食品中5-羟甲基糠醛的控制方法研究进展

5-羟甲基糠醛又称羟甲基糠醛(5-hydroxymethylfurfural, HMF),是食品热加工过程中产生的一种内源性污染物。研究报道HMF具有神经毒性、生殖毒性、基因毒性、致癌性等,因此须采取合适的方法控制其含量。本文综述了近年来有关降低食品中HMF方法的研究进展,旨在为加工更安全的食品提供理论指导。     

食品中糠醛和5-羟甲基糠醛的产生机理、含量检测及安全性评价研究进展

含糖丰富的食品在热加工过程中会产生大量的糠醛和5-羟甲基糠醛(HMF),不同食品加工后所产生的糠醛及HMF的含量有所差异,但当含量超过标准时就会对人体产生危害。因此,本文对食品中糠醛和HMF的产生机理、含量检测分析及安全性评价进行综述。     

反应条件对葡萄糖-甘氨酸美拉德反应体系中糠醛类化合物形成的影响

为了分析美拉德反应体系中糠醛类化合物的形成规律，本研究构建了葡萄糖-甘氨酸反应体系，探究了反应物配比、体系初始pH、加热时间和温度对5-羟甲基糠醛（5-Hydroxymethylfurfural,HMF）、2-糠醛（2-Furfural,F）和5-甲基糠醛（5-Methyl-2-furfural,MF）形成的影响，并分析了它们的形成动力学，预测了它们的表观活化能。结果显示：葡萄糖与甘氨酸的摩尔浓度比对糠醛类化合物的生成量有较大影响。HMF生成量随着摩尔浓度比的增大而持续增加，而F与MF的生成量在摩尔浓度比为1:1时达到最高值；酸性pH条件有利于HMF的形成，中性和碱性pH条件有利于F的形成，糠醛类化合物生成总量随着pH的增加而迅速减少；随着加热温度升高、加热时间延长，HMF、F和MF的生成量均逐渐增加；HMF和F的形成在温度较低时符合一级动力学模型（HMF:70～110℃；F:70℃），在温度较高时符合零级动力学模型（HMF:130℃；F:90～130℃）；MF的形成符合零级动力学模型（90～130℃）。本研究可对食品热加工过程中HMF、F和MF的生成和控制提供理论指导。     

美拉德反应过程中7种豆粉对丙烯酰胺和羟甲基糠醛形成的影响

丙烯酰胺和羟甲基糠醛是高温加工食品中产生的两种内源污染物。本文研究了7种豆类（黑豆、鹰嘴豆、绿豌豆、小扁豆、绿豆、黄豌豆和黄豆）的豆粉对天冬酰胺/葡萄糖反应体系中丙烯酰胺和羟甲基糠醛（HMF）形成的影响,以其为两者的控制提供参考。结果表明：采用全豆粉试验时,有5个品种的豆粉抑制丙烯酰胺（抑制率10.3~55%）形成,但都促进HMF的产生;去皮脱脂后的豆粉更能抑制丙烯酰胺形成。有趣的是,其中4个品种的豆皮也能抑制丙烯酰胺的产生。进一步研究发现,有5个品种的脱脂豆粉能消除已形成的丙烯酰胺,消除率为5.9%（绿豆粉）至28.5%（大豆粉）。通过统计本研究的39种处理发现,丙烯酰胺与HMF的形成量呈现负相关。     

美拉德反应过程中7种豆粉对丙烯酰胺和羟甲基糠醛形成的影响(英文)

丙烯酰胺和羟甲基糠醛是高温加工食品中产生的两种内源污染物。本文研究了7种豆类(黑豆、鹰嘴豆、绿豌豆、小扁豆、绿豆、黄豌豆和黄豆)的豆粉对天冬酰胺/葡萄糖反应体系中丙烯酰胺和羟甲基糠醛(HMF)形成的影响,以其为两者的控制提供参考。结果表明:采用全豆粉试验时,有5个品种的豆粉抑制丙烯酰胺(抑制率10.3~55%)形成,但都促进HMF的产生;去皮脱脂后的豆粉更能抑制丙烯酰胺形成。有趣的是,其中4个品种的豆皮也能抑制丙烯酰胺的产生。进一步研究发现,有5个品种的脱脂豆粉能消除已形成的丙烯酰胺,消除率为5.9%(绿豆粉)至28.5%(大豆粉)。通过统计本研究的39种处理发现,丙烯酰胺与HMF的形成量呈现负相关。     

食品中5-羟甲基糠醛的研究进展

5-羟甲基糠醛是糖类物质在高温或弱酸条件下脱水形成的醛类化合物,由于其潜在毒性而产生的安全问题愈来愈受到关注。阐述了近年来有关食品中5-羟甲基糠醛的形成机理、含量分析及抑制方法的研究进展,以期为解决食品中5-羟甲基糠醛的问题提供理论参考。     

丙氨酸与葡萄糖美拉德反应体系中HMF的形成分析

为了研究美拉德反应体系中5-羟甲基糠醛的形成规律,以丙氨酸与葡萄糖溶液为研究对象,通过改变加热时间和初始pH值,以HPLC测定分析5-羟甲基糠醛的形成量。结果表明,随着加热时间的延长,5-羟甲基糠醛的含量逐渐升高,12 h时,达到最大值0.122μg/m L;在3~12 h,5-羟甲基糠醛的形成量与加热时间成线性关系,符合零级动力学模型。酸性pH条件促进HMF的形成,而碱性pH条件抑制其形成。美拉德反应体系pH值在4.0~5.0之间时,与加热时间和初始pH值的关系不大。     

焦糖化与美拉德反应中DDMP、HMF及糠醛的生成研究

食品热加工中广泛存在的美拉德反应除赋予食品色香味外,还会生成有害或有异味物质,2,3-二氢-3,5-二羟基-6-甲基-4(H)-吡喃-4-酮（DDMP）、5-羟甲基糠醛（5-hydroxymethylfurfural,HMF）及糠醛就是其中重要的产物。本文分别建立了3种焦糖化和3种美拉德反应体系,研究DDMP、HMF和糠醛的生成规律。结果表明,HMF和糠醛分别容易在果糖和木糖焦糖化体系中生成,在美拉德反应体系中,赖氨酸的参与抑制了HMF和糠醛生成,促进了DDMP的生成。结合中间产物和终末产物的表征,单糖的结构差异是影响三种化合物生成的主要因素,赖氨酸会竞争性抑制单糖降解的焦糖化途径,从而抑制HMF和糠醛的生成。本文可对食品热加工业中DDMP、HMF和糠醛的生成、控制及定向合成提供指导。     

单花蜜中羟甲基糠醛生成反应动力学研究

羟甲基糠醛含量是评价蜂蜜质量的重要指标,研究羟甲基糠醛(HMF)生成反应的影响因素显得尤为重要。本论文在不同温度下对金银花蜜、枸杞蜜、椴树蜜恒温热处理2～10h,采用紫外分光光度计法测定这三种单花蜜中HMF含量随热处理时间的变化。结果表明:这三种单花蜜中HMF的生成反应表观上皆遵循一级反应动力学模型[HMF]t=[HMF]0exp(kt),其反应速度常数与热处理温度之间的关系表观上皆符合阿累尼乌斯方程k=kfexp(-Ea/RT)。结论:在蜂蜜热处理过程中,HMF的生成是必然的,蜂蜜质量的降低程度取决于HMF生成反应进行的速度和时间,温度越高,质量下降越快;但由于品种的不同,蜂蜜质量下降的速度与温度的关系并不相同。     

4种食品中5-羟甲基糠醛在模拟胃肠消化过程中的变化

研究了4种常见食品(咖啡、饼干、方便面、薯片)中5-羟甲基糠醛(5-hydroxymethylfurfural,HMF)在模拟胃肠消化过程中的变化规律。经过胃消化后,饼干、方便面和薯片中HMF的含量显著增长,说明这些食品中的HMF在加工和贮藏过程中被隐藏,在胃环境下又重新释放出来。胃消化物再经过肠消化后,4种食品中的HMF含量显著降低,而游离氨基酸含量显著增加,且不同食物中释放出的半胱氨酸含量与HMF消减量呈负相关,说明在肠道环境下,HMF可能与氨基酸、特别是半胱氨酸形成加合物导致HMF含量显著下降。由于HMF-半胱氨酸加合物的形成会降低HMF对Caco-2细胞的毒性,因此,在摄食HMF含量高的食品的同时,适量摄入蛋白质可消除HMF的危害。     

Ferulic acid and its position among the phenolic compounds of wheat

Ferulic acid (3-methoxy-4-hydroxycinnamic acid) is the main phenolic acid occurring in cell walls of monocotyledones. Due to its blue-and-white fluorescence it is easily identified and is located in the cereal grain morphological parts. Its 40-fold greater concentration was found in the cells walls of the seed coat and aleuronic layer than in the cells walls of endosperm. Most often, it is linked by ester bonds with hemicellulose chains, mainly with arabinose residues and it also polymerizes with lignin through ether bonds. However, ferulic acid in the pentosane molecules forms specific complexes with proteins through chemical bonds with amino acids. It is interesting to mention the theory of the pentosane gel formation in which a great role is assigned to ferulic acid. An oxidized form of ferulic acid-diferulic acid-produces gel formation by linking two pentosane or protein molecules. The blue-and-white fluorescence of ferulic acid can be applied to determine flour contamination with grain coat particles and its ability to form complexes with pentosanes and proteins is important in the formation of dough texture with its semi-elastic properties.     

Effect of pH on the properties of soy protein–pectin complexes

The interactions of a commercial soy protein isolate (SPI) and a 2:1 SPI:high methoxy pectin (PEC) complex were evaluated over a range of pH values (3-7). The SPI formed very large (> 50 ??m) and largely insoluble aggregates (< 10%) close to its isoelectric point (IEP, pH 4 and 5) and smaller, more soluble (> 80%) particles at higher and lower pH values. The addition of PEC increased the solubility of SPI close to its IEP (pH 4 and 5) and prevented the formation of very large aggregates. However, PEC reduced the solubility of SPI at higher and lower pH values presumably via a depletion mechanism. The ??-potential of diluted SPI dispersions decreased from positive to negative with increasing pH, passing through zero at pH 4.6, the isoelectric point (IEP) of the protein. At pH < 6, the addition of PEC reduced the charge of the protein suggesting the formation of a complex while at pH 6 or 7 there was no evidence of complex formation. The increased SPI solubility in the IEP in the presence of PEC is probably due to the formation of charged complex which do not aggregate while the decreased solubility of protein in the presence at high and low PEC is probably due to the formation of insoluble complexes and a depletion interaction respectively. Thermal treatment (30 min, 90 °C) enhanced the solubility of the SPI:PEC complexes close to the IEP (pH 4 and 5), but reduces it at low pH (pH 3). The SPI:PEC complexes could be manufactured in the form of a beverage at pilot scale where their solubility was enhanced by homogenization.     

5-Hydroxymethylfurfural als chemische und technologische Indikatorsubstanz bei der sauren Stärkehydrolyse

5-Hydroxymethylfurfural as a Chemical and Technological Indicator Substance in Acid Starch Hydrolysis. From the point of view of yield the formation of 5-hydroxymethylfurfural (HMF) is of no great importance in acid starch hydrolysis. As the percentual decomposition of glucose compared to HMF remains almost constant within the range of technological conditions, whereas with different reaction conditions highly varying amounts of coloring matter and HMF will occur, HMF has to continue reacting differentially. Following a characterization of the chemical individual HMF, its formation and decomposition at various p_H-values, it is shown that in the technological process the HMF-amount of starch hydrolysates is strongly dependant on production conditions. Especially compensation of high temperatures by means of increased acid concentrations as well as improving turbulence in the pasting phase will lead to a substantial decrease in the formation of HMF. Contents of coloring matter and protein are much less influenced, which makes HMF-content a true chemical-technological indicator. Participation of HMF in the formation of coloring matter in starch hydrolyzates obviously is only important in the high-acid range. Discolorations of hydrolyzates in the p_H-range around 5 do not coincide with changes in the HMF-content as is the case in the acid range of formation of HMF.     

Studies on the occurrence of non-enzymatic browning during storage of citrus juice

In freshly produced commercial citrus juice, aseptically filled in TetraBrik cartons, it has been demonstrated that nonenzymatic browning was mainly due to carbonyl compounds formed from l-ascorbic acid degradation. Contribution from sugar–amine reactions is negligible as evident from the constant total sugar content of degraded samples. The presence of amino acids and possibly other amino compounds, however, enhance browning. Although formation of 5-hydroxymethyl-furaldehyde (5-HMF) has been detected in degraded juice samples, its presence could not be used as an index of browning. 5-HMF has been found to be unreactive in the browning process in citrus juices and its contribution to browning in this type of products is insignificant, if not negligible. Increasing the l-ascorbic acid concentration extends the nutritional value of the product but also increases the severity of browning. Hence where l-ascorbic acid is added as an antioxidant in foods, care should be taken so that the amount added is just proportional to the level of oxygen present or to the amount of oxidizable substances.     

荸荠皮提取物对土豆脆片焙烤中丙烯酰胺抑制效果的影响

丙烯酰胺是高温油炸或焙烤食品加工时产生的潜在致癌物,对食品安全存在威胁。为从荸荠皮的提取分离物中筛选适用于土豆脆片焙烤加工的丙烯酰胺抑制剂,本文研究了荸荠皮70%丙酮总提取物及其不同极性萃取物对土豆脆片焙烤加工中丙烯酰胺抑制效果的影响,并进一步探讨正丁醇萃取物过大孔树脂分离纯化后的不同浓度乙醇洗脱液对土豆脆片中丙烯酰胺抑制效果的影响。结果表明,荸荠皮提取物对土豆脆片加工中丙烯酰胺的形成均有抑制作用。在荸荠皮70%丙酮总提取物及其不同极性萃取物中,正丁醇萃取物的抑制效果最好,在其最佳抑制浓度1.0×10-3 mg/mL时,抑制率达到17.14%。正丁醇萃取物过大孔树脂进一步分离后,其25%乙醇洗脱液对丙烯酰胺的抑制效果最好,在最佳抑制浓度1.0×10-5 mg/mL时,抑制率达到24.69%,比未分离前提高了44.05%,为从荸荠皮中提取分离高效的丙烯酰胺抑制成分指明了方向。     

Occurrence of halogenated furanones in U.S. drinking waters

Chlorinated and brominated forms of MX (3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone) were detected in the disinfected waters of six pairs of U.S. drinking watertreatment plants, with MX as high as approximately 310 ng/L in finished water. The strength of this study is in its comparison between pairs of plants that drew water from the same or similar watersheds and treated the raw source water with two contrasting disinfection and/or treatment schemes. As expected, the brominated MX-analogues were produced in greater abundance than MX from raw source waters with high bromide concentrations. Disinfection of waters with free chlorine produced more MX-analogues than disinfection with monochloramine. Use of chloramines as the residual disinfectant appeared to stabilize MX-analogues once they were formed. Pretreatment with ozone and biologically active granular activated carbon minimized MX-analogue formation upon subsequent chlorination or chloramination, either because MX precursors were altered by ozone, removed by granular activated carbon, or degraded by biological filtration. Pretreatment with chlorine dioxide did not minimize MX-analogue formation. In plant effluent samples, MX and chloroform were positively correlated (molar R = 0.7, N = 6). Similar formation patterns of MX-analogues, trihalomethanes, and haloacetic acids in these water treatment plants suggest that the three classes of disinfection byproduct follow a common formation mechanism from natural organic matter and chlorine.     

培养条件及表面活性剂的添加对纳豆芽孢杆菌生物膜形成的影响

采用改良的微孔板法培养纳豆芽孢杆菌(Bacillus subtilis natto),通过结晶紫染色定量分析产生的生物膜。结果表明:培养条件为pH 7、温度37℃、培养72 h且在5 g/100 mL葡萄糖-5 g/100 mL NaCl条件下成膜能力最佳。柠檬酸二铵和聚乙二醇-200(polyethylene glycol-200,PEG-200)随着质量浓度的增加对生物膜的形成量呈现先下降后上升的趋势,十二烷基磺酸钠(sodium dodecyl sulfate,SDS)抑制生物膜的形成,十六烷基三甲基溴化铵(cetyl trimethyl ammonium bromide,CTAB)促进生物膜的形成。所以低温抑制生物膜的形成,一定浓度的NaCl和葡萄糖促进生物膜形成,不同的表面活性剂对其生物膜的影响机制不同,为纳豆芽孢杆菌生物膜的研究提供理论基础。     

发酵剂抑制发酵肉制品中酪胺形成机制及效果的研究进展

酪胺是以酪氨酸为前体物质，经脱羧后形成的一种生物胺。消费者从食品中摄入过量的酪胺会导致头痛、高血压等健康问题。发酵肉制品由于富含蛋白质，且经长期发酵产生了复杂的微生物菌群和大量的酪氨酸，因此易形成酪胺并在产品中大量积累。应用不产生酪胺或具有降解酪胺功能的发酵剂是降低发酵肉制品中酪胺含量的新方法。本文介绍了发酵肉制品中酪胺的形成及其影响因素，重点综述了发酵剂的种类、特性和发酵剂抑制酪胺形成的机制和效果，旨在为通过发酵剂法抑制发酵肉制品中的酪胺形成与积累、提高发酵食品安全提供理论支持。     

The nanostructure's management is the basis for a functional fatty foods’ production

For the first time the functional types of butter with herbal supplements (HS) are developed. The effect of HS on micro-and nanostructure of developed types of butter was studied. It was established that the introduction of HS reduces the value of nanostructure's elements of butter in a 5 - 25 times. The nature and properties of HS influence the formation of the butter's nanostructure, the architecture and morphology of its nanoelements. According to comprehensive studies it was found that the decreasing of the size of butter's nanostructure's elements improves the structure, texture and rheological parameters of butter - it increases the thermal stability and plasticity, the ability of the structure to retain the liquid phase of fat and a structure's connection, prevents the formation of layered and brittle consistency of butter, promotes the formation of coagulation-crystallization structure dominated by coagulation, inhibits microbiological and biochemical spoilage of butter. According to the results of clinical trials and the conclusions of the Ministry of Health developed the kinds of butter are recommended to use in health care and dietary nutrition. Based on the results of the study it was recommended to use HS to control the formation of the butter's nanostructure and its quality, physical and chemical properties.     

Acrylamide removal from heated foods

The possibility to remove acrylamide from foods by exploiting its chemical physical properties was studied. Commercial biscuits and potato chips were subjected to vacuum treatments at different combinations of pressure, temperature and time. Results showed that acrylamide removal was achieved only in samples previously hydrated at water activity values higher than 0.83, and that, a maximum of acrylamide removal was obtained between 5 and 15 min of vacuum treatment at 6.67 Pa and 60 °C. By applying these process conditions, it was possible to remove 43% and 18% acrylamide from the biscuits and the potato chips, respectively. It was hypothesised that the vacuum treatment could favour acrylamide formation by promoting the decarboxylation of the Schiff base, a key intermediate of acrylamide formation. Although further research is needed to find out for each food category the process conditions that can maximise acrylamide removal while minimising its formation as well as to evaluate the effects on the sensory properties, this technology would represent a promising and alternative strategy to mitigation interventions aimed at reducing acrylamide levels in foods.