低温长混二次碱炼工艺在棉籽油精炼中的应用

为了在碱炼工段中将棉籽毛油中的棉酚脱除干净,避免因棉酚的存在而导致对一、二级棉籽油产生不良的影响,同时减少中性油的损耗,对于酸值在3 mgKOH/g以下的棉籽毛油采用低温长混碱炼工艺;而对于酸值在7～10 mgKOH/g的棉籽毛油则采用低温长混二次碱炼工艺.     

提高棉籽油精炼率新工艺

采用水化低温长混工艺,避免棉酚变性,棉油色泽固化,使油皂易于分离.毛油经预处理、除杂、脱胶后,在棉籽油离心脱皂前,加入适量浓度的食盐溶液.该工序降低了皂脚夹带的中性油含量,提高了棉籽油精炼率.     

棉籽油碱炼加工工艺的生产实践

介绍了低温长混工艺和低温长混加二次碱炼工艺特点及其在棉籽油生产中的应用。     

棉籽油碱炼过程中常见问题与对策

目前国内中小型植物油厂精炼棉籽油多采用间歇式精炼工艺。由于碱炼过程中各种成份，如中性油、磷脂、棉酚、游离脂肪酸、色素、蛋白质及粘液都要和碱液发生复杂的物理化学反应，使得棉籽油碱炼效果除受到毛油本身品质的影响外，还受到操作过程中的用碱量、碱液浓度、碱炼时的温度、搅拌速度及工人操作水平等多种因素的影响。在碱炼过程中难免出现这样那样的问题，如果处理不当，给生产带来不必要的麻烦，影响精炼率、精油品质和企业经济效益。本根据笔几年来的生产实际调查和实践，对棉籽油碱炼过程中常见的问题作一介绍，并提出一些处理方法，供从事油脂精炼生产人员参考。     

棉籽油生产过程中棉酚的影响与对策

介绍了棉籽中棉酚的存在与性质,以及棉酚在棉籽油生产过程中可能发生的变化及影响。在毛油制取过程中采用润湿蒸炒,加稀碱液蒸炒,湿式膨化等预处理工序都可有效降低毛油中棉酚含量并提高粕的品质。碱炼是公认的脱除棉酚最有效的方法,但炼耗较高。在脱除棉酚和磷脂后棉籽油也可以进行物理精炼,并可获得良好的工艺效果。提出了在棉籽油中加入适量的邻氨基苯甲酸,再结合其他工序脱除棉酚的方法。     

提高碱炼棉油精油率的探索

目前国内的中小型植物油厂精炼棉籽油多采用间歇式,由于碱炼过程油脂中各种成份如中性油、游离脂肪酸、磷脂、棉酚、色素、蛋白质以及粘液等都要和碱液发生复杂的物理化学反应,使得碱炼棉油精炼率除受到毛油本身的品质影响外,还受到操作过程中的下碱量、碱液浓度,碱炼时的温度以及搅拌速度等多种因素的影响。为了提高棉油精炼的操作水平,提高产品质量,降低原材料的消耗,我们开展了提高碱炼棉油精炼率的探索试验,使棉油的酸价炼耗比,由原来的1:1.56提高到1:1.01的水平,油品也达到GB1537-86质量标准和GB2716-81卫生标     

活性碳吸附棉籽油中色素的研究

一、概述精制后的棉籽油色泽浅黄、气味清淡、富含不饱和脂肪酸,是一种适于食用的尚好的植物油.毛棉油的色泽,随着制油工艺过程及其工艺条件的不同而相差很大,同时与棉籽的成熟程度如何亦关系密切.毛棉油一般呈深棕甚至赤褐色.棉油中的色素,主要由其特殊成分——棉酚和它的衍生物所造致的.传统的精炼法,一般采用氢氧化钠(烧碱)进行减炼,以中和油中的游离脂肪酸.在碱炼过程中,棉酚同时被转化成棉酚钠盐,被皂脚吸附.所以,通过碱炼,不仅使油中游离脂肪酸被最大限度去除,而且使棉油的色泽也得以较大程度的改观.但若想获得高级食用油,则还必须进行“脱色”和脱臭等工艺过程.     

棉籽油物理精炼实践

一般认为棉籽油不宜进行物理精炼的主要原因是其中含有棉酚,但只要工艺方案选择合理,采用合理的工艺条件,是完全可以对棉籽油进行物理精炼的。提出了针对棉籽油进行物理精炼的切实可行的工艺方案和要求,并在实际生产中加以应用,取得了良好的工艺效果和经济效益。棉籽油进行物理精炼时,应使用较低的温度,较高的真空度,将酸值降至2 mgKOH/g左右时改用碱炼脱酸,既可提高精炼率,又可脱除油中的棉酚。     

简易碱炼棉油方法的试验报告

扶沟县农民自制棉油的加工方法为棉籽生榨后碱炼,但由于碱炼工艺不规范,加碱量达不到碱炼效果要求,棉油中棉酚含量超标,当地出现了慢性棉酚中毒。为预防棉酚中毒,我们试验了一种简易碱炼方法,现报告如下。 1 材料与方法 1.1 取库存棉籽在68型榨油机上榨得毛棉油,将其分为6组各5公斤,碱液浓度     

棉饼浸出混合油碱炼中间试验报告

无产阶级文化大革命以来,我国油脂浸出工业有了很大发展,对增产油脂起了一定的作用。浸出法制油,是用溶剂(己烷)萃取油料中的油脂。溶剂和油脂的混合溶液,称为混合油。目前一般的工艺是:混合油蒸去溶剂得到毛油,毛油再经过精炼(碱炼或水化),才能提供食用。在蒸发溶剂的过程中,混合油所含的油脂伴随物,如磷酯、腊、脂肪酸、棉酚等发生不良变化,影响毛油质量,主要是颜色深(特别是棉籽油)、杂质多、酸价高。因此,浸出毛油碱炼时损失中性油较多,造成炼耗大等缺点。     

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.     

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.     

低温带皮菜籽粕微粉的不同粒级部分的功能特性

为研究低温带皮菜籽粕微粉的不同粒级部分的功能特性,以经低温脱脂的带皮菜籽粕为原料,经微粉碎后筛分成212~425μm、150~212μm和106~150μm的3个不同粒级的微粉样品,检测这些样品的吸水性、吸油性、乳化性和乳化稳定性、蛋白质体外消化率。结果表明:1 3个不同粒级的微粉样品之间的粗纤维含量存在显著差异,表明三者的结构组成成分有一定差异。23个微粉样品的乳化活性和乳化稳定性随粒度级别的减小而显著增加(P0.01)。33个微粉样品的蛋白质体外消化率随粒度级别的减小而显著增加(P0.01)。4不同粒级带皮菜籽粕微粉样品的吸水性与吸油性受其结构组成物质不同和粒度的双重影响,与粒度的相关性不明显。     

Microbiology of food taints

Fresh and processed foods are often spoilt by the presence of undesirable flavours and odours caused by microbial action. The aim of this paper is to review the current knowledge of microbiologically induced taints that occur in a wide range of foodstuffs, including meats, poultry, fish, crustaceans, milk, dairy products, fruits, vegetables, cereals and cereal products. Examples have been chosen where the compounds responsible for the taint have been identified and sufficient data obtained to demonstrate the involvement of microorganisms. However, in some cases the full identity of the causative organism may not have been elucidated. The types of microorganisms covered by this review include bacteria, fungi, yeasts, actinomycetes and cyanobacteria. Although cyanobacteria do not in general infect foods, their presence in aqueous systems and water supplies can lead to off-flavours in aquatic organisms and processed foodstuffs. Several examples of each of these processes are discussed. Wherever possible, the likely biosynthetic pathway used by the microorganism to produce the offending compound in a foodstuff is indicated.     

Analysis for organic residues from aids to polymerization used to make plastics intended for food contact

Polymers intended for food contact use have been analysed for organic residues which could be attributed to a range of substances employed as polymerization aids (e.g. initiators and catalysts). A wide range of polymers was extracted with solvents and the extracts analysed by gas chromatography-mass spectrometry (GC-MS). The overwhelming majority of substances identified were not derived from aids to polymerization but were oligomers, additives and adventitious contaminants. However, a small number of substances were identified as initiator residues. These included tetramethylsuccinonitrile (TMSN) which was observed in two polymers and it derived from recombination of two azobisisobutyronitrile (AIBN) initiator radicals. Methyl benzoate, benzoic acid, biphenyl and phenyl benzoate were detected in one poly(methyl methacrylate) sample and in two polyvinylchlorides and they are thought to be derived from benzoyl peroxide initiator. TMSN was subsequently targeted for analysis of poly-(methyl methacrylate) plastics using proton nuclear magnetic resonance spectrometry (¹     

Tests of potential functional barriers for laminated multilayer food packages. Part II: Medium molecular weight permeants

Experiments were performed to characterize the kinetics of the permeation of different medium molecular weight model permeants: bisphenol A, warfarin and anthracene, from liquid paraffin, through a surrogate potential functional barrier (25 microns-thick orientated polypropylene--OPP) into the food simulants olive oil and 3% (w/v) acetic acid. The characterization of permeation kinetics generally observed the permeation models previously reported to explain the experimental permeation results obtained for a low molecular weight group of model permeants. In general, the model permeants exhibited behaviour consistent with their relative molecular weights with respect to (a) the time taken to attain steady-state permeation into the food simulant in which they were more soluble, (b) their subsequent steady-state permeation rates, and (c) their partition between liquid paraffin and the OPP membrane.     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. I: Interlaboratory studies of methods of analysis

This paper describes the first part of a project undertaken to develop mussel reference materials for Paralytic Shellfish Poisoning (PSP) toxins. Two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin (STX) and decarbamoyl-saxitoxin (dc-STX) in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the second part of the project: the certification exercise. In the first study, 18 laboratories were asked to measure STX and dc-STX in rehydrated lyophilized mussel material and to identify as many other PSP toxins as possible with a method of their choice. In the second interlaboratory study, 15 laboratories were additionally asked to determine quantitatively STX and dc-STX in rehydrated lyophilized mussel and in a saxitoxin-enriched mussel material. The first study revealed that three out of four postcolumn derivatization methods and one pre-column derivatization method sufficed in principle to determine STX and dc-STX. Most participants (13 of 18) obtained acceptable calibration curves and recoveries. Saxitoxin was hardly detected in the rehydrated lyophilized mussels and results obtained for dc-STX yielded a CV of 58% at a mass fraction of 1.86 mg/kg. Most participants (14 out of 18) identified gonyautoxin-5 (GTX-5) in a hydrolysed extract provided. The first study led to provisional criteria for linearity, recovery and separation. The second study revealed that 6 out of 15 laboratories were able to meet these criteria. Results obtained for dc-STX yielded a CV of 19% at a mass fraction of 3.49mg/kg. Results obtained for STX in the saxitoxin-enriched material yielded a CV of 19% at a mass fraction of 0.34mg/kg. Saxitoxin could not be detected in the PSP-positive material. Hydrolysis was useful to confirm the identity of GTX5 and provided indicative information about C1 and C2 toxins in the PSP-positive material. The methods used in the second interlaboratory study showed sufficiently consistent analysis results to undertake a certification exercise to assign certified values for STX and dc-STX in lyophilized mussel.     

The Ministry of Environmental Protection Issued "Feasible Technology Guidelines for Pollution Prevention and Control in Wood Pulping Process of the Paper Industry (Trial)" and Two Other Guiding Technical Documents

On December 27t＂, 2013, the Ministry of Environmenta Protection announced that, in order to implement ＂The Environmental Protection Law of the People＇ s Republic of China＂, improve the working system in environmenta protection technologies, and promote technologica advancement in pollution prevention, the Ministry of Environmental Protection sponsored the formulation of three guiding technical documents including ＂Feasible Technology Guidelines for Pollution Prevention and Contro n Wood Pulping Process of the Paper Industry （Trial）＂     

1~(st) Intelli-Tissue~ EcoEc Tissue Machine Supplied by PMP Group Successfully Put into Operation in China

正On April 29th,2014,Intelli-Tissue EcoEc tissue machine supplied by PMP Group successfully put into operation at Hebei Xuesong Paper Co.,Ltd.,this is the first such kind of paper machine of PMP Group in China.