传统乳制品来源乳酸菌的发酵特性及其在酸奶中的应用

对从传统乳制品中分离出的4株保加利亚乳杆菌和4株嗜热链球菌发酵特性及应用进行研究。利用脱脂乳进行培养,以发酵时间、风味物质及贮藏过程中的p H、滴定酸度、持水力、粘度变化为指标,研究单菌株的发酵性能。进一步对较优发酵性能菌株复配,考察不同接种比例时酸奶的酸度、粘度、风味、感官等指标,研究其在酸奶中的应用。结果表明,保加利亚乳杆菌Lb.YNF-5和嗜热链球菌St.GST-6具有良好的发酵性能。通过对此两株菌进一步复配,最终确定当保加利亚乳杆菌(Lb.YNF-5):嗜热链球菌(St.GST-6)配比为1∶1时,酸奶产品品质最佳,发酵时间为5.8 h,粘度为7186.47 m Pa·s,感官评价得分为76分。本研究综合表明,菌株Lb.YNF-5和St.GST-6具有开发优良酸奶发酵剂的潜在价值。     

水苏糖对酸乳增菌效果的研究

以保加利亚乳杆菌、嗜热链球菌、嗜酸乳杆菌和双歧杆菌为发酵菌种,进行了水苏糖对酸乳增菌效果的研究。在Lb及St(菌种比例1∶1)的组合中,水苏糖添加量为0·8%时发酵时间缩短为4h(对照4·5h),菌数最高可达6·26×108cfu/mL(对照5·74×108cfu/mL)。在Lb、St及La(菌种比例1∶1∶1)的组合中,水苏糖添加量为0·7%~0·8%时发酵时间缩短为5h(对照5·5h),菌数最高可达5·51×108cfu/mL(对照5·28×108cfu/mL)。在Lb、St及BB(菌种比例1∶1∶2)的组合中,水苏糖添加量为0·8%时发酵时间缩短为4h(对照4·5h),菌数最高可达6·82×108cfu/mL(对照5·86×108cfu/mL)。在Lb、St、La及BB(菌种比例1∶1∶1∶2)的组合中,水苏糖添加量为0·8%时菌数最高可达6·29×108cfu/mL(对照5·45×108cfu/mL)。      

不同乳酸菌发酵对甘薯淀粉加工浆液营养功能成分及感官特性的影响

选用植物乳杆菌（Lactobacillus plantarum,Lp）、保加利亚乳杆菌（Lactobacillus bulgaricus,Lb）、嗜热链球菌（Streptococcus thermophilus,St）、戊糖片球菌（Pediococcus pentosus,Pp）、干酪乳杆菌（Lactobacillus casei,Lc）及商业Lp（SZ）分别对甘薯淀粉加工浆液进行发酵,比较不同乳酸菌发酵对甘薯淀粉加工浆液营养功能成分（蛋白质、灰分、可溶性膳食纤维、不溶性膳食纤维、总膳食纤维、总酸、总糖、乳酸、短链脂肪酸、总酚、游离氨基酸）及感官特性（电子鼻、电子舌、气相色谱-质谱、感官评价）的影响。结果表明：6 种乳酸菌发酵后,浆液中蛋白质、糖类、可溶性膳食纤维、不溶性膳食纤维及总膳食纤维含量显著下降;不同乳酸菌均表现出良好的发酵性能,发酵后浆液pH值从6.62下降到3.67～3.88,总酸质量浓度由0.29 g/100 mL提高至2.69～3.67 g/100 mL,且乳酸及短链脂肪酸含量显著上升;Lb和Lc发酵显著提高了浆液中总酚含量,分别提升了18.44%和17.78%;在发酵液中共检出16 种游离氨基酸,其中必需游离氨基酸含量显著上升;气相色谱-质谱结果表明,乳酸菌发酵可有效提升甘薯淀粉加工浆液中风味物质的种类和含量,改善其风味和口感,其中Pp、St和SZ发酵浆液的总体感官品质最好。上述研究结果可为乳酸菌发酵应用于甘薯淀粉加工浆液制备饮料的研发奠定理论支撑。     

传统乳制品来源乳酸菌的发酵特性及其在酸奶中的应用

对从传统乳制品中分离出的4株保加利亚乳杆菌和4株嗜热链球菌发酵特性及应用进行研究。利用脱脂乳进行培养,以发酵时间、风味物质及贮藏过程中的p H、滴定酸度、持水力、粘度变化为指标,研究单菌株的发酵性能。进一步对较优发酵性能菌株复配,考察不同接种比例时酸奶的酸度、粘度、风味、感官等指标,研究其在酸奶中的应用。结果表明,保加利亚乳杆菌Lb.YNF-5和嗜热链球菌St.GST-6具有良好的发酵性能。通过对此两株菌进一步复配,最终确定当保加利亚乳杆菌（Lb.YNF-5）:嗜热链球菌（St.GST-6）配比为1∶1时,酸奶产品品质最佳,发酵时间为5.8 h,粘度为7186.47 m Pa·s,感官评价得分为76分。本研究综合表明,菌株Lb.YNF-5和St.GST-6具有开发优良酸奶发酵剂的潜在价值。      

发酵带鱼乳酸菌种的筛选及其工艺优化

研究了四种发酵剂植物乳杆菌(Lp)、嗜酸乳杆菌(La)、干酪乳杆菌(Lc)、戊糖片球菌(Pp)的生长特性和发酵性能,筛选出适宜带鱼发酵的乳酸菌,并应用正交试验对发酵工艺进行优化。结果表明:适宜带鱼发酵的乳酸菌种为La和Pp,其最佳工艺条件为:糖用量5%、接种量0.2%、La与Pp菌种配比1:3。     

益生菌发酵糙米饮料的制作工艺及其营养价值研究

为了开发新型发酵糙米饮料产品,选取干酪乳杆菌、嗜酸乳杆菌、双歧杆菌、唾液乳杆菌、德式乳杆菌、酿酒酵母6株益生菌菌株进行了单菌和多菌复配发酵试验,通过发酵后产品的乳酸含量、p H值、氨基酸、水溶性肽等指标的检测与分析得到了最优发酵菌种组合为:干酪乳杆菌+嗜酸乳杆菌+双歧杆菌。以乳酸含量为主要指标,利用正交试验确定了发酵糙米饮料的最佳发酵工艺为料水比1.2∶10,接种量5%,发酵时间16 h。在此条件下,发酵饮料的乳酸含量为45 mmol/L,产品具有浓郁的发酵香味和米香味,滋味酸度适中,风味独特。通过与市售谷物饮料和市售乳酸菌饮料的营养指标对比发现,发酵糙米饮料综合了谷物饮料和乳酸菌饮料的优点,是一种高蛋白质,高膳食纤维,高活菌数,低脂肪,低能量的全面均衡营养型的饮料。     

黑豆乳酸发酵菌种的筛选

本实验以糖化的黑豆为基质,对五株乳酸菌的发酵性能进行了测试,其中嗜酸乳杆菌产酸最高,产酸速率最快。确定了嗜酸乳杆菌(La)、植物乳杆菌(Lp)和两岐双岐杆菌(Bb)为最佳菌种组合,确定了最佳种间比,即La:Lp:Bb=2:1:1,大豆汁为促生长物质。     

适于大豆干酪加工的乳酸菌发酵剂研究

以豆浆为发酵底物,对8株乳酸菌的凝乳性能进行了研究,检测了凝乳的黏度、酸度、双乙酰、胞外多糖和pH值为4.6可溶性氮含量,采用混合权重法对结果进行统计分析,得出凝乳性能的排序结果为Lb2→La→St1→Lb1→Sl→St2→Sc→Lc。此外,对8株乳酸菌的α-低聚半乳糖代谢能力进行了研究,乳杆菌代谢能力显著高于乳球菌。最后,优选出适于大豆干酪加工的乳酸菌发酵剂为St1和La。     

乳酸菌发酵对燕麦淀粉物化及热力学特性的影响

以燕麦粉为原料,分别利用植物乳杆菌(L.p)和旧金山乳杆菌(L.s)两种乳酸菌对其进行发酵,研究燕麦淀粉在发酵过程中各种物化及热力学特性的变化。结果表明：燕麦粉经过两种菌发酵后pH 值下降,且L.p 发酵的燕麦粉pH 值下降的速率和产酸量都大于L.s。但是到发酵后期,两种乳酸菌发酵的燕麦粉pH 值相近。发酵燕麦淀粉的溶解度和溶胀力都随着温度的升高而增加,在不同温度下,其溶胀力和溶解度在发酵过程中的变化趋势不同,经L.P 发酵的样品的溶胀力低于L.s,但溶解度大于经L.s 发酵的样品。快速黏度分析仪(RVA)和差示扫描量热仪(DSC)分析得到发酵过程中燕麦淀粉的变化：发酵后燕麦淀粉糊化过程中峰值黏度随着发酵时间的延长而降低,糊化起始温度提前,糊化所需时间延长,糊化焓升高,且L.s 发酵样品的糊化焓值高于L.p。发酵后燕麦淀粉的直链淀粉含量在发酵过程中呈上升趋势,L.p 发酵的样品的直链淀粉的含量高于L.s。     

水苏糖对酸乳增菌效果的研究

以保加利亚乳杆菌、嗜热链球菌、嗜酸乳杆菌和双歧杆菌为发酵菌种,进行了水苏糖对酸乳增茼效果的研究.在Lb及St(菌种比例1:1)的组合中,水苏糖添加量为0.8%时发酵时间缩短为4h(对照4.5h),菌教最高可达6.26 ×108cfu/mL(对照5.74 × 108cfu/mL).在Lh、St及La(菌种比例1:1:1)的组合中,水苏糖添加量为0.7%～0.8%时发酵时间缩短为5h(对照5.5h),菌数最高可达5.51 ×108cfu/mL(对照5.28×108cfu/mL).在Lb、St及BB(菌种比例1:1:2)的组合中,水苏糖添加量为0.8%时发酵时间缩短为4h(对照4.5h),菌教最高可达6.82×108cfu/mL(对照5.86×108cfu/mL).在Lb、St、La及BB(菌种比例1:1:1:2)的组合中,水苏糖添加量为0.8%时菌数最高可达6.29 × 108cfu/mL(对照5.45×106cfu/mL).     

Reliable identification of grapevine rootstock varieties using RAPD PCR on woody samples

Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.     

An internet compendium of analytical methods and spectroscopic information for monomers and additives used in food packaging plastics

An internet website (http://cpf.jrc.it/smt/) has been produced as a means of dissemination of methods of analysis and supporting spectroscopic information on monomers and additives used for food contact materials (principally packaging). The site which is aimed primarily at assisting food control laboratories in the European Union contains analytical information on monomers, starting substances and additives used in the manufacture of plastics materials. A searchable index is provided giving PM and CAS numbers for each of 255 substances. For each substance a data sheet gives regulatory information, chemical structures, physico-chemical information and background information on the use of the substance in particular plastics, and the food packaging applications. For monomers and starting substances (155 compounds) the infra-red and mass spectra are provided, and for additives (100 compounds); additionally proton NMR are available for about 50% of the entries. Where analytical methods have been developed for determining these substances as residual amounts in plastics or as trace amounts in food simulants these methods are also on the website. All information is provided in portable document file (PDF) format which means that high quality copies can be readily printed, using freely available Adobe Acrobat Reader software. The website will in future be maintained and up-dated by the European Commission's Joint Research Centre (JRC) as new substances are authorized for use by the European Commission (DG-ENTR formerly DGIII). Where analytical laboratories (food control or other) require reference substances these can be obtained free-ofcharge from a reference collection housed at the JRC and maintained in conjunction with this website compendium.     

Aroma characterization of various apricot varieties using headspace–solid phase microextraction combined with gas chromatography–mass spectrometry and gas chromatography–olfactometry

The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.     

Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.     

Analysis of benzo[a]pyrene in spiked fatty foods by second derivative synchronous spectrofluorimetry after microwave-assisted treatment of samples

A simple, rapid and inexpensive method has been developed for the determination of benzo[a     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. II: Certification study

This paper describes the second part of a project undertaken to develop certified mussel reference materials for paralytic shellfish poisoning toxins. In the first part two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin and decarbamoyl-saxitoxin in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the certification exercise. Fifteen laboratories participated in this certification study and were asked to measure saxitoxin and decarbamoyl-saxitoxin in rehydrated lyophilized mussel material and in a saxitoxin-enriched mussel material. The participants were allowed to use a method of their choice but with an extraction procedure to be strictly followed. The study included extra experiments to verify the detection limits for both saxitoxin and decarbamoyl-saxitoxin. Most participants (13 of 15) were able to meet all the criteria set for the certification study. Results for saxitoxin.2HCl yielded a certified mass fraction of <0.07 mg/kg in the rehydrated lyophilized mussels. Results obtained for decarbamoyl-saxitoxin.2HCl yielded a certified mass fraction of 1.59+/-0.20 mg/kg. The results for saxitoxin.2HCl in enriched blank mussel yielded a certified mass fraction of 0.48 +/- 0.06 mg/kg. These certified reference materials for paralytic shellfish poisoning toxins in lyophilized mussel material are the first available for laboratories to test their method for accuracy and performance.     

Detection of adulteration of locust bean gum with guar gum by capillary electrophoresis and polarized light microscopy

Capillary electrophoresis (CE) and polarized light microscopy (PLM) were utilized in the detection of the adulteration of locust bean gum with guar gum. For CE analyses, standards of locust bean and guar gums were extracted with 30% CH₃CN, removing the residual proteins from the gum matrix. A 8.75 mM NaH₂PO₄-20.6 mM Na₂B₄O₇ buffer, pH 9, was used to separate these proteins and to identify marker proteins that were present in the guar gum. These markers did not co-migrate with components in the extracts of mechanically processed locust bean gum, and are used as indicators of adulteration. Using PLM with toluidine blue and iodine staining techniques, unadulterated locust bean gum samples were distinguished from mixed samples through the differential staining of components in locust bean versus guar and tara gums. These experiments in the use of CE and PLM provide orthogonal and complementary methods for the verification of 'true' positives and the elimination of 'false' positives.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of the     

Chinese CTP Market

According to Printing and Printing Equipment Industries Association of China（PEIAC）＇s statistics to the plate manufucturer in China, in 2013, the actual offset plate production has reached 346 million square meters in China. Among them, the CTP production volume was 245 million square meters, up by 11% than that of last year; the total sales of the CTP plate was 239 million square meters, up by 13%.