调理猪排制品滚揉腌制工艺的优化

以猪背最长肌为原料,开发一种调理猪排制品,并先后采用单因素和L9(34)正交实验,以出品率和剪切力值为考察指标,对该调理猪排滚揉腌制工艺进行优化。结果表明:调理猪排制品的最佳滚揉腌制工艺条件为滚揉时间8h、滚揉机转速11r/min和腌制液添加量35%,采用该最佳滚揉腌制工艺条件生产加工的调理猪排出品率最高(83.57%),剪切力值最低(12.46N)。     

滚揉时间和食盐浓度对鸡肉调理制品的保水性及盐溶性蛋白质溶出量的影响

以鸡胸肉为实验材料,以腌制吸收率、蒸煮损失、压榨损失,盐溶性蛋白质的溶出量为评定指标,探讨了不同滚揉腌制条件对鸡肉的保水性及盐溶性蛋白质浸出量的影响。结果表明:在0~4℃环境中,延长滚揉时间(0.5~3h)、增加食盐添加量(0.5%~3%)均可显著提高鸡肉调理制品的保水性和出品率,增加盐溶性蛋白质的浓度。当食盐添加量为2.5%、滚揉时间为2.5h时,鸡肉调理制品的保水性、出品率和盐溶性蛋白质浓度均达到较高水平。     

滚揉工艺对牛肉品质的影响

为了缩短牛肉腌制时间,提高牛肉出品率和食用品质,在单因素实验的基础上,采用Box-Behnken设计和响应面分析法,对滚揉时间、复合磷酸盐添加量、真空度结合处理牛肉滚揉腌制工艺参数进行优化分析。结果表明:以滚揉时间、复合磷酸盐添加量、真空度为自变量,以剪切力和出品率为响应值,得到的二次多项式回归模型拟合度高(决定系数分别为R2=0.9761、R2=0.9876),失拟项不显著。滚揉时间、复合磷酸盐添加量、真空度三因素结合处理牛肉最佳滚揉腌制工艺为:滚揉时间6 h、复合磷酸盐添加量0.30%、真空度0.03 MPa,在此条件下牛肉的剪切力为4.13 kg,出品率为96.2%。与静置腌制相比,真空滚揉腌制能显著地(P<0.05)改善牛肉的嫩度,提高出品率,改善质构特性,提升食用品质。     

滚揉工艺对调理鸡胸肉制品出品率的影响

为探明滚揉工艺中滚揉里程、温度、真空度三因素结合处理对调理鸡胸肉制品出品率的影响,在单因素试验的基础上,采用Box-Behnken响应面法,对滚揉里程、温度、真空度结合处理调理鸡胸肉制品的工艺参数进行优化分析。结果表明：以滚揉里程、温度、真空度为自变量,出品率为响应值,得到的二次多项式回归模型拟合度高（决定系数R2=0.848 9）,失拟度低;温度和真空度的交互作用对产品的出品率有显著影响（P＜0.05）;滚揉里程、温度、真空度三因素结合处理调理鸡胸肉最佳工艺为：滚揉里程4 000 m、温度1 ℃、真空度0.07 MPa。应用此工艺对调理鸡胸肉制品进行加工,产品的实际出品率达到98.32%。     

响应面试验优化兔肉滚揉腌制工艺

在单因素试验基础上,研究滚揉里程、液肉百分比、复合磷酸盐添加量对腌制液吸收百分比和出品率的影响。通过Box-Behnken试验设计和响应面分析法确定兔肉真空滚揉腌制的最佳工艺。结果表明：兔肉最佳滚揉腌制工艺为滚揉里程351 m、液肉百分比38%、复合磷酸盐添加量0.37%,在此条件下得到腌制液吸收百分比为31.97%,出品率为98.83%。     

调理鸭肉饼保水性及品质研究

以鸭胸肉为原料,以食盐、复合磷酸盐、水、卡拉胶的添加量和滚揉时间为主要影响因素,以失水率、感官评分为检测指标,研究不同工艺条件下,对调理鸭肉饼保水性及感官品质等影响。结果表明,调理鸭肉饼最佳保水工艺条件为:食盐0.30%、复合磷酸盐0.35%、冰水14%、滚揉时间50min、卡拉胶0.35%。在此条件下,对调理鸭肉饼进行加工,能够保证失水率处在12%左右,所得到的调理鸭肉饼具有优良的品质。     

真空滚揉工艺优化对复合低钠替代盐调理牛肉的品质改善

为了满足复合低钠替代盐调理牛肉的工业化生产需求,该研究在单因素试验基础上,研究液料比、滚揉时间、真空度对腌制吸收率和蒸煮损失率的影响,通过中心组合（Box-Behnken）和响应面法确定调理牛肉真空滚揉的最佳工艺,并对静置腌制和滚揉腌制调理牛肉的质构特征、剪切力、水分分布、微观结构进行分析。结果所得最佳滚揉工艺参数：液料比32%、滚揉时间3.0 h、真空度0.06 MPa,在此条件下得到腌制吸收率24.65%,蒸煮损失率为26.39%。滚揉组调理牛肉的硬度、弹性、咀嚼性和剪切力均显著低于静腌组（P<0.05）,不易流动水和自由水弛豫时间显著低于静腌组（P<0.05）,并且自由水弛豫峰面积显著高于静腌组（P<0.05）。扫描电镜图显示,滚揉组的肌原纤维结构更加松散,并且有碎片化结构附着表面。结果表明,滚揉处理能够改善调理牛肉的质构特征,提高嫩度,提高保水性,微观上使肌原纤维产生碎片化结构。该研究为复合低钠替代盐调理牛肉的滚揉工艺提供技术支持,为营养型低钠调理肉制品工业化生产提供理论依据。     

调理鸭胸肉的加工工艺

传统的烤鸭口味香浓,回味悠长,一直深受广大消费者的欢迎,但不便于长时间存放.工业化的烤鸭产品在加工过程中需经高温杀菌,导致香味损失,口感老化.为给消费者提供更新鲜、美味、方便的烤鸭类产品,现采用中西式工艺加工,即鸭胸经老鸭汤腌制,再经注射、滚揉,速冻工艺制成调理鸭胸肉,消费者只需对调理鸭胸做加热处理即可做出肉质鲜嫩,风味独特的烤鸭胸、煎鸭排.     

滚揉腌制参数对速冻卤肉品质影响

研究以猪肉为原料,探究滚揉真空度、滚揉时间对速冻卤肉出品率、质构特性和营养成分等的影响。结果显示:增加滚揉真空度,腌制吸收率、出品率先增加后减少,卤肉水分、盐分含量逐渐增加(p0.05),蛋白质、脂肪、硬度、咀嚼性、胶粘性逐渐降低(p0.05),对卤肉灰分含量、弹性、凝聚性无显著影响(p0.05)。延长滚揉时间,腌制吸收率、出品率、水分、盐分、脂肪、灰分、硬度、弹性、咀嚼性、胶粘性先增加后减少(p0.05),蛋白质含量逐渐降低(p0.05),对凝聚性影响不显著(p0.05)。     

马铃薯淀粉添加量对真空滚揉调理鸡柳品质的影响

目的 探讨马铃薯淀粉结合真空滚揉腌制技术对调理鸡柳品质特性的影响。方法 通过测定调理鸡柳的出品率、蒸煮损失、水分含量、水分活度、色差、质构特征和剪切力等指标,探究不同马铃薯淀粉添加量（0.5、1.0、1.5、2.0和2.5%,w/w）对真空滚揉腌制调理鸡柳品质特性的影响。结果 随着马铃薯淀粉添加量的增加,调理鸡柳的出品率、嫩度、弹性、回复性、凝聚性、亮度值和红度值显著提高（P < 0.05）。然而,调理鸡柳的水分含量、水分活度、蒸煮损失、硬度则随着淀粉添加量的增加而显著下降（P < 0.05）,黄度值没有显著变化（P > 0.05）。结论 马铃薯淀粉的添加对真空滚揉腌制的调理鸡柳品质特性具有良好的促进作用,且以2.0%为最佳添加量。本研究为更高品质的调理鸡柳的工业生产提供技术支撑。     

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.     

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.     

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.     

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.     

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.