scholarly journals Volatile compounds in medlar fruit (Mespilus germanica L.) at two ripening stages

2013 ◽  
Vol 67 (3) ◽  
pp. 437-441 ◽  
Author(s):  
Milovan Velickovic ◽  
Dragan Radivojevic ◽  
Cedo Oparnica ◽  
Ninoslav Nikicevic ◽  
Marijana Zivkovic ◽  
...  

Medlar is the fruit of Mespilus germanica L. in the family of Rosaceae. The fruit can be eaten only if ?bletted? (softened by frost or longer storage). The effect of the maturation stages on the volatile compounds of the medlar fruit was investigated during two different stages. Volatile flavour substances were isolated from the minced pulp of unripe and full ripe medlar fruits by simultaneous steam distillation extraction (SDE) with methilen chloride as the extracting solvent. The concentrate was analysed by GC-FID-MS. Hexanoic and hexadecanoic acids were the predominant acids, hexanal and (E)-2-hexenal were the predominant aldehydes, (Z)-3-hexenol and hexanol were the predominant alcohols, with p-cymene, terpinen-4-ol, and ?-terpiene (the terpenes responsible for the characteristic medlar flavour) being also present. The C6 aliphatic compounds, such as hexanal and (E)-2-hexenal, were observed as the major volatile constituents in the green stage. In contrast, hexanol and (Z)-3-hexenol were the main volatiles in ripe fruits.

2019 ◽  
Vol 11 (1) ◽  
pp. 1-10
Author(s):  
Olawale Paul Olatidoye ◽  
Taofik Akinyemi Shittu ◽  
Samuel Olusegun Awonorin ◽  
Emmanuel Sunday Akin Ajisegiri

The use of inappropriate temperature-time combinations during the roasting of nuts could lead to quality defects, such as burnt taste, short shelf-life, rancidity, and poor flavour. In this study, cashew kernels were roasted in a forced airflow-drying oven for 20, 40,and 60 min at 100, 120, 140, and 160°C. The productswere evaluated for volatile flavour compounds and the sensory evaluation of the roasted cashew kernelsat different roasting conditions. The volatile fraction was isolated using the combined steam distillation–extraction procedure and identified by gas chromatography–flame-ionization detection (GC-FID). The consumer acceptability test was carried out by 100 panellists using nine point hedonic scales to assess preferences for like or dislike, colour, taste, texture, flavour,and overall acceptability. It was found that there were significant differences in flavour compounds between the different conditions of roasting. Twenty-nine volatile compounds were identified in both fresh and roasted cashew kernelscomprising five main classes,which consist of 12 hydrocarbons, eight aldehydes, four ketones, three alcohols,and one acid. The volatile compounds(mg/100g) ranged from 5.03x10-2to 1.20 (2-butanone), 7.46x10-6to 1.85 (hexanal), 8.91x10-6to 1.94 (acetone), 6.74x10-1to 2.24 (benzaldehyde). The amount of generated volatile compounds increased astheroasting temperature and time increased. The consumer acceptability test revealed that samples roasted for 40 or 60 min at 140°C produced the most acceptable product in terms of all the measured attributes. The study showed that the roasting conditions produced acceptable cashew kernelsof desirable colour and superior flavour quality that enhance direct and commercial utilization.


Author(s):  
I. GIOGIOS ◽  
N. KALOGEROPOULOS ◽  
K. GRIGORAKIS

The volatile compounds of highly commercialised fresh Mediterranean seafood species, including seven fish (sand-smelt Atherina boyeri, picarel Spicara smaris, hake Merluccius merluccius, pilchard Sardina pilchardus, bogue Boobps boops, anchovy Engraulis encrasicolus and striped-mullet Mullus barbatus), squid (Loligo vulgaris), shrimp (Parapenaeus longirostris) and mussel (Mytilus galloprovincialis), were evaluated by simultaneous steam distillation-extraction and subsequent GC-MS analysis. A total of 298 volatile compounds were detected. The mussels contained the highest total concentration of volatile compounds, while pilchard among fish species contained the highest number and concentrations of volatile compounds. Individual patterns of volatile compounds have been distinguished. The fish species when compared to the shellfish species studied, contained 6 to 30 times more 1-penten-3-ol, higher quantities of 2-ethylfuran, and 2,3-pentanedione, which was absent from the shellfish species. Pilchard is characterized by a high concentration of alcohols, shrimps by the high presence of amines and S-compounds, while mussels by high amounts of aldehydes, furans, and N-containing compounds (pyridine, pyrazines and pyrrols). The fatty acid-originating carbonyl compounds in fish seem to be related to the species’ fat content.


2013 ◽  
Vol 14 (2) ◽  
pp. 343 ◽  
Author(s):  
I. GIOGIOS ◽  
N KALOGEROPOULOS ◽  
K. GRIGORAKIS

The volatile compounds of highly commercialised fresh Mediterranean seafood species, including seven fish (sand-smelt Atherina boyeri, picarel Spicara smaris, hake Merluccius merluccius, pilchard Sardina pilchardus, bogue Boobps boops, anchovy Engraulis encrasicolus and striped-mullet Mullus barbatus), squid (Loligo vulgaris), shrimp (Parapenaeus longirostris) and mussel (Mytilus galloprovincialis), were evaluated by simultaneous steam distillation-extraction and subsequent GC-MS analysis. A total of 298 volatile compounds were detected. The mussels contained the highest total concentration of volatile compounds, while pilchard among fish species contained the highest number and concentrations of volatile compounds. Individual patterns of volatile compounds have been distinguished. The fish species when compared to the shellfish species studied, contained 6 to 30 times more 1-penten-3-ol, higher quantities of 2-ethylfuran, and 2,3-pentanedione, which was absent from the shellfish species. Pilchard is characterized by a high concentration of alcohols, shrimps by the high presence of amines and S-compounds, while mussels by high amounts of aldehydes, furans, and N-containing compounds (pyridine, pyrazines and pyrrols). The fatty acid-originating carbonyl compounds in fish seem to be related to the species’ fat content.


1985 ◽  
Vol 50 (10) ◽  
pp. 2115-2121 ◽  
Author(s):  
Václav Janda ◽  
Bohuslav Doležal

The phase equilibrium establishing in a microapparatus designed for the isolation and concentration of organic substances from water by continuous steam distillation-extraction is treated. This technique, used for the preconcentration of water pollutants followed by the gas chromatographic analysis of the extract, is suitable for organic substances with boiling temperatures higher than that of water which form azeotropic mixtures with water, the boiling temperatures of which are lower than those of water and the organic substances themselves. The organic solvent used for the extraction must have a very low boiling temperature. The recovery from the whole procedure and the concentration factor depend on the volumes of the water sample and the organic solvent as well as on the volume of the space where the extraction of the organic substance from the aqueous condensate takes place.


2013 ◽  
Vol 634-638 ◽  
pp. 1049-1053
Author(s):  
Hui Lin Cao ◽  
Shuang Ran Liang ◽  
Yang Tian ◽  
Zhi Ling Chen ◽  
Jian Ping Chao

Microwave-assisted steam extraction system combines the advantages of both conventional and modern technologies. MAE is probably going to be the leading technology in essential oil producing industry. In our research, one-factor and uniform experimental designs are used to determine the optimum extraction conditions, and the results are as follows: the extraction yield is measured as 2.30% with 3h of reflux time, when degree of pulverization is 90, immersing time is 3h, yield of solid to liquid equals 12: 1 ml/g. The chemicals in the production were examined by GC-MS. More than 40 kinds of chemicals were detected, which is consistent with that of the traditional steam extraction method. However, the extraction efficiency is dramatically increased when the steam extraction is assisted with microwave heating, and it is up to 3.8 times.


2009 ◽  
Vol 92 (3) ◽  
pp. 855-861 ◽  
Author(s):  
Tao Zhou ◽  
Bei Yang ◽  
Haiying Zhang ◽  
Yingjia Yu ◽  
Bin Chen ◽  
...  

Abstract Microwave distillation with concomitant solid-phase microextraction (MD-SPME) coupled with GC/MS was developed for identifying volatile compounds in the dried flowers of Chrysanthemum morifolium (CM). Different experimental parameters, including SPME fiber coating, microwave power, irradiation time, and water volume were optimized. The best results were obtained using carboxen/polydimethylsiloxane fiber with microwave irradiation at 400 W for 3 min and the addition of 1 mL water into 1.0 g sample. The proposed method allowed the isolation, extraction, and concentration of volatile compounds to be completed in a single step. This MD-SPME-GC/MS method has also been compared to the conventional steam distillation method followed by GC/MS for this identification. Thirty-two volatile compounds were identified using the newly developed MD-SPME-GC/MS process. Relative standard deviation values of <9.8 demonstrate good repeatability. In comparison, 27 compounds were identified by traditional steam distillation-GC/MS. Therefore, the proposed MD-SPME-GC/MS method is simple, rapid, and efficient for identifying volatile compounds in CM.


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