Model reactions on roast aroma formation

Summary After roasting a reaction mixture consisting ofd-glucose and phenylalanine, 155 volatile products were isolated and identified by diethyl ether extraction and high resolution gas chromatography/mass spectrometry. Among them, 64 furans, 43 aromatic benzoic compounds, 17 aliphatic compounds, 11 carbo-cyclic compounds, 3 pyrons, 10 pyrazines, 6 pyrroles, and 3 pyridines were identified. After cooking the model mixture, only 64 compounds were identified. Aromatic benzoic compounds were found to be the specific products of phenylalanine, which are predominantly formed by phenyl acetic aldehyde.

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Modell-Reaktionen zur Röstaroma-Bildung

Zusammenfassung Die mittels Diethylether-Extraktion aus der Umsetzung Vond-Glucose mit Phenylalanin isolierten Reaktionsprodukte wurden mittels HRGC/MS getrennt und identifiziert. Dabei wurden unter Röstbedingungen insgesamt 155 flüchtige Komponenten strukturell zugeordnet. Unter ihnen befanden sich 64 Furane, 43 benzoide Aromaten,17 Aliphaten, 11 Carbocyclen, 3 Pyrone, 10 Pyrazine, 6 Pyrrole und 3 Pyridine. Unter Kochbedingungen wurden lediglich 64 flüchtige Verbindungen identifziert. Aminosäure-spezifische Produkte sind benzoide Aromaten, die vor allem beim Rösten entstanden. Die Bildung einiger Kondensationsprodukte konnte auf Phenylacetaldehyd zurückgeführt werden.

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Dissertation Lutz Mevissen, TU Berlin 1986     

Model reactions on roast aroma formation

Summary After reaction of serine with glucose, fructose, diacetyl or cyclotene in an autoclave at 120° C, 150° C, or 180° C 338 volatile compounds (aliphatic and carbocyclic carbonyls, furans, furanones, pyranones, phenols, pyridines, pyrazines and pyrroles) were identified. The total amounts of some of these compound classes were determined and compared. Serine forms, beside glycolic aldehyde, also aminoethanol and some aliphatic aldehydes which lead to the formation of a great many compounds. Fructose obviously forms, under same conditions, more methylglyoxal than glucose, but generally the degradation products are identical. With rising temperature the number and amounts of reaction products increased some of which, like furylpyrazine and furfurylpyrazine, additionally required special intermolecular condensations. Diacetyl at 180° C obviously forms dimeric condensation products which, by further reactions, yield benzene compounds, 3-hydroxy-2,5,6-trimethylpyridine, 2-acetyl-4,5-furan and 2-acetyl-4,5-pyrrole. Cyclotene itself forms during heating numerous derivatives by condensation-, dehydration- or hydrogentransfer reactions. By reaction with NH₃ from serine, these derivatives formed imines which, by further reactions, yielded cyclopentapyrazines and dicyclopentapyrazines. Some mechanisms are proposed for the formation of pyrrolylalkanols, pyrrolopyrazines and products mentioned here.

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Modellreaktionen zur Röstaroma-Bildung XI. Erhitzen von Serin mit ausgewählten Zuckern und Zuckerabbauprodukten im Autoklaven

Zusammenfassung Die Umsetzung von Serin mit Glucose oder Fructose bzw. mit Diacetyl oder Cycloten im Autoklaven bei 120 °C, 150 °C bzw. 180 °C führte insgesamt zur Identifizierung von 338 flüchtigen Verbindungen wie aliphatische und carbocyclische Carbonyle, Furane, Furanone, Pyranone, Phenole, Pyridine, Pyrazine und Pyrrole. Die Gehalte dieser Substanzklassen wurden bestimmt und verglichen. Serin bildet neben Glykolaldehyd auch Aminoethanol sowie einige aliphatische Aldehyde und ermöglicht so die Entstehung zahlreicher Reaktionsprodukte. Fructose setzt bei Erhitzen offenbar mehr Methylglyoxal frei als Glucose, bildet im übrigen aber gleiche Abbauprodukte. Allgemein bilden sich mit steigender Temperatur steigende Anzahlen und Mengen von Reaktionsprodukten, von denen einige wie z.B. Furyl- und Furfurylpyrazine bestimmte, zusätzliche intermolekulare Kondensationen voraussetzen. Diacetyl bildet offensichtlich bei 180 °C dimere Kondensationsprodukte, die dann zu benzolaromatischen Verbindungen bzw. 3-Hydroxy-2,5,6-trimethylpyridin, 2-Acetyl-4,5-dimethylfuran bzw. -pyrrol weiterreagieren. Cycloten bildet schon allein durch Kondensation, Wasserabspaltung bzw. Wasserstofftransfer zahlreiche Derivate. In Gegenwart von Serin bilden sie mit NH₃ Amine, die zu Cyclopentapyrazinen bzw. Dicyclopentapyrazinen weiter reagieren. Es werden Mechanismen für die Bildung einer Reihe von Röstaromaprodukten wie Pyrrolalkanole, Pyrrolopyrazine sowie den bereits genannten Verbindungen vorgeschlagen.

     

Model reactions on roast aroma formation XII. Reaction of glucose with aspartic acid or asparagine at three different temperatures

Summary Equimolar mixtures of aspartic acid or asparagine and glucose were treated at three different temperatures (100° C, 150° C, 220° C). The volatile compounds soluble in diethyl ether were identified by GC/MS. Besides numerous well known compounds, which are not mentioned here, some aminopyridines, hydroxyethylpyridines, imidazoles and cyanopyrroles were identified; their formation pathways are discussed. Differences of product composition are demonstrated depending on reaction temperature and amino acid used.

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Modellreaktionen zur Röstaromabildung XII. Reaktionen von Glucose mit Asparaginsäure bzw. Asparagin bei drei verschiedenen Temperaturen

Zusammenfassung l-Asparaginsäure oderl-Asparagin wurde äquimolar mitd-Glucose bei drei Temperaturen (100 °C, 150 °C und 220 °C) umgesetzt. Die flüchtigen, etherlöslichen Reaktionsprodukte wurden anhand ihrer massenspektrometrischen Daten identifiziert. Neben zahlreichen, bereits bekannten Verbindungen wurden einige Aminopyridine, Hydroxyethylpyrazine, Imidazole und Cyanopyrrole identifiziert, die bisher zum Teil noch nicht im Zusammenhang mit der Maillard-Reaktion beschrieben worden sind. Ihre zum Teil durch Zusatzversuche abgesicherten Bildungswege werden diskutiert. Darüber hinaus werden Unterschiede in den Produktspektren, bezogen auf die Reaktionstemperatur bzw. die eingesetzte Aminosäure, aufgezeigt.

     

北京烤鸭香味气相指纹图谱技术研究初探

采用同时蒸馏提取对10批次的北京烤鸭香气成分进行提取,应用气相色谱-质谱联用技术对其进行分析,据此设立待测样品的合格性允差范围,初步建立了北京烤鸭香味的气相指纹图谱的研究方法。通过待测样品实验与参兑实验考察了气相指纹图谱用于风味质量控制的可行性。结果表明:北京烤鸭香味指纹图谱稳定性好,相似度高,具有较强的特征性和唯一性。该图谱能综合、准确地反映北京烤鸭的风味情况,能够成为评价北京烤鸭风味质量的一种有效手段。      

新疆烤羊肉串中杂环胺的生成规律研究进展

烤羊肉串, 作为新疆特色美食, 以其引人入胜的外观和独特的风味深受广大消费者追捧。然而, 这类经过高温加工的食品容易产生多种致癌物质, 其中之一就是杂环胺。杂环胺主要源自富含蛋白质的动物性食品, 具有强烈的致癌和致突变特性。过量摄入将会提高人体患癌风险, 对人体健康构成严重威胁。杂环胺的生成与反应底物、加工方式以及加工条件等密切相关。本文总结了杂环胺在热加工肉类中的分布状况及其生成的主要因素, 重点综述了新疆特色美食烤羊肉串中杂环胺的生成规律以及抑制策略, 旨在为今后新疆烤羊肉串的绿色加工以及杂环胺的减控方法提供科学理论依据。对消费者的健康饮食具有重要的指导意义。     

Effect of Carnobacterium piscicola on aroma formation in sausage mince

The metabolites from leucine degradation play a key role in sausage aroma. Leucine catabolism is particularly important in Carnobacterium piscicola. The purpose of the study was to determine the effect of C. piscicola inoculation on the aroma of a sausage model and on leucine catabolism. Sensory analysis and implantation of Carnobacterium were performed. Aromatic compound production from (3)H leucine added to the sausage model was measured by high-performance liquid chromatography. After 18 days of ripening, the level of Carnobacterium species was 10-fold higher in sausages inoculated with C.?piscicola than in the control sausages. Addition of C.?piscicola enhanced the development of sausage aroma. The leucine was 10% more degraded in the models inoculated with C. piscicola. 3-Methyl butanoic acid was the main metabolite detected and the highest production of α-ketoisocaproic acid and hydroxy α-ketoisocaproic acid were detected in the sausage model inoculated with C. piscicola.     

葡萄酒香气来源和形成研究进展

香气是衡量葡萄酒质量的一个重要部分。以葡萄酒香气的3大来源-品种香、发酵香、陈酿香为主线,对葡萄酒中活跃香气成份的形成进行概述。包括葡萄果实中的香气物质和葡萄利用酵母在酒精发酵时期产生的香气物质。同时,对苹果酸-乳酸发酵、葡萄酒的老化、成熟与葡萄酒香气的关联也进行了讨论,以期促进葡萄酒香气的进一步研究。     

Cooperation between wild lactococcal strains for cheese aroma formation

Several wild lactococcal strains were tested for their ability to produce aroma compounds during growth in milk. Strains were incubated alone and in combination with Lactococcus lactis IFPL730, which is characterized by showing α-keto acid decarboxylase activity. Volatile compounds from incubated milks were analyzed by means of solid-phase microextraction (SPME) and evaluated by gas chromatography–mass spectrometry (GC–MS). Incubated milks were also sniffed for sensory analysis to describe aroma attributes. The combination of L. lactis IFPL326 that showed the highest branched chain aminotransferase activity with IFPL730 contributed to the highest formation of leucine-derived volatile compounds, such as 3-methylbutanal, 3-methyl-1-butanol and 2-hydroxy-4-methyl pentanoic acid methyl ester. In addition, the milk incubated with this combination of strains was awarded, by the test panellists, the highest scores for “ripened cheese” attribute and aroma intensity. The results indicate that combination of L. lactis strains harbouring complementary catabolic routes can contribute to improved cheese aroma formation, the combined cultures with L. lactis IFPL730 resulting in higher volatile compound formation than isolate strains.     

烤肉的工业化生产工艺研究

以猪精肉为原料,采用现代工艺,开发一种烤肉制品.通过食盐添加量、复合磷酸盐添加量、真空滚揉时间、蒸煮时间等4个因素分别进行单因素试验与正交试验,以烤肉的感官特性为评价指标,得出烤肉工业化生产的最佳工艺.结果表明:当食盐的添加量为1.40％,复合磷酸盐的添加量为0.80％,滚揉10 h,蒸煮60 min时,制得的烤肉产品最佳.     

烧鸡感官评定研究

采用模糊数学法对不同系列的烧鸡感官质量进行综合评定,结果表明,三种不同系列的烧鸡感官评定级别从高到低为：A〉B〉C。     

烧鸡的防腐与保鲜

实验以烧鸡鸡肉为原材料,对烧鸡的防腐保鲜进行初步研究。根据培养条件培养鸡肉细菌来做抑菌试验,通过对不同防腐保鲜液的抑菌实验,筛选出最佳保鲜液;再结合真空包装和微波杀菌的保鲜方法,进行贮藏。结果表明:最佳复合保鲜剂配方为Nisin浓度0.05,溶菌酶浓度0.05,双乙酸钠浓度1的保鲜液。将烧鸡鸡肉浸泡于此保鲜液中60s,再进行真空包装和微波杀菌,在36℃条件下,至少可保藏11d,其微生物、感官指标均在国标允许范围内,可以有效延长鸡肉的保质期。     

Effect of Debaryomyces spp. on aroma formation and sensory quality of dry-fermented sausages

The effect of Debaryomyces spp. used in combination with starter cultures (lactic acid bacteria and staphylococci) was studied in the development of dry-fermented sausage aroma and final sensory quality. Volatile compounds were extracted by solid-phase micro extraction and analysed by gas chromatography-mass spectrometry. A paired comparison test was done to determine which sausage was preferred. Debaryomyces spp. showed an important effect on volatile generation during ripening by inhibiting the generation of lipid oxidation products and promoting the generation of ethyl esters that contribute to proper sausage aroma. However, the amount of Debaryomyces spp. used is important because larger amounts produced high generation of acids that mask the positive effect.     

环境因子对Maillard反应形成肉香味的影响

文章浅述了肉香味,重点研究肉的化学组成、体系的水分含量、pH、反应温度/时间以及缓冲体系等环境因子对Maillard反应形成肉香味的影响.同时,就目前该领域的发展方向提出了一些建议,以期为天然肉味香精的生产控制提供理论依据.     

A fermented meat model system for studies of microbial aroma formation

A fermented meat model system was developed, by which microbial formation of volatiles could be examined. The model was evaluated against dry, fermented sausages with respect to microbial growth, pH and volatile profiles. Fast and slowly acidified sausages and models were produced using the starter cultures Pediococcus pentosaceus and Staphylococcus xylosus. Volatiles were collected and analysed by dynamic headspace sampling and GC-MS. The analysis was primarily focused on volatiles arising from amino acid degradation and a total of 24 compounds, of which 19 were quantified, were used for multivariate data analysis. Growth of lactic acid bacteria was comparable for model and sausages, whereas survival of S. xylosus was better in the model. Multivariate analysis of volatiles showed that differences between fast and slowly acidified samples were identical for model and sausage. For both sausage and model, fast-acidified samples had a high content of ketones, sulphides and methyl-branched acids, whereas slowly acidified samples had the highest content of methyl-branched alcohols, aldehydes, their ethyl esters, phenylacetaldehyde and methional. Furthermore, model repeatability with respect to pH, microbial growth and volatile profiles was similar to sausage production. Based on these findings, the model system was considered valid for studies of aroma formation of meat cultures for fermented sausage.     

烤肠生产工艺优化研究

通过单因素和正交试验对烤肠的不同原辅料配比进行研究,得到了最佳工艺,即大豆分离蛋白、卡拉胶和磷酸盐的添加量分别为2.25%、0.5%、0.375%,使产品的结构和口感达到最佳.     

Enzyme catalyzed reactions and structure formation relationship in plastein reactions

α-Chymotrypsin and papain catalyzed formation of plastein from peptic hydrolyzate of soy protein is shown to take place without any change of the average molecular weight. Rheological studies of plastein in dependence of plastein reaction condition indicates that chemical reactions resulting in an increase of viscosity take place in the first minutes of the plastein reaction. After the expiration of this period structure formation processes take place lasting for 3–5 days which are not the result of α-chymotrypsin and papain catalyzed reactions.