Ahmet Salih Sonmezdag

Characterization of the Aroma-Active, Phenolic, and Lipid Profiles of the Pistachio (Pistacia vera L.) Nut as Affected by the Single and Double Roasting Process

The pistachio (Pistacia vera L.) nut is one of the most widely consumed edible nuts in the world. However, it is the roasting process that makes the pistachio commercially viable and valuable as it serves as the key step to improving the nuts hallmark sensory characteristics including flavor, color, and texture. Consequently, the present study explores the effects of the single-roasting and double-roasting process on the pistachios chemical composition, specifically aroma-active compounds, polyphenols, and lipids. Results showed the total polyphenol content of increased with the roasting treatment; however, not all phenolic compounds demonstrated this behavior. With regard to the aroma and aroma-active compounds, the results indicated that roasting process results in the development of characteristics and pleasant aroma of pistachio samples due to the Maillard reaction. With regard to lipids, the pistachio roasting treatment reduced the concentration of CN38 diacylglycerides while increasing the amount of elaidic acid.

Characterization of aroma-active and phenolic profiles of wild thyme (Thymus serpyllum) by GC-MS-Olfactometry and LC-ESI-MS/MS

The present study was designed to characterize the volatile, aroma-active and phenolic compounds of wild thyme. Volatile components of T. serpyllum were extracted by use of the purge and trap technique with dichloromethane and analyzed by gas chromatography–mass spectrometry (GC-MS). The extraction method gave highly representative aromatic extract of the studied sample based on the sensory analysis. A total of 24 compounds were identified and quantified in Thymus serpyllum. Terpenes were qualitatively and quantitatively the most dominant volatiles in the sample. Aroma extract dilution analysis (AEDA) was used for the first time for the determination of aroma-active compounds of Thymus serpyllum. In total, 12 aroma-active compounds were detected in the aromatic extract by GC-MS-Olfactometry and terpenes were the most abundant compounds. High-performance liquid chromatography/electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) method was used for the phenolic compounds analysis. 18 phenolic compounds were identified and quantified in the T. serpyllum. Luteolin 7-O-glucoside, luteolin and rosmarinic acid were the most abundant phenolics in this herb.

Characterization and comparative evaluation of volatile, phenolic and antioxidant properties of pistachio (Pistacia vera L.) hull

Abstract Pistachio hull is a good source of natural phenolics and antioxidants. Thanks to these bioactive molecules, the use of pistachio hull as nutritional ingredients in foods has attracted the interest of the food industry. In this study, phenolic compounds, antioxidant capacity, total phenol content, and volatile compounds were measured in the hull of two cultivars of pistachio, Uzun and Ohadi. LC-ESI-MS/MS method was used for the phenolic compounds analysis; 11 compounds were identified and quantified in the samples in which the major phenolic compound was gallic acid. The aroma composition of the pistachio hulls was isolated by SAFE (solvent-assisted flavor evaporation) method with dichloromethane and analyzed by GC–MS. Aroma compounds, including terpenes, acids, alcohols, phenols, and benzenes, were identified in both types of hulls, numbering 22 in the Uzun variety and 20 in the Ohadi. A significant linear correlation was confirmed between total phenolic compounds and antioxidant activity of hull extracts.

Identification of Aroma Compounds of Lamiaceae Species in Turkey Using the Purge and Trap Technique

The present research was planned to characterize the aroma composition of important members of the Lamiaceae family such as Salvia officinalis, Lavandula angustifolia and Mentha asiatica. Aroma components of the S. officinalis, L. angustifolia and M. asiatica were extracted with the purge and trap technique with dichloromethane and analyzed with the gas chromatography–mass spectrometry (GC–MS) technique. A total of 23, 33 and 33 aroma compounds were detected in Salvia officinalis, Lavandula angustifolia and Mentha asiatica, respectively including, acids, alcohols, aldehydes, esters, hydrocarbons and terpenes. Terpene compounds were both qualitatively and quantitatively the major chemical group among the identified aroma compounds, followed by esters. The main terpene compounds were 1,8-cineole, sabinene and linalool in Salvia officinalis, Lavandula angustifolia and Mentha asiatica, respectively. Among esters, linalyl acetate was the only and most important ester compound which was detected in all samples.

Pistachio oil (Pistacia vera L. cv. Uzun): characterization of key odorants in a representative aromatic extract by GC-MS-olfactometry and phenolic profile by LC-ESI-MS/MS

Volatile, aroma-active, and phenolic compounds of pistachio oil obtained from cv. Uzun were investigated in the current study. To obtain a representative aromatic extract, three of the most widely used extraction methods were compared using a representative test; the solvent-assisted flavour extraction (SAFE) aromatic extract from pistachio oil was found to be the most representative. A total of 50 aroma compounds were determined in pistachio oil and it was found that terpenes, aldehydes, and alcohols were the most abundant volatile compounds. Applying GC-MS-olfactometry and aroma extract dilution analysis (AEDA) resulted in a total of 14 aroma-active areas being detected in the extract of pistachio oil. In the phenolic fraction obtained by the LC-ESI-MS/MS method, a total of 12 phenolic compounds was found in the pistachio oil, of which seven compounds were reported for the first time. Eriodictyol-7-O-glucoside and protocatechuic acid were the most dominant phenolic compounds.

GC-MS olfactometric and LC-DAD-ESI-MS/MS characterization of key odorants and phenolic compounds in black dry-salted olives: Characterization of odorants and phenolic compounds in black olives

BACKGROUND Olives are processed in different ways depending on consumption habits, which vary between countries. Different de-bittering methods affect the aroma and aroma-active compounds of table olives. This study focused on analyzing the aroma and aroma-active compounds of black dry-salted olives using gas chromatography-mass spectrometry-olfactometry (GC-MS-O) techniques. RESULTS Thirty-nine volatile compounds which they have a total concentration of 29 459 µg kg-1 , were determined. Aroma extract dilution analysis (AEDA) was used to determine key aroma compounds of table olives. Based on the flavor dilution (FD) factor, the most powerful aroma-active compounds in the sample were methyl-2-methyl butyrate (tropical, sweet; FD: 512) and (Z)-3-hexenol (green, flowery; FD: 256). Phenolic compounds in table olives were also analyzed by LC-DAD-ESI-MS/MS. A total of 20 main phenolic compounds were identified and the highest content of phenolic compound was luteolin-7-glucoside (306 mg kg-1 ), followed by verbascoside (271 mg kg-1 ), oleuropein (231 mg kg-1 ), and hydroxytyrosol (3,4-DHPEA) (221 mg kg-1 ). CONCLUSION Alcohols, carboxylic acids, and lactones were qualitatively and quantitatively the dominant volatiles in black dry-salted olives. Results indicated that esters and alcohols were the major aroma-active compounds.

Volatile and key odourant compounds of Turkish Berberis crataegina fruit using GC-MS-Olfactometry

Abstract This research was conducted to identify the aroma and aroma-active compounds of Berberis crataegina for the first time. Volatile profile of B. crataegina was obtained using the purge and trap extraction method with dichloromethane. Gas chromatography was coupled to mass spectrometry (GC–MS) allowed the quantitative and qualitative detection of 22 compounds in the sample. Aldehydes were the main chemical group in the sample and followed by aromatic alcohols and lactone. Aroma extract dilution analysis was implemented for the specification of key odourants of B. crataegina. In total, eight key odourants were detected in the extract of the sample, using GC–MS–Olfactometry and aldehydes were the leading chemical group. The key odourants, found to be contributing to the overall aroma in B. crataegina, were nonanal (FD = 1024; green, flowery), hexanal (FD = 512; green) and linalool (FD = 256; flowery, rose) because of high FD factors.

Characterization of the key aroma compounds in tomato pastes as affected by hot and cold break process

The popular flavor of tomato and its products are primarily due to a complex mixture of acids, sugars, amino acids, minerals, and volatile compounds. Within this mixture, the aroma of tomato and its products is an important attribute that greatly influences consumer acceptability and preference. In the present study, tomato and its two types of pastes, produced from hot and cold break methods, were subject to sensory profiling, aroma, and aroma-active compounds analysis. The key aroma compounds in tomato and its two types of pastes were characterized by application of direct solvent extraction with dichloromethane/solvent assisted flavor evaporation (SAFE), gas chromatography–mass spectrometry–olfactometry (GC–MS–O) technique and aroma extract dilution analysis (AEDA). Fresh tomato and its paste volatiles were composed of alcohols, aldehydes, lactones, carboxylic acids, ketones, furans, esters, volatile phenols, 13-C norisoprenoid, terpene, and pyrrols. Via AEDA application, a total of 21 and 13 key odorants were detected in tomato and its pastes, respectively. In tomato pastes, lower numbers of aroma-active compounds than in fresh tomato were determined. The most important difference of aroma-active compounds in tomato and its pastes was hexanal, (Z)-3-hexenal, 2,3-butanediol, (Z)-3-hexenol, (E)-2-octenal, benzaldehyde, (E,Z)-2,6-nonadienal, methyl salicylate, β-ionone, 5-penthyl-2-(5H)-furanone and eugenol was not detected in tomato paste samples. On the basis of flavor dilution (FD) factors obtained by AEDA, the most powerful aroma-active compounds were (Z)-3-hexenal (FD = 512; green-grassy), 4-methyl-(5H)-furan-2-one (FD = 512; fruity), β-ionone (FD = 512; floral-violet) in tomato; 6-methyl-5-hepten-2-one (FD = 1024; green-leafy) in cold break tomato paste and furfural (FD = 512; pungent) in hot break tomato paste. In the sensory analysis, the tomato paste produced with the cold processing method was more acclaimed in terms of color, smell, taste and fruity aroma than the paste produced via the hot processing method.

Characterization of bioactive and volatile profiles of thyme ( Thymus vulgaris L.) teas as affected by infusion times

The influence of different infusion times on phenolic, volatile, antioxidant, and colour properties of thyme (Thymus vulgaris L.) teas was investigated in the present study. The thyme teas were prepared using freshly boiled water at infusion times of 0, 2, and 5 min. The effect of infusion time on phenolics, volatiles, and antioxidant properties was clearly observed. Among the phenolic compounds identified in the samples by LC–MS–MS, luteolin-diglucuronide-glucuronide and protocatechuic acid-hexoside were identified for the first time ever in thyme teas, with the most dominant phenolic compound in all samples subsequently being luteolin-diglucuronide-glucuronide. A significant correlation between the phenolic compounds and antioxidant properties demonstrates that phenolic compounds affected the antioxidant potential of the thyme tea infusions. A total of 27 volatile compounds were identified and quantified in the samples. The main chemical group of the volatile compounds in the thyme teas was terpenes and represented almost 90% of the total volatiles in thyme teas. Among the terpenes, thymol (61.74–78.82%), p-cymene (8.92–17.90%) and carvacrol (4.41–5.62%) being the most abundant volatiles in all the teas. Results obtained by sensory evaluation indicate that taste panelists preferred thyme tea prepared at a 0-min infusion time.