scholarly journals Volatile and Glycosidically Bound Composition of Loureiro and Alvarinho Wines

2008 ◽  
Vol 14 (4) ◽  
pp. 341-353 ◽  
Author(s):  
J.M. Oliveira ◽  
P. Oliveira ◽  
R.L. Baumes ◽  
M.O. Maia
Keyword(s):  
Fatty Acids ◽  
Organic Acids ◽  
Volatile Compounds ◽  
Volatile Fatty Acids ◽  
Free Fraction ◽  
Ethyl Esters ◽  
Gas Chromatography Mass Spectrometry ◽  
Volatile Phenols ◽  
Tropical Fruit ◽  
Fusel Alcohols

Composition of Loureiro and Alvarinho wines from the Vinhos Verdes region, regarding free volatile compounds as well as glycosidically bound aroma precursors, was exhaustively determined by gas chromatography—mass spectrometry after adsorption on XAD-2 resin. On the whole, were identified and quantified 120 volatile compounds in the free fraction and 77 glycosidically bound compounds, belonging to C6-compounds, alcohols, fatty acids ethyl esters, esters of organic acids, acetates, monoterpenic alcohols, monoterpenic oxides and diols, C13-norisoprenoids, volatile phenols, volatile fatty acids, and carbonyl compounds. Globally, the wines of the two cultivars present similar composition on volatiles. However, regarding varietal compounds, Loureiro wines were richer than Alvarinho ones with respect to C6-compounds and monoterpenic compounds, occurring the opposite for volatile phenols. It was also demonstrated that wines of both varieties might benefit the aroma reserve, present as glycoconjugates, as it is susceptible of being technologically explored. Linalool, Ho-trienol, (α-terpineol, contributing with fruity and floral notes, and (β-damascenone mostly for Alvarinho, confering tropical fruit notes, are the varietal compounds which may particularly influence the aroma of these wines. Respecting fermentative compounds, Alvarinho is also particularly rich in fatty acids ethyl esters related to lipid metabolism and acetates of fusel alcohols, which can provide it a fruity character; Loureiro contains higher levels of esters of organic acids and 2-phenylethanol, conferring fruity and floral notes. Sensory analysis agreed with chemical analyses showing a pronounced tree and tropical fruit character for Alvarinho wines while Loureiro wines present more intense citrus fruit notes.

Organic Acids and Anaerobic Microorganisms in the Contents of the Cholesteatoma SAC

1983 ◽  
Vol 92 (1) ◽  
pp. 91-96 ◽  
Author(s):  
Yukiko Iino ◽  
Tomonori Takasaka ◽  
Etsuro Hoshino ◽  
Yutaka Kaneko ◽  
Sachiko Tomioka ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Organic Acids ◽  
Volatile Fatty Acids ◽  
Chromatographic Technique ◽  
Anaerobic Conditions ◽  
Clostridium Species ◽  
Anaerobic Microorganisms ◽  
Aerobic And Anaerobic ◽  
Aerobic And Anaerobic Conditions

Organic acids in the contents of the cholesteatoma sac from 28 cases were studied by gas chromatographic technique. Five volatile fatty acids (acetate, propionate, isobutyrate, butyrate and isovalerate) and lactate were detected in large amounts, which may lower the pH of the cholesteatoma content. These acids were considered to be derived from products of anaerobic microorganisms. Therefore, the contents from 12 cases were cultured anaerobically in a glove box. Obligate microorganisms were identified in 92% of the cases and Peptococcus, Bacteroides, and Clostridium species were frequently isolated. In vitro, such obligate anaerobes produced various organic acids from the cholesteatoma content. Facultatives such as Staphylococcus aureus and Proteus mirabilis produced acetate in the content under aerobic and anaerobic conditions, whereas no organic acid was produced by Pseudomonas aeruginosa. Organic acids in the cholesteatoma content could be fermentative products made by the microorganisms, anaerobes and facultatives, which use the content as a substrate for acid production.

Simpler liquid-chromatographic screening for organic acid disorders.

1984 ◽  
Vol 30 (4) ◽  
pp. 542-546 ◽  
Author(s):  
M J Bennett ◽  
C E Bradey
Keyword(s):  
Mass Spectrometry ◽  
Fatty Acids ◽  
Gas Chromatography ◽  
Volatile Fatty Acids ◽  
Simultaneous Detection ◽  
Organic Aciduria ◽  
Gas Chromatography Mass Spectrometry ◽  
Identification System ◽  
Chromatographic Technique ◽  
Normal Infant

Abstract We describe an isocratic cation-exchange chromatographic technique, with ultraviolet detection, for determination of urinary organic acids. The method is useful for screening urines from neonates and infants suspected of having an organic aciduria, prior to confirmatory analysis by gas chromatography-mass spectrometry. Advantages of this technique over conventional gas chromatography include ease of sample preparation and the simultaneous detection of volatile fatty acids; limitations include its lack of an identification system like that of mass spectrometry, the presence of nonultraviolet-absorbing fatty acids, and the relatively long retention times of phenolic compounds. Chromatograms for patients with methylmalonic aciduria, propionic aciduria, isovaleric aciduria, beta-ketothiolase deficiency, lactic aciduria, and glutaric aciduria type II are compared with those for a normal infant.

scholarly journals Evaluation of Physiological Characteristics, Soluble Sugars, Organic Acids and Volatile Compounds in ‘Orin’ Apples (Malus domestica) at Different Ripening Stages

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 807
Author(s):  
Shunbo Yang ◽  
Zhipeng Meng ◽  
Yanan Li ◽  
Rongxin Chen ◽  
Yazhou Yang ◽  
...  
Keyword(s):  
Organic Acids ◽  
Volatile Compounds ◽  
Solid Phase ◽  
Soluble Sugars ◽  
Titratable Acidity ◽  
Fruit Weight ◽  
Physiological Characteristics ◽  
Gas Chromatography Mass Spectrometry ◽  
Apple Cultivar ◽  
Ripening Stages

‘Orin’ is a popular apple cultivar, which has a yellow-green appearance, pleasant taste, and unique aroma. However, few studies on the fruit quality characteristics of ‘Orin’ apples have been reported before. In this study, changes of the physiological characteristics were measured at different ripening stages, and the soluble sugars and organic acids were determined by high-performance liquid chromatography (HPLC). Volatile compounds were identified using the headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS). During the fruit ripening, the ‘Orin’ apple fruit weight, size, and total soluble solid were gradually increased by contrast with the titratable acidity, and the firmness decreased. The content of four soluble sugars reached the maximum at the 180 days after full bloom (DAFB) stage. Malic acid was measured as the most abundant organic acid in ‘Orin’ apples. Ethyl butyrate, hexyl propanoate, hexyl acetate and butyl acetate belonging to esters with high odor activity values (OAVs) could be responsible for the typical aroma of ‘Orin’ apples. The aim of this work was to provide information on the flavor characteristics of ‘Orin’ apples and promote this apple cultivar for marketing and processing in the future.

Production of Volatile Compounds in Cheese by Pseudomonas fragi Strains of Dairy Origin

2005 ◽  
Vol 68 (7) ◽  
pp. 1399-1407 ◽  
Author(s):  
PILAR MORALES ◽  
ESTRELLA FERNÁNDEZ-GARCÍA ◽  
MANUEL NUÑEZ
Keyword(s):  
Volatile Compounds ◽  
Dimethyl Sulfide ◽  
Outer Part ◽  
Raw Milk ◽  
Ethyl Esters ◽  
Gas Chromatography Mass Spectrometry ◽  
Pseudomonas Fragi ◽  
Ethyl Caproate ◽  
High Degree ◽  
Methyl Thiocyanate

Volatile compounds produced in cheese by five Pseudomonas fragi strains isolated from 1-day-old raw milk cheeses were investigated. Each strain was representative of a different biochemical group of isolates of identical phenotypic characteristics, according to identification with API 20 NE strips. The five strains were ascribed to the species P. fragi after 16S rRNA sequencing because of their high degree of coincidence with P. fragi ATCC 4973. In each of two experiments, carried out on different days, five cheeses were made at laboratory scale from pasteurized milk separately inoculated with approximately 105 CFU/ml of each P. fragi strain. After 12 days at 10°C, mean counts of P. fragi strains were close to 1010 CFU/g in the outer part of cheeses and close to 108 CFU/g in the inner part. A total of 131 volatile compounds, 49 of which were further characterized, were identified in cheeses by gas chromatography–mass spectrometry after extraction with a purge and trap apparatus. Abundances of compounds were generally higher in the outer part of cheeses. Production of volatile compounds was clearly strain dependent. Only two strains produced ethyl esters, and three produced nonethyl esters. Ethyl acetate, ethyl butyrate, ethyl caproate, methyl acetate, isopropyl acetate, and propyl tiglate were the major esters, and ethanol, 2-propanol, and 3-methyl butanol were the major alcohols. Undecene was the major hydrocarbon, dimethyl sulfide and methyl thiocyanate the major sulfur compounds, and 2-pentanone the major ketone. Two aromatic compounds, styrene and o-dichlorobenzene, were present in all cheeses.

scholarly journals Correlation among Metabolic Changes in Tea Plant Camellia sinensis (L.) Shoots, Green Tea Quality and the Application of Cow Manure to Tea Plantation Soils

Molecules ◽  
2021 ◽  
Vol 26 (20) ◽  
pp. 6180
Author(s):  
Litao Sun ◽  
Kai Fan ◽  
Linlin Wang ◽  
Dexin Ma ◽  
Yu Wang ◽  
...  
Keyword(s):  
Amino Acids ◽  
Fatty Acids ◽  
Organic Acids ◽  
Pearson Correlation ◽  
Late Summer ◽  
Quinic Acid ◽  
Tea Plant ◽  
Organic Manure ◽  
Gas Chromatography Mass Spectrometry ◽  
Cow Manure

Traditionally, the supplement of organic manure in tea plantations has been a common approach to improving soil fertility and promoting terroir compounds, as manifested by the coordinated increase in yield and quality for the resulting teas. However, information regarding the effect of organic manure in the metabolome of tea plants is still inadequate. The metabolite profiles of tea shoots applied with cow manure, urea or no fertilizer were studied using gas chromatography–mass spectrometry (GC–MS). In total, 73 metabolites were detected, and the modulated metabolites included mainly amino acids, organic acids and fatty acids. In particular, glutamine, quinic acid and proline accumulated more in tea shoots in soils treated with cow manure, but octadecanoic acid, hexadecanoic acid and eicosanoic acid were drastically reduced. Pearson correlation analysis indicated that organic acids and amino acids in tea shoots were the two major metabolite groups among the three treatments. The analysis of metabolic pathways demonstrated that the cow manure treatment significantly changed the enrichment of pathways related to amino acids, sugars and fatty acids. Sensory evaluation showed that the quality of green teas was higher when the plants used to make the tea were grown in soil treated with cow manure rather than urea during spring and late summer. The results indicated that the application of cow manure in soils changed the metabolic characteristics of tea shoots and improved the qualities of the resulting teas.

scholarly journals Determination of shelf-life using accelerated shelf-life testing (ASLT) method and characterization of the flavour components of freeze-dried durian (Durio zibethinus) products

Food Research ◽  
2021 ◽  
Vol 5 (S2) ◽  
pp. 98-106
Author(s):  
S. Darniadi ◽  
D.D. Handoko ◽  
S. Sunarmani ◽  
S. Widowati
Keyword(s):  
Moisture Content ◽  
Shelf Life ◽  
Volatile Compounds ◽  
Freeze Drying ◽  
Solid Phase ◽  
Gas Chromatography Mass Spectrometry ◽  
Life Testing ◽  
Tropical Fruit ◽  
Durio Zibethinus ◽  
Freeze Dried

Durian is a unique tropical fruit that has a strong smell and distinctive taste. It is a seasonal fruit and has a few days shelf-life. Freeze drying is known for preserving foods while maintaining its original shape and provide excellent rehydrated products. This study aimed to determine the shelf-life of freeze-dried (FD) durian products using the accelerated shelf-life testing (ASLT) method and to assess the flavour changes in fresh and freeze-dried durian products. The parameters used to determine shelf-life were moisture content and L* a* b* colour values of FD durian products for 28 days of storage at 30, 40, and 50oC. Flavour analysis using Solid Phase Microextraction (SPME) and Gas Chromatography-Mass Spectrometry (GCMS) was carried out on fresh durian pulp, FD durian for 30 hrs, and FD durian for 36 hrs. The estimation of shelf-life of FD durian products at storage temperatures of 25 and 30oC, respectively, were based on the following parameters: (1) moisture content: 41 and 37 days, (2) L*(brightness): 467 and 311 days, (3) a* (redness): 144 and 171 days, and (4) b*(yellowness): 43 and 46 days. A total of twenty-four volatile compounds contributed to the flavour of fresh durian fruit and five of them had concentrations of more than 10 ppm. The losses percentage of these five volatile compounds were in a range of 78-95% (FD durian for 30 hrs) and a range of 0- 100% (FD durian for 36 hrs). Freeze-drying technique on durian was able to extend shelflife and preserve flavour compounds.

scholarly journals Sealing effectiveness of different types of closures towards volatile phenols and haloanisoles

OENO One ◽  
2013 ◽  
Vol 47 (2) ◽  
pp. 145 ◽  
Author(s):  
Bruno Pereira ◽  
Paulo Lopes ◽  
Juliana Marques ◽  
Maria Pimenta ◽  
Cátia Alves ◽  
...  
Keyword(s):  
Volatile Compounds ◽  
Solid Phase Microextraction ◽  
Solid Phase ◽  
Gas Chromatography Mass Spectrometry ◽  
Labeled Compounds ◽  
Volatile Phenols ◽  
Effective Barrier ◽  
Different Types ◽  
Practical Information ◽  
Cork Stoppers

<p style="text-align: justify;"><strong>Aim</strong>: To determine if aerial contamination can induce the migration of volatile compounds through wine closures after bottling.</p><p style="text-align: justify;"><strong>Methods and results</strong>: Bottled white wines sealed with cork stoppers (natural and microagglomerate), synthetic closures and screw caps were stored under an environment contaminated with three deuterium-labeled compounds : (d<sub>5</sub>)-2,4,6-trichloroanisole (d<sub>5</sub>-TCA), (d<sub>4</sub>)-4-ethylphenol (d<sub>4</sub>-E4P) and (d<sub>5</sub>)-4-ethylguaiacol (d<sub>5</sub>-E4G). Wines, closure sections (outer, middle and inner) and screw cap liner were assessed over time for the concentration of different compounds by solid phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS). The results collected during 30 months of storage showed that large amounts of all compounds were essentially retained in the outer portion of cylindrical closures, both cork and synthetic. However, these compounds were able to penetrate through synthetics and screw caps and contaminate the wine.</p><p style="text-align: justify;"><strong>Conclusion</strong>: Cork stoppers have proven to be an effective barrier to the migration of aerial volatile compounds such as d<sub>5</sub>-TCA, d<sub>4</sub>-E4P and d<sub>5</sub>-E4G, whereas permeable closures such as synthetic and screwcap saranex did allow the migration of those compounds into bottled wines.</p><p style="text-align: justify;"><strong>Significance and impact of the study</strong>: This study provides practical information about the sealing properties of different closures for a sound decision-making with regard to packaging. To the best of our knowledge, this is the first report of post-bottling aerial contamination via migration of volatile compounds through wine closures.</p>

THE PRODUCTION OF ORGANIC ACIDS IN THE PIG: I. THE EFFECT OF DIET ON THE PROPORTIONS OF VOLATILE FATTY ACIDS IN PIG FECES

1962 ◽  
Vol 42 (1) ◽  
pp. 55-62 ◽  
Author(s):  
D. W. Friend ◽  
J. W. G. Nicholson ◽  
H. M. Cunningham
Keyword(s):  
Fatty Acids ◽  
Acetic Acid ◽  
Organic Acids ◽  
Volatile Fatty Acids ◽  
Statistical Significance ◽  
Valeric Acid ◽  
Crude Fiber ◽  
The Difference ◽  
Diet Level

Experiments were conducted to determine the effect of diet, level of feeding and age and/or weight on the proportions of volatile fatty acids (VFA) in the feces of pigs. Cellulose was added to the control ration fed in one experiment and dried whey or bran to that fed in another experiment. When the level of intake of the cellulose-supplemented ration was reduced, the digestibility of crude fiber in the ration increased. The proportion of fecal acetic acid also increased, but the difference observed did not reach statistical significance at P = 0.05. Differences in the proportion of acetic, butyric and valeric acid due to cellulose supplementation of the control ration were statistically significant (P < 0.05). The whey and the bran-supplemented rations gave statistically significant differences (P < 0.05 or P < 0.01) for the proportions of fecal valeric, propionic or acetic acid. The proportions of fecal VFA appeared to be relatively unaffected by the age and/or weight of pigs from weaning to market weight.

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