燕麦高纤食品基料加工技术及生理活性研究

燕麦膳食纤维是一种高级食用纤维,其中以-葡聚糖为主要成分的可溶性膳食纤维占到1/3左右,简述了燕麦高纤食品基料的改性活化加工工艺及其生理活性研究。结果证明,燕麦高纤食品基料具有调节血脂、血糖、改善肠道环境和润肠通便等多种生理活性功能,有益于预防多种现代文明疾病。     

面粉特性对燕麦挂面品质的影响

为了探究面粉特性对燕麦挂面品质的影响,测定了7种小麦粉的粉质特性、拉伸特性、麦谷蛋白大聚体(GMP)干质量、面筋蛋白及其亚基组成,用其制作燕麦挂面,并通过相关性分析研究面粉特性对燕麦挂面品质的影响。结果表明,面粉的吸水率与燕麦挂面的硬度、适口性、韧性和感官总分呈正相关;拉伸能量、延伸度、最大拉伸阻力与燕麦挂面的拉断距离呈正相关;GMP干质量与燕麦挂面的硬度、黏附性、拉断力和适口性呈正相关;高相对分子质量麦谷蛋白亚基(HMW-GS)与燕麦挂面的硬度、咀嚼性、拉断力和适口性均呈正相关。麦谷蛋白与面筋蛋白比值与燕麦挂面的硬度、拉断力和适口性呈正相关。因此,吸水率高、GMP干质量大、HMW-GS相对含量高、麦谷蛋白与面筋蛋白比值大、拉伸特性好的面粉适合加工燕麦挂面。     

燕麦膳食纤维汉堡肉饼的研制

以中国裸燕麦的麸皮为主要原料，采用多种现代食品新技术，经分离、富集、活化等工艺加工后制成燕麦膳食纤维基料，然后将燕麦膳食纤维添加于汉堡肉饼中，研究了燕麦膳食纤维基料在汉堡肉饼中的应用特性及不同添加比例燕麦膳食纤维基料对汉堡肉饼的影响。     

燕麦粉添加量和干燥条件对燕麦挂面品质的影响

为改进燕麦挂面干燥工艺,研究温度、相对湿度及燕麦添加量对其品质的影响。以小麦粉与燕麦粉为原料,制作不同燕麦添加量(0,10%,20%,30%)的燕麦挂面,在不同温度(40,50,60℃)、相对湿度(55%,65%,75%)的条件下干燥,测定其色泽、抗弯曲特性、蒸煮品质、质构品质、酸度、脂肪酸值、β-葡聚糖含量、微观结构,评价挂面的感官品质,分析不同温度、相对湿度及燕麦添加量对燕麦挂面品质的影响。结果表明：在40℃的条件下干燥时,挂面具有更低的的b^*值、更大的折断距离以及更低的酸度和脂肪酸含量(P <0.05);在相对湿度为75%时,挂面的b^*值更高、抗弯曲强度和折断距离更大、酸度和脂肪酸含量更高(P <0.05);在燕麦粉添加量为30%时,挂面的L^*值更低、a^*值更高、抗弯曲强度折断距离更小、酸度、脂肪酸和β-葡聚糖含量更高(P <0.05)。低温高湿(40℃/75%)干燥处理能改善燕麦挂面的色泽、蒸煮及质构品质,微观结构致密,感官评分较好,可用于燕麦挂面的干燥。     

燕麦膳食纤维咀嚼片的工艺研究

以中国裸燕麦的麸皮为主要原料,采用多种现代食品新技术,经挤压膨化、超微粉碎等工艺加工后制成燕麦膳食纤维基料.将燕麦膳食纤维基料、麦芽糖醇、山梨糖醇和低聚异麦芽糖等主要原料,经混合、造粒、干燥、压片等工序加工后,制成低热量,具有调节血脂、血糖,改善肠道环境和润肠通便等保健功能的燕麦膳食纤维咀嚼片.     

燕麦挂面生产工艺优化研究

以燕麦粉和小麦粉为原料,以燕麦挂面的断条率及感官评价为指标,采用单因素和正交优化试验确定燕麦挂面的制作工艺。研究结果表明:燕麦挂面制备过程中,燕麦粉质量分数为8%,加水量为32%,海藻酸钠质量分数为0.2%时,制备的燕麦挂面感官品质最佳。     

添加燕麦麸皮对挂面品质特性的影响

为了了解燕麦麸皮对挂面品质特性的影响,在面粉中分别添加0、5%、10%、20%、30%燕麦麸皮,并对挂面的蒸煮品质、质构特性和感官品质进行了测定。结果显示:添加燕麦麸皮显著增大了挂面的蒸煮损失、吸水率和混汤吸光值(p0.05),改善了面条的断条率(p0.05);随着燕麦麸皮添加量的增加,挂面的硬度、咀嚼性显著增大(p0.05),而粘性和弹性呈下降趋势,挂面的感官品质变差。燕麦麸皮的添加量为20%时,挂面的综合品质最好。因此,燕麦麸皮的添加,改变了挂面的蒸煮品质、质构特性和感官品质。     

杂粮原料对其挂面淀粉消化性的影响及内在因素研究

本文以五种杂粮粉为原料,通过体外模拟消化试验研究了杂粮原料对其挂面体外淀粉消化特性和估计血糖生成指数（eGI）的影响。结果表明：杂粮挂面的eGI值由高到低为：大麦>青稞>苦荞>燕麦>高粱。采用差示扫描量热仪、傅里叶红外光谱仪和X射线衍射仪等手段分析了杂粮挂面淀粉理化特性差异。高粱糊化温度和焓值显著高于其他杂粮（P<0.05）;燕麦和高粱挂面直链淀粉含量和淀粉相对结晶度较高,且具有较多短程有序结构和较强氢键强度。采用组分分离法探究了内源性酚类物质和脂肪对挂面消化特性的影响,内源性多酚和脂肪的脱除使面条淀粉消化率明显升高。该研究为开发低GI食品提供了参考依据。     

燕麦营养挂面的研制

综述了燕麦的营养价值和保健功能,通过添加燕麦粉于面条中,对其品质进行了分析。研制出的燕麦挂面既具有传统挂面的特点,又具有燕麦的营养保健功能。     

预糊化处理对高含量燕麦挂面品质的影响

为研究燕麦预糊化处理对高含量燕麦挂面品质的影响,本文采用蒸制、挤压膨化和滚筒干燥对燕麦进行预糊化处理,分析不同类型与添加量的预糊化燕麦粉对混合粉(燕麦粉总量为70%)糊化特性及挂面力学特性、蒸煮品质和煮后面条质构特性的影响。结果表明,随着预糊化粉添加量升高,混合粉的室温粘度增大;混合粉的热粘度与蒸制燕麦粉(SOF)添加量成正相关,与挤压预糊化粉(EOF)和滚筒预糊化粉(DOF)添加量成负相关。SOF添加量为70%时,燕麦挂面品质最好;而EOF和DOF添加量为8.75%时,挂面品质最好。相比之下,前者的弹性模量、断裂应力、断裂位移、咀嚼性更大,黏附性、蒸煮损失率更小。综上,添加预糊化粉可以改善挂面品质,采用SOF制备的燕麦挂面品质最佳。     

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.