发酵条件对红树莓果酒花色苷含量和酒精度的影响及其对体内α-葡萄糖苷酶抑制研究

通过单因素实验探究发酵温度、发酵时间、酵母菌添加量、SO₂添加量和初始pH对红树莓果酒花色苷含量和酒精度的影响。通过α-葡萄糖苷酶抑制和荧光光谱分析来探究在最佳发酵工艺条件下获得的红树莓果酒花色苷的降糖活性。研究结果表明最佳红树莓果酒发酵工艺为:发酵温度22℃、发酵时间8d、酵母菌添加量0.20%、SO₂添加量100mg/L和初始pH3.4,在此条件下,所得花色苷含量和酒精度分别为(4.75±0.18)mg/L和(13.02±0.38)%vol。在最优发酵工艺下获得的红树莓果酒花色苷能显著抑制α-葡萄糖苷酶活性,其抑制率的IC₅₀为(48.65±0.73)μg/mL。荧光光谱数据分析发现红树莓果酒花色苷通过与α-葡萄糖苷酶结合成复合物,引发α-葡萄糖苷酶的静态荧光猝灭。研究结果为开发新型的功能性饮品提供重要参考依据。     

发酵条件对红树莓果酒花色苷含量和酒精度的影响及其对体内α-葡萄糖苷酶抑制研究

通过单因素实验探究发酵温度、发酵时间、酵母菌添加量、SO₂添加量和初始pH对红树莓果酒花色苷含量和酒精度的影响。通过α-葡萄糖苷酶抑制和荧光光谱分析来探究在最佳发酵工艺条件下获得的红树莓果酒花色苷的降糖活性。研究结果表明最佳红树莓果酒发酵工艺为:发酵温度22℃、发酵时间8d、酵母菌添加量0.20%、SO₂添加量100mg/L和初始pH3.4,在此条件下,所得花色苷含量和酒精度分别为(4.75±0.18)mg/L和(13.02±0.38)%vol。在最优发酵工艺下获得的红树莓果酒花色苷能显著抑制α-葡萄糖苷酶活性,其抑制率的IC₅₀为(48.65±0.73)μg/mL。荧光光谱数据分析发现红树莓果酒花色苷通过与α-葡萄糖苷酶结合成复合物,引发α-葡萄糖苷酶的静态荧光猝灭。研究结果为开发新型的功能性饮品提供重要参考依据。     

黑枸杞干红葡萄酒发酵工艺

以酿酒葡萄梅鹿辄、黑枸杞为原料,开展干红葡萄酒发酵工艺研究,以黑枸杞添加量、酵母添加量、发酵时间为因素,以感官评价为主,以还原糖、酒精度和总花色苷含量为辅助评价指标,通过正交试验确定黑枸杞干红葡萄酒最佳发酵工艺为:黑枸杞添加量4%、酵母添加量0.15 g/kg、发酵时间18 d,得到的黑枸杞干红葡萄酒的还原糖含量为3.89 g/L,酒精度为12.4%vol,总花色苷含量为416.56 mg/L。     

紫薯黄冠梨复合果酒酿制工艺研究

以紫薯、黄冠梨为主要原料,经淀粉酶液化,果胶酶和糖化酶糖化,添加白砂糖,经酵母菌发酵,制得紫薯梨复合果酒,采用单因素实验和正交试验优化制备工艺。结果表明,淀粉酶对紫薯液化过程的最佳条件为酶添加量0.12%,酶解pH值6.0,酶解温度50℃,酶解时间30 min,此时出汁率为68.00%。果胶酶、糖化酶对混合果汁酶解过程的最佳条件为酶添加量0.10%,酶解pH值4.0,酶解温度50℃,酶解时间90 min,此时混合果汁的出汁率为70.65%,最优配方及发酵工艺条件为:物料比1∶5,紫薯∶梨为1∶1,酵母添加量4%,白砂糖添加量15%,28℃发酵5天,制得紫薯梨复合果酒,测得复合果酒的酒精度为12.8%。     

一种复合果酒的研制

以红树莓、菠萝和甜瓜为原料,经酶解制汁、发酵及下胶澄清稳定处理,制得发酵复合果酒。经过单因素试验和正交试验,以酒精度为评价指标,确定最佳发酵工艺参数为红树莓汁∶菠萝汁∶甜瓜汁配比2∶1∶1、初始糖度24 °Bx、初始pH值4.0、酵母接种量0.4 g/L,酒精度为11%vol。以透光率为考察指标,确定最佳澄清工艺参数为：膨润土添加量0.4 g/L,澄清温度25 ℃,澄清时间12 d,透光率达到95.60%。酿制的果酒酒精度适宜,果酒呈暗红色,酒液清亮无浑浊,口感爽适纯净,香气协调优雅。     

氮源种类及浓度对蜂蜜酒发酵和杂醇油含量的影响

探讨氮源种类及浓度对蜂蜜酒发酵和杂醇油含量的影响,为蜂蜜酒的酿造提供参考.实验以酿酒酵母(Saccharomyces cerevisiae Hansen)1450为实验菌株,以荆条蜜为原料,分别添加硫酸铵、磷酸铵、磷酸氢二铵、乙酸铵、酵母膏、蛋白胨和豆芽汁作为蜂蜜酒发酵培养基氮源.依据GB/T 15038-2006<葡萄酒、果酒通用分析方法>测定发酵液酒精度、还原糖、总酸和挥发酸,用二甲氨基苯甲醛比色法测定杂醇油.结果表明,铵盐中以磷酸氢二铵酒精度高,有机氮源中以酵母膏酒精度高,添加有机氮源蜂蜜酒中杂醇油含量高.     

苹果树莓复合果酒酿造工艺研究

本研究以苹果和树莓为原料,通过单因素和正交试验确定苹果树莓混合果汁酶法浸提工艺和混合果酒发酵工艺的条件。结果表明,苹果树莓适宜混合原料比为100∶30,采用果胶酶处理取汁最佳工艺参数为果胶酶酶解温度40℃、酶添加量0.13%、酶解时间为2 h,其中,果胶酶酶解温度对出汁率具有极显著影响(p0.01)。以酿酒酵母32168发酵苹果树莓果酒的最佳发酵工艺参数为发酵温度28℃、糖添加量4%、接种量5%,其中,发酵温度和糖添加量对酒精发酵力具有极显著影响(p0.01),此条件下苹果树莓复合果酒酒精度达到11.2%vol。     

雪梨枇杷果酒主发酵工艺优化及挥发性成分分析

采用雪梨和枇杷作为原材料,探讨雪梨枇杷复合果酒主发酵的最佳工艺条件。以酒精度、pH、总酸、透光率、还原糖和感官评价为指标,通过单因素实验和正交试验确定雪梨与枇杷体积比、酵母接种量、SO₂添加量,对成品进行微生物指标的测定,并且利用顶空固相微萃取结合GC-MS分析雪梨枇杷果酒中挥发性成分种类以及相对含量。结果表明,以雪梨和枇杷为原料进行发酵,雪梨枇杷体积比为6:4,发酵原浆初始pH为3.5,SO₂添加量为80 mg/L,酵母接种量为0.4 g/L,5 d发酵结束后,得到果酒酒精度为9.51%vol,透光率达到91.5%,总酸为7.60 g/L,pH为3.56,还原糖为8.32 g/L,在此工艺条件下发酵果酒感官评价得分为91分,各因素对果酒酒精度影响次序为:初始pH > 酵母接种量 > 雪梨枇杷体积比 > SO₂添加量。并且测得该雪梨枇杷复合果酒的菌群总数为11 CFU/mL以及大肠菌群数小于10-9MPN/mL,均符合标准。通过分析其挥发性成分,雪梨枇杷果酒共检测出30种挥发性化合物,相对含量较高的为醇类和酯类,占总挥发性成分的87.82%,对果酒的香味起着积极作用。     

黑莓汁树脂降酸工艺研究及其复合果汁制备

基于紫薯糖液可提供一定糖分及其酰基化花色苷可提高花色苷稳定性,研究不同阴离子交换树脂和流速对黑莓汁降酸效果及紫薯糖液对黑莓汁口感的影响,比较黑莓紫薯复合果汁、黑莓汁和紫薯汁在加速贮藏期间花色苷含量的变化,探究紫薯糖液对黑莓汁花色苷稳定性的影响。结果表明,8种树脂对黑莓汁均有不同程度的降酸效果和花色苷、可溶性固形物吸附作用,其中LXZ-67树脂最适于黑莓汁降酸,脱酸率为55.6%,花色苷和可溶性固形物保留率分别为81.4%、87.1%,综合考虑生产效率和花色苷保留率,适宜生产流速为20 BV/h。黑莓汁与紫薯糖液的最佳调配比例为4∶1,此时复合果汁酸甜适口、香气浓郁。加速贮藏期间花色苷降解速率由大到小为黑莓汁复合果汁紫薯汁,表明紫薯糖液可提高黑莓汁花色苷稳定性。     

紫薯酒低温发酵工艺及酚类物质动态变化分析

研究紫薯低温发酵制备紫薯酒工艺,并分析酚类物质和花青素在紫薯酒发酵和储藏过程中的动态变化。结果表明,紫薯酒发酵最佳工艺条件为:NaHSO_3添加量50 mg/L,紫薯浆初始糖度20°Bx,酵母添加量0.125%,在15℃低温条件下发酵14 d。在此条件下,所得紫薯酒酒精度为11.8%vol,SO_2含量为48 mg/L,总酸含量为5.9 g/L,总糖含量为3.8 g/L,干浸出物含量为14 g/L,色泽呈紫红色,清澈透亮,没有悬浮杂质,有浓郁的紫薯香与酒香,入口甘甜爽口,有典型的紫薯果酒的特征,综合感官评定得分87分。总酚和花青素动态分析表明,紫薯酒发酵过程中总体呈现先上升后下降趋势。试验结果为紫甘薯酒的开发利用提供科学依据。     

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.     

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%.     

Preparatory Work of Print China 2015 is Going Smoothly

正Held at Guangdong Modern International Exhibition Center,Print China 2015 will cover 7exhibition halls,besides the original Hall No.3,4,5,6,7,the newly built F zone of Hall 3 will be used too.The total area will be140,000 square meters.Hall 3:Offset and large printing equipment,package printing equipment,post press