葡萄糖、谷氨酸钠对番茄红素提取率的影响研究

研究了葡萄糖、谷氨酸钠对仍具生理活性的番茄匀浆中番茄红素合成量及提取率的影响,结果表明:在番茄匀浆中添加葡萄糖3.0%、谷氨酸钠2.5%、TBHQ0.03%,25℃下恒温处理60min后,其乙酸乙酯提取物中番茄红素的含量提高了39.8%。     

乙烯利对番茄红素提取率的影响研究

综合研究了乙烯利提高番茄匀浆中番茄红素合成量及细胞溶出率的作用,实验表明,最佳条件为调番茄匀浆pH5.0,添加乙烯利1.4%,BHT0.03%,25℃下恒温处理90min,50℃下恒温处理90min,其乙酸乙酯提取物中番茄红素的含量提高了53.3%。     

番茄品种、成熟度和热处理对番茄中番茄红素含量的影响

使用高效液相色谱(HPLC)法测定，发现含有Crimson gene(og)的番茄含有较高量的番茄红素(5086—5786mg／100g鲜品)，而无此基因的只含有2622—4318mg／100g鲜果。比较了来自赤道地区的番茄，发现番茄匀浆的颜色比番茄表面颜色更可以作为番茄红素含量的指示剂。番茄中番茄红素的含量不受乙烯的影响，在100℃下，加热4、8、16分钟也无影响。     

固体发酵纳豆激酶培养基的优化

研究蔗糖、葡萄糖、谷氨酸钠3种培养基对固体发酵纳豆激酶的影响,发现添加蔗糖和谷氨酸钠能提高纳豆激酶酶活,而添加葡萄糖反而抑制酶活.优化后的培养基为:4%蔗糖、0%葡萄糖、2%谷氨酸钠.     

不同前处理方法对番茄红素提取率的影响研究

通过对番茄酱进行酶解法、反复冷冻法、加碱法、研磨法、加盐增加渗透压法等各种细胞破壁的处理,确定自溶法是提高番茄红素萃取率最经济有效的方法。进一步实验表明,番茄打酱时加入0.01%的Vc,然后调pH为5,加入2%的乙烯,50℃处理30min,可得到番茄红素含量较高的番茄酱。     

番茄油树脂成分分析及番茄红素的稳定性

对番茄油树脂中的脂肪酸组成和类胡萝卜素进行了分析测定,并研究了番茄油树脂在贮存过程中番茄红素的稳定性.结果表明,番茄油树脂中含有较多的脂肪酸甘油酯(65%)和不皂化物(27%),主要含不饱和脂肪酸(74%～75%),其中亚油酸质量分数为51%～52%,油酸质量分数为22%～23%.番茄油树脂中类胡萝卜素主要是番茄红素,另外有少量的β-胡萝卜素.番茄油树脂贮存过程中番茄红素较为稳定,贮存条件以避光充氮效果最好.     

顶空气相色谱法测定玉米中的乙烯利残留

利用顶空-气相色谱-氢火焰离子化分析方法(HS-GC-FID)对玉米中乙烯利残留量进行了测定,并分析了不同顶空和色谱条件对玉米中乙烯利残留测定的影响,建立了玉米中乙烯利残留量的顶空-气相色谱检测方法。玉米样品经甲醇提取、离心、浓缩,采用HS-GC-FID法测定其中乙烯利含量。方法的线性相关系数为0.9999,相对标准偏差为1.07%～5.70%,样品加标回收率为72.01%～90.85%,方法的最低检出限为0.1mg/kg。该方法简单、易操作,适于玉米中乙烯利的定量分析。     

QuEChERS-气相色谱-串联质谱法测定果蔬中乙烯菌核利及其代谢物的残留量

建立了改进的QuEChERS方法结合气相色谱/质谱(GC/MS)法快速测定果蔬中乙烯菌核利及其代谢物3,5-二氯苯胺残留量的方法。研究改良了QuEChERS方法中吸附剂的种类和用量,用乙酸乙酯提取番茄、黄瓜、生菜、芹菜、柑橘和葡萄中乙烯菌核利及其代谢物残留,经乙二胺-N-丙基硅烷(PSA)粉80 mg、石墨化碳黑(GCB)粉50 mg吸附杂质净化后,GC/MS外标法定量。结果表明,乙烯菌核利及其代谢物3,5-二氯苯胺在0.02～0.25μg/m L的质量浓度范围内呈线性关系,相关系数为0.997和0.998。乙烯菌核利及其代谢物在番茄、黄瓜、生菜、芹菜、柑橘和葡萄中的添加水平为0.05～3.0mg/kg时平均回收率范围均处于81.67%～113.33%之间,相对标准偏差(RSD)小于9.47%,方法的检出限(LOD,S/N=3)乙烯菌核利在4.2～15.5μg/kg之间,3,5-二氯苯胺在6.3～17.6μg/kg之间。本方法具有快速、简便、灵敏等特点,能满足果蔬中残留乙烯菌核利及其代谢物的检测要求。     

番茄饮料中番茄红素的检测及稳定性研究

对番茄饮料中番茄红素的提取和分析方法进行了研究。测定了市售5种番茄饮料,确定了番茄饮料中番茄红素以石油醚为提取溶剂,超声波辅助提取法为最佳提取方法,回收率91%;分别用分光光度法和高效液相色谱法作为定量分析方法,并进行了比对。试验还对番茄饮料中的番茄红素稳定性进行了研究,结果表明:番茄饮料中的番茄红素在常温和冷藏条件下比较稳定,而番茄红素溶液在紫外光照下易损失。     

番茄红素保健果酒的生产方法

研究以番茄为原料,经过酒精发酵生产番茄红素保健果酒的工艺。采用臭氧水浓度为1.0mg/L,对番茄进行处理,作用时间2min,可杀灭95%以上的微生物,减少了发酵过程中SO2的用量。加入50mg/L的果胶酶,使番茄的出汁率提高到71.7%,番茄皮渣用石油醚-丙酮混合试剂在pH8、40℃浸取4h,提取番茄红素。番茄汁经过前发酵、后发酵、陈酿得到番茄酒,将番茄红素加入到番茄酒液中获得番茄红素保健果酒。     

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.     

Focus on China's Paper Industry

In the English section of this issue, 〈China Paper Newsletters〉 will introduce ＂National Development and Reform Commission Issued Announcement for Selection of Major Preliminary Research Projects for the ＇13th Five-Year Plan＇＂, ＂2013 Annual Report of China＇s Paper Industry＂, and news of projects and other policies.     

Listen to downstream & search for innovation

正Nowadays,textile enterprises are all taking efforts in transformation and upgrading,like improving producing capacity and optimizing production structure to face market downturn.It claimed a higher request to the standard of textile equipments.In the upcoming of ITMA ASIA+CITME 2014exhibition,this magazine have interviewed several branch associations and a series of relative enterprises,to summarize industrial developing status