油脂返色及其控制技术研究进展

油脂在储存、销售等过程中,色泽会变深,产生"返色"现象,导致感官品质下降,影响油脂产品的销售,甚至影响油脂企业的信誉及发展,尚未得到解决。在对国内外文献统计的基础上,归纳总结了γ-生育酚、磷脂、金属离子、脂溶性色素等油脂返色因素以及在原料质量、加工过程、储存环境3个关键环节的返色控制技术,并对目前油脂返色研究中存在的问题和今后的研究重点作了总结和展望,以期为油脂工业解决油脂返色问题提供参考。     

油脂返色机理分析和防止对策

大豆油和菜籽油返色现象是精炼生产中经常遇到的问题。为了进一步探讨油脂返色机理，防止油脂返色给销售环节带来不必要的麻烦，结合在色拉油生产中的认识，分析了油脂返色机理，返色主要由油脂自动氧化造成的。通过采取降低脱胶油含磷量、使用低活性白土、降低脱臭温度及严格各段过滤等措施，可减缓色拉油返色速率，使大豆色拉油色泽控制在Y4、R0．1，6h加热实验色泽从R0．1升到R0．3；菜籽油储存10d后色泽回升值在R0．3、Y3．5。通过生产工艺的调整，基本上控制了油脂返色。     

精炼大豆油返色研究

返色现象是油脂精炼生产中经常遇到的问题,至今还没有从根本上找出有效的解决措施.从毛油来源、生产工艺条件及TBHQ的添加量等方面进行试验性研究,结果表明,不同产地的毛油质量差异较大,精炼得到的成品油返色时间也有很大不同;生产工艺条件对大豆油返色的影响较大,且添加TBHQ能有效延缓油脂的氧化、返色.     

β-胡萝卜素、甾醇、磷脂、生育酚对油脂回色的影响

以中链脂肪酸甘油酯(MCT)为研究体系,采用105℃烘箱加热、30 d见光储存、30 d避光储存回色实验方法,系统研究了β-胡萝卜素、甾醇、磷脂和生育酚对油脂回色的影响。结果表明:β-胡萝卜素和甾醇不会对油脂回色造成影响;磷脂虽能加深油脂颜色,但不能造成油脂颜色可逆变化,因此也不是油脂回色的主要原因;生育酚是油脂回色的主要因素,微量的生育酚损失即可引起油脂颜色显著变化。     

食用植物油返色原因及其防止对策

返色现象是植物油精炼后会经常遇到问题,如何有效控制返色现象,提高油脂品质稳定性,是油脂行业迫切需要解决难题。该文论述食用植物油返色原因及其防止对策研究进展。     

油脂回色机理及影响因素研究进展

油脂回色是长期困扰油脂工业界的问题,相关研究起步较早但系统研究较少,且主要集中在亚洲。对油脂回色机理、影响油脂回色的主要因素如油料的水分、品种、前处理过程、油脂的制取过程、油脂精炼过程及油脂储存条件进行综述,以期能为油脂回色后续深入研究及油脂工业上对回色的控制提供参考。     

玉米油返色现象研究

该文报道对上海市场四种品牌玉米油返色情况研究,实验结果显示,在相同光照储存条件下,四种玉米油返色情况各不相同;同一种玉米油返色达到最大值时所用时间从少到多依次为:日光灯照射、自然散光、避光;且玉米油自身品质,对返色现象发生有较大影响,金属离子铜和铁含量高的玉米油色泽变化明显,存在多次返色现象。     

玉米油和大豆油回色关键因素及控制措施研究

近百年来,国内外针对油脂回色进行了长期深入的研究,但食用油产品的回色现象还是时有发生,影响回色的关键因素尚无定论,效果显著且能应用于工业化生产的控制技术仍需深入研究。本文通过研究玉米油和大豆油的回色程度和生育酚损失量及油脂氧化指标,发现脱臭油的全氧化值决定了成品油的回色程度。合适的脱臭条件能尽量去除小分子氧化产物,降低成品油的全氧化值,回色程度可由3.1降至1.6,保证了产品色泽稳定性;储存期间,抑制回色的关键就是控制氧化,对成品油采取合理的抗氧化措施可降低81.8%的回色程度,也是抑制油脂回色的有效举措。这为企业解决玉米油和大豆油回色问题提供了一定的支持。     

轮换油脂的精炼

四级油或脱胶油在储存1～2年后,受到光和热等环境因素影响,油脂结构产生变化,酸值增加、过氧化值发生阶段性变化,增加精炼难度和炼耗,精炼成品油可能出现返色、游离脂肪酸含量回升、白土消耗量增加.采用中和工艺、调整脱色和脱臭工艺参数、引进冷冻真空,用同种新鲜油混合轮换油进行精炼,以降低生产成本,保证成品油的化学稳定性.     

几种天然抗氧化剂对乳化香肠色度值的影响

肉类加工过程中,发色、护色、褪色及变色问题都是影响肉制品外观品质的重要因素。肉制品在储存和销售过程中易因光照和氧化作用而褪色。对乳化香肠的色泽在贮藏中的变化进行了研究,采用色差计对天然抗氧化剂对肉制品的护色效果进行测定。研究表明,茶多酚、迷迭香提取物、竹叶抗氧化物对香肠的色泽保持有显著影响（p〈0.05）。     

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.