油脂复合抗氧化剂抗氧化协同增效作用的研究

以易氧化酸败的核桃油为试验原料，取等量的9组样品，将抗氧化剂TBHQ、PG、BHT、VE及增效剂柠檬酸、抗坏血酸(VC)分别以不同的组合方式和配比添加到上述9组样品中，然后与空白样一起利用Schall烘箱法每隔24h测一次过氧化值(POV)，比较它们的氧化稳定性。试验结果表明：添加0．02％TBHQ、0．01％PG和0．015％VC复合抗氧化剂的油样(在60℃通风条件下贮藏17d)的过氧化值最低为0．75meq／kg，经计算其在20℃存储保质期可达20个月以上。     

几种抗氧化剂对核桃油抗氧化性能的研究

用schhal烘箱法研究了几种不同的抗氧化剂及增效剂对核桃油的抗氧化性能，结果表明：特丁基对苯二酚（TBHQ）的抗氧化性能最好，抗坏血酸和柠檬酸均是TBHQ和BHT（2，6－二叔丁基对－甲酚）的良好增效剂，二者都能显著提高TBHQ和BHT的抗氧化性能，选用TBHQ和柠檬酸复合，TBHQ与抗坏血酸复合作为核油的抗氧化剂，可使核桃油在20℃下的贮藏时间从1．9个月分别延到19．9个月和25．9个月。研究结果还表明效果较好的抗氧化剂与效果较差的抗氧化剂复合时具有牵制作用。     

油脂复合抗氧化剂抗氧化协同增效作用的研究

以易氧化酸败的核桃油为试验原料 ,取等量的 9组样品 ,将抗氧化剂TBHQ、PG、BHT、VE 及增效剂柠檬酸、抗坏血酸 (VC)分别以不同的组合方式和配比添加到上述 9组样品中 ,然后与空白样一起利用Schall烘箱法每隔 2 4h测一次过氧化值 (POV) ,比较它们的氧化稳定性。试验结果表明 :添加 0 0 2 %TBHQ、 0 0 1 %PG和 0 0 1 5 %VC 复合抗氧化剂的油样 (在 6 0℃通风条件下贮藏 1 7d)的过氧化值最低为 0 75meq/kg ,经计算其在 2 0℃存储保质期可达 2 0个月以上     

精制核桃油生产工艺及其氧化稳定性的研究

研究了利用物理压榨法制备核桃油及其精炼工艺，然后取等重的9组样品，分别添加不同的抗氧化剂TBHQ、PG、BHT、VE及增效剂柠檬酸、抗坏血酸(Vc)，与空白样一起利用Schaal烘箱法每隔24h测一次过氧化值(POV)，比较它们的氧化稳定性。试验结果表明：焙炒、脱酸、脱胶是精制核桃油的关键工序，其工艺条件依次为：焙炒温度130℃、时间30min；碱法脱酸：碱液浓度11％、碱炼初温40℃。加碱量为理论碱量和超碱量之和；磷酸脱胶：油重0．2％的85％磷酸、3％的水、温度保持在60℃；添加0．02％TBHQ、0．01％PG和0．015％Vc复合抗氧化剂的油样(在60℃通风条件下贮藏408h的过氧化值最低为0．75meq／kg，国家标准规定过氧化值≤10nmeq／kg，经计算其在20℃存储保质期可达22个月以上。     

不同抗氧化剂协同效应对花生油稳定性的影响

以过氧化值(POV)作为油脂稳定性的评价指标,采用Schaal烘箱法,研究了TBHQ、BHA、BHT及复合抗氧化剂对花生油稳定性的影响.结果表明,复合抗氧化剂的抗氧化效果优于单一抗氧化剂的,柠檬酸对抗氧化剂有协同增效作用,花生油中添加0.015%TBHQ、0.005%BHT和0.01%柠檬酸抗氧化效果显著.     

非洲山毛豆油抗氧化稳定性研究

采用Schaal烘箱法,以过氧化值(POV)为指标,研究不同抗氧化剂种类以及质量对山毛豆油抗氧化稳定性的影响。结果表明,TBHQ对山毛豆油具有良好的抗氧化效果,柠檬酸、抗坏血酸、植酸对TBHQ和BHT复合而成的抗氧化剂表现出较强的抗氧化协同增效作用,协同作用强弱依次为Vc>植酸>柠檬酸;添加0.0150%TBHQ+0.005%BHT+0.01%Vc复配而成的抗氧化剂,可使山毛豆油在20℃条件下的预期贮藏时间从不到4个月延长至13个月。     

核桃油自氧化及其抗氧化的实验研究

以过氧化值(P0V)为指标研究了温度、时间对核桃油自氧化过程的影响及添加抗氧化剂对核桃油抗氧化性能的影响。结果表明,温度、时间对核桃油的氧化过程有高度显著的影响。TBHQ对核桃油具有较好的抗氧化性能,抗坏血酸和柠檬酸对TBHQ均表现出较强的协同抗氧化效应,且抗坏血酸的协同抗氧化性优于柠檬酸。使用0.015％TBHQ+0.01％柠檬酸或0.015％TBHQ+0.01％抗坏血酸为核桃油的抗氧化剂,可使核桃油在15℃下的贮藏期从2.9个月分别延长至29.8个月和38.9个月。     

抗氧化剂对蘑菇酱抗氧化性能的影响

采用schhal烘箱法,以过氧化值和酸价为指标研究了不同抗氧化剂对蘑菇酱抗氧化性能的影响。结果表明:相同添加量下,TBHQ对蘑菇酱抗氧化效果最好,但是0.02%TBHQ抗氧化效果不如0.015%TBHQ和0.005%BHT复配的抗氧化剂,抗坏血酸和柠檬酸均对复合抗氧化剂有较强的抗氧化协同增效作用,抗坏血酸的抗氧化协同增效作用优于柠檬酸。因此选用0.01%Vc+0.015%TBHQ+0.005%BHT作为蘑菇酱的抗氧化剂,可使蘑菇酱在20℃条件下的贮藏时间从256 d延长到576 d。     

脂溶性茶多酚对火麻仁油的抗氧化作用研究

以过氧化值(POV)作为油脂氧化程度的评价指标,采用Schaal烘箱法,研究天然抗氧化剂脂溶性茶多酚(LTP)在火麻仁油中的抗氧化作用,并比较LTP与合成抗氧化剂叔丁基对苯二酚(TBHQ)、二丁基羟基甲苯(BHT)在火麻仁油中的抗氧化效果。结果表明:LTP在火麻仁油中具有良好的抗氧化作用,且抗氧化效果与添加量有关,最适添加量为100 mg/kg。在相同添加浓度(100 mg/kg)条件下,经7 d 60℃强化氧化后,LTP、TBHQ及BHT对火麻仁油过氧化值抑制率分别为50.9%,75.7%和11.2%。     

延长花生蛋白粉保质期的研究

研究了采用添加抗氧化剂、抗氧化增效剂、充氮包装等方法延长花生蛋白粉的保质期.通过加速储藏试验,测定过氧化值和酸价确定保质期.结果表明,添加TBHQ0.008%+柠檬酸0.04%配合充氮包装,在60 ℃条件下贮藏24 d时过氧化值为3.15 mmol/kg、酸价为0.604 mg/g,均不超过国家标准,相当于20℃保质期12个月.     

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.     

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.     

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.     

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.     

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.     

Analysis on Economic Indicators from 62 Enterprises in Printing Machinery Industry in Q1 2014

Operation of printing machine industry was still unsatisfactory in the first quarter of 2014.Analysis on operation of printing machine industry.a.Market demand was not strong;sales of product undulated and declined.According to the statistics,the total industrial output value fell by 19.28% in the first quarter of 2014 than the average quarter value in 2013; industrial added value decreased by 4.16%; sales revenue dropped by 22.83%. h. Business operation of enterprises was in poor condition. c. R＆D of new products is an important transformation guarantee for enterprises. d. To take self explore new ways upgrading advantages,and explore new ways.