Olfactory and quantitative analysis of volatiles in elderberry (Sambucus nigra L) juice processed from seven cultivars

Aroma compounds emitted from elderberry juices processed from seven cultivars were collected by the dynamic headspace technique and analysed by GC–FID and GC–MS. Forty aroma compounds were identified and quantified, including nine compounds which had not previously been detected in elderberry juice. Significant differences were found among cultivars in the concentration levels of 30 compounds. The sensory characteristics of the individual aroma compounds in elderberry juice were determined by a GC‐sniffing technique, and the compounds were grouped according to their odour. The characteristic elderberry odour is due to dihydroedulan and β‐damascenone, of which the former occurs in relatively high concentrations in the headspace of elderberry juice. The fruity group consisted of aliphatic alcohols and aldehydes and aromatic esters, of which 1‐pentanal, 2‐methyl‐1‐propanol, 2‐ and 3‐methyl‐1‐butanol, 1‐octanal, 1‐octanol and methyl and ethyl benzoate contributed with fruity notes. In the flowery group, 1‐nonanal, nerol oxide and (Z)‐ and (E)‐rose oxide contributed with characteristic elder flower odour, whereas other flowery notes were associated with hotrienol, linalool and α‐terpineol. Fresh and grassy odours were correlated with 1‐hexanal, (E)‐2‐hexen‐1‐al, (Z)‐3‐hexen‐1‐ol, (E)‐2‐hexen‐1‐ol and (E)‐2‐octen‐1‐al of the grassy group, whereas 1‐octen‐3‐ol and 1‐octen‐3‐one of the agrestic group contributed significantly with the characteristic aroma of mushrooms. © 2000 Society of Chemical Industry     

Evaluation of colouring ability of main European elderberry (Sambucus nigra L.) varieties as potential resources of natural food colourants

Profiling and quantitative analysis of anthocyanins in five elderberry (Sambucus nigra L.) varieties, namely ‘Haschberg’, ‘Samocco’, ‘Samyl’, ‘Samident’ and ‘Sampo’, were performed in six different maturity stages from two consecutive years (2012 and 2013) and from two growing areas in Hungary. Cyanidin‐3‐O‐sambubioside‐5‐O‐glucoside, cyanidin‐3‐O‐sambubioside and cyanidin‐3‐O‐glucoside were found and identified by HPLC‐Q/TOF‐MS as major anthocyanins and were quantified by HPLC‐UV/Vis. In optimum maturity stage, ‘Samocco’ showed the highest anthocyanin content with an average of 1237 mg per 100 g dry weight in both growing areas and vintages. The dominant anthocyanin component of Samocco variety was cyanidin‐3‐O‐sambubioside, which is according to literature more stable against technology processing than cyanidin‐3‐O‐glucoside found in the other four investigated elderberry varieties in the highest concentration. ‘Samocco’, if grown under the climatic conditions of the Carpathian basin, might be a promising alternative variety for growing as raw material for natural food colourant processing industry.     

Selection of elderberry (Sambucus nigra L.) genotypes best suited for the preparation of elderflower extracts rich in flavonoids and phenolic acids

The importance of raw material and extraction parameters for obtaining a high content of flavonoids and phenolic acids in elderflower extracts was investigated. Nine phenolic acids (3-O-, 4-O-, and 5-O-caffeoylquinic acid, 3-O- and 5-O-p-coumaroylquinic acid, 1,5-di-O-, 3,4-di-O-, 3,5-di-O- and 4,5-di-O-caffeoylquinic acid) and six flavonol glycosides (quercetin-3-O-rutinoside, quercetin-3-O-glucoside, kaempferol-3-O-rutinoside, isorhamnetin-3-O-rutinoside, isorhamnetin-3-O-glucoside, and quercetin-3-O-6″-acetylglucoside) were identified and quantified in elderflowers and/or extracts thereof by liquid chromatography-mass spectrometry (LC-MS) and high-performance liquid chromatography-diode array detection (HPLC-DAD), respectively. The yield of elderflower extracts depended significantly on processing conditions and raw material properties and the maximum yield of elderflower extract was obtained by extraction for a maximum of 10 days at 4 °C using an extraction liquid consisting of a maximum of 20 w/w % sugars and 5% citric acid. The effects of the extraction liquid composition and raw material on the concentration of phenolic acids and flavonol glycosides in elderflower extracts were determined by factor analysis. Several elderberry genotypes were found to be useful for processing of elderflower extracts with a relative high concentration of phenolic acids and flavonol glycosides.     

糖化酵母在干啤酒生产中应用的研究（Ⅰ）──具有糖化酶活性和去除POF1基因的糖化酵母的选育

比较了多株单、双倍体糖化酵母，选出糖化酶活性及发酵度较高的糖化酵母单倍体──Ｓｏｃ．ｄｉａｓｔａｔｉｃｕｓ２６０６７－４４。同时发现糖化酵母单倍体菌株的酶活性高于二倍体菌株。含有ＰＯＦ１基因的糖化酵母（ｐｏｆ＋表型）可脱羧肉桂酸形成苯乙烯，ｐｏｆ－菌株无此能力。通过气相色谱检测肉桂酸－酒花麦汁发酵液中的苯乙烯含量，可以鉴别出去除ＰＯＦｌ基因的菌株。本文利用酵母菌的群体杂交法，通过Ｓ．ｄｉａｓｔａｔｉｃｕｓ２６０６７－４４与酿酒酵母单倍体杂交，获得１株糖化酶活性及发酵度较高，并且去除了ＰＯＦ１基因的单倍体菌株Ｈ－３（２）－２（ａ，ＳＴＡ，ｐｏｆ－）·     

蜜环菌人工菌棒基质碳氮比对乌天麻产量及营养品质的影响

分析蜜环菌人工菌棒基质碳氮比对乌天麻产量及基本营养成分含量的影响,并对乌天麻氨基酸品质进行评价。方法 通过大棚内随机区组实验,测定不同种植模式下乌天麻的基本营养成分含量,对其进行单因素方差分析和多重比较,并通过氨基酸评分法对乌天麻中氨基酸营养价值进行评价。结果 蜜环菌人工菌棒基质碳氮比对乌天麻的产量、基本营养成分含量及氨基酸的营养品质均有显著的影响;蜜环菌人工菌棒基质碳氮比为75.94时种植的乌天麻,乌天麻各项营养指标接近对照种植的乌天麻的各项营养指标,显著大于蜜环菌人工菌棒基质碳氮比为60.69、126.39时种植的乌天麻的各项营养指标。蜜环菌人工菌棒基质碳氮比为75.94时种植的乌天麻,其乌天麻必需氨基酸含量与总氨基酸含量的比值为37.03%接近40%,必需氨基酸含量与非必需氨基酸含量的比值为58.79%接近60%,必需氨基酸的氨基酸比值、必需氨基酸的比值系数分、必需氨基酸比值系数与联合国粮食及农业组织/世界卫生组织提出的氨基酸理想模式较接近。结论 利用蜜环菌人工菌棒种植乌天麻可以获得基本营养成分含量高、氨基酸丰富、必需氨基酸的组成比例相对合理、符合人体吸收利用需求、具有较高营养价值的乌天麻。     

水相体系中固定化Acetobacter sp.CCTCC M209061细胞催化(S)-3-氯苯丙醇不对称合成

光学纯的3-氯苯丙醇是合成抗抑郁类药物的重要中间体。本论文报道了水相体系中固定化Acetobacter sp.CCTCC M209061细胞高效、高选择性地催化3-氯苯丙酮不对称还原为(S)-3-氯苯丙醇,采用聚乙烯醇与海藻酸钠的混合载体对醋酸杆菌细胞进行固定化,所得的固定化细胞的稳定性(热稳定性、p H稳定性及操作稳定性)均明显优于游离细胞。同时,固定化后的微生物细胞具有较好的重复利用性,连续反应3个批次后固定化细胞仍保留了80.0%以上的活性,而游离细胞的相对活性则小于20%。在所研究的体系中,葡萄糖为该反应的最佳辅底物,其最适浓度为50.0 mmol/L;该反应体系中的最适缓冲液p H值、反应温度、底物浓度分别为5.5、30℃和3.0 mmol/L。在此条件下,反应的初速度、产率以及产物的e.e.值依次为1.77 m M/h,88.9%和99.0%以上。     

137Caesium in samples of wild-grown Boletus edulis Bull. from Lucca province (Tuscany,Italy) and other Italian and European geographical areas

ABSTRACT

Samples of the edible mushroom Boletus edulis Bull. were studied to assess the risk for human health related to their content of the artificial radionuclide ¹³⁷Cs. Fresh B. edulis carpophores were collected in four undeveloped microhabitats of Lucca province (Tuscany, North-Central Italy). Dried non-cultivated samples coming from this same district and 11 other Italian provinces or European countries were instead purchased fromcommercial sources. Contents of ¹³⁷Cs, reported as Bq kg^?1 dry weight (dw), were measured by γ-spectrometry. The radionuclide concentration varied depending on the gathering site in fresh samples, with 41.8 ± 5.2 Bq kg^?1 dw at site 1 (Tosco-Emiliani Apennine) and four-fold less, 12.8 ± 1.3 Bq kg^?1 dw, at site 2 (Apuan Alps). Moreover, fresh or dried carpophores from Lucca province displayed among the lowest ¹³⁷Cs contents in Europe. Average ¹³⁷Cs levels in all analysed samples were substantially below the legal threshold for edible mushrooms, 600 Bq kg^?1 dw. Conclusively, we report that ¹³⁷Cs amounts in B. edulis depend on both the distance from the Chernobyl accident and multifactorial features of collection sites. We also show that the consumption of European B. edulis does not represent a major health risk with respect to ¹³⁷Cs radio contamination.     

Morphology,FTIR fingerprint and survivability of encapsulated lactic bacteria (Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus) in simulated gastric juice and intestinal juice

Microencapsulation of bacteria in hydrocolloid beads is known as a potential way to enhance and protect their survivability in the digestive tract. We encapsulated a mix of two lactic bacteria (Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus) in sodium alginate (AG) and chitosan (CH) matrices. The morphological parameters of beads containing bacteria were comparatively measured. The FTIR fingerprint can discriminate the presence of bacteria into the beads, identifying specific absorption peaks for bacteria located at 1750, 2852 and 2926 cm^?1. To check the survivability of bacteria, beads were incubated in simulated gastric juice (pH 1.5) and intestinal juice (pH 7.2) for different periods of time, up to 120 min. The 2% AG beads, better than CH beads, provided best protection of bacterial survivability. Encapsulated mix of S. thermophilus and L. delbrueckii subsp. bulgaricus can behave as a probiotic bacteria, viable, surviving in the simulated gastric and intestinal juice.     

Expression,purification, and characterization of N-acetylglucosaminylphosphatidylinositol de-N-acetylase (ScGpi12), the enzyme that catalyses the second step of GPI biosynthesis in S. cerevisiae

ScGpi12 is a 304 amino residue long endoplasmic reticulum membrane protein, which participates in the de-N-acetylation of N-acetylglucosaminyl phosphatidylinositol to produce glucosaminyl phosphatidylinositol in the second step of GPI anchor biosynthesis pathway in Saccharomyces cerevisiae. ScGpi12 was cloned in a pMAL-c2x vector and expressed heterologously in Rosetta-gami (DE3) strain of E. coli. Affinity purification of the protein yielded low amounts of the MBP-tagged enzyme, which was active. To the best of our knowledge, this is the first successful purification of full-length Gpi12 enzyme, without the accompanying GroEL that was seen in other studies. The presence of the tag did not greatly alter the activity of the enzyme. ScGpi12 was optimally active in the pH range of 6.5–8.5 and at 30 °C. It was not sensitive to treatment with EDTA but was stimulated by multiple divalent cations. The divalent cation did not alter the pH profile of the enzyme, suggesting no role of the divalent metal in creating a nucleophile for catalysis. Divalent cations did, however, enhance the turnover number of the enzyme for its substrate, suggesting that they are probably required for the production of a catalytically competent active site by bringing the active site residues within optimum distance of the substrate for catalysis.     

DNA identification of two laboratory colonies of the weevils, Sitophilus oryzae (L.) and S. zeamais Motschulsky (Coleoptera: Curculionidae) in Taiwan

DNA amplification fingerprinting (DAF) and nuclear ribosomal DNA (nrDNA) amplification were used to discriminate between two laboratory colonies of two closely related species of weevils: the rice weevil, Sitophilus oryzae (L.), and the maize weevil, S. zeamais Motschulsky. For DAF, three sets of primers (aldolase, prolactin receptor, and interleukin-1β) were used for identification by polymerase chain reaction (PCR) and agarose gel electrophoresis, and the highly similar patterns of the resultant amplicons reconfirmed that the two weevils are closely related. The fragments of nrDNA amplification showed that for S. oryzae and S. zeamais, the homologies of the nucleotide sequences of the internal transcribed spacer regions, ITS-1 and ITS-2, were unusually high, at 96% and 97%, respectively. Based on the ITS-1 and ITS-2 sequences, two species-specific primer sets were designed: with the primer set ITS3/So, the predicted 450 bp DNA fragment was yielded with S. oryzae genomic DNA after PCR amplification (n=10), but no PCR product was obtained with S. zeamais (n=10); with the primer set ITS3/Sz, the same 10 S. zeamais specimens yielded a 550 bp DNA fragment, but S. oryzae yielded no amplicons. In view of the difficulty of distinguishing between these two closely related species, the specificity and availability of these two primer sets might prove to be a useful tool for distinguishing between them. However, the nrDNA sequences of the ITS-1 and ITS-2 regions of geographically isolated populations of both weevils still need to be elucidated, and the applicability of this technique to different geographical populations will need to be confirmed by further study.     

Determination of 2,4,6-triiodoresorcinol and other side reaction products and intermediates in the colour additive FD&C Red No. 3 (erythrosine) using high-performance liquid chromatography

An HPLC method was developed for the quantitative determination of 2,4,6-triiodoresorcinol (I3R), 2-(2',4'-dihydroxy-3',5'-diiodobenzoyl)benzoic acid, resorcinol, phthalic acid, and sodium iodide in the colour additive FD&C Red No. 3 (erythrosine) (R3). Due to the fast decomposition of I3R in aqueous solutions, the dye portions analysed were dissolved in methanol and the determinations were performed in the freshly-made solutions. The HPLC method is rapid (50 min total analysis cycle, ∼16 min to detect I3R and the other intermediates), simple to implement, and generates only small amounts of solvent waste. It was found to be applicable for use in routine batch-certification as shown by the analysis of test portions from 24 lots of R3 submitted for US-certification by domestic and foreign manufacturers during the past three years.