Identification and quantification of anthocyanins in the berries of Pistacia lentiscus L., Phillyrea latifolia L. and Rubia peregrina L.

Anthocyanin composition in the berries of Pistacia lentiscus L., Phillyrea latifolia L. and Rubia peregrina L., three wild shrubs which are widely distributed in the Mediterranean region, was determined for the first time. The pigments were extracted from the berries with 0.1% HCl methanol solution, purified on a C-18 solid-phase cartridge and characterized by means of high-performance liquid chromatography (HPLC)–diode array detection (DAD)–mass spectrometry (MS) analysis. The major anthocyanin of P. lentiscus berries has been identified as cyanidin 3-O-glucoside. Delphinidin 3-O-glucoside and cyanidin 3-O-arabinoside have also been found in minor quantities. The major anthocyanin in the extracts of P. latifolia and R. peregrina berries was cyanidin 3-O-rutinoside. Low quantities of cyanidin 3-O-glucoside have also been found. The attractive color and the great abundance of these plants in the Mediterranean area make them a new and very good source of natural pigments and antioxidant agents.     

沙棘资源开发与沙棘黄酮提取

综述了国内以往沙棘资源的利用情况及其存在的问题,着重介绍了沙棘黄酮,并对沙棘黄酮的提取方法进行了初步探讨。     

Nutritional study of raw and popped seed proteins of Amaranthus caudatus L and Amaranthuscruentus L

The nutritional value of raw and popped (similar to popcorn preparation) seed proteins of two amaranth species, Amaranthus caudatus L and A cruentus L, was investigated. After popping, the true protein content in A caudatus and A cruentus decreased by 9 and 13% respectively. Among the amino acids, the loss of tyrosine due to the popping effect was the highest, followed by phenylalanine and methionine. Leucine was the first limiting amino acid in the raw samples, followed by lysine, while the reverse order was observed in the popped samples. The in vivo protein quality of raw and popped seeds was tested with male weanling rats and compared with wheat flour and casein samples. There was no difference between the in vivo digestibility of the raw and the popped seeds, although the in vitro digestibility was slightly higher for the popped samples. The protein efficiency ratio (PER) for all the amaranth seed samples was higher than that for the wheat sample, while the PER for the raw amaranth seed samples was close to that for the casein reference protein. The rat blood serum levels of total cholesterol, triglycerides and high‐density lipoprotein cholesterol for all the amaranth samples were lower than those for the reference protein, while the wheat flour sample showed the lowest values. Copyright © 2004 Society of Chemical Industry     

枸杞嫩茎叶护绿技术及质量控制研究

以新鲜的枸杞嫩茎叶为原料,采用L9(34)正交试验,研究不同种类护绿剂在不同漂烫条件下,对枸杞嫩茎叶护绿效果的影响及其过程中的质量控制,得出最佳护色技术。试验结果表明:用Zn2 (0.04%)、Na2SO3(0.02%)的护绿剂,在pH为6.5、95℃条件下漂烫1.5min,护绿效果最好且能较好地保持原有质地。     

Cuticular leaf waxes. III. Free and esterified acids and alcohols in Chenopodium album L., Lolium perenne L. and Stellaria media L

The wax esters from the leaf surface of the monocotyledon Lolium perenne L. and the dicotyledons Chenopodium album L. and Stellaria media L. have been analysed for the first time by gas-liquid chromatography (g.l.c.). The esterified acids and alcohols have been obtained and their compositions compared with those of the free acids and alcohols for the three plant species. Preferential esterification of the shorter chain acids has been noted. The presence of alkyl acetates in the two dicotyledons and many branched chain components in S. media is reported. It is proposed that two distinct pools of fatty alcohols are available for the biosynthesis of the esters.     

Imitation milks from Cicer arietinum (L.), Vigna unguiculata (L.) walpers and Vigna radiata (L.) wilczek and other legumes

Vegetable milks were prepared in the laboratory from mung bean [Vigna radiata (L.) Wilczek], cowpea [Vigna unguiculata (L.) Walpers] and chick-pea [Cicer arietinum (L.)] by homogenisation of a filtered aqueous extract of the ground legume with soya bean oil. Emulsions stable to pasteurisation were made from the first two. Pigeon pea [Cajanus cajan (L.)] and black gram [Vigna mungo (L.) Hepper)] were found to be unsuitable as bases for milks prepared by simple processing. The nitrogen, oil, sugar and ash contents of the first three legumes, and of milks prepared from them, were determined. Imitation milks are intended to resemble animal milks nutritionally, and whilst the contents of potassium and phosphorus were acceptable, these vegetable milks were low in sodium, calcium and zinc. The trypsin inhibitory activity, whilst low in comparison with soya milk, was partially stable to pasteurisation. The amino acid composition indicated that it would be desirable to complement legume proteins with cereal proteins to prepare vegetable milks.     

Viability of commercial probiotic cultures (L. acidophilus, Bifidobacterium sp., L. casei, L. paracasei and L. rhamnosus) in cheddar cheese

Six batches of cheddar cheese were manufactured containing different combinations of commercially available probiotic cultures from three suppliers. Duplicate cheeses contained the organisms of each supplier, a Bifidobacterium spp. (each supplier), a Lactobacillus acidophilus (2 suppliers), and either Lactobacillus casei, Lactobacillus paracasei, or Lactobacillus rhamnosus. Using selective media, the different strains were assessed for viability during cheddar cheese maturation over 32 weeks. The Bifidobacterium sp. remained at high numbers with the three strains being present in cheese at 4 x 10(7), 1.4 x 10(8), and 5 x 10(8) CFU/g after 32 weeks. Similarly the L. casei (2 x 10(7) CFU/g), L. paracasei (1.6 x 10(7) CFU/g), and L. rhamnosus (9 x 10(8) CFU/g) strains survived well; however, the L. acidophilus strains performed poorly with both decreasing in a similar manner to be present at 3.6 x 10(3) CFU/g and 4.9 x 10(3) CFU/g after 32 weeks. This study indicates that cheddar cheese is a good vehicle for a variety of commercial probiotics but survival of L. acidophilus strains will need to be improved.     

乳酸及固体乳酸盐在啤酒和饮料中的应用

<正>乳酸和乳酸钙1．天然健康的食品添加剂乳酸在多种食品中被当作天然的保鲜剂已有几个世纪的历史,可以通过糖液发酵生成,呈非常浅的黄色至无色。乳酸是一个含有不对称碳原子的最小的分子之一,包含L和D两种同分异构体。L型乳酸天然存在于动物体、人体组织以及肉、奶制品、泡菜、牛肉和葡萄酒等各种食品中当中。L乳酸钙是L乳酸的钙盐,以固体形式存在。由于具有适中的酸度,优秀的抗菌效果,更为重要的是由于其在动物肌体及人体中自然存在的特点,L-乳酸以及L-乳酸盐在食品加工领域中正得到越来越广泛的应用。     

基于MALDI-TOF MS技术对李斯特氏菌属两种细菌的快速鉴定

为提高基质辅助激光解析电离飞行时间质谱技术(MALDI-TOF MS)在李斯特氏菌属鉴定中的分辨能力,建立快速准确鉴定单增和英诺克李斯特氏菌的质谱学方法。通过采集79株单增和57株英诺克李斯特氏菌的指纹图谱,利用Clin Pro tools软件对数据进行统计学分析,建立数学判别模型并验证其准确性。峰统计结果显示,两组数据峰强度差异显著的特征峰有16个,推测出单增李斯特氏菌生物标志物6个,英诺克李斯特氏菌10个,发现在单增李斯特氏菌中质量峰3985/7970 u和3972/7942 u是独立且连锁存在。基于遗传算法的判别模型交叉验证率和检测识别能力最强,分别为99.44%和100.00%,经验证准确率达到96%以上,可实现对单增和英诺克李斯特氏菌的快速准确鉴定。同时,利用Bruker Biotyper软件将以上菌株建库形成了实验室内部李斯特氏菌谱库,对8株未测李斯特氏菌进行搜库鉴定,匹配分数均高于商品化数据库,提升了MALDI-TOF MS对李斯特菌属的自动鉴定能力。     

枸杞菜热风干燥工艺研究

研究枸杞菜的热风干燥工艺条件,通过试验确定0.04%Zn(CHCOO)2和0.02%Na2SO3为混合护色剂,保硬剂为0.3?Cl2溶液,保硬浸泡时间为20min。并运用L9(33)正交试验确定漂烫和干燥的最佳工艺条件为95℃热水中漂烫2min,干燥温度为85～95℃。     

蒺藜对L.acidophilus和L.bulgaricus生长的影响

研究了不同浓度的蒺藜药液及药液离心与否对嗜酸乳杆菌和保加利亚乳杆菌生长的影响。结果表明，蒺藜药液培养嗜酸乳杆菌和保加利亚乳杆菌的最佳浓度均为0．111g／mL；药液离心对嗜酸乳杆菌的生长和药液的pH几乎没有影响；药液离心对保加利亚乳杆菌的生长和药液的pH均有较大影响，与对照相比，其菌体减少，pH升高。     

苦瓜的研究与开发

苦瓜是近年来兴起的一种保健食品,本文对苦瓜的生物学特性、药用价值、食用价值及其产品的研究与开发进行综述。     

嗜酸乳杆菌产生β-半乳糖苷酶活力的测定及数学模型的建立

以MRS为培养摹，对L．acidophilus Ind-1和L．acidophilus Lakcid两菌株产生β—半乳糖苷酶的活力进行了研究。结果表明，采用1％SDS：氯仿=1：10细胞破壁β—半乳糖苷酶的提取率较高，37℃ 36h培养，L．acidophilus Ind-2和Lacidophilus Lakcid可以产生2．229μ moleONP／L．min和1．808μ moleONP／L．min的β—半乳糖苷酶，且该酶在MRS培养基中积累的数学模型为Logistic和Mistcherlich方程。     

Glycine max (L.) Merr., Vigna radiata L. and Medicago sativa L. sprouts: A natural source of bioactive compounds

The consumption of sprouts, common in Asia, has been growing in western countries, once they are a natural healthy food and considered as a valuable dietary supplement. Comparing with their mature counterparts, sprouts are usually richer in health-promoting phytochemicals. So, the nutritional composition and the biological potential of widely consumed sprouts of three species – Glycine max (L.) Merr., Vigna radiata L. and Medicago sativa L. – were compared for the first time. Phenolic compounds and phytosterols were analyzed by HPLC–DAD and organic acids by HPLC–UV. The volatile profile was determined by HS-SPME/GC–IT/MS. Fourteen phenolic compounds (including four isoflavones), three sterols one triterpene, sixteen fatty acids, seven organic acids and thirty volatile compounds were determined. The antioxidant activity was assessed against DPPH^?, superoxide and nitric oxide radicals. G. max sprouts were the most active against DPPH^? (IC₅₀ = 1.337 mg/mL), while those of M. sativa were the most effective against superoxide and nitric oxide radicals (IC₅₀ = 67 μg/mL and IC₅₀ = 426 μg/mL, respectively). Data provide evidence of great similarities between G. max and M. sativa sprouts, both being rich in phenolic compounds, fatty acids and volatiles, and exhibiting better antioxidant activity. On the other hand, V. radiata showed higher amounts of sterols, triterpenes and organic acids. In this study it was found that the sprouts are a good source of bioactive compounds in our diet with health-promoting antioxidants.     

Identification of Puffer Fish of the Genus Lagocephalus: L. lunaris,L. spadiceus and L. inermis,Using Multiplex PCR

A multiplex PCR assay was developed to identify widespread poison-containing puffer fishes of the genus Lagocephalus: L. lunaris, L. spadiceus and L. inermis, using a novel KUGEN_ILSspec primer set which is specific for 12S ribosomal RNA (12S rRNA) and Cytochrome b (Cyt b) genes. KUGEN_ILSspec set is composed of fish positive-amplified primers that produced a 289-bp fragment while L. lunaris-, L. spadiceus- and L. inermis-specific primers produced 123-, 196- and 493-bp fragments, respectively. The sensitivity of this primer set was found to be high as it was capable of amplifying targeted DNA at concentrations as low as 1 ng/μL. Moreover, the primer set was shown to amplify intact DNA and species-specific fragments from heat-processed food. Consequently, multiplex PCR technique in combination with KUGEN_ILSspec primer set could offer an effective measure for detecting poisonous puffer fish contamination in both fresh and processed fish products, which will greatly aid in public health control and law enforcing endeavors.     

Influence of pH and temperature on growth and bacteriocin production by Leuconostoc mesenteroides L124 and Lactobacillus curvatus L442

The aim of this study was to investigate the relationship between the microbial growth, the bacteriocin production and the effect of pH and temperature on the occurrence and the concentration of the maximum activity, to optimize the bacteriocin synthesis during the growth cycle. Two bacteriocins produced by lactic acid strains Leuconostoc mesenteroides L124 and Lactobacillus curvatus L442 were studied. A slight increase of the final biomass resulted in the improvement of the bacteriocin activity in the growth medium under controlled pH (5.0 and 5.5). Temperature and pH had a significant effect on the production of the two bacteriocins and was enhanced by the relatively low growth rates. The optimum production conditions of the bacteriocins did not coincide with those for growth. The optimum pH and temperature values for growth were 6.0-6.5 and 30?°C and for bacteriocin production were 5.5 and 25?°C.     

扛板归及苦菜黄酮类物质超声波提取工艺优化及其抗氧化活性

研究了扛板归黄酮超声波提取条件及其抗氧化作用,并与苦菜黄酮的含量及其抗氧化作用进行了对比。采用单因素和正交实验得出扛板归黄酮的最佳提取条件为料液比1∶50,体积分数65%乙醇,超声波处理时间50min,在此条件下扛板归黄酮的最高得率为70.77mg/g,苦菜黄酮得率为18.54mg/g。两种黄酮类物质在不同体系中对·OH的清除作用不同,水杨酸体系苦菜黄酮对·OH的清除效果强于扛板归黄酮,分别是芦丁和VC的7.9倍和1.35倍,而在邻二氮菲体系扛板归黄酮对·OH的清除效果高于苦菜黄酮,大约是芦丁和VC的2.5倍。