高酸海棠果麸皮果醋酒精发酵工艺优化及品质分析

以新疆高酸海棠果和麸皮为原料制备果醋。以酒精度为考察指标,通过正交试验优化酒精发酵工艺。同时分析发酵前后挥发性成分、氨基酸含量的变化及果醋的抗氧化活性。结果表明,酒精发酵最优工艺为:酵母接种量0.08%、发酵温度30℃,初始糖度16%,麸皮量5%,发酵醪酒精度达9.51%vol。发酵前氨基酸总量为62.57μg/m L,发酵后氨基酸总量为95.37μg/m L,其含量提高了49.44%。经顶空固相微萃取-气质联用仪测定挥发性成分,果醋中共检出26种挥发性香气成分,其中酯类、醇类和羧酸类化合物分别占挥发性成分总量的41.59%, 30.18%和16.81%,与发酵前相比,果醋的羧酸类、醇类和酯类含量均有提高;果醋对DPPH自由基、ABTS+自由基的IC50值分别为0.464 0±0.044 69 mg/mL、0.471 4±0.022 74 mg/mL,果醋具有一定的抗氧化活性。     

雪莲菌发酵豇豆工艺优化及其挥发性风味成分分析

利用雪莲菌对豇豆进行发酵,以感官评分和总酸含量为评价指标,采用单因素和正交试验对发酵工艺进行优化;并采用高效液相色谱（HPLC）法和气相色谱—质谱联用（GC-MS）分析发酵前后风味物质的变化。结果表明,最佳发酵工艺条件为盐添加量4%,雪莲菌接种量1.5%,发酵温度25 ℃,发酵时间4 d ,此条件下感官评分为87分,总酸含量为3.40 g/kg。雪莲菌发酵后共检出72种挥发性风味物质,与原料相比,新产生了56种挥发性风味物质。除醛类物质外,其他挥发性风味物质相对含量均增加,且醇类和酯类含量较高。与自然发酵相比,雪莲菌发酵后的挥发性物质种类和含量也较高。     

乳酸菌发酵枸杞过程中理化指标及风味物质的变化

本文以保加利亚乳杆菌与嗜热链球菌组合发酵枸杞,研究其最佳发酵工艺条件,并分析了发酵过程中理化指标及风味物质成分的变化。以发酵后产品的感官评分为指标,确定了乳酸菌发酵枸杞的最佳工艺参数为:以保加利亚乳酸菌与嗜热链球菌(1∶1)组合发酵,料液比8∶1 g/100 mL、接种量4%、发酵时间24 h,此时成品的感官评分81分。乳酸菌发酵枸杞过程中可滴定酸逐渐上升,pH及还原糖含量不断下降,活菌数、可溶性固形物含量、可溶性蛋白含量呈先升后降的趋势。利用固相微萃取-气质联用的技术从发酵后的枸杞液中分离出63种挥发物质,主要包括12种酯类、16种醛类、15种酮类、13种醇类、4种酸类、3种芳香杂环类,其中新增加了41种挥发性物质。发酵24 h后,醛类、酮类挥发性风味物质的相对含量呈降低趋势,酯类、酸类及芳香杂环类挥发性风味物质的相对含量呈增加趋势。     

益生菌发酵苹果浆工艺优化及发酵前后挥发性风味成分分析

以苹果浆为原料,研究益生菌混菌发酵苹果浆工艺条件及发酵前后挥发性风味成分的变化。选取Lactobacillus plantarum 21805、Lactobacillus acidophilus 20250混合发酵苹果浆,以活菌数和感官评分为评价指标,研究乳酸菌接种量、发酵温度、发酵时间、菌种比例、灭菌条件、苹果浆料液比对发酵苹果浆品质的影响,在单因素试验基础上采用正交试验对发酵工艺进行优化,并采用顶空固相微萃取和气相色谱-质谱联用方法分析苹果浆发酵前后挥发性风味成分的变化。结果表明,益生菌发酵苹果浆最佳工艺条件为发酵温度32 ℃、发酵时间36 h、接种量2%、菌种比例4∶1、苹果浆料液比2∶1（g/mL）,灭菌条件为100 ℃、15 min,在此条件下,发酵苹果浆风味良好,活菌数达到8.93（lg（CFU/mL））。苹果浆经益生菌发酵后共检出27 种挥发性风味物质,其中醇类6 种、酯类10 种、酮类5 种、醛类2 种等。与发酵前相比,苹果浆发酵后新产生15 种挥发性风味物质。发酵后酯类、醇类和酮类挥发性风味物质相对含量呈增加趋势,而醛类挥发性风味物质呈降低趋势。经聚类分析,苹果浆经乳酸菌发酵后其挥发性风味物质改变显著。     

凯里白酸汤发酵过程中挥发性风味物质的变化

采用顶空固相微萃取技术(HS-SPME)和气相色谱-质谱(GC-MS)联用技术,分析白酸汤发酵过程中各类挥发性风味物质的动态变化规律,并利用主成分分析法对挥发性风味物质进行评价。实验结果表明,发酵过程中共检测出40种挥发性风味成分,包括9种酸类、13种醇类、4种酯类、4种醛类、3种酮类、1种酚类和6种萜烯类;酸类、醇类、酯类和萜烯类物质占主导地位,其相对含量占总挥发性化合物的98%以上。发酵过程中,酸类、醇类、酯类、醛类的种类数量和相对含量随发酵进行缓慢增加;酯类、酚类和萜烯类物质的相对含量先增加后降低。主成分分析得到22种主要的挥发性风味物质,发酵第3天时白酸汤的综合得分最高,风味最佳。     

高盐辣椒发酵过程中主要成分及风味的变化

以辣椒为原料、以高盐辣椒发酵过程为研究对象,测定在不同发酵时段的辣椒总酸含量与亚硝酸盐总量,利用固相微萃取技术和气相色谱-质谱联用技术测定不同发酵时间高盐辣椒中的挥发性成分,并利用主成分分析法与聚类分析法对挥发性成分进行评价。结果表明:酸度在发酵阶段变化不大,亚硝酸盐含量在全过程中未超过国家标准,共鉴定出包括烯烃类(4种)、芳香族类(9种)、醇类(13种)、醛类(7种)、酮类(3种)、酸类(2种)、酯类(18种)等7类化合物。随着发酵的进行,初始阶段辣椒中的醇类、酸类与酯类成分含量有所增加,而后醇类与酯类成分含量继续增加,而酸类减少,最终各类成分含量更为均衡。主成分分析得出22种主要的挥发性成分。在整个发酵过程的第24天时的样品风味最为协调。     

高盐发酵辣椒过程中主要成分及风味的变化研究

以辣椒为原料、以高盐辣椒发酵过程为研究对象,测定在不同发酵时段的辣椒总酸含量与亚硝酸盐总量,利用固相微萃取技术和气相色谱-质谱联用技术测定不同发酵时间高盐辣椒中的挥发性成分,并利用主成分分析法与聚类分析法对挥发性成分进行评价。结果表明：酸度在发酵阶段变化不大,亚硝酸盐含量在全过程中未超过国家标准,共鉴定出包括烯烃类（4 种）、芳香族类（9 种）、醇类（13 种）、醛类（7 种）、酮类（3 种）、酸类（2 种）、酯类（18 种）等7 类化合物。随着发酵的进行,初始阶段辣椒中的醇类、酸类与酯类成分含量有所增加,而后醇类与酯类成分含量继续增加,而酸类减少,最终各类成分含量更为均衡。主成分分析得出22 种主要的挥发性成分。在整个发酵过程的第24天时的样品风味最为协调。     

黑枸杞格瓦斯的研制及挥发性成分分析

采用单因素试验及正交试验,对以大麦芽、焦香麦芽、黑枸杞为原料的格瓦斯发酵工艺进行优化,并利用顶空固相微萃取-气相色谱-质谱联用技术(SPME-GC-MS)分析黑枸杞格瓦斯挥发性风味成分。结果表明:黑枸杞格瓦斯最佳发酵工艺为:大麦芽与焦香麦芽质量比7︰3、黑枸杞汁10%、酒花添加量0.02%、料水比1︰10 (g/m L)、发酵温度20℃、接种量3%、接种比例(酵母菌与乳酸菌体积比) 4︰2、发酵时间20 h。黑枸杞格瓦斯共鉴定出76种挥发性风味物质,其中包括醇类18种,酯类15种,酸类14种,醛类11种,烃类6种,酚类5种,酮类4种及其他化合物3种。黑枸杞格瓦斯中主要风味物质为醇类、酯类、酸类物质。     

枸杞果酒低温发酵工艺优化及挥发性风味物质分析

以枸杞汁为原料,感官评价为考察指标,利用单因素试验与正交试验优化枸杞果酒的发酵工艺,同时利用顶空固相微萃取结合气相色谱质谱联用（HS-SPME-GC-MS）技术分析枸杞果酒中挥发性风味物质种类及相对含量。结果表明,枸杞果酒最佳发酵工艺为初始pH值6.0,初始糖度16%,接种量0.7%,18 ℃条件下静置发酵8 d。在此优化条件下,枸杞果酒的感官评分为96分,酒精度为6.28%vol,残糖量为8.33 g/L;通过分析其挥发性风味物质发现,枸杞果酒中共检测出40种化合物,相对含量较高的为醇类和酯类,共占总挥发性成分的71.09%,发酵过程对酒体产生了影响,醇类和酯类对枸杞果酒的香味起着积极的作用。     

自然发酵与接种发酵燕麦醪糟的挥发性成分分析

采用顶空固相微萃取与气相色谱-质谱联用技术分析自然发酵与接种发酵2 种方式燕麦醪糟的挥发性成分,探讨2 种方式下燕麦醪糟挥发性成分的差异性,进而为接种发酵燕麦醪糟工业化生产提供理论依据。结果表明,2 种发酵方式生产燕麦醪糟的挥发性香气成分分别为62、65 种,主要包括酯类、酸类、醇类、醛酮类、杂环类、烃类,主成分分析发现酯类、醇类、杂环类为正影响挥发性物质;接种发酵燕麦醪糟的主要挥发性香气成分为醇类（58.31%）、酯类（20.70%）、酸类（16.75%）,自然发酵燕麦醪糟主要挥发性香气成分为酸类（61.94%）、酯类（18.89%）、醇类（13.58%）;接种发酵燕麦醪糟的酯类、醇类、杂环类成分含量显著高于自然发酵组,酸类成分显著低于自然发酵组。挥发性香气组分分析有助于明确燕麦醪糟接种发酵的可行性,以期为接种发酵燕麦醪糟的品质评价和定向生产提供理论基础。     

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.     

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     

INFOPRINT 2014 was Successfully Held in Dongguan

Sponsored by Printing and Printing Equipment Industries Association of China （PEIAC） and organized by Print China magazine, the Seventeenth Beijing International Printing Information Conference （INFOPRINT 2014） was successfully held on 11th Dec. 2014 at Dongguan Exhibition International Hotel.