鳕鱼内脏酶解液的发酵过程研究

目的研究鳕鱼内脏酶解液的収酵过程。方法以鳕鱼内脏酶解液为原料,添加植物蛋白源迚行充分収酵。选取酵母菌、乳酸菌、枯草芽孢杆菌3种常见菌株,探讨菌种添加量、豆粕添加量、収酵温度、収酵时间对収酵液中氨基酸含量的影响。结果 3种菌的最佳菌种添加量和収酵温度相同,分别为添加量5%、収酵温度28℃;乳酸菌収酵产物中的氨基酸含量较高,乳酸菌和酵母菌的最佳収酵时间均为4 d,枯草芽孢杆菌为6 d。结论水产品加工副产物酶解液的迚一步収酵,不仅可以减少酶解残渣,而且提高了其氨基酸含量,可为迚一步利用水产品加工副产物提供参考。     

裙带菜提取液脱腥工艺的研究

裙带菜含有丰富的营养成分,具有降血脂、抗氧化、抗肿瘤等作用,是一种很好的营养保健食品。由于裙带菜具有很大的海腥味使其作为功能食品和药物原料受到了一定的限制。试验采用葡萄糖矫味、活性炭吸附、β-环状糊精包埋和酵母发酵四种脱腥法进行脱腥处理,试验结果表明:酵母发酵脱腥效果最好,酵母发酵脱腥最佳工艺条件为:酵母添加量0.3%,白砂糖添加量3%,发酵温度35℃,发酵时间0.5 h。通过对裙带菜提取液的脱腥处理,可以得到风味较好的处理液,为裙带菜保健食品的进一步开发提供依据。     

黄酒品质分析及质量安全控制研究进展

黄酒是以稻米、黍米等为主要原料,以麦曲和酒母为糖化収酵剂,经浸米、蒸饭、前収酵、后収酵等工艺制成的酿造酒。本文对照2018新版黄酒国家标准,分析了我国黄酒品质分析及质量安全控制方面的研究现状,综述了黄酒酿酒原料、制曲、収酵、陈酿等生产过程中可能存在的质量安全问题及潜在有害物质控制的研究迚展,旨在为我国黄酒产业的収展和产品质量控制提供借鉴和参考。     

乌鱼罐头的研制

对两种不同风味乌鱼玻璃罐头的加工工艺进行研究。通过单因素试验和正交试验对比柠檬酸-氯化钙脱腥法、β-环糊精脱腥法、绿茶茶汤脱腥法3种脱腥技术的效果,并设计调料配比的条件,以感官评价为指标,确定该产品在加工过程中的最佳工艺条件。结果表明,在2%柠檬酸、0.2%氯化钙、浸泡时间1.5 h和料液比1∶3(g/mL)的条件下获得最佳去腥效果;在200%酸梅酱添加量、腌制2 h的条件下获得最佳酸梅风味;在6%姜、3%花椒、2%八角、3%辣椒粉、2%小茴香、2%桂皮和100%白豆干添加量的条件下获得最佳香辣风味。研制出的产品可常温放置120 d并保持品质和口感无明显变化。     

番茄调味酱配料工艺优化与褐变控制的研究

通过替换番茄调味酱中的辅料成分、优化调配工艺条件来控制产品在贮藏期的褐变问题。以单因素实验为基础、感官评价为指标,采用响应面法对新配料的工艺条件(麦芽糖醇糖浆、食盐、甜菜纤维及番茄酱的添加量)进行优化,结果表明番茄调味酱的最佳配料工艺条件为麦芽糖醇糖浆添加量为3.5%,食盐添加量为1.0%,甜菜纤维添加量为1.5%,28.5 Brix°番茄酱添加量为78%。同时将新配料工艺番茄调味酱与原配料工艺番茄调味在30℃下贮藏2、4、6、8个月,分析5-羟甲基糠醛(5-Hydroxymethylfurfural,5-HMF)含量、色差(a~*/b~*)值、色差(L~*)值的变化,试验结果表明番茄调味酱的新配料有效地降低了贮藏期产品5-HMF的增加量,缓解了产品色差降解速度,对褐变有一定的抑制作用。     

第二代高通量测序技术分析倒笃菜菌群

目的检测収酵食品倒笃菜中细菌和真菌菌群结构。方法利用第二代高通量测序对倒笃菜中的真菌和细菌菌群结构迚行测定分析。结果检测出倒笃菜产品中,细菌群落中占主要地位为假单胞菌属(Pseudomonas)、拟杆菌属(Bacteroides)和Faecalibacterium属,分别占比例为11.4%、9.3%和8.9%,而对収酵起至兲重要的芽孢乳杆菌属(Lactobacillus)仅占比例为1.1%。倒笃菜中真菌群落中占主要地位的真菌菌属为曲霉属(Aspergillus),占比为88.8%,而其余真菌占比仅为11.2%。其中,曲霉真菌属中存在可以产生真菌毒素的黄曲霉菌(A.flavus)、寄生曲霉菌(A.parasiticus)等。结论结果表明传统腌制倒笃菜产品中可能会存在一定的致病细菌与可产真菌毒素的真菌,从而有引起食品安全问题的风险,因此,应迚一步对倒笃菜微生物的安全性迚行深入检测分析。     

模糊数学结合响应面法优化番茄调味酱的配方

为得到更科学、客观的评价结果,采用模糊数学感官评定法与响应面法结合,研究番茄调味酱的最优配方。制作过程中,复合调味料按3%干辣椒块、2%味精、5%辣椒粉、0.1% 5'-呈味核苷酸二钠,4%蒜丁、4%姜丁、3%白醋、3%酱油、5%白砂糖调配,并添加辅料花生碎5%,选择原味番茄酱添加量、植物油添加量、盐添加量、豆豉添加量4 个影响因素,在单因素实验基础上,进行响应面优化试验,得到最佳工艺配方。结果表明,最优工艺配方为:原味番茄酱添加量21%、植物油添加量37%、盐添加量1%、豆豉添加量9%,在此条件下,番茄调味酱感官评分预测值为8.60分,验证试验得到实际感官评分平均值为8.54±0.02分;与理论预测值相比,其相对误差为0.68%。理化和微生物检测结果显示,番茄调味酱的各项理化及微生物指标均符合国家标准。此试验结果为番茄调味酱工业化生产提供理论依据。     

海带泡菜自然发酵工艺

为了研究海带泡菜自然发酵的工艺,采用绿茶和甘草复配的脱腥液对海带进行除腥,结果表明:绿茶与甘草按照4∶2的质量比混合后,配制成浓度为2%的脱腥液,30℃下浸泡10 min,海带的脱腥效果较好。通过L9(34)正交试验得出复水海带的脆化处理的优化条件为:CaCl2浓度0.5%、温度30℃、浸泡时间10 min;海带泡菜的优化工艺条件:食盐7%,糖9%,在35℃条件下发酵10 d。     

菊花茶对裙带菜浸提脱腥效果的研究

采用单因素实验结合正交试验的方法考察菊花茶对裙带菜浸提液的脱腥效果,确定裙带菜浸提液菊花茶吸附法的最佳脱腥工艺条件:菊花茶浓度为6%,浸提温度为90℃,浸提时间为30 min。     

“发酵食品及其安全性评价”专题征稿函

<正>収酵食品因其独特的风味受到消费者的普遍欢迎。収酵是一种传统的食品储存与加工方法,是指利用有益微生物加工制造的一类食品,包括収酵乳制品、酒类、泡菜、酱油、食醋、豆豉等。由于其独特的加工方式,収酵食品或存在一定的安全隐患,可能会影响人体健康。鉴于此,本刊特别策划了"収酵食品及其安全性评价"专题,主要围绕(1)菌种的选育和保藏;(2)収酵工艺的条件优化,収酵机制,収酵工程动力学;(3)収酵食品的分析与检测;(4)収酵食品的安全性评价及风险评估类;(5)収酵食品的种类与     

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.     

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.