The possibility of fipronil pesticide electrochemical determination assisted by cobalt (III) oxyhydroxide was determined
in this study. The redox pair CoO(OH)/CoO2 was used in this process. The correspondent mathematical model was
developed and analyzed by means of linear stability theory and bifurcation analysis. It was shown that the
oxyhydroxide may be applied as an efficient electrode modifier in the detection of fipronil in neutral and lightly alkaline
media. Electrochemical response was clear and easy to interpret. The possibility of oscillatory and monotonic
instabilities was also verified.
Bacillus sphaericus is a biopesticide that is highly effective for the control of mosquitos under harsh conditions such
as polluted areas and UV light. In addition to its bioactivity, it produces proteases. In this present study, the
composition of media comprising corn steep liquor (CSL) and molasses was optimised using response surface
methodology (RSM) with a central composite design (CCD). Four different scenarios were arranged involving sole
biopesticide and protease optimization (Scenarios 1 and 2), biopesticide optimization with protease as a by-product
(Scenario 3) and protease optimization with biopesticide as a by-product (Scenario 4). The optimization of the
simultaneous production of biopesticide and protease was not satisfactory to obtain large amounts of both products;
however, when the production aim was a sole production with a by-product, optimal working conditions could be
achieved. Also, according to industrial view, Scenario 1 is the only possible process for large scale systems.
Extraction yield and product quality of olive oil depend on various factors, particularly fruit’s maturity and processing
methods. In this present study, kneading process was optimized by response surface methodology in terms of oil yield
and quality parameters. As a sample, olive fruits were used at two different maturity stages (purple versus black
stages). Prediction of response was proposed with a full quadratic second order regression equation, and regression
parameters were checked for each model in order to evaluate model’s adequacy. Proposed models for yield and
some quality parameters of olive oil were good enough for a successful prediction of experimental results. Oil yield
was maximized as free acidity and peroxide value were controlled under the specified corresponding values for “extra
virgin olive oil”. Optimal kneading conditions for oil production were at 30°C for 45 min for purple fruits and 28°C for 55
min for black counterparts.
The aim of this study was to determine physicochemical and microbiological properties of sucuk produced with
different heat treatment temperatures. The effect of heat treatment at 60 (for 15 minutes), 65 (for 10 minutes) and
70°C (as reached) on chemical (pH, moisture, fat, protein, salt, ash, free fatty acidity, thiobarbituric acid reactive
substances, residual nitrite, nitrosomyoglobin, total pigments, nitrosomyoglobin conversion ratio), physical (L*, a*, b*,
nitrozation, discolorization), microbiological (total mesophilic aerobic bacterial counts, Staphylococcus and
Micrococcus counts and lactic acid bacteria counts) and sensory quality characteristics of heat treated sucuk were
investigated. Results were compared with traditional sucuk samples produced under commercial conditions. Heattreated sucuks were fermented for 3 days and traditional ones were fermented for 9 days under controlled conditions.
Significant differences in physicochemical and sensory properties of produced sucuks were observed during
production. The overall quality attributes of traditional sucuk were different in comparison to heat treated sucuks.
Decreases in residual nitrite, nitrosomyoglobin and total pigment amounts in heat treatment process were determined.
Nitrosopigment transformation ratio increased; however, in terms of physicochemical, microbiological and sensory
properties, heat treatment at 60°C for 15 minutes resulted in sucuk samples with better acceptability.
High performance liquid chromatography (HPLC) system was used to determine phenolic contents of dietetic tea
samples (n=10) marketed in Turkey. The most abundant phenolic compounds were gallic acid (ND–6.98 mg/100 g
dw), protocatechuic acid (0.98–45.61 mg/100 g dw), 4-hydroxybenzoic acid (ND–31.56 mg/100 g dw), chlorogenic
acid (ND–0.73 mg/100 g dw), caffeic acid (11.27–154.55 mg/100 g dw), p-coumaric acid (ND–6.56 mg/100 g dw),
ferulic acid (ND–1.13 mg/100 g dw), ellagic acid (0.10–1.76 mg/100 g dw), epicatechin (7.59–290.07 mg/100 g dw),
rutin (ND–49.95 mg/100 g dw) and quercetin (1.15–10.50 mg/100 g dw). Based on the results of this study, sensitivity
and accuracy were good. Calibration curves had a good linearity for all compounds (r2>0.999). The quantitation limit
ranged 0.010 to 0.050 µg/g in dietetic tea products. Recoveries were in the range of 86.45-97.35%. Results had good
accuracy and reproducibility.
Key Words:Phenolic compound, Dietetic tea, HPLC.
7
Karbon Fiber Destekli Kabin Kurutucuda Farklı Sıcaklıklarda Elma Dilimlerinin Kurutulmasının İncelenmesi: Kurutma Karakteristikleri ve
Performans Değerlendirmesi
Investigation of Drying of Apple Slices in Carbon Fiber Assisted Cabin Dryer at Different Temperatures: Drying Characteristics and Performance Evaluation
Drying behaviour of apple slices in carbon fiber assisted cabin dryer (CFACD) was investigated, and performance
evaluation of the process was conducted. The compatibilities of fourteen different thin layer drying models to the
experimental data were examined. The highest corrected coefficient of determination, the lowest reduced chi-square
and the lowest root mean square error were chosen as the model compatibility criterion. "Diffusion approach" model
was determined as best model describing the drying behavior. Effective diffusion coefficient (Deff) was found between
2.06x10-10 and 4.56x10-10 m2/s. For the temperature between 60-80°C, energy efficiency was in the range of 10.51-
13.12% while exergy efficiency values were between 9.44-11.64%. The specific moisture removal rate of apple slices
in KFKK was found as 4.44*10-5±0.00, 4.85*10-5±0.00, 5.63*10-5±0.00 kg removed water/kJ for the drying
temperatures of 60, 70 and 80°C, respectively.
In this study, the physicochemical and microbiological characteristics of kefir produced from homogenized milk at four
different pressures (15, 15/5, 30 and 30/5 MPa) in single-stage or two-stages were determined. Kefirs were stored at
4°C for 30 days. Dry matter, ash, fat and protein contents of samples were determined on the first day of storage
while pH, titratable acidity and rheological and microbiological properties of samples were determined on the 1st, 15th and 30th days of storage. Moreover, particle sizes were determined in milk homogenized at different pressures. With
an increase in the homogenization pressure and stage, the D[4,3] (µm) and D[3,2] (µm) values of milk samples
increased while their specific surface area values decreased. At the end of the storage period, pH, viscosity,
thixotropy and consistency coefficient values, lactobacilli, lactococci, total mesophilic aerobic bacteria and yeast
counts decreased in kefir samples. The highest viscosity, thixotropy and consistency coefficient values were
determined in samples produced at 15 MPa in a single-stage, and the highest counts of lactobacillus, lactococcus and
yeast were in samples produced with non-homogenized milk.
Key Words:Particle size, Homogenization, Kefir.
9
Organik ve Konvansiyonel Fındıkların (Corylus avellana L.) Bazı Fiziksel Özellikleri
Some Physical Properties of Organic and Conventional Hazelnuts (Corylus avellana L.)
In recent years, the relationship between nutrition and health has been clearly presented in the light of scientific
studies. Recently, consumers have been demanding for healthier foods; therefore, organic (ecological) agriculture and
organic food applications have emerged to meet this demand. Organic hazelnut production has limited and its
agriculture tends to increase gradually in recent years. In this study, various pomological analyses were carried out on
samples belonging to Tombul, Foşa, Sivri, Çakıldak, Mincane and Palaz varieties of commercial importance grown in
the Black Sea Region of Turkey (Trabzon, Ordu, Samsun and Düzce cities) where organic and conventional hazelnut
production was located. Results indicated that conventional samples had higher values in terms of nut width, kernel
length, kernel width, kernel thickness, nut weight, kernel weight and shell thickness values. There was no difference in
nut length, nut thickness, internal cavity, kernel percentage, good kernels and the rate of defected kernel between two
types of hazelnuts.
With the increasing trend of consumers towards healthier products in order to be able to live a better life, the demand
for functional foods is also increasing day by day. When functional food groups consumed in various countries are
considered, milk and dairy products are usually at the top of the list, and accordingly, the number of studies aiming to
give functional properties to milk and dairy products are also quite high. Among these products, ice cream is also
important because its nutritional value is high and the composition is one of the milk products that can be modified
most easily. When studies on functionalization of ice cream are reviewed, it is seen that various researches have
been carried out on enhancing the product more probiotic and prebiotics, whey, dietary fibers, omega-3 fatty acids
and minerals enrichment, reducing fat and / or sugar content and increasing antioxidant capacity. The amount of ice
cream consumed per capita in Turkey is increasing gradually, and this shows that the work to be done on functional
ice cream will also be intensified. In this study, researches on the production of functional ice cream were reviewed.
Key Words:Functional food, Ice cream, Health.
11
Peynir Üretimi İçin Sütü Pıhtılaştıran Enzimlere Genel Bir Bakış ve Güncel Gelişmeler
An Overview of Milk-Coagulating Enzymes in Cheese Production and Recent Developments
Enzymes obtained from different sources and made ready for further use, which also coagulate caseins, are called
milk coagulant enzyme, cheese rennet or rennet. For thousands of years, rennet (in general rennin/chymosin) from
the abomasus section in stomachs of young ruminants animals has been obtained, and it has been used as milk
coagulant in cheese making. As cheese production and consumption in the world have been increasing gradually, the
steady declining supply of calf rennet has accelerated the acquisition of enzymes that can be used in place of
alternative sources of calf rennet, and the search for highly efficient production methods has become compulsory.
Studies on alternative sources for calf rennet are categorized as (i) the coagulants obtained from herbal sources
(herbal rennet), (ii) the rennet source, the microbial cheese rennets consisting of proteolytic enzymes and obtained
directly from microorganisms (microbial rennet), (iii) the transfer of genetic material responsible for rennin enzyme
production to certain microorganisms, (recombinant chymosin), which is composed of enzymes identical to the renin
enzyme that it produces. Recombinant chymosin is rapidly becoming a subject of research together with developing
gene technology. In this review, the effects of animal, plant and microbial origin enzymes/cheese rennets on milk
clotting and cheese ripening stages are discussed.
The presence of microorganisms, which we share our bodies, has been known for years. The human body is a
structure that hosts both its own genome and genome belonging to a group of microbes that live together. However,
changes in our lifestyle and new molecular compounds we encounter cause various effects on microorganisms.
Recent studies also indicate that these groups of microorganisms have more serious impact on human health than
expected. Enlightening this structure and interaction between them will obviously make important contributions on
microbiome’s impact on human health and even in determining the treatment of diseases.
Aroma, which has a great influence on consumer preferences and economic value, has an important place in the food
industry. These volatile and sensitive valuable components can be encapsulated with shells or matrices of coating
materials such as monomers or polymers. The encapsulation of aroma components, which are usually liquid at room
temperatures, can provide advantages such as protection from environmental factors and increased shelf life when
the product is in a powder form. Techniques such as spray drying, spray cooling, extrusion, freeze drying,
coacervation and molecular inclusion are used in the encapsulation of aroma components. In this study, studies on
the encapsulation of aroma components with various technologies used in the food industry are reviewed.
Pesticides commonly used worldwide are chemicals used as agricultural, industrial, domestic and war materials.
Although pesticides are very strongly associated with many health problems, there is a serious lack of monitoring and
identification of these pollutants. Conventional chromatographic methods such as high performance liquid
chromatography, capillary electrophoresis and mass spectrometry are effective methods for pesticide analysis in foods.
However, these methods have considerable limitations in terms of complex processes, time-consuming preparatory
steps, expensive equipment and expert staff requirements. Biosensors are preferred devices for the determination of
pesticides because of their simplicity, high sensitivity, short analysis time and low analysis cost, as well as their
applicability to real time measurements. For more than fifteen years, biosensors based on enzyme inhibition have been
developed to monitor pesticide residues for food control and safety. Conductive polymers have been used during
constructions of these pesticide biosensors. In this study, studies on biosensors used for pesticide analyses were
summarized and then researches on acetylcholinesterase inhibition based biosensors developed by using conducting
polymers for pesticide analyses were reviewed.
Turkey, especially Southeastern Anatolian Region, has an important place in the world ranking as well as an
economic value in terms of pistachio production. Pistachios, which are from nuts with hard shells, have positive
effects on health. Pistachios have rich nutritional content in terms of protein, fat and fatty acids, fiber, vitamins and
minerals. As a rich source of phenolic compounds, pistachios take attention with a high antioxidant activity. Various
researchers have reported that pistachio consumption may have beneficial effects on hypertension, cancer, diabetes
and cardiovascular diseases. In this present study, the place and the importance of pistachios in human nutrition and
health are reviewed.