The flavour of plums (Prunus domestica L.). An examination of the aroma components of plum juice from the cultivar victoria

Vacuum steam distillation followed by solvent extraction, chemical separation and examination of the final extract by gas chromatography, and gas chromatography-mass spectrometry, enabled 73 volatile components to be identified in juices prepared from plums of the cultivar Victoria. Of these, odour evaluation of the gas chromato-graphic exit as the components were being separated, indicated that benzaldehyde, linalool, ethyl nonanoate, methyl cinnamate and γ-decalactone contribute to ?plum’? aroma. Milling the plums, as opposed to merely removing the stones prior to enzyming and expressing the juice, increased the concentrations of hexanol and cis 3-hexenol and also produced hexanal and trans 2-hexenal, these four components giving rise to the characteristic ?green’? aroma of juice prepared in this way.     

The neutral volatile components of Czechoslovak plum brandy

Summary The volatile flavour-significant components of Czechoslovak plum brandy were isolated, separated on a silica gel column and then analyzed by gas chromatography and combined gas chromatography mass spectrometry. The analysis led to the identification of 107 compounds, 17 identified tentatively, 7 hydrocarbons, 47 esters, 1 lactone, 9 carbonyls, 7 acetals, 31 alcohols and 5 phenols. It was found that higher aliphatic aldehydes (nonanal and some others), 2-undecanone, benzaldehyde, damascenone, benzyl acetate, ethyl phenylacetate, phenylethyl acetat, ethyl 3-phenylpropionate, methyl cinnamate, ethyl cinnamates and several other compounds were the most significant contributors to the typical plum brandy-like flavour.

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Die neutralen, flüchtigen Bestandteile tschechoslowakischer Zwetschgengeiste

Zusammenfassung Die flüchtigen aromacharakteristischen Bestandteile tschechoslowakischer Zwetschgengeiste wurden isoliert, auf Silicagelkolonnen getrennt und dann durch Gaschromatographie, kombiniert mit Massenspektrometrie analysiert. Die Analyse führte zur Identifizierung von 107 Verbindungen, davon 17 provisorisch: 7 Kohlenwasserstoffe, 47 Ester, 1 Lacton, 9 Carbonyle, 7 Acetale, 31 Alkohole und 5 Phenole. Die charakteristischen Bestandteile des typischen Zwetschgengeistaromas waren die höheren aliphatischen Aldehyde (Nonal and ähnliche), 2-Undecanon, Benzaldehyde, Damascenon, Benzylacetat, Ethylphenylacetat, Phenethylacetat, Ethyl-3-phenylpropionat, Methyl- und Ethylzimtsäureester and mehrere andere Verbindungen.

     

The volatile flavour components of commercial port wines

Gas chromatographic-mass spectrometric examination of aroma extracts from both Ruby and Tawny port has led to the identification of 141 components, notably 2-methoxyphenol, dihydro-2-(3H)-furanone, β-methyl-γ-octalactone, cis-4-hydroxy-methyl-2-methyl-l,3-dioxolane, ethyl pyroglutamate and vitispirane. Odour evaluation of the components separated by gas chromatography indicates five regions as being of potential importance in port. 2-Methoxyphenol and dihydro-2-(3H)-furanone were found in two of these regions, three others being associated with esters of succinic acid. None of these components can, however, wholly explain the port-like odour.     

Volatile flavour components of watercress

Using previously reported methods of sample preparation an essence of watercress was obtained which proved to contain only four major components. All are glucosinolate degradation products with 3-phenylpropionitrile the major compound, although the related 2-phenylethyl isothiocyanate is most important in flavour terms. The other compounds obtained are long chain ω-methylthioalkyl nitriles.     

Volatile flavour components of eggs

Using a modified Likens and Nickerson extraction apparatus and a gas entrainment method of concentration by low temperature—high vacuum distillation, approximately 115 volatile flavour components of the hen's egg were obtained. These were separated by gas chromatography and the majority were identified by combined gas chromatography-mass spectrometry. The odours of some of the separated components were described.     

Non-volatile flavour components of Ganoderma tsugae

Ganoderma tsugae Murrill are currently popular and used in the formulation of nutraceuticals and as functional foods. The non-volatile components in the form of mature and baby fruit bodies (Ling chih), mycelia and fermentation filtrate from submerged culture were studied. Mycelia and filtrate contained significantly higher moisture contents (10.3% and 19.8%) and higher contents of carbohydrates, reducing sugars, crude ash and crude protein. Four forms of G. tsugae contained from 7.65% to 10.1% dry weight of total soluble sugars and polyols. Total free amino acid contents ranged from 2.50 to 149 mg g⁻¹ dry weight and in the descending order of filtrate, mycelia, baby Ling chih and Ling chih. Contents of monosodium glutamate-like components ranged from 0.16 to 26.0 mg g⁻¹ whereas, contents of sweet components ranged from 0.50 to 24.6 mg g⁻¹. The bitter components were predominant. Contents of total and flavour 5^′-nucleotides were high in filtrate (5.48 and 3.10 mg g⁻¹, respectively). The umami intensities were expected to be in the descending order of filtrate, mycelia, baby Ling chih and Ling chih.     

Volatile flavour components of malt extract

The Likens-Nickerson concurrent steam distillation-solvent extraction apparatus was used to obtain an essence from malt extract. The essence was submitted to combined gas chromatography-mass spectrometry (g.c.-m.s.), to examination by sulphurspecific and nitrogen-specific detectors, and to sensory evaluation of the components eluted from gas chromatographic capillary columns. Some 33 compounds were identified by direct examination by g.c.-m.s., another 14 by trapping and re-injection, which provides an efficient method of concentration, and a further six, which had not been previously identified due to interference from the solvent peak, by the use of charcoal adsorption traps. Results indicate that several compounds need to be combined to simulate malt flavour. The odour contributions of several components are discussed.     

Volatile flavour components of garden cress

Using previously reported methods of sample preparation an essence of garden cress was obtained which proved to contain only 11 components. Eight have been identified, all glucosinolate degradation products (isothiocyanates and nitriles), and provide over 95% of the sample. Benzyl derivatives, from glucotropaeolin, are the most abundant. No thiocyanates were obtained.     

Volatile flavour components of coriander leaf

Using previously reported methods of sample preparation an essence of coriander leaf was obtained which proved to contain over 25 components. Most of these have been identified, with aliphatic aldehydes providing nearly 90% of the sample. C₁₂ aldehydes are the most abundant.     

Volatile flavour components of marula juice

Summary The volatile aromatics of marula fruit picked in the Republic of South Africa were enriched by means of an established liquid-liquid extraction technique. GC and GC-MS analyses were employed to identify 60 components with Kovats Indices lower than 2,000 (CW20M).Sesquiterpene hydrocarbons formed the most abundant group of compounds, with -caryophyllene being the major constituent of all analyzed samples. 33 sesquiterpene hydrocarbons could be detected of which 22 were identified, including all major components. Significant differences between the analyzed samples were observed only within the sesquiterpene fraction. - Odour assesment indicated the absence of compounds with impact character.

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Flüchtige Aromastoffe von Marula-Salt

Zusammenfassung Die flüchtigen Aromastoffe von Marula-Saft, hergestellt aus in Südafrika gelesenen Früchten, wurden mit einer bewährten Flüssig-Flüssig-Extraktionsmethode angereichert. Mittels GC und GC-MS wurden 60 Verbindungen identifiziert, deren Kovats-Indices auf CW20M niedriger als 2000 lagen.Sesquiterpen Kohlenwasserstoffe bildeten die vorherrschende Gruppe von Verbindungen, wobei -Caryophyllen Hauptbestandteil aller untersuchter Proben war. Insgesamt wurden 33 Sesquiterpenkohlenwasserstoffe detektiert, von denen 22 positiv identifiziert wurden, einschließlich aller Hauptkomponenten. Deutliche Unterschiede innerhalb der Aromafraktion der untersuchten Proben waren nur bei den Sesquiterpenen festzustellen.Geruchstests der gaschromatographisch getrennten Verbindungen ließen das Fehlen von Verbindungen mit impact charakter erkennen.

     

Volatile flavour components of cooked potato

Extracts of the steam volatiles of cooked potatoes and of a dehydrated, granular potato product have been prepared. High-boiling fatty acids preponderated and were removed prior to concentration and examination of the resulting essences by combined gas chromatography-mass spectrometry-odour assessment. Thirty-five components were identified in potato essences and 20 in a potato granule essence. Chemical and retention data indicated that 2-methoxy-3-ethylpyrazine

1 For clarity in this paper, the methoxy substituent is assigned the 2-position in pyrazines, and is written first, irrespective of the rules of nomenclature.

was present in potato volatiles and mass spectral evidence was obtained of its presence in potato sprout essence. Synthetic work confirmed the known characteristic raw potato odour of 2-methoxy-3-ethylpyrazine and demonstrated that isomers do not possess it. Lack of volatiles rather than off-flavour is believed to account for the differences between the flavour of cooked potatoes and of the potato product examined.     

Volatile flavour components of Allium grayi regal

The volatile flavour components of Allium grayi Regal have been investigated by a combination of chromatographic and spectroscopic methods. Among the more than 90 component peaks observed by capillary gas chromatography of the oil obtained by ether extraction of the steam distillate, 47 compounds were positively identified. They included 11 sulphur compounds, 5 alcohols, 7 aldehydes, 3 ketones, 2 furanones and 19 miscellaneous compounds.     

Characterisation of bound flavour components in kiwifruit

Glycosidically bound volatiles in kiwifruit have been studied. The compounds were isolated from kiwifruit juice by absorption onto a column of Amberlite XAD-2 followed by washing with pentane and elution with methanol. Volatiles were released by enzymic hydrolysis with β-glucosidase. Major components found and identified by GC-MS were E-hex-2-enal and benzaldehyde. Compounds not previously identified in kiwifruit include octan-3-ol, camphor, 4-methylbenzaldehyde, 2-hydroxybenzaldehyde, neral, geranial, methyl 2-hydroxybenzoate, nerol, geraniol and 2-phenylethanol.     

Relative volatilities of some onion flavour components

The volatilities of propanethiol, 2,5-dimethylthiophene, methyl propyl sulphide, dimethyl disulphide, dipropyl disulphide, allyl methyl sulphide, diallyl sulphide, diallyl disulphide, acetaldehyde, propionaldehyde, methanol, ethanol, 1-propanol and 2-propanol in dilute water solutions were studied experimentally by gas chromatography. The volatilities of these compounds varied appreciably. They were higher for thiols, thiophenes, and monosulphides, than disulphides, aldehydes or alcohols. The results for aldehydes and alcohols confirm earlier theoretical predictions by other authors that at 25°C the volatility, in very dilute solution, increases as the carbon chain gets longer.     

甘梅味紫薯山药夹心薯片的加工工艺研究

以紫薯粉、山药粉、白面、甘梅粉为主要原料,以感官评定为标准,通过单因素实验,正交试验,研究甘梅味紫薯山药夹心薯片的最优工艺。结果显示甘梅味紫薯山药夹心薯片的最佳配方为紫薯粉添加量20%、白面添加量75%、甘梅粉添加量3.75%(以山药粉添加量为基准)。于烤箱中烘烤(设置烤箱上层温度为150℃、下层温度为240℃)110 s,翻面,再烘烤110s,取出,加入1.25%(以山药粉添加量为基准)的果酱,即可得到酸甜可口,香气诱人,营养丰富的甘梅味紫薯山药夹心薯片。     

青梅酒香气成分的研究

采用顶空-气相色谱-质谱法对浸泡青梅酒的香气成分进行了分析,共鉴定出21种化合物,其中相对含量较高的物质为乙酸乙酯、异丁醇、异戊醇、苯甲醛、苯甲酸乙酯。通过比较浸泡基酒、青梅汁及青梅酒3者的香气成分,得出苯甲醛和苯甲酸乙酯为青梅浸泡过程中形成的典型性香气成分;以叔戊醇为内标物,利用气相色谱法对青梅酒的5种主要香气成分进行了定量分析,测得其含量依次为64.56、142.80、135.23、37.25、11.10mg/L。     

Variations in the volatile flavour components of eggs

Previously developed techniques for the collection and analysis of the volatile flavour components of the hen's egg¹ have been employed in a comparative survey of the variations in the nature of the flavour components in samples from different types of egg and egg products. Whilst no significant differences were observed between the results for battery eggs and free range eggs, and between those for white-shelled and brown-shelled eggs, differences were observed between eggs of different ages and between egg yolk and whole egg. Two types of dried egg were also studied.     

Changes in volatile flavour components of soybeans during roasting

Volatile concentrates were prepared from whole soybeans, roasted at 200°C for 10, 20 and 30 min, by steam distillation under reduced pressure followed by ether extraction, and analysed by gas chromatography and gas chromatography-mass spectrometry, in comparison with the volatile concentrate from raw soybean flour.Major flavour components of raw soybean, such as n-hexanol, 1-octen-3-ol and n-hexanal, decreased during the course of roasting, but the rate of this decrease was not rapid, especially between 10 and 20 minutes' roasting. During the roasting period, alkylated pyrazines, oxygenated furans, oxygenated pyrroles and phenols were formed or increased markedly. On the other hand, sensory evaluation showed that a flavour change to ‘desirable’ from ‘beany’ or ‘objectionable’ occurred between 10 and 20 minutes' roasting. These results suggest that roast flavour masks the ‘beany’ flavour in soybean.