泡菜制作中亚硝酸盐的产生规律研究

实验室自制泡菜,检测了不同温度、盐浓度、不同人工接种量等条件下,泡菜发酵过程中亚硝酸盐的产生规律,以及相应的产品品质。结果表明:37℃腌制的泡菜亚硝酸盐峰值最低且发酵最快;30℃腌制的泡菜亚硝酸盐峰值最高;28℃和33℃腌制的泡菜的亚硝酸盐峰值居于中间。37℃与33℃条件下腌制的泡菜香味较浓、脆度差、酸度高,28℃条件下腌制的泡菜香味较淡、脆度好、酸度适中。4%盐浓度腌制的泡菜亚硝酸盐峰值最高但发酵最快;6%盐浓度腌制的泡菜亚硝酸盐峰值最低,发酵发酵速度居中;8%盐浓度腌制的泡菜发酵速度最慢且口感不好。4%接种量腌制的泡菜亚硝酸盐峰值最低,乳酸发酵最快,发酵周期最短;自然接种腌制的泡菜亚硝酸盐峰值最高,乳酸发酵最慢,发酵周期最长;2%接种量腌制的泡菜介于两者之间。由此得到泡菜腌制的最佳条件分别为:温度28℃,盐浓度6%,人工接种量4%。     

罗汉果在乳酸菌发酵食品泡菜中的应用研究

以包心芥菜和胡萝卜为原料,两者比为3:2,添加罗汉果水煎汁,采用正交实验方法制作泡菜,并结合泡菜中乳酸菌数及维持高含菌量的时间,得出最佳工艺条件为:罗汉果汁量4%、盐浓度4%、糖浓度1%、接种量3%、发酵温度30℃,发酵时间5d.根据此条件,开发出了具有消暑止渴、清热解毒、止咳化痰等功效的新型泡菜保健食品.     

LP-7501S用于发酵萝卜中亚硝酸盐降解工艺的研究

为使泡菜中亚硝酸盐快速降解,利用从自然发酵泡菜中筛选出的一株具有高效降解亚硝酸盐功能的优势菌株LP-7501S,对泡菜进行强化发酵,以蔗糖添加量、食盐添加量、氮源添加量、发酵时间和发酵温度进行单因素试验与正交试验,研究其最佳发酵工艺。结果表明最优发酵工艺为:蔗糖添加量0.7%、食盐添加量4%、氮源添加量0.7%、发酵时间84h、发酵温度30℃。在此发酵条件下,测得发酵萝卜中总酸含量为0.73g/100g,亚硝酸盐可快速降解,含量为0.432mg/kg。     

乳酸菌发酵保健泡菜的研制

将具有保健功能的红枣、枸杞适量添加到泡菜中,采用乳酸菌纯种发酵,研制营养保健功能更全面,对人体健康起着积极作用的乳酸菌发酵保健泡菜。通过单因素试验和正交试验得乳酸菌发酵保健泡菜的最佳工艺条件为:加糖量3%、加盐量3%、接种量8%、红枣枸杞量12%。在此条件下,制作乳酸菌发酵保健泡菜,并和自然发酵泡菜进行品质对比。实验结果表明:乳酸菌发酵泡菜能有效地降低亚硝酸盐含量,缩短发酵周期,提高泡菜品质。该产品感官评定为优,亚硝酸盐含量为9.1 mg/kg,总酸含量为0.86%(以乳酸计),乳酸菌含量为1.17×108cfu/mL,大肠菌群阴性,未检出致病菌。     

植物乳杆菌纯种半固态发酵泡菜工艺条件的研究

对产细菌素植物乳杆菌P158纯种半固态发酵泡菜工艺条件进行了研究。采用正交试验设计,并应用模糊数学综合评判法进行感官评价,确定泡菜产品的最佳工艺参数。结果表明,产细菌素植物乳杆菌纯种半固态发酵泡菜的最佳工艺参数为:盐4%、糖3%、接种量0.1%、发酵温度34℃。在该工艺条件下,制备的泡菜产品口味纯正,品质良好,为泡菜发酵生产探索了一条新路。     

低盐功能糖枸杞、百合泡菜工艺研究

文章对低盐功能糖枸杞、百合泡菜工艺进行了研究,试验结果表明,泡菜最佳发酵条件为枸杞量20%,食盐浓度3%,发酵时间7天,低聚果糖添加量4%(以百合量100%为基准),砂糖添加量为5%,所得产品色香味俱佳,理化指标和微生物指标均符合相关国家标准。     

接种法制作芡实茎泡菜工艺研究

以芡实茎为原料,探讨接种法制作芡实茎泡菜的工艺。以产酸率、感官评价的综合评分为评价指标,通过正交实验优化得出芡实茎泡菜最佳工艺:乳酸菌接种量5%,食盐添加量6%,白砂糖添加量4%,在此条件下所得的泡菜综合评分为190.1,明显高于自然发酵所得芡实茎泡菜的综合评分(144.6)。在发酵期间,接种法制作的芡实茎泡菜中亚硝酸盐含量始终低于自然发酵制作的芡实茎泡菜,亚硝酸盐峰值为2.099mg/kg,低于国家标准,优于自然发酵。     

乳酸菌发酵型枸杞泡菜最佳工艺条件研究

以包心芥菜和白萝卜为原料,在两者比为3:2下,添加枸杞制得泡菜.采用正交试验,得出最佳工艺条件为:枸杞量6%,盐浓度4%,糖浓度1%,接种量3%,发酵温度30℃,发酵时间4d.用此工艺制作的泡菜具有很好的色、香、味.文中最后还简要讨论了枸杞泡菜的发展前景.     

直投式乳酸菌发酵黄瓜泡菜工艺的研究

采用单因素实验和正交试验设计对直投式乳酸菌制剂生产黄瓜泡菜的加工工艺进行研究。结果表明:人工发酵生产泡菜的最佳工艺参数为直投式乳酸菌制剂添加量1‰、蔗糖4%、食盐8%、姜4%、蒜4%、氯化钙0.3%、最适发酵温度30℃、发酵周期5天。在此条件下制备的泡菜色泽正常、香气柔和、口感清脆、滋味可口。     

甘薯泡菜的生产工艺

以甘薯为主要原料,以植物乳杆菌作为菌种生产甘薯泡菜并对其接种量,香辛料添加量和食盐浓度等发酵工艺参数进行优化,还对其发酵规律进行了初步研究.结果:甘薯泡菜的最佳发酵工艺条件为:菌种接种量1%,香辛料的添加量0.3%;食盐浓度4%,发酵温度(18±2)℃,发酵时间8 d.     

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.     

Chlorohydrins of bisphenol A diglycidyl ether (BADGE) and of bisphenol F diglycidyl ether (BFDGE) in canned foods and ready-to-drink coffees from the Japanese market

BADGE.2HCl and BFDGE.2HCl were determined in 28 samples of ready-to-drink canned coffee and 18 samples of canned vegetables (10 corn, 5 tomatoes and 3 others), all from the Japanese market. HPLC was used as the principal analytical method and GCMS for confirmation of relevant LC fractions. BADGE.2HCl was found to be present in one canned coffee and five samples of corn, BFDGE.2HCl in four samples of canned tomatoes and in one canned corn. No sample was found which exceeded the 1mg/kg limit of the EU for the BADGE chlorohydrins. However the highest concentration was found for the sum of BFDGE.2HCl and BFDGE.HCl.H₂O at a level of 1.5mg/kg. A Beilstein test confirmed that all cans containing foods contaminated with BADGE.2HCl or BFDGE.2HCl had at lest one part coated with a PVC organosol.     

European priorities for research to support legislation in the area of food contact materials and articles

A strong science base is required to underpin the planning and decision-making process involved in determining future European community legislation on materials and articles in contact with food. Significant progress has been made in the past 5 years in European funded work in this area, with many developments contributing to a much better understanding of the migration process, and better and simpler approaches to food control. In this paper this progress is reviewed against previously identified work-areas (identified in 1994) and conclusions are reached about future requirements for R&D to support legislation on food contact materials and articles over the next 5 or so years.     

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.     

Textural Properties of Cold-set Gels Induced from Heat-denatured Whey Protein Isolates

A 9% whey protein (WP) isolate solution at pH 7.0 was heat-denatured at 80°C for 30 min. Size-exclusion HPLC showed that native WP formed soluble aggregates after heat-treatment. Additions of CaCl2 (10–40 mM), NaCl (50–400 mM) or glucono-delta-lactone (GDL, 0.4–2.0%, w/v) or hydrolysis by a protease from Bacillus licheniformis caused gelation of the denatured solution at 45°C. Textural parameters, hardness, adhesiveness, and cohesiveness of the gels so formed changed markedly with concentration of added salts or pH by added GDL. Maximum gel hardness occurred at 200 mM NaCl or pH 4.7. Increasing CaCl2 concentration continuously increased gel hardness. Generally, GDL-induced gels were harder than salt-induced gels, and much harder than the protease-induced gel.     

Influence des ions sur le pouvoir hydratant de l'ure e: e tude sur peau de porc ex vivo

This study deals with the influence of ions (NaCl and MgSO4) in a W/O emulsion containing 10% urea. Moisturization kinetics are assessed by corneometry on pig skin ex vivo. The formula's influence on urea penetration is measured by infrared spectrometry with an ATR device and the stripping method. Corneometry and spectroscopy were chosen to record simultaneously the hydratation levels and urea localization into superficial cell layers. Urea crystallization after evaporation of emulsions and aqueous solutions is described. Results show that urea does not hydrate nor penetrate when applied to the skin through an aqueous gel. In a W/O emulsion, sodium chloride increases the ability of urea to moisturize without improving penetration. In vitro urea crystallization is disturbed by sodium chloride or magnesium sulphate for solutions and emulsions. This stabilization by ions is correlated with good moisturization values. The stabilization of urea in the solute state provided by ions increases its water epidermal binding capacity without enhancing penetration.     

Occurrence of bisphenol-F-diglycidyl ether (BFDGE) in fish canned in oil

The levels of bisphenol-F-diglycidyl ether (BFDGE) were quantified as part of a European survey on the migration of residues of epoxy resins into oil from canned fish. The contents of BFDGE in cans, lids and fish collected from all 15 Member States of the European Union and Switzerland were analysed in 382 samples. Cans and lids were separately extracted with acetonitrile. The extraction from fish was carried out with hexane followed by re-extraction with acetonitrile. The analysis was performed by reverse phase HPL C with fluorescence detection. BFDGE could be detected in 12% of the fish, 24% of the cans and 18% of the lids. Only 3% of the fish contained BFDGE in concentrations considerably above 1mg/kg. In addition to the presented data, a comparison was made with the levels of BADGE (bisphenol-A-diglycidyl ether)analysed in the same products in the context of a previous study.     

Analysis on Economic Indicators from 62 Enterprises in Printing Machinery Industry in Q1 2014

Operation of printing machine industry was still unsatisfactory in the first quarter of 2014.Analysis on operation of printing machine industry.a.Market demand was not strong;sales of product undulated and declined.According to the statistics,the total industrial output value fell by 19.28% in the first quarter of 2014 than the average quarter value in 2013; industrial added value decreased by 4.16%; sales revenue dropped by 22.83%. h. Business operation of enterprises was in poor condition. c. R＆D of new products is an important transformation guarantee for enterprises. d. To take self explore new ways upgrading advantages,and explore new ways.