Phytochemistry, nutritional and pharmacological properties of Artocarpus heterophyllus Lam (jackfruit): A review

Artocarpus heterophyllus Lam, commonly known as the jackfruit tree and belonging to the family Moraceae, is an exotic tree originally native to the Western Ghats of India. The fruits are of dietary use and are an important source of carbohydrate, protein, fat, minerals and vitamins. The heart wood is a very durable timber and is used in the preparation of furniture. The bark, roots, leaves, and fruit are attributed with diverse medicinal properties and are used in the various traditional and folk systems of medicine to treat a range of ailments. Preclinical studies have shown that jackfruit possesses antioxidant, anti-inflammatory, antibacterial, anticariogenic, antifungal, antineoplastic, hypoglycemic, wound healing effects and causes a transient decrease in the sexual activity. Clinical studies have also shown that the decoction of the leaves possesses hypoglycemic effects in both healthy individuals and non-insulin-dependent diabetic patients. Phytochemical studies have shown that jackfruit contains useful compounds like the flavonoids, sterols and prenylflavones which may have been responsible for the various pharmacological properties. The present paper reviews the nutritional value, culinary uses, the phytochemical compounds, traditional usage and validated pharmacological properties of jackfruit.     

Anti yeast activities of some essential oils in growth medium, fruit juices and milk

The anti-yeast activities of four essential oils (EOs) from clary sage, juniper, lemon and marjoram against wild-type isolates of the food-related yeasts Geotrichum candidum, Pichia anomala, Saccharomyces cerevisiae and Schizosaccharomyces pombe in malt extract (ME) medium, apple juice and milk were investigated. Minimal inhibitory concentrations (MICs) for the EOs and their main components were determined and the checkerboard method was used to calculate fractional inhibitory concentration (FIC) indices for the combinations of EOs or components. The most sensitive yeast was S. pombe (MICs of 0.0625-0.125 μl/ml) while G. candidum proved to be the most insensitive (MICs of 0.5-2 μl/ml). In general, the lag phases were lengthened by increasing EO concentrations, while significant reduction of growth rates was obtained only at the highest EO concentrations. The anti-yeast effects of the EOs were good in the acidic pH range optimal for yeasts growth. Combinations of juniper and clary sage EOs resulted in additive effects in the case of S. cerevisiae and G. candidum, but all other combinations showed no interaction. The combination of α-pinene and limonene led to synergism, while the combination of α-pinene with linalool resulted in an additive effect. Cloudy apple juice protected the yeasts against the effect of lemon EO: the lag phases were shorter and the growth rates higher than in clear apple juice. Lemon EO decreased the growth rate of G. candidum in skimmed milk in a dose-independent manner. Our results show that by adding lemon EO to clear apple juice a new, harmonic taste can be achieved and open storage time could be prolonged.     

大蒜抑菌成分提取工艺优化

通过采用超声波辅助提取法,对不同提取条件下大蒜提取液抗番茄晚疫病菌作用进行比较,优选出最佳提取工艺,并测定了其最小抑菌质量浓度、最小杀菌质量浓度。研究结果表明:大蒜提取液以体积分数30%乙醇作为提取溶剂,在40℃超声波辅助提取3 h,提取次数为3次,料液比为1∶5(g/mL),得到大蒜提取液抑菌效果最佳的条件。在此条件下大蒜对番茄晚疫病菌的抑菌直径为37.2 mm。大蒜提取液对番茄晚疫病菌最小抑菌质量浓度为12.5 mg/mL,最小杀菌质量浓度为25 mg/mL。     

Comparison of the microbiological influence on the electro-chemical potential of stainless steel between macro- and micro-areas of specimens

The microbiologically caused ennoblement appears in natural waters on all stainless steels equally and has been described in numerous publications. In addition to an external polarization of such a system, temperature, oxygen and pH-levels, supply of nutrients and/or the supply of substances to restrain biological activity have a direct influence on the rate of the potential rise. The final value of the potential is substantially regulated by the biological system and is independent of the steel composition.At the University of Applied Sciences in Konstanz, Germany, the potential rise of stainless steels has been examined in experimental set-ups. Up to recently, only effects on the open circuit potential of specimens have been measured. In order to further understand the mechanisms behind the potential rise, these specimens have been divided into micro-areas and Microelectrodes have been introduced to measure the electro-chemical potential of the micro-areas. The experimental set-up not only allows for the average mapping of the potential distribution over a specimen's surface, it further allows for learning more of the processes behind the rise of the electro-chemical potential.Influences of availability of nutrients, biocides, oxygen, and other factors on the free corrosion potential on the whole system as well as on the micro-areas have been examined and compared.It has been observed that the use of biocides resulted in a rapid decrease of the free corrosion potential, however only a very limited decrease of the potential within the micro-areas could be measured. Experiments with an external polarization of the specimens resulted in similar curves with quantitatively different potential differences. This paper is to present results of some of the conducted experiments with possible theories.     

The chemistry and medicinal uses of the underutilized Indian fruit tree Garcinia indica Choisy (kokum): A review

Garcinia indica Choisy Syn Brindonia indica, commonly known as kokum and belonging to Guttiferae family, is a plant native to certain regions of India. The trees yield fruits annually in the summer season during the months of March to May. The fruits are green when raw and red to dark purple when fully ripe. They are used to prepare juice, pickles and as acidulant in curries. In the traditional Indian system of medicine the Ayurveda and in various folk systems of medicine, the fruit rinds and leaves are used to treat various inflammatory ailments, rheumatic pain and bowel complaints. The kokum butter prepared from the seed is of both commercial and medicinal use. Chemical studies have shown that the rind contains protein, tannin, pectin, sugars, fat, organic acids like (−)-hydroxycitric acid, hydroxycitric acid lactone and citric acid; the anthocyanins, cyanidin-3-glucoside and cyanidin-3-sambubioside; and the polyisoprenylated phenolics garcinol and isogarcinol. Preclinical studies have shown that kokum or and some of its phytochemicals possess antibacterial, antifungal, anti-ulcerogenic, cardioprotective, anticancer, chemopreventive, free radical scavenging, antioxidant and anti-obesity effects. The present paper reviews the nutritional value, the phytochemical compounds, traditional uses and validated pharmacological properties of kokum.     

乳链球菌素最小抑菌浓度(MIC)测定及理化性质分析

金黄色葡萄球菌是一种常见的食品致病菌,能引起严重的感染。乳链球菌素(nisin)是世界卫生组织公认的天然食品防腐剂。采用二倍梯度稀释法探究nisin对金黄葡萄球菌的最小抑菌浓度(MIC),通过琼脂平板扩散法分析nisin的理化性质。结果表明,nisin对金黄色葡萄球菌的最小抑菌浓度为2.34μg/mL。理化性质分析发现,nisin在pH为2~6状态下,抑菌效果好,在pH7~11抑菌活性逐渐减弱。Nisin在100℃以下热处理,活性保持良好,120℃处理仍有部分活性,说明其耐热稳定性好。胰蛋白酶、木瓜蛋白酶、蛋白酶K处理nisin,抑菌活性均有一定的削弱,其中蛋白酶K削弱最为明显。Triton-100、Tween20表面活性剂对nisin抑菌活性有细微的协同作用,但SDS可明显抑制其抑菌活性。     

Chemical composition, in vitro anti-yeast activity and fruit juice preservation potential of lemon grass oil

The anti-yeast activity of lemon grass oil was evaluated against several food spoiling yeasts (Saccharomyces cerevisiae, Zygosaccharomyces bailii, Aureobasidium pullulans, Candida diversa, Pichia fermentans, Pichia kluyveri, Pichia anomala and Hansenula polymorpha) through disc diffusion and microbroth dilution method. The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) varied from 0.28 to 1.3 mg/ml and 0.56 to 4.5 mg/ml, respectively, where highest MIC (2.25 mg/ml) was shown by A. pullulans and lowest MIC (0.28 mg/ml) was shown by C. diversa and P. anomala. Kill time assay was conducted for selected three yeast strains where S. cerevisiae showed highest reduction (3 log cfu) in viability within 24 h exposure of lemon grass oil at MFC level. Further, the anti-yeast efficacy of lemon grass oil alone and in combination with thermal treatment was evaluated in real food system i.e. mixed fruit juices. Chemical composition analysis of lemon grass oil by gas chromatography–mass spectrometry (GC–MS) revealed that the dominant compounds were geranial (40.5%), neral (30.7%), geranyl acetate (5.1%), caryophyllene (2.5%). Present results established the superior performance of integrated (thermal–lemon grass oil) treatment over the individual exposure (lemon grass oil or thermal treatment alone) for fruit juice preservation.     

超临界CO2萃取辣根精油及其在酱油中的应用

采用超临界CO2萃取辣根精油,研究萃取压力、萃取温度和萃取时间对得率的影响,并利用正交试验优化最适的萃取条件,将萃取的辣根精油进行最小抑菌浓度(minimal inhibitory concentration,MIC)和酱油中应用的实验。结果表明:当萃取压力25MPa、萃取温度40℃、萃取时间90min时,辣根精油得率为0.91%;辣根精油对大肠杆菌和枯草芽孢杆菌的MIC均为0.04μL/mL;与添加1.0g/kg苯甲酸钠相比,单独添加0.04μL/mL辣根精油或同时添加0.02μL/mL辣根精油和0.5g/kg苯甲酸钠,均使酱油在37℃条件下保藏30d品质良好,其中同时添加两种物质的应用性更好。     

蜜环菌抑菌作用的初步研究

采用滤纸片法、液体培养法和活菌计数法,研究了蜜环菌菌索提取液对常见微生物的抑制作用。通过测定MIC值,蜜环菌的抑菌能力依次为:大肠杆菌>金黄色葡萄球菌>枯草芽孢杆菌>啤酒酵母菌。15%的蜜环菌浸提液可抑制细菌生长,高于20%的蜜环菌浸提液可对霉菌和酵母菌产生抑制作用。     

丁香和肉桂挥发油的提取、主要成分测定及其抗菌活性研究

本文采用水蒸汽蒸馏法提取丁香和肉桂的挥发油,并对所得挥发油主要成分进行气相测定,通过体外抗菌试验,比较了这两种挥发油及其主要成分和目前常用化学防腐剂苯甲酸钠和山梨酸钾对金黄色葡萄球菌、大肠杆菌、枯草芽孢杆菌、沙门氏菌和志贺氏菌等5株食品中常见污染菌的抗菌作用。结果表明丁香油中丁香酚含量为78.1%,肉桂油中肉桂醛含量为86.8%;这两种挥发油及其主要成分丁香酚和肉桂醛的抗菌作用均强于两种化学防腐剂,其中肉桂油与其主要成分肉桂醛表现出的抗菌活性最强,最小抑菌浓度(MIC)为200～1600mg/L;仅为苯甲酸钠和山梨酸钾MIC(6400～25600mg/L)的1/64～1/16;丁香油及其主要成分丁香酚的抗菌活性次之,MIC为800～1600mg/L,相当于苯甲酸钠和山梨酸钾MIC的1/16～1/8。