蓝莓酵素发酵工艺优化

以新鲜蓝莓为原料,植物乳杆菌（Lactobacillus plantarum）和酵母菌作为发酵菌种,以蛋白酶活力及超氧化物歧化酶（SOD）活力为评价指标,通过单因素试验和正交试验优化最佳发酵工艺条件。结果表明,植物乳杆菌（Lactobacillus plantarum）单独发酵蓝莓酵素时,发酵工艺条件为植物乳杆菌接种量为4%,39 ℃条件下发酵1 d。在此条件下蛋白酶活力及SOD酶活力分别为39.44 U/mL和84.17 U/g。植物乳杆菌（Lactobacillus plantarum）和酵母菌复合菌种发酵工艺条件为同时接入4%植物乳杆菌与0.15%的酵母菌,34 ℃条件下培养4 d,蛋白酶活力及SOD酶活力分别达到了55.76 U/mL和81.27 U/g,该方式是最佳的蓝莓酵素制备工艺。     

蓝莓酵素复合菌种发酵工艺优化及品质分析

该研究以蓝莓为主要原料,以酵母菌、植物乳杆菌(Lactobacillus plantarum)、干酪乳杆菌(Lactobacillus casei)为发酵菌种制备蓝莓酵素,以超氧化物歧化酶(SOD)酶活性为考察指标,首先通过均匀设计试验确定复合菌种的最佳接种量;其次通过单因素试验,考察发酵时间、发酵温度、初始总可溶性固形物含量及料液比对SOD活力的影响;最后通过响应面试验获得最佳发酵工艺条件。结果表明,酵母菌、植物乳杆菌、干酪乳杆菌三种菌株的最佳接种量分别为0.1%、2%、0.47%,蓝莓酵素的最佳发酵工艺条件为发酵时间41.5 h,发酵温度31℃,初始总可溶性固形物含量12°Bx,料液比1∶5(g:m L),在此优化条件下,蓝莓酵素的pH值为3.14,酒精度为0.2%vol,总酚含量为3.14 mg/mL,花色苷含量为26.06 mg/mL,乳酸菌活菌数为1.01×10⁷CFU/m L,SOD酶活性为103.01 U/m L。     

香蕉酵素发酵过程中的组分及抗氧化活性变化研究

以香蕉为材料,分别通过自然发酵、酵母菌发酵、植物乳杆菌发酵制作香蕉酵素,测定酵素在发酵过程中组分及抗氧化活性的变化。结果表明自然发酵和酵母菌发酵、植物乳杆菌发酵的香蕉酵素其DPPH自由基和羟自由基清除能力随着时间的延长而增长,DPPH自由基最高清除率分别可达到48.97%、79.54%和69.79%,羟自由基清除率最高可分别达37.68%、49.97%和45.38%。酵母菌发酵、植物乳杆菌发酵的香蕉酵素SOD和碱性蛋白酶活力随着时间的延长而逐渐增强,达到最大值后呈现相对稳定的状态,而自然发酵的香蕉酵素多糖含量达到最大值后呈逐渐减弱趋势,三种酵素SOD最高酶活力分别达到89.5、86.79和48.35 U/mL,碱性蛋白酶的最高酶活分别为67.90、66.58和32.28 U/g。酵母菌和植物乳杆菌发酵的香蕉酵素多糖的含量随着发酵时间的延长出现先增加后稳定的变化趋势,最大含量为20.45 和19.9 mg/g,而自然发酵的香蕉酵素达到最大值17.31 mg/g后呈逐渐下降趋势。自然发酵的香蕉酵素各项指标均低于酵母菌和植物乳杆菌发酵的香蕉酵素,并且接种酵母菌的酵素各项指标都高于接种植物乳杆菌的香蕉酵素,但差异不明显,说明这两种菌均可用于接种香蕉制作酵素。     

乳杆菌强化发酵对苦荞酵素抗氧化特性及风味的影响

为提高苦荞酵素的口感与抗氧化能力，以还原力、SOD酶活力作为主要指标，分别考察植物乳杆菌(LBS8、MRS5)、副植物乳杆菌(MC6)、副干酪乳杆菌(SL1)4株乳杆菌强化发酵苦荞酵素情况，筛选1株优良菌株并研究其接种量、初始糖度、发酵温度、料液比对苦荞酵素发酵的影响，通过单因素实验及正交试验优化苦荞酵素发酵工艺。结果表明，植物乳杆菌LBS8发酵苦荞酵素还原力、SOD酶活力更强，将其作为强化菌株经单因素实验与正交优化，得到最佳工艺条件为：接种量6%，初始糖度16°Brix，发酵温度32℃，料液比1:7。所得酵素中还原力相当于0.753 mg/mL VC标准溶液，SOD酶活力为272.12 U/mL，总黄酮含量为0.521 mg/mL，总酚含量为2.75 mg/mL，谷胱甘肽含量为0.273 mg/mL，与对照组相比均有显著提升。通过GC-MS分析，苦荞酵素中含有乙酸乙酯、亚油酸乙酯、十一酸乙酯、丁二酮等特征性香味物质，赋予苦荞酵素独特的风味。与市售酵素发酵剂相比，利用植物乳杆菌强化发酵酵素总黄酮增加247%，总酚增加2%，谷胱甘肽增加36.5%，还原力提高30.73%，抗氧化能力提高3...     

芸豆酵素复合发酵工艺优化

利用乳酸菌和酵母菌复合菌系制备酵素,通过多菌种单因素试验优化发酵菌种条件并确定复合发酵接种顺序及发酵时间。结果表明:最优发酵方式为先接种酵母菌预发酵后再接种乳酸菌,最佳复合发酵条件为装瓶量30mL(250mL)、pH 5.0、接种0.20%酵母菌、30℃振荡培养24h;再接种3.0%复合乳酸菌(植物乳杆菌嗜酸乳杆菌为11),37℃培养24h;4℃低温静置发酵24h,酵素产香。该条件得到的芸豆酵素上清液色泽通透呈黄色,气味清冽,活菌数显著增加,超氧化物歧化酶活力(SOD)达224.09U/mL。     

响应面法优化沙棘酵素多菌种发酵工艺

以沙棘（Hippophae rhamnoides L.）为原料,利用酿酒酵母（Saccharomyces cerevisiae）、异常汉逊酵母（Hansenula anomala）和植物乳杆菌（Lactiplantibacillus plantarum）多菌种发酵制备沙棘酵素。以超氧化物歧化酶（SOD）、pH、可溶性固形物含量、总酸含量、感官评分、还原力等为评价指标,采用单因素试验及响应面法优化沙棘酵素多菌种发酵工艺。结果表明,沙棘酵素多菌种最佳发酵工艺为初始pH 5.18、酿酒酵母∶异常汉逊酵母∶植物乳植物杆菌1.0∶1.6∶2.6、接种量10.25%。在此工艺条件下,沙棘酵素产品的SOD活性最高,达到2 206.67 U/mL,p H为2.23,总酸含量为78.60 mg/mL,可溶性固形物含量为2.68°Bx,乙醇含量为0.05 g/100 mL,总酚含量为18.85 mg/mL,总黄酮含量为12.49 mg/mL,维生素C(VC)含量为6.48 mg/mL,多糖含量为22.49 mg/mL,还原力（OD700 nm值）为2.65,产品色泽透亮金黄,香气浓郁,感官评分为9.1分,...     

辣椒酵素益生菌复合发酵制剂的筛选

以前期试验筛选出的植物乳杆菌、酿酒酵母、醋酸菌为研究对象,从中选择2组益生菌复合发酵剂L1(植物乳杆菌和酿酒酵母)、L2(植物乳杆菌、酿酒酵母和醋酸菌)制作辣椒酵素,并与传统自然发酵L0做对比。通过观察发酵过程中总酸、pH值、酒精度以及主要功效酶活力(超氧化物歧化酶活力、脂肪酶活力)等主要质量指标的变化规律,筛选出最适合辣椒酵素发酵的一种菌种组合。试验结果表明:混菌发酵对辣椒酵素的品质有明显的改善。发酵第15天,L1、L2与L0相比,总酸含量分别提高了36.53%,31.42%;脂肪酶活力分别提高了99.22%,96.27%;SOD活力分别提高了6.93%,0.91%;pH值分别降低了10.35%,11.05%。此时L1的感官评分最高为(88.75±0.88),总酸含量为34.82g/L,酒精含量为0.023g/L,pH值为3.75,SOD酶活力为88.71U/mL,脂肪酶活力45.75U/L,明显优于L2。植物乳杆菌和酿酒酵母复合的发酵剂适用于辣椒酵素的发酵。     

采用Box-Behnken设计优化玫瑰花酵素发酵工艺及其抗氧化活性的测定

本研究以玫瑰干花瓣为主要原料,采用复合乳酸菌发酵,优化玫瑰花酵素发酵工艺技术。以发酵时间、初始pH、接种量、发酵温度为考察因素,以SOD（超氧化歧化酶）酶活力及总酚含量作为评价指标,采用响应面优化结合Box-Behnken设计试验获得最佳发酵工艺条件。此外,研究还利用DPPH（1, 1-二苯基-2-三硝基苯肼）、ABTS（2, 2'-联氮-双-3-乙基苯并噻唑啉-6-磺酸）和FRAP（铁离子还原法）法检测玫瑰花酵素液发酵前后的体外抗氧化活性,并测定了玫瑰花酵素液发酵前后的SOD酶活力、总酚含量、黄酮含量、花色苷含量、pH和可滴定酸等指标。结果表明,玫瑰花酵素液发酵最佳工艺条件为:发酵时间68 h,初始 pH 5.4,接种量1 g,发酵温度32 ℃。该条件下测得玫瑰花酵素液SOD酶活力为132.07 U/mL,总酚含量为6.28 mg/mL,总黄酮含量为3.48 mg/mL,花色苷含量为5.64 mg/100 mL,可滴定酸为2.82 g/100 g,较发酵之前均有较大的提高。当发酵前后玫瑰酵素液、8 mg/mL Vc体积分数为0.45%时,DPPH自由基清除率分别为73.32%、83.70%、35.05%,ABTS自由基清除率分别为82.18%、92.74%、52.82%,FRAP值分别为0.25、0.28、0.115。DPPH、ABTS、FRAP三种不同的抗氧化方法结果均表明玫瑰酵素液发酵后的抗氧化能力最强。     

蓝莓皮渣酵素的制备及其理化特性

以果酒及果汁生产过程中废弃的蓝莓皮渣为原料,以酵母菌和植物乳杆菌为发酵剂,进行蓝莓皮渣酵素发酵工艺的研究。通过单因素试验和正交试验确定酵母菌最佳发酵工艺条件为:发酵液初始pH 5.0、发酵时间12h、糖添加量6%、接种量0.15%。酵母菌发酵12 h后接种0.5%的植物乳杆菌, 37℃继续发酵27 h,保持温度在6～8℃,静置使其产香。发酵终点时, pH 3.12,可滴定酸含量0.52%。功能性成分中,总酚含量为4.31%,原花青素含量为3.66mg/m L,同时,发酵前后,还原力、羟基自由基清除能力和DPPH自由基清除能力分别提高了1.24倍, 8.1%和5.0%。所得蓝莓皮渣酵素风味适宜,且伴有浓郁的蓝莓香气。     

植物乳杆菌发酵桑葚酵素工艺优化及质量评价

目的:解决新鲜桑葚难以保存的问题，将新鲜桑葚制成桑葚酵素。方法:以新鲜桑葚汁为原料，植物乳杆菌为生产菌种，总酚含量为评价指标，通过单因素试验结合响应面试验优化了植物乳杆菌桑葚酵素的发酵工艺，并对桑葚酵素的理化、微生物及感官质量指标进行评价。结果:优化后发酵工艺条件为发酵时间40 h、发酵温度32℃、接种量25%,所制得的植物乳杆菌桑葚酵素的总酚含量达(43.48±0.67)μg/mL,是未经发酵的桑葚汁的1.62倍，可溶性固体物含量为5.36%,pH值为4.08±0.01,微生物指标满足国家标准；桑葚酵素呈紫红、色泽均匀，具有浓郁的桑葚果香和发酵的香味、无异味，酸味柔和、风味好，有光泽、无杂质及沉淀。结论:经植物乳杆菌发酵制得桑葚酵素的过程有生物活性物质产生，有利于提高桑葚酵素质量。     

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.     

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.     

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.     

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.     

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.     

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.     

Contribution of European research to risk analysis

The European Commission's, Quality of Life Research Programme, Key Action 1—Health, Food & Nutrition is mission-oriented and aims, amongst other things, at providing a healthy, safe and high-quality food supply leading to reinforced consumer confidence in the safety of European food. Its objectives also include the enhancing of the competitiveness of the European food supply. Key Action 1 is currently supporting a number of different types of European collaborative projects in the area of risk analysis. The objectives of these projects range from the development and validation of prevention strategies including the reduction of consumers risks; development and validation of new modelling approaches; harmonization of risk assessment principles, methodologies, and terminology; standardization of methods and systems used for the safety evaluation of transgenic food; providing of tools for the evaluation of human viral contamination of shellfish and quality control; new methodologies for assessing the potential of unintended effects of genetically modified (genetically modified) foods; development of a risk assessment model for Cryptosporidium parvum related to the food and water industries; to the development of a communication platform for genetically modified organism, producers, retailers, regulatory authorities and consumer groups to improve safety assessment procedures, risk management strategies and risk communication; development and validation of new methods for safety testing of transgenic food; evaluation of the safety and efficacy of iron supplementation in pregnant women; evaluation of the potential cancer-preventing activity of pro- and pre-biotic ('synbiotic') combinations in human volunteers. An overview of these projects is presented here.     

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.