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    Analysis of Coffee
    (CRC Press, 2023) Güçlü, Gamze; Oussou, Kouame Fulbert; Kelebek, Haşim; Selli, Serkan
    The aroma and taste, which make up the flavor, are undoubtedly the most important aspects of coffee quality and its acceptance by coffee drinkers. Increasing demand for coffee and its products together with consumer preference in coffee brewing and flavor has oriented significant research interest in food research centers to fully understand its aroma and odorant composition and complexity. The complication of coffee flavor arises from the physical and chemical composition of genotypes, cultivation practices, growing location, processing, roasting, and brewing technique. The volatile substances that influence the coffee flavor and impact consumer acceptance remain challenging to characterize and elucidate. The composition of non-volatiles, volatiles, and aroma-active compounds associated with coffee flavor has been fully investigated before. However, the analytical methods employed and the challenges associated with the volatile substances of coffee and its products and the recent trends in advanced instrumental methods to mitigate the errors in these analyses need to be evaluated in detail. The selection of volatile recovery methods and their optimization coupled with gas chromatography and data analysis is crucial to untangle an understanding of complex coffee datasets, especially the flavor and quality of coffee and its products. This chapter reviews the benefits of cutting-edge analytical techniques applied to the coffee aroma and taste components from cultivation to preparation, volatile extraction, identification, quantification, and data analysis using chemometric concepts. © 2024 selection and editorial matter, Leo M. L. Nollet and Matteo Bordiga; individual chapters, the contributors.
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    Antioxidant activity in olive oils
    (Elsevier, 2020) Güçlü, Gamze; Kelebek, Haşim; Selli, Serkan
    Olive oils can serve as an excellent source of valuable bioactive compounds. The current chapter presents a brief overview of the antioxidant properties present in a wide range of olive oils, including the role of bioactive compounds. There is an increasing demand for the consumption of olive oil in the world due to its health benefits and impacts on cardiovascular diseases, diabetes, most types of cancer, inflammation, and metabolic diseases. The antioxidant properties are mainly correlated to the health-promoting components of olive oil such as phenolic compounds, tocopherols, squalenes, pigments, and sterols. These components make olive oil one of the most important, healthy edible oils worldwide. Therefore the consumption of olive oil, especially the virgin form, can be recommended not only because of its antioxidative character but also due to other important positive effects from its bioactive compounds on human health. © 2021 Elsevier Inc.
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    Application of Molecularly Imprinted Polymers for the Detection of Volatile and Off-Odor Compounds in Food Matrices
    (Amer Chemical Soc, 2022) Cengiz, Nurten; Güçlü, Gamze; Kelebek, Haşim; Capanoglu, Esra; Selli, Serkan
    Molecularly imprinted polymers (MIPs) are synthetic receptors having specific cavities intended for a template molecule with a retention mechanism that depends on molecular recognition of the targeted constituent. They were initially established for the detection of minor molecules including drugs, pesticides, or pollutants. One of the most remarkable areas where MIPs have potential utilization is in food analysis, especially in terms of volatile compounds which are found in very low concentrations in foods but play a crucial role for consumer preference and acceptance. In recent years, these polymers have been used extensively for sensing volatile organic and off-odor compounds in terms of food quality for selective high-extraction purposes. This review first summarizes the basic principles and production processes of MIPs. Second, their recent applications in the separation, identification, and quantification of volatile and off-odor compounds in food samples are elucidated.
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    Aroma-active compounds, sensory profile, and phenolic composition of Fondillon
    (Elsevier Sci Ltd, 2020) Issa-Issa, Hanan; Güçlü, Gamze; Noguera-Artiaga, Luis; Lopez-Lluch, David; Poveda, Rafael; Kelebek, Haşim; Selli, Serkan
    The Fondillon is a wine made from overripe grapes of the Monastrell variety, which is characterized by a high alcohol content and a minimum barrel ageing of 10 years. The objective of this study was to analyze the Fondillon volatile composition, key aroma-active compounds, sensory profile and phenolic composition. Fifty-four volatile compounds were identified, quantified and classified as alcohols, esters, acids, aldehydes, lactones, phenols, hydrocarbons and ketone. From these compounds, 22 aroma-active compounds were identified, with phenylethyl alcohol, diethyl succinate and ethyl lactate having the highest flavor dilution factor. The Fondillon wines were characterized by having high intensity of alcohol, fruity and toasted odor and flavor notes, and long aftertaste. Besides, 25 phenolic compounds were also identified and quantified; the phenolic acids (gallic, protocatechuic and syringic acids) were the predominant phenolic compounds.
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    Biochemistry, antioxidant, and antimicrobial properties of hazelnut (Corylus avellana L.) oil
    (Elsevier, 2022) Selli, Serkan; Güçlü, Gamze; Sevindik, Onur; Kelebek, Haşim
    Hazelnut (Corylusavellana L.) is a very important shelled nut in Turkey as well as in Italy, Azerbaijan, and the USA. It is one of the most widely used nuts worldwide due to its nutritional and taste properties. Because of its health-beneficial properties, it has been designated as a functional food. Hazelnut oil comprises well-proportioned aroma, fatty acid, phenolic, and antioxidant profile are responsible for the protection against detrimental elements particularly the free radicals. This chapter gives an outline of the scientific works available on the biochemical (fatty acids, aroma, key odorants, phenolics), antioxidant and antimicrobial properties of hazelnut oil. Owing to its unique health-beneficial, nutritional, and bioactive properties, hazelnut oil has recently found its place on the vastly competitive global edible oil market. © 2022 Elsevier Inc. All rights reserved.
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    Characterization of aroma and aroma-active compounds of black carrot ( Daucus carota L. ssp. sativus var. atrorubens Alef.) pomace by aroma extract dilution analysis
    (Cell Press, 2024) Buyukkurt, Özlem Kılıç; Güçlü, Gamze; Sevindik, Onur; Kelebek, Haşim; Kelebek, Pinar Kadiroglu; Selli, Serkan
    The aim of this study was to characterize the aroma and aroma-active compounds of black carrot pomace, a valuable by-product of black carrot juice industry. Aroma compounds were analyzed using GC-MS-O and extracted via the SAFE technique. The extract samples were determined to represent the odor of black carrot pomace quite well according to the results of the representative test. Accordingly, the aromatic extract scored 77.7 mm for intensity and 87 mm for similarity on a 100 mm unstructured scale. A total of 47 volatile constituents were identified and quantified including terpenes (20), alcohols (11), acids (7), esters (4), ketones (4), and lactone (1). It was observed that terpenes were the major aroma group. The use of aroma extract dilution analysis (AEDA) revealed only 29 of these compounds as aroma-active constituents. Phenylethyl alcohol (FD:512, OAV: 2488, rose) and phenylethyl acetate (FD:256, OAV:280, rose) were the aroma substances providing the strongest rose odor. Following these compounds, acetic acid (vinegar), dimethyl-propanedioic acid (pungent), (E)-beta-caryophyllene (salty cheese) and elemicin (spicy) were identified as other strong aroma-actives with FD values of 128 contributing to the characteristic odor of the black carrot pomace samples. The odor activity values (OAVs) ranged from 1 to 2488. The highest OAVs represent the high aromatic active compounds (FD >= 128). The distinctive aroma and rich color of black carrot pomace make it a recommended choice for enhancing flavor and adding natural coloring to food products.
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    Characterization of aroma and phenolic composition of carrot (Daucus carota 'Nantes') powders obtained from intermittent microwave drying using GC-MS and LC-MS/MS
    (Elsevier, 2020) Keser, Duygu; Güçlü, Gamze; Kelebek, Haşim; Keskin, Muharrem; Soysal, Yurtsever; Sekerli, Yunus Emre; Arslan, Aysel
    Carrot is an important food in human nutrition. The effects of different microwave (MW) powers on the aroma, phenolic and antioxidant properties of MW-dried and powdered carrot samples were investigated. Fresh carrot samples (Daucus ca rota 'Nantes') were dried using seven different MW power levels of 150, 200, 250, 300, 350, 400 and 450 W (0.50, 0.67, 0.83, 1.00, 1.17, 1.33 and 1.50 W/g, respectively). The aroma compounds of the carrot samples were extracted by purge and trap method and determined by gas chromatography-mass spectrometry (GC MS). In fresh samples, terpenes were identified as the dominant aroma group and a significant reduction was found in the amount of these compounds depending on the applied MW power level. Terpinolene, (E)-gamma-bisabolene, elemicin and myristicin were identified as dominant terpenes. In the dried samples, aldehydes, furans, alcohols, acids and pyrazines were determined as major components depending on the applied MW power levels. Hexanal, 3-methyl-butanal, acetic acid and hexanoic acid were dominant in the dried samples. For the determination of the phenolic compounds, the method of liquid chromatography coupled with tandem mass spectrometry (LC MS/MS) was employed. As a result of the analysis, a total of seven phenolic compounds, two of which were more dominant (3-caffeoylquinic acid and di-caffeic acid derivative) were identified. The total phenolic content of the carrot samples dried with lower MW power level of 150 and 200 W (0.50 and 0.67 W/g) was found to be relatively better preserved. When both aroma and phenolic compounds were evaluated, it was observed that they were better preserved in the carrot samples dried with low MW power levels (150 and 200W). (C) 2019 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.
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    Characterization of aroma-active compounds and stable carbon isotope ratios in Turkish pine honeys from two different regions
    (Wiley, 2021) Selli, Serkan; Güçlü, Gamze; Sevindik, Onur; Yetisen, Mehmet; Kelebek, Haşim
    Turkey and Greece are the foremost countries in pine honey production, owing their reputation for this distinction to the natural distribution of pine (Pinus brutia and Pinus halepensis) trees found there. The aim of this study was to determine the effects of geographic differences on the aroma, aroma-active compounds, and other related properties of pine honey. Solvent-assisted flavor evaporation was applied to isolate aroma compounds in the pine honey samples. Aroma extract dilution analysis was used to screen the aroma-active compounds within the pine honey, using gas chromatography-mass spectrometry-olfactometry. Pine honey from the Marmaris region of Turkey had a total volatile concentration of twofold of that found in Turkey's Bolu region's honey. Phenylacetaldehyde, exhibiting a honey and caramel odor note, was the most important aroma-active compound found in both pine honey samples. Along with aroma-active compounds, carbon isotope values, the textural, and color properties of the pine honeys were determined and compared in this study. Practical applications Pine honey, especially in Turkey and Greece, has gained growing interest from both producers and consumers. Until recently, there has been a lack of information about its aroma-active compounds and some physicochemical characteristics. Therefore, this study focused on determining the aroma-active compounds, carbon isotope values, and textural properties of pine honey obtained from two different regions of Turkey. The results of this analysis showed that there are obvious differences in the types and content levels of volatile and aroma-active components found in the pine honey samples, depending on the region from which the honey was obtained. In addition, the carbon isotope ratio is a crucial parameter needed to identify and distinguish between the distinct honeys.
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    Characterization of Aroma-Active Compounds in Seed Extract of Black Cumin (Nigella sativa L.) by Aroma Extract Dilution Analysis
    (Mdpi, 2018) Kesen, Songul; Amanpour, Armin; Sarhir, Salwa Tsouli; Sevindik, Onur; Güçlü, Gamze; Kelebek, Haşim; Selli, Serkan
    Turkish Nigella sativa L. seed extracts were used to detect the aroma and key odorant compounds of the spice using gas chromatography-mass spectrometry-olfactometry (GC-MS-O). Volatile compounds were extracted by the purge and trap extraction (PTE) method. A total of 32 volatile compounds consisting of different chemical classes acids (13), alcohols (7), phenols (3), terpene (1), esters (2), ketones (2), aldehyde (1), lactone (1) and hydrocarbons (2) were determined. The amounts of volatile compounds were found to be 21,544 mu g kg(-1). The application of aroma extract dilution analysis (AEDA) revealed the presence of 13 odor-active compounds alcohols (2), carboxylic acids (4), phenols (2), terpene (1), ketone (1), hydrocarbon (1) and unknown compounds (2) in Nigella sativa L. extract. Flavor dilution (FD) factors of key odorants ranged between 4 and 1024, while odor activity values (OAV) were in the range of 1.0 to 170.8. Acetoin was the only aroma-active ketone detected in Nigella sativa L. seed extracts. It had the strongest aroma (FD = 1024) and provided a buttery odor. This compound represented the most abundant compound of overall aroma profile with a concentration of 9394 mu g kg(-1), followed by isobutanoic acid (FD = 512 with a concentration of 218 mu g kg(-1)) and contributed a powerful aroma and a cheesy characteristic odor.
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    Characterization of key aroma compounds in fresh and roasted terebinth fruits using aroma extract dilution analysis and GC-MS-Olfactometry
    (Elsevier, 2019) Amanpour, Armin; Güçlü, Gamze; Kelebek, Haşim; Selli, Serkan
    Aroma, key aroma compounds, and their odor activity values of fresh and roasted P. terebinthus fruits were studied. Aroma compounds were extracted by the solvent-assisted flavor evaporation technique and analyzed by GC-MS-Olfactometry for the first time. A total of 64 different aroma compounds were detected (57 in fresh and 62 in roasted samples), including terpenes (34), acids (8), aldehydes (4), ketones (4), pyrazines (5), alcohols (5), pyrrole (1), furan (1), lactone (1) and ester (1). Terpenes were the predominant group followed by acids. Aroma profiles of both samples were quite analogous. Nonetheless, pinocarvone and dodecanoic acid were detected only in fresh fruits, while pyrazine class, 5-methylfurfural and gamma-butyrolactone were emerged only in roasted fruits. Aroma extract dilution analysis (AEDA) was applied for the first time and revealed 31 key aroma compounds. Among them, the most powerful key aroma compounds with the greatest FD factors were alpha-pinene and beta-myrcene.
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    Characterization of phenolic compounds in sweet lime (Citrus limetta) peel and freshly squeezed juices by LC-DAD-ESI-MS/MS and their antioxidant activity
    (Springer, 2019) Buyukkurt, Özlem Kılıç; Güçlü, Gamze; Kelebek, Haşim; Selli, Serkan
    Sweet lime (Citrus limetta) is one of the citrus species and it is generally consumed fresh or processed to fruit juice. The squeezing method of fruit is an important factor affecting the quantity and composition of phenolic compounds of the juice. The aim of this study was to identify and quantify the phenolic compounds and determine the antioxidant activities of sweet lime peel and juices. For this purpose, sweet lime juices were prepared using two different methods. Firstly, sweet lime fruits were hand-squeezed without peeling. Secondly, fruits were hand-squeezed after the manual removal of the peel. The phenolic compounds of the peel and the two types of juices were analyzed by LC-DAD-ESI-MS/MS. Twenty phenolic compounds were determined in all extracts, 18 of which were flavonoids and two were phenolic acids. The major compound was hesperidin both in the peel and juices. The procyanidin B dimer and luteolin were detected for the first time in sweet lime peel and juices in the present study. The amount of phenolic compounds of the peel was significantly higher than those of the juices. The total phenolic contents of the sweet lime juice increased about 13% from 444.55 to 502.54 mg/L due to the effect of the peel. The antioxidant capacity of the peel was found to be higher than those of the juices resulting from its high phenolic content.
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    Characterization of volatile compounds in the water samples from rainbow trout aquaculture ponds eliciting off-odors: understanding locational and seasonal effects
    (Springer, 2024) Cengiz, Nurten; Güçlü, Gamze; Kelebek, Haşim; Mazi, Hidayet; Selli, Serkan
    The quality of water used in aquaculture ponds is one of the crucial factors influencing the smell and sensory properties of fish. The water samples were taken from the rainbow trout fish ponds from three different fish farms in three provinces in Türkiye in four different seasons. The samples were analyzed for the volatile components by employing HS-SPME/GC–MS. Seven different volatile groups including aldehydes, ketones, esters, alcohols, volatile phenols, terpenes and other aromatic substances were identified in the samples. Among these, aldehydes were found to be the most dominant. (E)-2-Heptenal, nonanal, acetophenone, and 2-ethyl-1-hexanol are thought to be responsible for the off-odors in the water that have the potential to cause off-odors in fish. It was also determined that the amounts of these compounds increases in winter due to lower water temperature. Fish producers should monitor water quality on a regular basis to prevent off-odor compounds that degrade fish quality. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2024.
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    Comparative assessment of volatile and phenolic profiles of fresh black carrot (Daucus carota L.) and powders prepared by three drying methods
    (Elsevier, 2021) Keskin, Muharrem; Güçlü, Gamze; Sekerli, Yunus Emre; Soysal, Yurtsever; Selli, Serkan; Kelebek, Haşim
    Drying is a common method in the post-harvest processing of fruits and vegetables and it can play a crucial role on the quality of the final product. This work examined the influence of three drying processes (freeze-drying: FD, intermittent microwave drying: IMWD and hot air convective drying: HACD) on the aroma and phenolic constituents of black carrot which is an essential vegetable in terms of its nutritive and health benefits. It was found that the drying process had substantial effects on the aroma and phenolic compositions of the black carrot powder samples. GC-MS analysis revealed a total of 32 volatiles in all samples. The FD samples had more numbers of aroma compounds after the fresh samples. Prevailing aroma groups were terpenes and alcohols. The highest amount of volatiles was found in the FD samples meaning that the FD played a crucial role in conserving the volatiles as compared to the HACD and IMWD. HPLC-DAD-ESI-MS/MS analysis yielded 34 constituents including 22 colorless phenolics and 12 anthocyanins. Regarding the phenolics, the highest amount was quantified in the HACD and IMWD samples. Chlorogenic acids were the major phenolic acids. The FD and IMWD caused a decline in the amount of anthocyanins while HACD resulted in an increase. Sensory analysis revealed that the FD method conserved the aroma to a greater extent and its overall acceptability was higher.
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    Comparative Elucidation of Aroma, Key Odorants, and Fatty Acid Profiles of Ivorian Shea Butter Prepared by Three Different Extraction Methods
    (Mdpi, 2022) Oussou, Kouame Fulbert; Güçlü, Gamze; Sevindik, Onur; Starowicz, Malgorzata; Kelebek, Haşim; Selli, Serkan
    In the present study, the volatile compounds, key odorants, and fatty acid profiles of Ivorian shea butter produced by cold press extraction (CPE), solvent extraction (SE) and traditional extraction (TE) methods were investigated for the first time. The aroma compounds of shea butter were extracted by the purge and trap method and analyzed by the gas chromatography-mass spectrometry and olfactometry (GC-MS/O) technique. Totals of 51, 49 and 46 aroma compounds were determined in samples from CPE, SE and TE, respectively. It was observed that the volatile compounds of studied material dominated after CPE, in which alcohols (11) were the most abundant chemical group, followed by aldehydes (10) and acids (7). The application of aroma extract dilution analysis (AEDA) resulted in 22, 20, and 16 key odorants in shea butter from CPE, SE and TE, respectively. 3-Hexanol with flavor dilution (FD) factors (2048 in CPS, 1024 in SE and 64 in TE) was found to be the most active aroma compound in all samples. In the fatty acid fraction obtained using the gas chromatography-flame ionization detector (GC-FID) method, 22, 24 and 19 fatty acids were detected in samples after CPE, SE and TE, respectively. The highest number of fatty acids was determined in shea butter using CPE (89.98%). Stearic and oleic acids were the most dominant fatty acids, and all samples of shea butter were rich sources of saturated fatty acids (SFAs). Moreover, the SE samples showed the highest values of DPPH (238.36 mu M TEq/kg) and ABTS (534.96 mu M TEq/kg), while the CPE samples had the highest total phenolic content (104.64 mg GAE/kg). Principal component analysis (PCA) clearly indicated that the extraction technique could quantitatively or qualitatively induce changes. Thus, this investigation demonstrated that extraction methods have a considerable impact on the quality and chemical composition of the presented material.
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    Comparative elucidation of colour, volatile and phenolic profiles of black carrot (Daucus carota L.) pomace and powders prepared by five different drying methods
    (Elsevier Ltd, 2022) Polat, Suleyman; Güçlü, Gamze; Kelebek, Haşim; Keskin, Muharrem; Selli, Serkan
    Black carrot pomace is a juice industry by-product that can be easily spoiled due to its high moisture content and usually considered as waste; however, it is a valuable product with high amount of bioactive compounds that can be recovered for further application in several industrial fields. Drying is an effective method for the preservation of this product. Thus, the influence of five drying methods (FD: freeze drying, MWD: microwave drying, CD: convective drying, VCD: vacuum/convective drying, CHD: conductive hydro drying) on colour, phenolics and volatiles of pomace were investigated. Findings revealed that drying process decreased the amount of anthocyanins, colourless phenolics and volatile compounds. CHD resulted in similar colour quality and yielded a better preservation of colour and phenolics while FD provided dried sample with an aroma quality similar to fresh sample. The shorter duration of the CHD makes it a better choice. © 2021 Elsevier Ltd
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    Comparative elucidation of phenolic compounds in Albanian olive oils using LC-DAD-ESI-MS/MS
    (Taylor & Francis Inc, 2020) Topi, Dritan; Güçlü, Gamze; Kelebek, Haşim; Selli, Serkan
    Olive oils may provide health benefits, including the prevention of coronary heart diseases, cancers, and the modification of immune and inflammatory responses. These benefits mainly originate from the phenolic compounds found in olive oil. There has been no study on the advanced characterization of Albanian olive oils from various cultivars regarding phenolic compounds. Hence, a comprehensive characterization of phenolic compounds is carried out in Albanian monocultivar virgin olive oils from five different cultivars, including Kalinjot, Bardhi Tirana, Ulliri-i-Zi Tirana, Krips Kruja, and Bardhi Kruja for the first time. Liquid chromatography coupled to diode array detection and electrospray ionization tandem mass spectrometry (LC-DAD-ESI-MS/MS) is employed for the determination of phenolic compounds. In total, 18 compounds were identified in all samples, including phenolic alcohols, phenolic acids, secoiridoids, flavonoids, and phenolic aldehydes. Significant quantitative differences were detected among the cultivars, with the highest concentrations detected in virgin olive oil (VOO) from cv. Ulli-i-Zi. Secoiridoids were found in abundance, in general, followed by phenolic alcohols, and in this group, 3,4-DHPEA-EDA and p-HPEA-EDA stood out as dominant compounds, especially in Kalinjot virgin olive oils. Regarding phenolic alcohols, 3,4-DHPEA-AC was determined as the main phenolic compound. Phenolic profiles were found to be significantly different among the olive oil samples of different cultivars. Principal component analyses (PCA) displayed the differentiation of samples in terms of phenolic compounds.
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    Comparative elucidation on the phenolic fingerprint, sugars and antioxidant activity of white, orange and purple-fleshed sweet potatoes (Ipomoea batatas L.) as affected by different cooking methods
    (Cell Press, 2023) Güçlü, Gamze; Dagli, Mumine Melike; Aksay, Ozge; Keskin, Muharrem; Kelebek, Haşim; Selli, Serkan
    In this study, three cooking methods (baking, boiling, sous vide (SV)) were applied to Turkish sweet potatoes with three flesh colors (white, orange, purple) to examine the effects of the product color and cooking methods on the total phenolics, antioxidant activity, sugars, phenolic acids, and anthocyanins. LC-MS-MS was employed in the characterization of these compounds. It was observed that the product color and cooking method significantly affected the concentrations of bioactive compounds like polyphenols. Both the highest total phenolic content (11.36 mg/g) and antioxidant activity (DPPH (50.3 & mu;M TE/g) and ABTS (63.53 & mu;M TE/g)) were determined in the purple sweet potato cooked with the SV method. 10 phenolic acids were quantified in all samples which were in the highest amounts in the orange colored samples followed by the purple samples. Baking resulted in the highest total phenolic acids in all samples. 13 anthocyanins were detected in the purple-colored samples, while the SV cooking best preserved the anthocyanins. In sum, purple sweet potatoes cooked by SV are recommended for higher phenolic contents, antioxidant capacity and anthocyanins.
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    Comparison of phenolic profile and some physicochemical properties of Uzun pistachios as influenced by different harvest period
    (Wiley, 2020) Kelebek, Haşim; Sönmezdağ, Ahmet S.; Güçlü, Gamze; Cengiz, Nurten; Uzlasir, Turkan; Kadiroglu, Pinar; Selli, Serkan
    Pistachios, which are among the top 50 healthiest foods, are rich in antioxidants and are a major source of phenolic compounds known for their related antioxidant benefits. The ripening stage is of paramount importance for food processing since the chemical composition of this fruit is heavily influenced by its level of maturity. For instance, immature pistachios are preferred to be used in desserts, sauces, ice-creams, and chocolate, while mature pistachios are more often consumed as a roasted snack. In this study, the changes in color properties, fatty acids, phenolic compounds, and antioxidant activity at four different maturity periods of the Turkish Uzun pistachio variety were investigated. A total of 13 phenolic compounds were identified and characterized by LC-DAD-ESI/MSn, with a total amount varying between 136 and 210 mg/kg. Catechin, daidzin, and genistin accounted for the highest amount of the total phenolics. The phenolic compounds and antioxidant capacities of the pistachios decreased as the maturation period extended and these two parameters displayed a linear correlation. With regard to fatty acids, Oleic acid had the highest concentration in all the samples, followed by Linoleic and Palmitic acids. The oil yield and fatty acids of pistachio also increased as maturation periods extended in the samples. Practical applications Pistachios have a high nutritional value and many health benefits, with their rich content of phenolic compounds and fatty acids. The ripening period could lead to differences in phenolic compounds and other bioactive properties. The findings of this research could be helpful to determine the optimal maturity index of the pistachios for their usage in specific foods. Thus, it may lead to a decrease in production costs, with use of the most expensive ingredients becoming more efficient.
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    Decoding the Changes of Volatiles and Key Odorants of Fresh Garlic and Black Garlic Produced with Different Parameters by GC-MS-Olfactometry
    (Amer Chemical Soc, 2024) Sasmaz, Hatice Kubra; Güçlü, Gamze; Sevindik, Onur; Selli, Serkan; Kelebek, Haşim
    The effects of production parameters on aroma compounds were elucidated by conducting a detailed comparison between fresh and black garlic samples, providing new insights that contribute to the existing body of literature on aroma compound analysis in garlic. A total of 113 aroma compounds were identified including sulfur compounds, aldehydes, ketones, pyrazines, furans, thiophenes, volatile alcohols, and acids. The aroma profile of the black garlic samples varied depending on factors such as temperature, humidity, and fermentation duration. The black garlic sample with the highest aroma quantity was the one produced at the lowest temperature, humidity, and duration. Additionally, a total of 34 aroma-active compounds that create the characteristic odor of fresh and black garlic samples were determined by GC-MS-O and aroma extract dilution analysis (AEDA). The fresh garlic sample contained allyl methyl disulfide and diallyl disulfide, which are responsible for the characteristic garlic odor, while in the black garlic samples, furfuryl alcohol was found to be the most dominant aroma-active compound. The findings of this study will help better elucidate the impacts of production process parameters on the aroma and aroma-active profiles of black garlic.
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    Determination of Volatiles by Odor Activity Value and Phenolics of cv. Ayvalik Early-Harvest Olive Oil
    (Mdpi, 2016) Güçlü, Gamze; Sevindik, Onur; Kelebek, Haşim; Selli, Serkan
    Ayvalik is an important olive cultivar producing high quality oils in Turkey. In the present study, volatile and phenolic compositions of early-harvest extra virgin olive oil (cv. Ayvalik) were determined. The solvent-assisted flavor evaporation (SAFE) technique was used for the extraction of volatile components. The aromatic extract obtained by SAFE was representative of the olive oil odor. A total of 32 aroma compounds, including alcohols, aldehydes, terpenes, esters, and an acid, were identified in the olive oil. Aldehydes and alcohols were qualitatively and quantitatively the most dominant volatiles in the oil sample. Of these, six volatile components presented odor activity values (OAVs) greater than one, with (Z)-3-hexenal (green), hexanal (green-sweet) and nonanal (fatty-pungent) being those with the highest OAVs in olive oil. A total of 14 phenolic compounds were identified and quantified by liquid chromatography combined with a diode array detector and ion spray mass spectrometry. The major phenolic compounds were found as 3,4-DHPEA-EDA, 3,4-DHPEA-EA and p-HPEA-EDA.