扇贝清洗分级一体装置的设计

本文通过分析扇贝加工各个阶段工作,结合国内外扇贝加工机械的发展现状,设计出集扇贝清洗和分级工作于一体的加工装置。该装置根据扇贝贝壳结构特点和生理特性设计出双排毛刷辊清洗方式,根据扇贝的外形尺寸特点设计出对辊式扇贝分级方式,并将清洗与分级工作通过食品输送带连接,实现清洗分级一次性完成。清洗毛刷辊两排运动速度不同,上排毛刷辊转速为200 r/min,下排布置在两侧毛刷辊转速为120 r/min,下排布置在中间毛刷辊转速为360 r/min,并通过与高速气流配合工作,加强了清洗效果。清洗后的扇贝经过食品输送带的传送进入到分级部分,采用螺旋对辊进行分级,分级辊转速为67 r/min,分级辊可改变直径、倾角可调节,提高分级的准确性、可靠性。扇贝清洗分级一体装置的设计减少扇贝加工中劳动量的投入,节约扇贝加工时间,保证扇贝鲜活程度,为扇贝加工行业提供可靠的加工机具。     

毛刷辊式扇贝清洗机

为减少海湾扇贝加工过程中人工的参与,提出螺旋毛刷辊式清洗海湾扇贝的方法,结合相关清洗机构,针对海湾扇贝的特点对主要功能部件进行了改良和创新设计。采用空心的螺旋毛刷辊同时起到清洗和运输的作用,毛刷辊上方设有喷水管,毛刷辊与水共同作用使清洗效果更好。     

即食扇贝柱丝生产技术研究

以新鲜扇贝为原料,清洗后预煮处理,将分离的扇贝柱先在4~6℃下入味30 min,再采用65℃下烘制2.5 h,静置2 h后,在85℃下烘制1.0 h的分段烘制方式,经缝隙为3 mm的对辊压扎后,在120 r/min的转速下打丝,调配后灌装杀菌,制得了一款即食扇贝柱丝产品。试验中探讨了烘制方式、压扎对辊间隙、打丝转速等不同工艺条件对扇贝柱成丝效果的影响,还对提高产品的风味、稳定性和货架期展开了研究,为扇贝柱丝产品的生产提供理论依据。     

揉搓式马铃薯脱皮装置设计及试验研究

为提高马铃薯脱皮率并降低破损率,采用揉搓原理,设计了一种马铃薯脱皮装置。该装置由喷水装置、出料控制装置、锁紧装置、脱皮辊、螺旋毛刷辊等构成,通过脱皮辊和螺旋毛刷辊对马铃薯揉搓进行脱皮,确立了影响马铃薯脱皮的主要因素为辊转速、脱皮时间和喂入量,并进行了脱皮试验。结果表明,随着辊转速的增大,脱皮时间的延长,质量损失率均呈现增大的趋势,而增大喂入量,质量损失率降低。该脱皮装置试验的工作参数为辊转速205r/min,去皮时间3.5min,喂料量105 kg/h时,马铃薯质量损失率仅为11.1%。同时,提出揉搓式马铃薯脱皮装置自动化提升方案为采用PLC和变频器对主电动机、水泵、进料口挡板、出料口挡板进行控制。     

对辊式海湾扇贝分级设备的设计

通过对海湾扇贝分级设备现状分析,提出研发专用扇贝分级设备的必要性。通过对海湾扇贝形态特征性状中对重量特征性状的相关性分析,确定了以扇贝壳长进行分级的对辊式扇贝分级机设计方案。通过两种开槽形式试验效果的比较,确定了在两辊表面开出的螺旋沟槽,运用拼成的椭圆形螺旋分级孔长轴尺寸的变化来实现扇贝的分级。并试制了简易的试验装置,对分级效果进行了验证试验。确定了分级辊结构,为扇贝分级设备的研制奠定了基础。     

自制笔涂胶辊涂料机

低硬度胶辊能合理解决牵伸区摩擦及对纤维的控制,提高了成纱条干水平;但是胶辊因表面板涂层不匀而造成的机械波问题,却影响了产品总的质量水平和企业的市场竞争力。为此,我们自制了一台笔涂胶辊涂料机见图1,通过生产使用,效果比较满意。图1笔涂胶辊涂料机示意该机利用FA502型卷绕套筒,用后轻重轴进行配合、锭带传动。其电机转速为1 390 r/min、功率220 W,设计轴转速为400 r/min。操作时用1号羊毛刷,一只手握住胶辊芯轴中心部位,一头利用轴的转动,另一只手用羊毛刷往胶辊表面涂匀涂料,刷完一头后调转过来刷另一头。该机具有如下优点:a)能很…     

海湾扇贝性状分析及V型轮辊式分级机设计

对海湾扇贝的形态性状对重量性状的影响进行定量分析,确定壳长作为分级工作的关键性状;结合海湾扇贝物理性状特点,设计一种V型轮辊式分级机;利用Solid-works搭建V型轮辊式海湾扇贝分级机三维整机模型;进行验证实验,结果表明,V型轮辊式分级机设计合理、结构新颖,可以实现高效率和高精度扇贝分级。     

挤压式杏核破壳机试验研究

针对当前杏核破壳生产率低、碎仁率高的问题,设计一种杏核破壳机,对其结构及杏核破壳受力情况进行介绍。以明星杏杏核为试验材料,选取喂料速度、破壳间隙、主动辊转速3个因素对杏核破壳进行正交试验分析。结果表明:破壳间隙对破壳效果的影响极显著,喂料速度、主动辊转速对破壳效果影响不显著;当喂料速度400kg/h、破壳间隙在9mm、主动辊转速400r/min时,破壳率为99.65%,整仁率为96.87%,破壳效果最好。相同喂料速度与主动辊转速条件下,其他品种杏核的破壳试验,验证表明当破壳间隙小于杏核厚度约2 mm时,破壳率在98%以上,整仁率在95%以上。     

金针菇发酵罐深层发酵条件的研究

采用IOL发酵罐发酵,考察了搅拌转速和通气比对金针菇菌丝生长的影响,研究结果表明,搅拌转速和通气比显著影响金针菇菌丝的生长,并得出较为优化的培养条件为:培养温度26℃,发酵前期适宜的通气比为1:1(v/v·m),搅拌转速为160r/min,发酵中期(2d后),通气比为1:1.5(v/v·m),搅拌转速为180r/min;发酵后期(8d后)适宜的通气比为1:0.8(v/v·m),搅拌转速为140r/min.研究了发酵液pH值、还原糖和氨基酸态氮含量与菌丝生长的相关性,研究结果表明,当发酵液中还原糖和氨基酸态氮含量分别为2.95g/100 mL和9.66mg/100mL、pH 5.8时,菌丝生物量最大,高达2.652g/100mL.     

螺旋藻藻蓝蛋白微囊的制备工艺

以壳聚糖和海藻酸钠为囊材,对螺旋藻藻蓝蛋白（C-PC）进行微囊,通过试验确定了制备藻酸钠壳聚糖C-PC微囊的最佳工艺条件：壳聚糖的脱乙酰度为74%,转速600r/min,搅拌时间30min,针头距离凝胶浴液面10cm,滴加速度30滴/min,海藻酸钠浓度2.5%（w/v）,壳聚糖浓度0.6%（w/v）,C-PC和海藻酸钠的质量比1∶4（w/w）,CaCl2浓度2.0%（w/v）。     

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.     

An internet compendium of analytical methods and spectroscopic information for monomers and additives used in food packaging plastics

An internet website (http://cpf.jrc.it/smt/) has been produced as a means of dissemination of methods of analysis and supporting spectroscopic information on monomers and additives used for food contact materials (principally packaging). The site which is aimed primarily at assisting food control laboratories in the European Union contains analytical information on monomers, starting substances and additives used in the manufacture of plastics materials. A searchable index is provided giving PM and CAS numbers for each of 255 substances. For each substance a data sheet gives regulatory information, chemical structures, physico-chemical information and background information on the use of the substance in particular plastics, and the food packaging applications. For monomers and starting substances (155 compounds) the infra-red and mass spectra are provided, and for additives (100 compounds); additionally proton NMR are available for about 50% of the entries. Where analytical methods have been developed for determining these substances as residual amounts in plastics or as trace amounts in food simulants these methods are also on the website. All information is provided in portable document file (PDF) format which means that high quality copies can be readily printed, using freely available Adobe Acrobat Reader software. The website will in future be maintained and up-dated by the European Commission's Joint Research Centre (JRC) as new substances are authorized for use by the European Commission (DG-ENTR formerly DGIII). Where analytical laboratories (food control or other) require reference substances these can be obtained free-ofcharge from a reference collection housed at the JRC and maintained in conjunction with this website compendium.     

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.     

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.     

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.     

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.     

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.     

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.