Nevzat Artik

Ankara University · Department of Food Engineering

This comprehensive analysis provides a detailed examination of the impacts of climate change on the agricultural sector, offering sustainable solutions with the objective of ensuring global food security. The detrimental impact of climate change on agricultural production, including global warming, significant alterations in precipitation patterns,...

The determination of optimal levels of green tea amount and brewing time would have a crucial role in the accumulation of desired aromatic volatile compounds to meet worldwide market demand. Aroma is the most important factor influencing tea consumers' choices along with taste, price, and brand. This study aims to determine how the brewing time and...

Tea consumers’ choices are primarily influenced by taste, aroma, price, and brand while making tea selections; however, they are less likely to consider the phytochemical content and nutritional benefits of tea. Although studies on the phenolic content of green tea under various extraction conditions have been published, to the best of our knowledg...

Bu çalışmada Ankara ve çevresinde 2000 yılı içerisinde yetiştirilen bazı taze sebze ve meyve örnekleri materyal olarak kullanıldı. Bu örneklere ait nitrat miktarları enzimatik Boehringer Mannheim GmbH metodu ile belirlendi. Nitrat içeriğinin taze sebzelerde 0.00-3019.41 mg/kg, taze meyvelerde ise 0.00-126.19 mg/kg arasında değiştiği saptandı. Nitra...

In this study, it was aimed to use the gypsum extract as an emulsifier in ice cream production. For this purpose, the effect of different ratios of gypsum extract on the steady, dynamic rheological properties and microstructural properties of the ice cream mix was aimed. All of the ice cream mix samples showed non newtonian shear thinning character...

Hazelnut is a very important nutrient in terms of human health. It is widely consumed as natural and roasted. Aromatic components could be used as marker for export criteria in hazelnut. Thus, this study aimed pre-liminary to compare the aroma profile of some hazelnut varieties and to determine the effect of roasting on aroma component in natural h...

In the current study, the Central Composite Design was applied to optimize HS-SPME extraction in order to detect 2,3,5,6 tetramethyl pyrazine in isomalt contaning milk chocolate. The optimal conditions for the three experimental responses influencing SPME efficiency were 10 min, 40 min and 57 °C for equilibration time, extraction time and extractio...

The chapter is composed of antioxidant content of fresh-cut fruits and vegetables, factors affecting antioxidant capacity and preservation of antioxidants in fresh cut produce.

Bu çalışmada Beyaz peynirde farklı starter kültür kullanımının olgunlaşma süresince laktoz değişimi üzerine etkisi araştırılmıştır. Termofilik (Streptococcus thermophilus ve Lactobacillus dellbruecki subsp. bulgaricus) ve mezofilik (Lactococcus lactis subsp. cremoris ve Lactococcus lactis subsp. lactis) kültür kullanılarak üretilen peynirde 90 günl...

Athletes should consume a wide variety of foods that meet their energy needs and provide optimum amounts of carbohydrate, protein, fat, vitamins, minerals and other important food components. Especially, carbohydrates are the most essential nutrient in an athlete’s diet because they are the only fuel that can sustain intense exercise for extended d...

In this study, sugar-free dark chocolate was produced from isomalt and maltitol by β V seeding technique as an alternative to conventional tempering process. The effect of β V seed concentrations on the particle size distribution, textural, rheological and melting properties of the end products was studied, and the results were compared with those...

-In this study, the total phenolic contents (TPC) and phenolic profiles of defatted 17 hazelnuts were investigated. All samples were gathered in harvesting period from Black Sea Region (Ordu and Giresun prefecture) of Turkey. Methanolic extraction was used for taking the phenolics from the hazelnut varieties. The highest TPC was determined in Minca...

The alterations of phenolic compounds and antioxidant capacity of sour grape juice were investigated during the concentration process stages. Phenolics and antioxidant properties of the samples changed more at the vacuum evaporation stage than that of the other stages. After evaporation, the antioxidant capacity of the samples decreased approximate...

Potato (Solanum tuberosum L.) is a widely consumed food in the world.To ensure that potatoes produced the season are consumption throughout during the year, storing in a home environment it is preferred in Turkey.This leads to some nutrient losses in potatoes. Agria, which has been widely produced in Turkey for use in this study and which is prefer...

The potato (Solanum tuberosum L.) is an important food crop worldwide. Potato tubers can be stored to provide continuity of supply between production seasons, but it is important that they be stored under appropriate conditions as incorrect storage will result in deterioration in end user quality and may increase glycoalkaloid levels. We have inves...

In the present study, it was aimed to produce sucrose-free milk chocolate including isomalt or maltitol by βV seeding technique as an alternative to conventional tempering process which was performed by using temper machine (47–27–32 °C). For this aim, conched milk chocolates were melted and crystallized with βV seeds added at different concentrati...

In this study, sugar-free dark chocolate was produced from isomalt and maltitol by βV seeding technique as an alternative to conventional tempering process. The effect of βV seed concentrations on the particle size distribution (PSD), textural, rheological and melting properties of the final products were examined and the results were compared with...

Phenolic compounds obtained from fruits have recently gained a great attention due to their bioactive roles. However, they are sensitive and they can be easily affected by physicochemical factors that create a great challenge to incorporate them into the food products. Hence, this work aimed to investigate microencapsulation of these compounds to p...

Genetically Modified Organisms (GMOs) are plants, animals or microorganisms that have been altered using genetic insertion or deletion via technology (also called genetic engineering or GE). Corn is one of the main inputs of both food and feed production. Also it is a major commodity of which many transgenic varieties are commercially available. In...

Society expects engineers to make technological innovations and changes that are definitely applicable and economical. In today's Turkey, there are 193 universities that provide training in different branches. 109 of these universities are state universities and 5.5 million students in total receive their education from these universities. 50 of th...

Residues and contaminants can be found in foods of animal origin are various, they cancontaminate with lots of ways. Among these, natural (mycotoxins, patogen microorganisms etc.) or chemical toxic compounds and heavy metals [dioxin, DDT (dichlorodiphenyltrichloroethane), PCB’s (polychlorinated biphenyl compounds), lead, cadmium etc.) and veterinar...

In the present study, chocolates were investigated that had been prepared according to the composition specified as a result of this previous work (9.00 % w/w inulin and 34.0 % w/w maltitol) Certain physical (particle size distribution [PSD], brightness, chroma, water activity and hardness) and rheological features of the samples resulting from the...

Alternative sweeteners are food additives, can replace the sugar alone or in combination with each other, each sweetener has its own properties , may be involved with each other in certain characteristics and are selected by the producers depending on the taste , sweetness , stability and cost which are either nutrient or not nutrient alternatives...

Polydextrose, a functional food ingredient, is potentially a prebiotic substance. The rise in diet-related illness has led consumers to take a greater interest in the ingredients of food products. In the present study, in an effort to obtain a prebiotic milk chocolate, the effects of various levels of polydextrose (0, 60, 90 and 120 g/kg) and the u...

Turkiye genelindeki kentli tuketicileri %2.83’luk orneklem hata payi ile yansitacak nitelik ve dizayna sahip olmasi nedeni ile bir ilk olma ozelligine sahip bu calisma yuz-yuze gorusme teknigi kullanilarak hane ve is yerlerinde tabakalandirilmis tesadufi ornekleme yontemi ile belirlenmis tuketicilerin (n=1222) genetik modifikasyon (GM) ve GM gidala...

The effects of various process conditions on the extraction of caffeic acid derivatives (CADs) from the aerial parts of Echinacea purpurea specimens grown in Turkey through supercritical fluid extraction (SFE) and two conventional techniques (ultrasound and shaker) were determined by LC-MS/MS. The concentrations of caftaric acid, cichoric acid, chl...

Tocopherol contents of seven popular walnut varieties grown in Turkey were determined. The effects of storage temperature, oxygen permeability of packaging material and walnut variety on the tocopherol content of vacuum‐packed walnut kernels were also examined during the 12 months of storage. α‐, γ‐ and δ‐tocopherol were identified and quantified i...

The present study, which is a first because it has a quality and design reflecting urbanite consumers across Turkey with a sampling tolerance of 2.83%, was conducted by using face-to-face interview technique with consumers (n=1222) specified through stratified random sampling method layered in homes and offices to determine awareness of genetic mod...

In the present study, the effects of inulin as a prebiotic substance at various levels (PSL) (0, 60, 90 and 120 g/kg) in milk chocolate, as well as the use of varying conching time (CT) (3.50, 4.0 and 4.50 h) and refining conditions (20.0, 25.0 and 28.0 µm as the mean particle size, D[4,3]) in the sample preparation process were examined with respe...

Milk is important because of its composition, its consumption prevalence, and its use as a raw material for many food products. The milk's shelf life, reliability during processing, and quality conservation should be considered by the consumer. However, in Turkey, raw milk is sold unpackaged and untreated (by physical processes or heat treatment) b...

In this study, the effects of storage temperature, O2 permeability of packaging materials and variety on phenolic content and free radical-scavenging activity of vacuum-packaged walnut kernels were studied over a 12 months storage period. Methyl gallate (23.70 . 93.75 mg/kg), ellagic acid (137.95 . 569.22 mg/kg), and an ellagic acid pentoside (270....

Solid–liquid extraction of resveratrol and viniferin from grape cane samples was described by using first-order kinetic model, Peleg's model, two-site kinetic model and modified Gompertz equation. Goodness of fits of the models were evaluated by comparing the adjusted determination coefficient and root mean square error and mean percentage error va...

The present study, which is a first because it has a quality and design reflecting urbanite consumers across Turkey, was conducted by using face-to-face interview technique with consumers specified through random sampling method (n=1222) layered in homes and offices. An investigation was conducted to determine awareness of genetic modification and...

In this study, anthocyanins in three fresh fig varieties (Ficus carica L.) cultivated in Turkey were characterised and quantified by HPLC/DAD and HPLC/MS. In addition, the carotenoid composition of Sarılop and Sarızeybek, yellow fig varieties, was determined, and then the ripening‐ and drying‐related changes in carotenoids and surface colour of fig...

Lycopene, an acyclic, open chain, unsaturated carotenoid having 13 double bonds, of which 11 are conjugated, arranged in a linear array, is considered to be a pigment of potential commercial importance in the emerging market for nutraceutical products because of its function as a health-promoting ingredient. Lycopene has received a great deal of at...

This study performed quantitative identifications of phytoestrogenic compounds, such as free and conjugated isoflavones, lignans, coumestrol and various flavonoids, on six different vegetable samples by a triple quadrupole liquid chromatography-tandem mass spectroscopy (LC-MS/MS) technique following different pretreatments, such as conventional ext...

The effects effects of storage temperature, oxygen permeability of packaging material and variety on oxidative stability of vacuum-packaged walnut kernels were studied over a 12 months storage period. The oxidation experiments applied to two popular walnut varieties (Yalova-1 and Yalova-3) grown in Turkey. The peroxide values and hexanal contents o...

Some widely consumed legumes could potentially be used as alternatives to soy as a source of dietary isoflavones. In this study, 6 legumes (chickpea, red kidney bean, haricot bean, yellow lentil, red lentil and green lentil) were analysed to determine their contents for 10 different isoflavones (both free and conjugated). Methanolic extracts obtain...

Estrogen is a hormone, which is produced in ovary and testis; however, it has many biological effects besides the reproductive system. Phytoestrogens are the compounds, which have estrogen-like structure and activities, taking place in structure of various edible plants at different levels and in different compositions. These compounds attracted no...

ZET Domates ve ürünlerinde en önemli kalite kriterlerinden biri, ürünün küf yüküdür. Domates ve ürünlerinde küf yükü; Howard küf sayım (HMC) metoduna göre yapılmaktadır. Küf yükü, son ürünün hijyenik koşullarda üretilip üretilmediğini göstermesi açısından önemlidir. Küf yükünün maksimum sınırı ülkeden ülkeye değişmekle birlikte % 40-60 (pozitif ala...

In this research, traditional Turkish delight (lokum) was colored with black carrot juice concentrate, and the variations in anthocyanin content, during storage at different temperatures (12, 20 and 30C) for 5‐month periods, were observed by spectrophotometer and high‐performance liquid chromatography. Analysis of kinetic data suggested a first‐ord...

ZET Solanacea familyasının bir cinsi olan kırmızıbiberlerin kapsaisinoit miktarı, önemli bir kalite kriteri olduğu gibi birçok ülkede sınıflandırmada dikkate alınmaktadır. Kapsaisinoitler içersinde en önemli acılık maddesi kapsaisindir (% 69). Diğerleri ise dihidrokapsaisin (% 22), nordihidrokapsaisin (% 7), homokapsaisin (% 1) ve homodihidrokapsai...

Health claims that characterize the relationship between a substance (e.g., a food or food component) and a disease (e.g., cancer or cardiovascular disease) or health-related condition (e.g., hypertension) require premarket approval by organizations as the Turkey Agriculture and Rural Affairs Ministry, Europena Food Safety Authority (EFSA), the US...

In this study, the effects of storage temperature (10, 20, and 37°C) and time (0, 2, 4, and 6 months) on the HMF and color values in strawberry, cherry and apricot jams were studied. Results showed that the HMF and total color difference (ΔE) values of all jams were increased linearly with storage time and higher values were found at higher storage...

Twelve hazelnut cultivars taken from Bolu-Akçakoca, West Black Sea Region of Turkey, were evaluated in terms of bioactive properties such as fat and fatty acid composition, protein and amino acid, water-soluble and water-insoluble vitamins, ash and mineral content at 2 consecutive years. Considerable differences were observed among cultivars for al...

The total saponin content, components and fatty acid composition of 14 different Tahini Halvah samples were investigated. Total saponin was determined by HPLC. The quantities of moisture, oil, protein, ash, total sugar and brix were determined with various methods. The fatty acid composition was determined by GC. Moisture, oil, protein, ash, total...

To evaluate the current nationwide iodine status in Turkey by determining urinary iodine concentrations (UIC) and household salt iodine content. A follow- up monitoring study was also conducted in 30 urban areas. A school-based survey was conducted in 2007 by using multistage 'proportionate to population size' (PPS) cluster sampling method. The stu...

Interest in ellagitannins and ellagic acid has increased over the past few years due to its properties as a micronutrient. Ellagitannins are complex plant polyphenols composed of hexahydroxydiphenoyl moieties esterified to a sugar. Fruits (especially berries and nuts) are rich sources of ellagitannins and ellagic acid, a hydrolytic product of ellag...

Trans-resveratrol and trans-ε-viniferin were extracted from milled grape canes using pressurized low-polarity water. The effects of temperature were significant for both compounds (p ≤ 0.05): extraction at 160°C resulted in a 40% loss of trans-resveratrol compared to 95°C while reduction of trans-ε-viniferin at both temperatures remained at 30%. In...

Thermal degradation of ergosterol in tomato paste serum was studied at different pH (4.5, 4.3, 3.9, 3.7 and 3.5,) and heating periods (0, 10, 20, 30 and 50min) over the temperature range of 70 to 95 °C. Analysis of kinetic data suggested a first-order reaction for the degradation of ergosterol with the half-lives of 301.4–36.7, 239.0–33.7, 203.9–29...

In this study, total phenolic contents and antioxidant activities of grape seed extracts obtained from twelve different grape seeds from common varieties grown in Turkey were determined. Grape seeds were extracted with 70% acetone and extraction yield of grape seed were calculated. The total phenolic content of grape seed extracts were determined b...

The effect of activated charcoals (0, 0.5, 1.0, 2.0 and 3.0 g/L of powdered and granular activated charcoals) on the content of several water-soluble vitamins in apple juice was studied. Apple juice samples with activated carbon added were mixed for 0 (control), 5, 10, 20, and 30 min, respectively. The content of water-soluble vitamins was analyzed...

Etude des modifications dans les proprietes rheologiques d'un gel de globuline, a 20 degres C et 4 degres C en fonction du temps de chauffage. Les relations entre les proprietes rheologiques et la structure fine du gel et les liaisons intermoleculaires a l'interieur du gel sont discutees

In this study, chemical composition of the 17 different hazelnut varieties grown in the Black Sea Region of Turkey was investigated. The main fatty acids in hazelnut varieties were oleic (79.4%), linoleic (13.0%) and palmitic acid (5.4%). The ratios of polyunsaturated/saturated and unsaturated/saturated fatty acids of hazelnuts varieties were found...

The major flavan-3-ols composition and antioxidant activity of the seeds of 12 different common grape varieties that grow in Turkey were investigated. The quantities of gallic acid, catechin, epicatechin and total flavan-3-ol were determined with high performance liquid chromatography (HPLC) and spectrophotometric method in grape seeds extracts. Ga...

The seasonal changes of total carbohydrates, fructose, glucose and sucrose of the bark tissues of 'Tombul', 'Palaz', 'Kalinkara', 'Çakildak' and 'Sivri' cvs. grown in East (Düzce) and West Black Sea regions (Giresun) were determined by HPLC. Similar to other fruit species, fructose, glucose and sucrose levels decreased from the end of spring to sum...

In this research the major pungent components of chilli peppers, namely capsaicin, dihydrocapsaicin and nordihydrocapsaicin, were determined by high-performance liquid chromatography. Chilli pepper varieties Maraş, Süs, Cin and Isot were collected from different regions (Maraş and Urfa) of Turkey. Capsaicin, dihydrocapsaicin and nordihydrocapsaicin...

The poor precision of the "percentage of discarded fruits" and "Howard mold count" methods has increased the importance of ergosterol for the microbiological quality evaluation of tomato and tomato products. Ergosterol, a constituent of the cell wall of some important vegetable parasites, such as molds, has been recently recognized as a potential o...

There is a need to develop a chemical method to determine the amount of decayed tomatoes used to produce tomato products. Tomato pulp samples produced from surface decayed tomatoes as sound, 30, 60 and 100% were tested for pH, brix, titrable acidity, Hunter L, a and b, Howard Mold Count (HMC) and ergosterol values. Tomato pomace for each decay port...

Glucose and fructose as sugar sources were added to raisin concentrate called Pekmez in Turkey at the ratio of 10–25% and 50% w/w, to simulate adulteration in order to develop a statistical regression model. Sugar composition was analyzed with standard enzymatic methods and mineral matters were determined with atomic absorption spectrophotometry. A...