脂肪相关酶类在干腌肉制品风味形成过程中的作用

风味是消费者选择食品的主要依据之一。风味的形成是个复杂的生化反应过程,对其的研究至今依旧还未完全明晰。干腌肉制品由于其具有独特的风味而受到消费者的广泛欢迎,经过复杂的加工过程形成了其特征性风味物质,其中较大部分是由脂类水解、氧化而来,随之还会通过美拉德等反应形成各种风味物质。脂类物质是风味物质形成的前体物质,脂质的酶控反应是干腌肉制品风味物质产生的决定性因素。本文对国内外各类干腌肉制品中脂肪水解酶、磷脂酶和脂肪氧合酶在加工过程中的活性变化及其在干腌肉制品中的作用进行了归纳;概述了这几类酶对不同种类风味物质及产品感官品质的影响;综述了加工因素介导这些酶类对风味物质形成的调控作用。为科学认识干腌肉制品风味物质的形成机理、传统工艺改进和参数优化提供参考。     

西班牙研究高压处理对serrano干腌火腿挥发性风味物质的影响北大核心

Serrano干腌火腿是西班牙的传统火腿,深受消费者的喜爱。Serrano干腌火腿的香气包括醛类、醇类、酮类、酸类和烷烃等多种物质,这些物质的形成与火腿成熟期间的肌内脂肪氧化降解、蛋白质酶解等息息相关。肌内脂肪是干腌火腿风味形成的基础物质,同时,火腿加工过程中的盐含量直接影响到产品的最终品质,盐能够降低产品的水分活度、增加蛋白的溶解、影响蛋白水解、脂肪分解和脂肪氧化,并直接影响到产品的风味。     

模拟物流运输条件下冻半干金鲳鱼品质和风味变化

目的:探究半干金鲳鱼在模拟实际运输温度下的品质和风味变化。方法:以冻半干金鲳鱼为研究对象,模拟其在不同温度下的物流运输过程,测定了解冻损失率、肌原纤维蛋白构象的变化、蛋白质和脂质氧化等理化指标以及风味物质的变化规律。结果:半干金鲳鱼的蛋白质和脂质氧化程度均随运输时间的延长显著升高(P<0.05),且温度越高氧化程度越显著(P<0.05),此过程中蛋白质发生聚集且变性程度严重,而解冻损失率仅随温度升高显著增大(P<0.05)。共检测出17种氨基酸,总氨基酸、鲜味氨基酸和苦味氨基酸含量随着运输时间的延长均呈先显著上升后下降的趋势(P<0.05),温度对其含量则无显著影响(P>0.05)。半干金鲳鱼的主要挥发性物质为醛类、烃类和醇类,其中高温运输组的醛类含量显著下降,而烃类物质含量显著上升(P<0.05)。结论:冻半干金鲳鱼在较低温下运输能够减缓蛋白质的变性程度以及蛋白质和脂质氧化程度,并使其富有更多良好的风味物质。     

不同解冻方式对干制武昌鱼品质及挥发性风味的影响

目的 研究不同解冻方式对武昌鱼干制前后品质及挥发性风味的影响。方法 通过电子鼻及气相色谱-质谱法（electronic nose, gas chromatography-mass spectrometry,GC-MS）等技术分析4种解冻方式对干制武昌鱼风味的影响。结合理化指标（脂肪含量、蛋白含量、色度、硫代巴比妥酸值）的测定结果,综合评价不同解冻方式对干制武昌鱼的品质。结果 电子鼻能够很好的区分4种解冻方式对干制前后武昌鱼气味差异,静水解冻武昌鱼能够较大保留武昌鱼的原始气味,结合GC-MS结果,静水解冻武昌鱼干制后风味差异主要来源于醛、醇类物质的贡献。研究发现,较其他解冻方式,静水解冻不仅所需时间较少,且汁液流失率较低;静水解冻后干制武昌鱼的蛋白质含量最高,低温解冻后干燥武昌鱼的脂肪含量最高;静水解冻干制大幅度增加了武昌鱼的a*,给予干制武昌鱼良好的色泽,并且对氧化具有一定的抑制作用,通过自然解冻干制后对武昌鱼的黄度值具有显著抑制作用。结论 综合分析静水解冻较其他3种解冻方式更利于干制武昌鱼的品质及风味的形成。     

大豆蛋白制品风味物质分析

大豆蛋白制品风味是食品业必须考虑问题。在大豆及其制品贮藏与加工过程中,脂质酶促氧化和非酶促氧化对大豆蛋白制品风味形成起着重要作用,发生聚集大豆蛋白质也增加对风味物质结合。该文简要介绍这方面进展及为改善大豆蛋白制品风味所作努力,同时比较风味物质分析方法。     

蛋白质氧化与腊肉品质调控

氧化反应贯穿于整个腊肉加工过程,适度氧化能促进风味物质的形成,但过度氧化会导致腊肉发生哈败。蛋白质是腊肉的主要成分,在加工与贮藏过程中会发生一系列氧化变化,包括产生氧化标志产物、小分子挥发性物质,发生物理结构改变等,从而对腊肉的风味产生重要影响,但其氧化进程和作用机制并不明确。本文对蛋白质氧化机制、蛋白质氧化对肉类品质的影响、蛋白质氧化控制、腊肉中蛋白质氧化研究现状进行综述,为进一步开展研究,揭示腊肉中蛋白质氧化演变规律,阐明蛋白氧化在腊肉品质形成与保持中的作用机制,实现腊肉加工中氧化的精准控制提供参考。     

传统日晒与阴干干腌武昌鱼挥发性风味物质的形成及脂肪氧化的变化

为探究传统干腌鱼的挥发性风味物质,本研究以新鲜武昌鱼为原料,采用日晒、阴干两种传统干制方式对腌制武昌鱼进行加工,并通过测定过氧化值、酸价、茴香胺值、共轭二稀与共轭三稀、羰基价、脂肪酸含量,结合挥发性化合物测定、电子鼻及感官评价来探究传统干腌武昌鱼特征风味物质的形成和风味差异。结果显示：日晒干制的武昌鱼,其过氧化值、酸价、茴香胺值、多烯指数、羰基价均高于阴干和未干制组。日晒武昌鱼的不饱和脂肪酸相对含量要低于阴干和未干制的武昌鱼,尤其是油酸（C18:1n9）、亚油酸（C18:2n9）、亚麻酸（C18:3n3）。日晒对武昌鱼整体气味和挥发性风味物质影响较大。日晒武昌鱼挥发性物质有28种,阴干武昌鱼有23种,未干制组为20种。日晒干制武昌鱼具有更强的哈喇味和肉香味,阴干武昌鱼有更显著的鱼腥味和哈喇味。相关性结果表明：武昌鱼的香气物质与脂肪氧化呈显著正相关,与典型的单不饱和脂肪酸和多不饱和脂肪酸呈负相关。脂肪氧化是干腌鱼香气形成的重要途径,日晒促进了脂肪氧化、干腌武昌鱼风味的形成和香气积累。     

真空冷冻干燥对牡蛎品质的影响

我国牡蛎产量丰富,除部分鲜销外很多加工为干制品,然而传统牡蛎干制品复水性差、产品附加值低。为了得到高品质的牡蛎干制品,本研究对牡蛎进行真空冷冻干燥加工,并对冻干加工牡蛎的复水性、质构和蛋白、脂肪及部分滋味成分含量的变化情况进行探讨。研究结果表明:牡蛎的共晶点和共熔点温度分别为-25℃和-17.5℃,牡蛎在-30℃~-35℃条件下预冻2 h,在冷阱温度达到-40℃后在真空度20 Pa条件下干燥15 h得到干品;与对照产品(市售蚝干)相比,冻干牡蛎复水性较好,其在20 min即可复水完全,复水比为3.68;冻干牡蛎的质构也优于对照,除脂肪含量较低外,蛋白质和几种滋味成分含量也均高于对照。由此可见,真空冻干燥不仅可以减少牡蛎干制时的蛋白损失,且能够较好保持质构和原有风味,可以用于高品质牡蛎干制品的加工。     

不同风干工艺处理的武昌鱼鱼肉品质和风味的变化

以腌制武昌鱼为原料进行干制,通过测定热泵干燥、热风干燥、冷风干燥、联合干燥四种风干工艺处理下的武昌鱼鱼肉脂质氧化理化指标,感官,色泽,质构特性,电子鼻,挥发性风味成分变化,分析不同干燥工艺处理对武昌鱼品质特性和风味变化的影响。热泵干燥的武昌鱼脂质氧化程度更显著,初级产物氢过氧化物含量最高为4 mmol/kg,脂质氧化二级产物丙二醛含量最高为 0.68 mg/kg,感官评分结果最好（8.6分）、质构表现最好;冷风干燥处理的武昌鱼色泽表现最差,热风、热泵、联合干燥处理的武昌鱼差异较小;热风干燥处理的武昌鱼硬度最大53.96 N、热泵干燥处理的武昌鱼弹性最大;电子鼻检测表明四种干燥工艺处理武昌鱼风味呈现显著性差异（P<0.05）;挥发性风味物质检测发现联合干燥处理武昌鱼挥发性风味物质含量最多21种,热泵处理挥发性风味物质含量最低仅有6种。综上所述联合干燥处理的武昌鱼鱼肉,脂质氧化程度硬度低、弹性好、挥发性风味物质含量多种类丰富。     

天然抗氧化剂对鱼糜及鱼糜制品抗氧化能力及品质影响的研究进展

鱼糜及鱼糜制品中富含多不饱和脂肪酸和蛋白质,在冷藏鱼糜及鱼糜制品贮藏和运输中极易发生脂肪氧化和蛋白质氧化,使风味、品质以及凝胶特性降低。抗氧化剂可以有效抑制鱼糜及鱼糜制品脂肪和蛋白质的氧化。天然抗氧化剂相对于化学合成抗氧化剂具有更安全、更高效等优点。因此,在鱼糜及鱼糜制品中添加天然抗氧化剂是一种更为安全可接受的抗氧化手段,能有效抑制蛋白质降解、脂肪氧化、腥味增加及微生物引起的腐败变质等问题,从而有效提高产品品质、风味和凝胶特性。本文主要综述了天然抗氧化剂的种类、来源、抗氧化作用机理以及其对鱼糜及鱼糜制品的影响等,可为天然抗氧化剂在鱼糜产品中的应用提供参考。     

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.     

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.     

Review of techniques to manufacture micro-hydrogel particles for the food industry and their applications

Microgels are ‘soft’ microscopic cross-linked polymeric particles that are being increasingly exploited in a variety of industries for rheology control, encapsulation and targeted delivery. They are valued because of the ability to tune their functionality to address specific applications in oil recovery, coatings, drug delivery, cosmetics, personal care and foods. Food microgels are typically biopolymer hydrogels in the form of microspheres, nanospheres (also called nanogels), spheroids and fibres. The utilisation of engineered microgels in foods has so far been limited, despite their great potential to address several needs in the food industry, including: satiety control, encapsulation of phytonutrients and prebiotics, texture control for healthier food formulations (e.g. reduced fat products), and targeting delivery to specific areas in the digestive tract. We review the scientific and patent literature on the utilisation and manufacturing methods for producing microgels with an emphasis on micro-hydrogels for food applications.     

12—A CRITIQUE OF SOME HYPOTHESES RELATING TO THE HETEROGENEITY OF THE HIGH-SULPHUR PROTEINS OF WOOL

Joubert and Burns prepared a large number of fractions from the high-sulphur proteins of wool and estimated their molecular weights and amino-acid compositions. Their data have been re-examined in order to look for statistically significant interrelations between amino acids and between the proportion of various amino acids and molecular weight. Statistical analysis of the data is also used to examine the credibility of some hypotheses concerning the mechanism of keratin biosynthesis and to provide further evidence for the existence of families of proteins within the high-sulphur fractions of wool.     

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.     

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 Latest Data about Development of Chinese Printing Industry in 2013

In the 2014 China（Shanghai）International Printing Week,Director Wang Yanbin released the latest data about development of Chinese printing industry in 2013.According to statistics,in 2013,the total output value of Chinese printing industry exceeded 1trillion Yuan for the first time,reaching 1.03985 trillion Yuan.There were 105,000 printing enterprises in China,employees were 3.415 million.The total asset was 1.06247 trillion Yuan;     

The State Council Issued "Directory of Government Approved Investment Projects(2013 Edition)"

正On December 2nd,2013,the State Council issued the notification of"Directory of Government Approved Investment Projects(2013 Edition)"(hereafter referred to as"notification").It is pointed out in the"notification"that in order to further deepen reforms in investment systems and administrative examination and approval systems,simplify administrative procedures and delegate powers to lower levels,earnestly     

China textile machinery: taking off in progress

正Among the 1600 exhibitors who take apart in the ITMA ASIA+CITME2014 2/3 are Chinese manufactures.If the numerous figures failed to attract your attention,the increase of quality should draw your focus.To adopt the demand of developing textile machine market,domestic textile machinery enterprises now follow the slogan of"technology drives development"to enhance product competitiveness.Our domestic sellers will showcase product ranging from spinning,weaving,dyeing and printing,     

Top Ten News of China's Paper Industry 2013

On December 24th, 2013, the meeting on the selection of top 10 news of China＇s paper industry 2013 sponsored by 〈China Paper Newsletters〉 was held in Beijing. The yearly selection of the top l0 news, which began in 2000, has become a brand activity widely recognized in the industry thanks to the support from the authorities at all levels and public participation.