基于模糊数学感官评价法优化液熏鲍生产工艺

目的对液熏鲍加工工艺进行优化研究。方法以新鲜鲍为原料,通过选择色泽、质地和风味为评价指标,确定合理的因素权重,建立感官综合评价评分体系,并采用响应面法对液熏鲍加工工艺进行优化,探讨了不同浸泡温度、浸泡时间、烘干温度和烘干时间对液熏制品感官指标的影响。结果基于模糊数学感官评价法确定了液熏鲍最佳的加工工艺条件为:浸泡温度55℃,浸泡时间2.3 h,烘干温度67℃,烘干时间20 min。结论本工艺所得液熏鲍具有外观好、光泽感好、呈烟熏色、烟熏香味浓郁、肉质富有弹性等特点。     

利用液熏法熏制军曹鱼片的工艺研究

以军曹鱼片为原料,利用液熏法,通过正交实验与感官评价相结合的实验方法,研究了浸渍、熏制条件对熏军曹鱼片品质的影响,确定了利用液熏技术熏制军曹鱼片的工艺条件。研究结果表明,浸泡烟熏液SmokezP-50的浓度为6%,浸渍时间为2h,浸渍温度为25℃。熏制干燥的条件为：第一次干燥温度为50℃,烘干时间为1h,取出后,将烟熏液SmokezEnviro24P均匀喷洒在鱼片表面,进行第二次干燥,温度为85℃,干燥时间为2h。液熏军曹鱼片产品品质良好,营养丰富,感官评分为93.2分,理化指标和微生物指标均符合国家安全卫生标准。     

响应面分析优化荧光衍生法测定硫熏党参及其饮片二氧化硫残留量的研究

将党参样品分别硫熏0、30、60、90 min,并加工炮制为节子货、厚片、米炒、蜜制四个规格的饮片,对不同硫熏时间党参及其饮片SO₂残留量进行研究。通过单因素实验及响应面优化试验确定最佳衍生条件为:缓冲溶液pH为6.6,缓冲溶液用量为1.5 mL,邻苯二甲醛用量为2.1 mL,乙酸铵浓度为2.5 mmol/L,乙酸铵用量为2.0 mL,反应温度、反应时间和静置时间分别为50 ℃、5 min及40 min,在此条件下测得平均荧光强度为955865.21。荧光衍生法方法考察结果显示:亚硫酸钠浓度在0.01~0.2 μg/mL之间,其荧光强度有较好的线性关系,检测限为1.89×10-3 μg/mL;精密度、稳定性、重复性RSD分别为:0.76%、4.13%和1.59%,平均回收率98.61%,RSD为4.89%,且专属性考察结果较好。荧光衍生法可作为党参SO₂残留量测定的方法,其测得结果与酸碱滴定法测定结果相比平均高24.87%。SO₂残留量测定结果表明:党参硫熏0、30 min原药材SO₂残留量未超出药典标准,而硫熏60、90 min原药材SO₂残留量超出药典标准;硫熏党参经加工炮制后,饮片较原药材SO₂残留量明显降低,蜜制饮片SO₂残留量最低。     

液熏灌肠产品加工工艺研究

为提高液熏灌肠产品的品质,考察低温肉制品生产中滚揉前处理条件和蒸煮环节对液熏制品的影响,通过正交试验设计确定最佳工艺参数为滚揉时间3.5h、滚揉速度13r/min、静置腌制4h;蒸煮的最佳工艺参数为蒸煮温度82℃、时间30min;此条件下得到的液熏灌肠产品的品质综合评价效果最好。     

液熏斑点叉尾鮰加工工艺研究

以斑点叉尾鮰为原料,开发液熏型鮰鱼肉食品。优化了加工过程中鱼肉去腥配方,选择合适液熏剂熏制鱼肉,研究熏液浓度、液熏方法、熟制工艺对产品品质影响及食盐在熏液中的渗透率。结果表明:去腥剂为绿茶水,去腥时间1.5h,鱼肉与去腥剂质量比为1∶10,去腥温度为15℃时,有最佳去腥效果;熏液Ⅱ号在质量分数为3%时,在10～15℃条件下采用浸渍法液熏鱼肉,之后在150～180℃油温下油炸或90℃烘干熟制,可得风味鲜美产品;加熏液腌液能阻碍食盐渗透,并随时间延长,食盐渗透量与不加熏液条件下相当。     

糖熏色素的纯化工艺及稳定性研究

目的:对糖熏色素进行纯化,研究糖熏色素的结构与性质。方法:本文利用大孔吸附树脂对糖熏色素进行纯化,并对纯化后糖熏色素的稳定性进行了研究。结果:XAD-7型大孔吸附树脂对糖熏色素具有较好的吸附和解吸能力。糖熏色素静态吸附与解吸工艺的最佳工艺条件为糖熏色素粗提液浓度60 μg/mL,糖熏色素粗提液pH8.0,吸附温度35 ℃,解吸液浓度40%乙醇,pH10.0,解吸温度40 ℃。其动态吸附与解吸的最佳工艺条件为径高比为1:6,上样流速2.0 mL/min,样液浓度400 μg/mL,解吸液浓度40%乙醇,解吸流速为1.5 mL/min。结论:糖熏色素经XAD-7型树脂静态和动态工艺纯化后,其纯度分别提高45.13%和36.55%,经纯化后的糖熏色素易溶解,溶液澄清且呈现亮黄色,对光敏感但具有较高的热稳定性,初步推测其为Ⅰ类焦糖色素。     

液熏法生产熏鳗的工艺研究

为了解决烟熏鳗鱼加工过程中油脂外溢及氧化的技术难题,并控制微生物生长,研究液熏法生产熏鳗的技术。通过控制烘烤温度及时间防止油脂外溢及氧化,并保持鲜度。对腌液的成分、浸渍条件及鳗鱼的烘烤条件进行了优化,确定了鳗鱼液熏的加工工艺条件,并对其工艺稳定性及产品保藏性进行了研究。结果表明,利用液熏法制备熏鳗适宜的工艺是:盐液质量分数6%,熏液质量分数8%,浸渍时间5h,烘烤温度85℃。用该工艺生产液熏鳗鱼,不仅有效地解决了油脂外溢引起过氧化值快速增加的技术难题,还控制了微生物的生长,保证了产品的安全性。该工艺稳定性好,产品卫生安全,各批次产品间的相对标准偏差小于6%。在冷冻状态下保藏6个月后其菌落总数、大肠菌群及过氧化值均符合国家卫生标准。对该工艺进一步研究及应用,有助于推动鳗鱼加工技术的进步。     

液熏罗非鱼片的加工工艺

采用正交试验与感官评定相结合的试验方法,确定了采用液熏技术生产烟熏罗非鱼片的工艺技术条件,即采用烟熏液浸渍与喷雾相结合的熏制工艺,具体工艺参数为:食盐浓度150 g/L,腌渍时间60 min,熏液浸渍浓度25%,熏液浸渍时间5 min,喷雾熏液流量4L/h,喷雾烟熏时间20 min,干燥时间60 min。在此工艺条件下生产的烟熏罗非鱼片适合大众的口味,综合评分高。     

液熏重组鸡骨肉干的加工工艺研究

以新鲜鸡壳(鸡胸壳)为原料,开发液熏重组鸡骨肉干.优化了加工过程中影响产品质构的配方,选择合适的烟熏液来熏制重组鸡骨肉干,研究了烟熏液的浓度和pH、烟熏液对重组鸡骨肉糜含盐量的影响和微波-热风干燥过程对产品的影响.结果表明最佳配方为10%精皮胶、0.12%多聚磷酸钠,25%水和2%食盐;山楂核烟熏香味液和山楂核着色烟熏液在质量分数分别为3‰和2‰时,采用直接混合法液熏重组鸡骨肉干,之后在微波功率与液熏重组鸡骨肉干的质量之比值为8 W/g的条件下成型2 min和80℃热风干燥195 min,可得到美味的产品.加烟熏液可以使产品中初始的食盐含量较高,但上升较慢,可能烟熏液阻碍食盐渗透,但随时间延长,食盐最终含量与不加烟熏液相当.比较液熏以后和未经液熏的重组鸡骨肉干的理化性质和微生物指标,结果表明,液熏重组鸡骨肉干有较高的营养成分含量和较长的保藏时间.     

熏制条件对熏马肠感官和质构的影响及其工艺优化

研究了熏制条件对熏马肠感官和质构特性的影响,并优化了熏制工艺.采用感官评定和质构分析法,研究了烟熏温度、烟熏时间、熏烟浓度和熏制时的空气湿度对熏马肠的感官品质和质构特性的影响,并采用正交设计方法优化熏制条件.结果表明:烟熏温度对熏马肠感官品质的影响最大,其次为空气湿度、熏烟浓度、烟熏时间,最终确定的熏马肠最优熏制条件为:烟熏温度50℃,烟熏时间6h,熏烟浓度80％(s/s),空气湿度50％.此条件下制得的熏马肠具有较好的硬度、咀嚼性、弹性和粘聚性,且具有较佳的外观、色泽、组织状态及滋味和气味,说明该工艺条件是稳定可行的.     

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.