嫩化剂在牛肉干制品的应用研究

选择不同嫩化剂氯化钙、复合磷酸盐、木瓜蛋白酶,针对嫩化剂对牛肉干剪切力及质构的影响进行了研究。结果表明:在相同工艺条件下,不同嫩化剂对牛肉干剪切力及质构的影响是有差别的,综合产品品质和生产成本,木瓜蛋白酶和氯化钙的复配嫰化剂为最佳选择,通过对复配实验分析,得到最佳配比为1∶9,最佳添加量为1%,最佳嫩化温度为55℃,最佳嫩化时间为2h。     

嫩化型猪肉脯的加工技术优化

以剪切力或感官评价为考察指标,研制嫩化型猪肉脯。通过单因素试验和正交试验,探讨嫩化剂和加工工艺对肉脯嫩度的影响。结果表明：最佳的肉脯嫩化剂配方(m/m)为木瓜蛋白酶添加量0.035%、乳酸钠添加量2%、复合多聚磷酸盐添加量0.4%、氯化钙添加量0.1%;最佳的肉脯嫩化工艺条件为拌料20min、静置15min、热风炉45～85℃程序升温干燥5h。在最适条件下生产的嫩化型肉脯出品率55%、水分含量13.7%、蛋白质含量40.8%、嫩度与空白相比提高了136%。     

猪肉脯嫩化技术的研究

采用单因素实验和正交实验方法优化和评价木瓜蛋白酶、复合多聚磷酸盐、氯化钙和糖类保湿剂对肉脯嫩度的影响。实验结果表明:木瓜蛋白酶、复合多聚磷酸盐、氯化钙和糖类保湿剂都可增加肉脯的嫩度,但用量应适当,添加量过大,反而使肉脯的感官品质变差;肉脯嫩化的最佳配比为木瓜蛋白酶0.4‰、复合多聚磷酸盐0.4%、氯化钙0.1%、山梨糖醇1.5%。     

超声波协同复合嫩化剂对生鲜猪肉嫩度的影响

采用超声波协同氯化钙及复合磷酸盐(三聚磷酸钠、六偏磷酸钠)对生鲜猪肉进行嫩化后,以植物蛋白酶(木瓜蛋白酶、菠萝蛋白酶)对其进行酶法嫩化,在单因素试验基础上通过正交试验,以剪切力为考察指标,探讨生鲜猪肉最优嫩化工艺条件。结果表明:超声功率、超声时间、复合磷酸盐添加量、植物蛋白酶添加量、酶作用温度影响显著,氯化钙添加量及水浴时间影响不显著,各因素对剪切力影响的主次关系为超声时间植物蛋白酶添加量超声功率酶作用温度复合磷酸盐添加量氯化钙添加量水浴时间。功率150 W条件下超声处理25min、1.0%氯化钙、0.20%复合磷酸盐、0.03%植物蛋白酶、酶作用温度20℃、水浴30 min,生鲜猪肉剪切力最小,肉最嫩。     

超声波-微波设备联合嫩化淘汰蛋鸡鸡胸肉

一种新型的超声-微波设备应用在淘汰蛋鸡的嫩化。对超声波、微波及超声-微波联合作用3种不同嫩化淘汰蛋鸡的方法进行探讨,结果表明,超声波-微波联合作用较任何单一方法的嫩化效果均好。在超声-微波的基础上,结合复合嫩化剂处理淘汰蛋鸡。采用L₉（3⁴）正交试验对处理条件进行优化,以探讨超声-微波与嫩化剂对蛋鸡嫩化效果的影响。结果表明:各因素对蛋鸡剪切力的影响主次顺序为超声-微波时间>木瓜蛋白酶>氯化钙>复合磷酸盐;最佳组合为功率400W、超声-微波10min,超声/间隙时间4s/4s、1.5%CaCl₂、1.0%复合磷酸盐、450U/g木瓜蛋白酶,可达到较好的嫩化效果。此时蛋鸡肉的剪切力为2.09kg/cm²。方差分析表明,超声-微波及木瓜蛋白酶对淘汰蛋鸡嫩化效果显著,而复合磷酸盐嫩化效果不显著。嫩化后的蛋鸡口感大大提高,经感官评定与肉鸡口感接近。     

嫩化技术应用于青椒牦牛肉丝的研究

分别使用化学方法和酶法对青椒牦牛肉丝进行嫩化,采用正交试验,以剪切力值和感官评分为评定指标,研究了在油温加热情况下菠萝蛋白酶、木瓜蛋白酶、碳酸氢钠和复合磷酸盐对西藏牦牛肉丝的嫩化效果。结果表明,菠萝蛋白酶、木瓜蛋白酶、碳酸氢钠、复合磷酸盐的添加量分别为0.04%、0.012%、3.6%、0.1%时评定指标最佳。     

嫩化型五香猪肉干的加工工艺

采用全新技术，对猪肉进行嫩化、水煮、配料、复煮、腌制、微波熟化、微波脱水干燥等工艺处理，最终得到嫩化剂配方为1％氯化钙，0．1％木瓜蛋白酶，0．4％复合磷酸盐，嫩化温度55℃，嫩化时间2h，得到的成品色泽棕红，口感脆嫩爽口。     

木瓜蛋白酶嫩化调理猪排工艺条件的优化

本文以猪后肘肉为原料,制备调理猪排,采用响应面回归设计探究木瓜蛋白酶嫩化调理猪排的最佳工艺条件。以木瓜蛋白酶添加量、嫩化时间和嫩化温度为嫩化因子,以剪切力和感官评价为主要衡量指标,通过单因素试验和响应曲面试验,确定调理猪排的木瓜蛋白酶最佳嫩化工艺参数。结果表明,酶添加量、嫩化时间、嫩化温度对调理猪排的剪切力、感官评价、持水力、质构均有显著性影响(p0.05),木瓜蛋白酶可以有效降低调理猪排的剪切力,提高肉的食用品质;确定了木瓜蛋白酶嫩化调理猪排的最佳工艺:酶添加量340.00 U/g,嫩化时间15.00 min,嫩化温度49.00℃,在此条件下制作的调理猪排嫩度适宜,且无苦味等异味,感官评价较好,剪切力2.48 kg,感官评分90.14,为调理肉制品工业化生产中的酶嫩化技术应用奠定基础。     

复合磷酸盐和木瓜蛋白酶对猪肉脯嫩化效果对比研究

主要对复合磷酸盐和木瓜蛋白酶嫩化猪肉脯的效果进行了对比研究。先利用响应面法优化得到了复合磷酸盐嫩化猪肉脯的最佳工艺条件:焦磷酸钠浓度0.3085g/100 mL;三聚磷酸钠浓度0.2102g/100 mL;六偏磷酸钠浓度0.2571g/100 mL;嫩化时间8h。然后利用正交试验优化得到了木瓜蛋白酶嫩化猪肉脯的最优工艺条件:木瓜蛋白酶用量360U/g,作用温度70℃,作用时间20 m in。最后对这两种嫩化方法的嫩化效果进行了对比,结果发现,复合磷酸盐和木瓜蛋白酶对猪肉脯剪切力下降的幅度分别为26.8%和46.9%,说明木瓜蛋白酶的嫩化效果更好,因此选择木瓜蛋白酶作为对猪肉脯的嫩化方法。     

CaCl_2、复合磷酸盐及木瓜蛋白酶对河鲈鱼肉的嫩化作用

以河鲈鱼为研究对象,以剪切力为考察指标,研究CaCl2、复合磷酸盐、木瓜蛋白酶对鲈鱼半成品的嫩化效果。在单因素试验基础上,采用正交试验设计,对影响鱼肉剪切力的嫩化剂及其添加量进行三因素三水平的优化试验,最后利用扫描电镜,对未嫩化和复合嫩化剂嫩化后的鱼肉微观结构进行观察。结果表明:CaCl21.2 g/kg、复合磷酸盐1.2 g/kg、木瓜蛋白酶1.8 g/kg为最优嫩化剂组合,经该组合嫩化后,鱼肉剪切力最低可降至(8.40±0.13)N(注射方式)和(7.28±0.52)N(涂抹方式);用扫描电镜观察,鱼肉嫩化后肌纤维变宽、纤维密度降低、纤维间连接组织较少,致密结构变得蓬松。该嫩化剂组合对河鲈鱼肉嫩化效果良好。     

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.