚大新高梨贮藏效果的影响。结果表明:中草药以虎杖、黄苓和苦参等3种抑菌材料为原料的提取混合液对引起采后梨常见的贮藏病害梨轮纹病和梨黑星病害有一定抑制作用,而且随着提取液浓度的增加,抑制作用越强。中草药提取液和淀粉复合膜涂膜处理能延长晚大新高梨的贮藏寿命,使果实内呼吸强度、硬度和Vc含量变化明显低于对照组,延缓果实的物质消耗,减少果实与贮藏环境的物质交换,由于中草药中活性成分的作用抑制病原菌生长,减少果实腐烂;膜的特性及其对果实酶的诱导作用,有效抑制果实的呼吸强度,提高SOD活性,从而达到保鲜目的。     

Gac fruit (Momordica cochinchinensis Spreng.): a rich source of bioactive compounds and its potential health benefits

Gac (Momordica cochinchinensis Spreng.) is a tropical vine originating from South and South‐East Asia. Gac fruit has traditionally been used in Asia to provide red colour for cuisines and enhance visional health. Recently, Gac fruit has emerged as a potential source of carotenoids, especially lycopene and β‐carotene. Carotenoids and other identified bioactives from this fruit including phenolics, flavonoids and trypsin inhibitors are associated with many beneficial bioactivities such as antioxidant, anticancer and provitamin A activities. In addition to the traditional utilisation, commercial products like Gac powder and Gac oil have been manufactured as natural colourants and medicinal supplements. This paper is a review of the scientific literature on the nutritional composition, biological activities and processing of Gac fruit.     

Nutritional and therapeutic potentials of rambutan fruit (<Emphasis Type="Italic">Nephelium lappaceum</Emphasis> L.) and the by-products: a review

The progressive development of functional foods and herbal medicine has enthused many researchers to explore novel plant sources. In this regard, the rambutan fruit (Nephelium lappaceum L.) appears to be a promising candidate primarily due to its nutritional and bioactive compositions. With that, this particular review presents a systematic depiction of chemical composition and bioactivities of the rambutan fruit peel, pulp, and seed. Numerous reports do not provide sufficient data pertaining to cultivar, stage of maturity or the environment of fruit, yet the summarized data suggest a myriad of therapeutic potentials derived from the rambutan fruit. In fact, the rambutan fruit has been proven to possess phytochemicals that demonstrate anticancer, anti-allergic, anti-obesity, antidiabetic, anti-HIV, antimicrobial, anti-dengue, anti-hypercholesterolemic, and antihyperglycemic effects in varied in-vitro and in-vivo models. Nonetheless, advance studies are indispensable to further highlight the therapeutic mechanisms involved. In addition, a phytochemical analysis would further establish the rambutan fruit as a sustainable candidate in developing functional foods and pharmaceuticals.     

变废为宝——葡萄天然提取物大有可为

<正>近年来葡萄的需求持续增长,一方面是由于葡萄酒行业“井喷”式的发展,而用于各种饮品的葡萄汁的抢手是另一个原因。葡萄酒或葡萄汁生产使用的主要是果肉,而皮和籽则一般作为渣滓处理。其实皮和籽都是葡萄天然提取物的良好来源,只是没有得到足够的重视。例如许多葡萄酒生产企业将红葡萄汁脱色后作白葡萄汁使用,脱下的天然     

雪莲果发酵酒的防褐变技术研究

在不影响雪莲果果酒发酵过程和品质的前提下,通过添加抗坏血酸、柠檬酸、蜂蜜、菠萝汁等抗褐变剂来解决雪莲果果酒生产中的褐变问题,得到营养成分损失少、风味佳、色泽鲜亮的雪莲果果酒。结果表明,抑制雪莲果褐变程度的先后顺序为柠檬酸>抗坏血酸>菠萝汁雪莲混合比,蜂蜜在雪莲果酒陈酿期会产生深色物质,不适宜作为雪莲果果酒的抗褐变剂。影响感官的顺序分别为菠萝汁雪莲混合比>抗坏血酸>柠檬酸,最后得出抑制雪莲果酒褐变的最佳组合为抗坏血酸的添加量1.00%,柠檬酸的添加量0.75%,菠萝雪莲混合比为1:4。     

Antioxidant and anticancer activities of high pressure-assisted extract of longan (Dimocarpus longan Lour.) fruit pericarp

Longan fruit pericarp was extracted with 50% ethanol employing high pressure (500 MPa) and conventional extraction methods. Total phenolic contents of high pressure-assisted extract of longan (HPEL) and conventional extract of longan (CEL) were 20.8 and 14.6 mg gallic acid equivalents/g dry weight, respectively. Subsequently, the antioxidant activities of these extracts were analyzed employing various antioxidant model systems including 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, superoxide anion radical scavenging activity, total antioxidant capacity, and lipid peroxidation inhibitory activity. In addition, anticancer activity was also tested using HepG2, A549, and SGC 7901 cancer cell lines. HPEL showed excellent antioxidant and anticancer activities and were higher than CEL. Three phenolic compounds, namely gallic acid, corilagin, and ellagic acid, were identified and quantified by external standard methods. Compared with CEL, HPEL exhibited higher extraction effectiveness in terms of higher extraction yield, higher phenolic content, and higher antioxidant and anticancer activity with shorter extraction time.

Industrial relevance

This study was focused to evaluate the antioxidant and anticancer activity of longan fruit pericarp by high-pressure treatment. The high-pressure treatment provided a better way of utilizing longan fruit pericarp as a readily accessible source of the natural anticancer and antioxidant in food and pharmaceutical industry.     

Limonoids as cancer chemopreventive agents

Nutritional research on the health benefits of substances in plant foods has recently advanced to a new stage. The research frontier has moved from study of classical vitamin deficiency diseases to study of the thousands of phytochemicals that may have important physiological effects. Recent research suggests that citrus fruit consumers may be getting another health benefit from orange juice and other citrus products called limonoids, which appear to possess substantial anticancer activity. Limonoids are highly oxidized triterpenes present in Rutaceae and Maliaceae families. Several citrus limonoids have recently been subjected to anticancer screening utilizing laboratory animals and human breast cancer cells. The experimental results described that citrus limonoids may provide substantial anticancer actions. The compounds have been shown to be free of toxic effects in animal models, so potential exists for the use of limonoids against human cancer in either natural fruits, in citrus fortified with limonoids, or in purified forms of specific limonoids. Although the initial studies are very promising they have been conducted primarily with in vitro cell culture and animal models. Thus, research is needed to determine whether the limonoids may be useful in preventing or treating cancer in humans. Copyright © 2005 Society of Chemical Industry