Sürdürülebilir Kalkınma Amaçları
Yayınlar
- Derleme MakaleAçık Erişim2026Postbiotics in Dairy: A Comprehensive Review of Applications and Health Impacts
Kaya, Yasemin; Aktaş, Haktan; Meral-Aktaş, Hacer; Ürkek, Bayram; Gürbüz-Kaçan, Zeynep; Çiftçi, Esengül; Erkaya-Kotan, Tuba; Şengül, Mustafa; Çetin, Bülent
Purpose of Review: This review aims to provide a comprehensive overview of postbiotics—defined as non-viable microbial cells, cell components, and microbial metabolites—and their emerging role in dairy products. It focuses on their functional, technological, and health-promoting properties in various dairy matrices, including yoghurt, cheese, kefir, fermented milk, and ice cream. Additionally, the review highlights the potential of postbiotics as stable and safe alternatives to probiotics in the development of functional dairy foods. Recent Findings: Recent evidence demonstrates that postbiotics such as exopolysaccharides (EPS), bacteriocins, short-chain fatty acids (SCFAs), bioactive peptides, and organic acids significantly enhance both the nutritional value and technological quality of dairy products. These compounds have been shown to improve texture, sensory attributes, shelf life, and microbial safety while exerting biological activities, including antimicrobial, antioxidant, immunomodulatory, and gut health–promoting effects. Compared with probiotics, postbiotics offer greater stability during processing and storage as well as reduced safety concerns, particularly for vulnerable populations. Summary: Postbiotics represent a promising strategy for advancing functional and sustainable dairy products by combining health benefits with technological improvements. Their applications in functional food formulation, biopreservation, and bioactive compound delivery are rapidly expanding. However, challenges remain regarding standardised production processes, accurate quantification of bioactive components, and clinical validation of health claims. Future research should focus on optimising postbiotic production and strengthening evidence for their physiological effects to support their broader incorporation into next-generation dairy products.
- MakaleAçık Erişim2026Effect of sloe berry (Prunus spinosa L.) powder addition on physicochemical, rheological, antioxidant, and sensory properties of stirred yoghurt: a multivariate approach
Yeniçeri, Esra; Ürkek, Bayram; Şengül, Mustafa
In this study, stirred yogurt was produced using sloe berry powder at different ratios (0, 2, 4, 6, and 8%) and stored for 21 days. The effect of sloe berry powder addition on physicochemical properties was limited, whereas the effect of storage period was more pronounced. Lactic cocci and lactic bacilli counts ranged between 7.78–8.93 log CFU/g and 6.19–9.13 log CFU/g, respectively. Yeast and mold were detected in all samples after 14 days of storage. All color parameters were significantly affected by sloe berry powder addition (p <.001), whereas storage period had no significant effect (p >.05). Total phenolic content and antioxidant capacity increased with increasing levels of sloe berry powder. Only the potassium (K) content was affected by the addition of sloe berry powder. Viscosity and consistency values increased in yogurts containing 6% and 8% sloe berry powder on days 14 and 21 of storage. Sensory scores decreased in all samples at the end of storage. Principal component and correlation analyses indicated that the addition of sloe berry powder and storage period exerted distinct effects on the evaluated parameters. Overall, sloe berry powder can be considered a promising ingredient for the development of nutritional and functional stirred yogurt.
- MakaleAçık Erişim2026Potentially Toxic Metal Levels in Cheeses Produced in Türkiye: Regional Variation, Milk Source, Ripening Stage, Production Type, and Associated Dietary Exposure and Health Risk
Gürmeriç, Hüseyin Ender; Şengül, Mustafa; Basaran, Burhan
This study investigated potentially toxic metal (PTM) levels in cheeses produced in different regions of Türkiye and evaluated the associated dietary exposure and non-carcinogenic health risk. A total of 84 cheese samples were collected from seven geographical regions and classified according to milk source, ripening stage, and production type. After microwave-assisted acid digestion, PTM levels were quantified by inductively coupled plasma mass spectrometry (ICP-MS), and exposure and non-carcinogenic risk were evaluated using Estimated Daily Intake (EDI), Target Hazard Quotient (THQ), and Hazard Index (HI). Aluminium (Al), iron (Fe), and zinc (Zn) ranged from <0.00215 to 7.29,<0.00769 to 38.8, and 0.68 to 56.6 mg/kg wet weight, respectively, whereas chromium (Cr), nickel (Ni), copper (Cu), selenium (Se), cadmium (Cd), and lead (Pb) ranged from <0.58 to 244, <1.26 to 369, <1.88 to 4067, <0.91 to 1378, <0.06 to 12.3, and <2.19 to 1754 µg/kg wet weight, respectively. Values marked with “<” represent concentrations below the limit of quantification (LOQ). Arsenic (As) was not detected in any sample. Significant differences were observed for selected PTMs according to ripening stage, milk source, production type, and region (p<0.05). The toxicological contribution (TC) values for nutritional PTM exposure were low. THQ and HI values remained below 1, suggesting a low overall non-carcinogenic risk; however, Pb exceedances in some samples indicate the need for continued PTM monitoring.
- MakaleAçık Erişim2025Comparison of different animal milks on microbiological, physicochemical, sensory properties, and volatile component profile of Kefir
Meral-Aktaş, Hacer; Ürkek, Bayram; Aktaş, Haktan; Baltacı, Cemalettin; Çetin, Bülent; Şengül, Mustafa
In this study, the effects of cow, buffalo, ewe, and goat milk on the microbiological, physicochemical, sensory properties, and volatile component profile of kefir were examined during storage. Key microbial counts, including lactic cocci, lactic bacilli, and yeast, varied among kefirs, with lactic bacilli and lactic cocci decreasing over time, while yeast counts increased. The titratable acidity ranged from 1.12 to 1.16%, and pH values varied between 4.51 and 4.83. Sensory analysis showed that cow milk kefir received the highest consumer appreciation, while goat milk kefir was least favored. Notably, ewe milk kefir contained the highest benzoic acid content. Principal component analysis identified distinct clusters in the volatile profiles of the kefirs. Our results suggest that buffalo and ewe milk kefirs may be viable alternatives to cow milk kefir, with potential for consumer acceptance based on sensory properties.
- MakaleAçık Erişim2024The aroma profile of butter produceusing different starter cultures; [Aromatski profil maslaca proizvedenih korištenjem različitih starter kultura]
Şengül, Mustafa; Akgül, Halil İbrahim; Ürkek, Bayram
The aroma of fermented dairy products is greatly influenced by starter cultures and by the lactic acid bacteria strains that are used as starter cultures. Experimental butter samples were produced using no starter culture, by a commercial starter culture (Lactococcus lactis subsp. lactis, Lactococcus lactis subsp. cremoris, Lactococcus lactis subsp. lactis biovar. diacetylactis, Leuconostoc mesenteroides), by a prepared bacteria mix (Lactococcus lactis subsp. lactis EM1, Lactococcus lactis subsp. cremoris EM28, Lactococcus lactis subsp. lactis biovar. diacetylactis G49, Leuconostoc mesenteroides B3), and by a prepared bacteria mix fortified with Lactobacillus rhamnosus B19 (L. rhamnosus B19). The aroma profile of the butter samples was investigated using a gas chromatography mass spectometry method (GC-MS). A total of 92 components were determined in the butter samples, including acids (12), alcohols (20), aldehydes (9), alkanes (6), esters (8), ketones (19) and several other aroma compounds (18). The sample containing the prepared starter culture had the most detectable aroma components, while the lowest number of aromatic components were found in the sample without a starter culture. 2,3-butanedione (diacetyl) was not detected in the sample without a starter culture. 2-Butanone 3-hydroxy-(acetoin) content was the highest in the sample containing the commercial starter culture and the lowest in the sample without a starter culture.
- MakaleAçık Erişim2024Assessment of the antioxidant and ACE-inhibitory activities and some quality characteristics of Kaşar cheese produced by probiotic Lactobacillus acidophilus
Gürmeriç, Hüseyin Ender; Şengül, Mustafa; Erkaya-Kotan, Tuba
In this study, four types of Kaşar cheese were produced using raw milk (C), starter culture (Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus) (S), starter culture + probiotic Lactobacillus acidophilus ATCC 4356 (SLA), and probiotic L. acidophilus ATCC 4356 (LA) were produced and ripened at 6 ± 2 °C for 150 days. The physicochemical, microbiological, proteolysis, electrophoretic (Urea-PAGE), ACE-inhibitory, and antioxidant activity analyses of vacuum-packed Kaşar cheeses were performed on 5, 30, 60, 90, 120, and 150 days of ripening. During ripening, no significant differences (p > 0.05) were detected in total solids, fat, and protein values of Kaşar cheeses. Titratable acidity, water-soluble nitrogen (WSN), ripening index (RI), and electrophoresis results of cheese samples showed an increase while pH values decreased. Also, the degradation products of αs1-casein were higher than those of β-casein. The number of probiotic L. acidophilus ATCC 4356 after scalding decreased by an average of 1.57 log cfu/g. However, probiotic bacteria count increased during ripening and maintained their viability. The addition of L. acidophilus ATCC 4356 improved the bioactivity, electrophoresis, titratable acidity, and ripening index results of Kaşar cheese. ACE-inhibitory activity of Kaşar cheeses increased during ripening and had the highest value on the 150th day of ripening. Furthermore, antioxidant activity of Kaşar cheeses increased on the 60th day of ripening and then decreased. Consequently, the combination of probiotic bacteria and starter culture had a positive effect on the physicochemical, microbiological, and proteolytic properties of Kaşar cheese.
- MakaleYalnız künye2024Evaluation of Spreadable Kefir Produced from Different Milks in Terms of Some Quality Criteria
Aktaş, Haktan; Meral Aktaş, Hacer; Ürkek, Bayram; Şengül, Mustafa; Çetin, Bülent
Kefir, which has many beneficial effects on health, is one of the most consumed fermented milk products worldwide. It is important to increase consumption of the fermented product for public health. In this study, it was aimed to increase the beneficial effects of kefir on public health. Therefore, kefirs produced from different types of milk (cow, buffalo, sheep, and goat) were concentrated, and obtained spreadable kefir samples were investigated in terms of their microbiological characteristic (lactic bacilli, lactic cocci, yeasts and moulds, total bacteria, and coliform bacteria), benzoic acid content, physicochemical properties (fat, total solid, ash content, acidity, pH, syneresis, viscosity, colour, and rheological properties), and sensory characteristic. It was determined that APC, lactic bacilli, lactic cocci, and yeast counts of the concentrated kefir samples changed between 6.90 and 8.64, 6.89 and 8.61, 7.42 and 8.72, and 2.17 and 5.39 log CFU/g, respectively, during storage. Mould and coliform bacteria were not detected in the samples. The concentrated kefir samples contained benzoic acid in the range of 18.30–119.58 mg/L. Results from this study showed that type of milk caused differences on APC, lactic bacilli, lactic cocci and yeast count, total solids, ash, fat, acidity, pH, syneresis, colour, viscosity and rheological parameters, and benzoic acid content. In addition, milk type affected sensory properties of the kefirs. Concentrated kefirs produced from cow and buffalo milk were the most liked by panellists. Finally, it was determined that concentrated kefir was favoured as a new product by most of the panellists.
- MakaleAçık Erişim2024Evaluation of microbiological, antioxidant, thermal, rheological and sensory properties of ice cream fermented with kefir culture and flavored with mint (Menthaspicata L.)
Öztürk-Yalçın, Feyza; Ürkek, Bayram; Şengül, Mustafa
Kefir is a healthy fermented dairy product, while ice cream is one of the most consumed dairy products. In this research, ice cream was fermented using a commercial kefir culture and flavored with a mint aroma in different proportions: 0% (KI), 0.2% (KIM2), 0.4% (KIM4), and 0.6% (KIM6). The study investigated the microbiological, thermal, rheological, textural, compositional, and sensory properties as well as antioxidant activity of kefir ice cream samples during 45-day storage. The lactic bacilli, lactic cocci, and Leuconostoc counts of samples were >7 log CFU/g, while the yeast counts were <4 log CFU/g. The microbiological properties (except for yeast counts) of the samples were coherent with legal limits. Antioxidant values (except for samples KIM2 and KIM6) values did not indicate significant differences (p <.05). The pH and melting rate values of the samples decreased with the addition of mint flavor, while acidity values increased. The addition of mint aroma caused significant changes in the thermal properties of ice cream. The overrun, a*, WI, and hardness values of the samples decreased based on the mint flavor concentration, whereas the viscosity and rheological increased. Samples KI and KIM2 were scored higher than other samples for all sensory properties. As a result, fermented ice cream flavored (0.2% mint) with mint could be produced as a desirable dairy product with potential functional properties.
- MakaleAçık Erişim2023Piyasada satılan yoğurtların fizikokimyasal, mikrobiyolojik ve ade-inhibitör aktivitelerinin belirlenmesi
Gürbüz, Zeynep; Şengül, Mustafa; Erkaya, Tuba; Gürmeriç, Hüseyin Ender
Bu çalışmada, Erzurum piyasasında satılan 12 adet farklı ticari yoğurt örneğinin fizikokimyasal, mikrobiyolojik ve reolojik özellikleri ile Anjiyotensin Dönüştürücü Enzim (ADE)-inhibitör aktiviteleri belirlenmiştir. Yoğurtların kurumadde, yağ, protein, serum ayrılması, pH ve viskozite değerleri %11.11-18.05, %1.25-4.70, %3.28-4.66, 0.95-9.00 ml/25g, 3.79-4.61, 7913.0-30425.0 cP aralığında değişmiştir. Mikrobiyolojik analiz sonuçlarına göre yoğurtların L. bulgaricus ve S. thermophilus sayıları ise sırasıyla 5.67-8.32 ve 6.12-8.5 log kob/g aralığında bulunmuştur. Yoğurtların ADE-inhibitör aktivite % ve IC50 analiz sonuçları sırasıyla %55.57-77.90 ve 0.91-1.80 mg/ml arasında değişim göstermiştir. Yoğurt örneklerinin hepsi ADE-inhibitör aktivite göstermiş ve sonuçlar arasında önemli farklar (P <0.05) olduğu ortaya konulmuştur.
- MakaleAçık Erişim2023Determination of Elemental Contents and Microbiological and Chemical Properties of Çökelek Cheeses Consumed in Turkey
Kalaycı, Nagihan; Ürkek, Bayram; Öztürk, Feyza; Şengül, Mustafa; Çiftçi, Esengül
The Çökelek samples what 30 different were collected from randomly local bazaars to investigate heavy metal contaminant and mineral levels and some physicochemical and microbiological properties of samples. While the Pb was identified in 6 of the 30 samples, the As was only found in 4 of the samples. The mean major and trace element contents of Çökelek samples were ordered as Na > P > Ca > K > Mg and Al > Zn > Ni > Cu, respectively. The physicochemical properties indicated a high deviation among samples. The mean total solids, ash, salt, fat, protein waters soluble nitrogen contents, and sample ripening index were 29.83%, 1.88%, 0.68%, 4.31%, 19.84%, 0.33%, and 1.79%, respectively. The mean total aerobic mesophilic bacteria (TAMB) count of Çökelek samples was found as 8.26 log CFU g−1. The coliform bacteria and yeast-mold counts were detected in 11 and 27 of 30 samples, respectively. The mean coliform and yeast-mold counts were 1.82 log CFU g−1 and 7.11 log CFU g−1, respectively. Traditional cheeses are not mentioned in legal laws such as the Turkish Food Codex. So, there is no legal limit and standard production processes. This situation is a problem in terms of traditional cheese quality. For this reason, traditional cheese should perform further studied, and determine the legal limits.
- MakaleAçık Erişim2022Effect of blueberry addition on antioxidant activity, textural, microbiological and physicochemical properties of strained yoghurt
Şengül, Mustafa; Can, Büşra; Ürkek, Bayram; Gürbüz-Kaçan, Zeynep
In this research, the microbiological, physicochemical, rheological, textural, sensory properties and antioxidant activity of blueberry pulp added (0, 4%, 8% and 12%) strained yoghurt samples were investigated during a 28 day storage period. The Lactobacillus delbrueckii spp. bulgaricus and Streptococcus thermophilus counts in the samples were found to have decreased at the end of the storage period. The lightness, yellowness/blueness and whiteness index values showed a decrease depending on the addition of blueberry, while the redness/greenness values increased. The addition of blueberry had a negative the effects on the fat and protein values, while it had a positive effect on the total solids values. The storage period did not significantly change any of the physicochemical, colorimetric or rheological properties of the strained yoghurt samples. The general acceptability scores of the sample containing 12% blueberry were higher than the other samples. The antioxidant activities and total phenolic content of the strained yoghurt samples increased in accordance with blueberry concentration, while the firmness and work of the shear values decreased. In conclusion, it was determined that the addition of blueberry pulp at a 12% ratio could be used to enhance the nutritional and functional properties of strained yoghurts.
- MakaleAçık Erişim2022Antioxidant capacity and rheological, textural properties of ice cream produced from camel's milk with blueberry
Sayar, Esra; Şengül, Mustafa; Ürkek, Bayram
Blueberry was added to ice cream samples produced from camel's milk at different concentrations. The physicochemical, rheological, and sensory properties, total phenolic content (TPC), and antioxidant capacity of samples were investigated. The acidity and hardness values of the samples increased, but total solids, fat, protein, pH, ash, overrun values, and complete meltdown time significantly decreased with increasing concentration of blueberry. The L* and b* values decreased, while a* and H° values increased due to the presence of natural colorants in blueberry. The viscosity and consistency coefficient values of ice cream samples decreased depending on the blueberry concentration, whereas TPC and antioxidant capacity increased. The addition of blueberry did not have any affirmative or negative effect on the sensory properties of samples except for appearance, color, and flavor scores. Consequently, blueberry could be added to the ice cream produced using camel's milk at less than a ratio of 10% to improve its nutritional properties. Novelty impact statement: Ice cream made from camel's milk with blueberry is a novel dairy product. It is a functional product due to its high antioxidant activity and total phenolic component. The addition of blueberry does not have a negative effect on the sensory properties of the ice cream. As a result, blueberry and camel's milk could be used in new ice cream formulations to produce a nutritional and functional product.
- MakaleYalnız künye2021Determination of Quality of Raw Milk Collected from Atatürk University Agriculture Faculty Pilot Dairy Plant
Gürbüz, Zeynep; Şengül, Mustafa; Ürkek, Bayram; Erkaya, Tuba; Akgül, Halil İbrahim
In this study, the quality of produced products have a great importance. For this purpose, raw milk samples is obtained from Atatürk University Dairy Plant for every four seasons separately (summer, autumn, winter, spring) to protect human health and produce quality products. Physical and chemical properties (dry matter, fat, ash, protein, specific gravity, acidity and pH) of raw milk samples and microbiological (somatic cell count, total aerobic mesophilic bacteria (TAMB), mould, yeast, coliform bacteria and Staphylococcus aureus (S. aureus)) properties were investigated. Dry matter, ash (P<0.05) and fat (P<0.01) values of raw milk samples were affected significantly by dairy farm, meanwhile protein, specific gravity, pH and acidity values were not affected (P>0.05). Seasons had a significant effect on dry matter, protein, fat (P<0.05), ash and pH (P<0.01) values of raw milk samples. But, seasons did not have a significant effect on only specific gravity and acidity values (P>0.05). TAMB, yeast, mould counts indicated significantly changes based on dairy farms and seasons. On the other hand, coliform bacteria was not affected (P>0.05) by dairy farms and seasons. S. aureus counts were affected statistically by only seasons (P<0.01).
- MakaleYalnız künye2021CHİA (Salvia hispanica L.) İLAVESİNİN DONDURMANIN FİZİKOKİMYASAL VE DUYUSAL ÖZELLİKLERİNE ETKİSİ
Şengül, Mustafa; Ürkek, Bayram; Gürmeriç, Hüseyin Ender
Bu çalışmada, %5, %10, %15 ve %20 oranlarında Chia tohumu (Salvia hispanica L.) ilave edilerek üretilendondurma örneklerinin fizikokimyasal ve duyusal özellikleri araştırılmıştır. Araştırma sonucunda, dondurmaörneklerinin %kuru madde, %kül, %protein ve ilk damlama zamanı değerleri chia tohumukonsantrasyonundaki artışa bağlı olarak yükselirken, %yağ, pH ve erime oranı değerlerinin düştüğübelirlenmiştir. Dondurma örneklerinin viskozite değerleri artan chia tohumu oranına bağlı olarakyükselmiştir. Chia tohumu ilavesi dondurma örneklerinin kolorimetrik özellikleri üzerinde önemlideğişiklilere neden olduğu ve L* ve beyazlık indeksi değerlerinin yükselen chia tohumu konsantrasyonu iledüştüğü tespit edilmiştir. Panelistler tarafından en yüksek duyusal puanlar kontrol örneğine verilmiştir. %5chia tohumu ilaveli örnekler renk ve görünüş, sakısımızsı yapı ve genel kabul edilebilirlik bakımındanistatistiksel olarak diğer chia içeren örneklerden daha yüksek puanlara sahip olduğu ortaya konulmuştur.Sonuç olarak, %5 oranında chia tohumu ilavesinin dondurmanın fizikokimyasal özelliklerini iyileştirmek veaynı zamanda besleyici değerini artırmak için doğal bir kaynak olarak kullanılabileceği sonucuna varılmıştır.Anahtar Kelimeler: Dondurma, chia tohumu, fizikokimyasal özellikler, duyusal özellikler
- MakaleAçık Erişim2020Ticari kefirlerin bazı kalite parametrelerinin belirlenmesi
Ünal, Fatma Nur; Kalyas, Alperen; Gürbüz, Zeynep; Şengül, Mustafa; Ürkek, Bayram
Bu çalışmada, piyasada satışa sunulan 6 adet farklı ticari kefir örneği incelenmiştir. Kefir örneklerinin bazı fizikokimyasal (% kurumadde, % yağ, pH, % asitlik, % su bağlama kapasitesi), reolojik (viskozite, kıvam katsayısı, akış davranış indeksi), mikrobiyolojik (laktobasil, laktokok, maya-küf ve koliform bakteri sayıları) ve duyusal özellikleri araştırılmıştır. K4 kodlu örnek en yüksek viskozite (50 rpm’de 461.90 cP) ve kıvam katsayısı (K 8.16) değerlerine sahip olduğu ortaya konulmuştur. Diğer taraftan, K5 kodlu örneğin su tutma kapasitesi (%38.75) ve viskozite (100 rpm’de 285.87 cP) değerleri en yüksek değerlere sahip olduğu tespit edilmiştir. Kefir örneklerinin ortalama laktobasil, laktokok ve maya-küf sayıları sırasıyla 8.15-9.09, 8.39-9.34 ve 4.38-5.37 log kob/mL arasında değiştiği belirlenmiştir. 6 örneğin hiçbirinde koliform bakteri tespit edilememiştir. Duyusal değerlendirme sonucunda tüm kefir örnekleri değerlendirilen duyusal karakteristikler açısından panelistler tarafından düşük puanlar almıştır.
- MakaleAçık Erişim2020Determination of physicochemical and microbiological properties and fatty acid composition of butter produced in Trabzon, Turkey
Akgül, Halil İbrahim; Şengül, Mustafa; Ürkek, Bayram; Kotan, Tuba Erkaya
In this study, the some physicochemical properties, fatty acid compositions and microbiological properties of butter samples were studied. Butter samples (n = 30) were randomly collected from different local markets. Thus, butter samples were evaluated in terms of Turkish regulations, food safety and quality. The mean values of the butter samples for peroxide value (PV), iodine value (IV), saponification value (SV), Polenske value, Reichert-Meissl (RM) and Refractive index (RI) values were determined as 0.85 mEqO2 kg-1, 30.03, 220.09, 1.30, 25.60 and 1.4611, respectively. The moisture and fat values were not in harmony with Turkish Food Codex Butter, Other Milk Fat Based Spreadable Products and Anhydrous Milkfat Notification (the highest moisture content 16%, the lowest fat content 80%) in 23 and 13 butter samples, respectively. The salt values were coherent with Turkish Food Codex in all butter samples. Conjugated linoleic acid (CLA) rate of the butter samples was ranged from 0.15 to 1.32%. The average values of coliforms, total aerobic mesophilic bacteria (TAMB) and mould and yeasts counts were determined as 1.67, 6.33 and 5.22 log CFU g-1, respectively.
- MakaleYalnız künye2019Antioxidant Activity, Physiochemical and Sensory Characteristics of Ice Cream Incorporated with Sloe Berry (Prunus spinosa L.)
Ürkek, Bayram; Şengül, Mustafa; Akgül, Halil İbrahim; Kotan, Tuba Erkaya
The aim of this study was to determine the influence of sloe berry (SB) addition at different ratios on the physical, chemical, antioxidant, colour and sensory properties and mineral contents of ice creams. The increment of SB led to the an increase of titratable acidity, overrun, viscosity and ash values, first dripping and complete melting times; in contrast, it decreased the total solid, pH and fat values. Mn and Zn values were affected significantly (P < 0.05) by the addition of SB but other element levels were not affected. L* and b* values decreased significantly in all samples as compared with control sample, while a*, H°, C* and ∆E* increased significantly with addition of SB. Antioxidant activity was the highest in the sample containing 15 % SB (w/w) among ice cream samples. The ice cream samples containing 15 % SB had higher score than the control sample in terms of colour and appearance, gumming structure and general acceptability.
- MakaleAçık Erişim2018Determination of Some Physicochemical Properties, Fatty Acid Composition and Antioxidant Capacity, of Organic and Conventional Milk in Turkey Produced
Ürkek, Bayram; Şengül, Mustafa
In this study, determination of effect of production systems (conventional and organic) and time of milk collection on some physicochemical properties, fatty acids and antioxidant capacity of conventional and organic raw milk in produced Turkey were aimed. In this research, the milk samples was collected from nine conventional farms and nine organic farms at bimonthly years for one year. Fatty acid composition, antioxidant capacity, total phenolic matter, dry matter, fat, protein, ash, titratable acidity (lactic acid %) and pH values of organic and conventional milk were investigated. According to results of this research, the mean values of conventional and organic milk samples respectively for dry matter, fat, protein, ash, specific gravity, acidity and pH was determined as 12.06-11.97%, 3.67-3.50%, 3.33-3.34%, 0.67-0.66%, 1.0381-1.0381 g mL- 1, 0.18-0.16% and 6.67-6.73, respectively. Conjugated linoliec acid proportions changed between 1.39% and 2.87% in organic milk, between 1.67% and 2.96% in conventional milk. Consequently, the farm production type did not have effects on the milk compassion (dry matter, fat, protein and ash), fatty acid composition, EC50 and total phenolic compounds. On the other hand, the significant variations in the fat, protein, fatty acid proportions, EC50, inhibition and total phenolic compound values were determined as regarding time of milk collection.
- MakaleAçık Erişim2017Prevalence and comparing of some microbiological properties, somatic cell count and antibiotic residue of organic and conventional raw milk produced in Turkey
Ürkek, Bayram; Şengül, Mustafa; Erkaya, Tuba; Aksakal, Vecihi
The aim of this study was to investigate the effects of production systems and milk collection periods on the somatic cell count (SCC), some microbiological properties, total aerobic mesophilic bacteria (TAMB), coliform, Staphylococcus aureus (S. aureus), yeast and mould) and antibiotic residue of milk; in Turkey. Milk samples were collected from 9 conventional farms and 9 organic farms during one year time, at six different months (December 2013 to October 2014), and all farms were selected from the same geographical locations. All organically managed farms had organic production certificates given by the Republic of Turkey Ministry of Food, Agriculture and Livestock. The count of TAMB, coliform, and coagulase positive S. aureus were affected by production systems at the level of p<0.01; yeast and mold, and somatic cell count (SCC) were affected at the level of p<0.05. But, differences according to months were statistically significant only on TAMB (p<0.01) and coliform (p<0.05) counts. The general means of TAMB, coliform and yeast and mould counts of the organic milk (OM) were significantly lower (p<0.05), while the general means of SCC and coagulase positive S. aureus count of the OM was significantly higher (p<0.05) compared to conventional milk (CM). Antibiotic residue was determined in one of the CM sample and in two of the OM samples. Our study is the first research that compared conventional and organic milk in Turkey. This study indicated that the microbiological quality of OM was the higher in terms of TAMB, coliform and yeast and mould, whereas was the lower in relation to SCC and coagulase positive S. aureus counts. But, the quality of both milk types should be improved.
- MakaleYalnız künye2015Probiotic butter: Stability, free fatty acid composition and some quality parameters during refrigerated storage
Erkaya, Tuba; Ürkek, Bayram; Doğru, Ünsal; Çetin, Bülent; Şengül, Mustafa
This study was carried out to determine whether butter can be a carrier for probiotics by observing the survivability of selected probiotic strains during cold storage. The effects of using probiotic adjunct cultures (Lactobacillus acidophilus ATCC 4356 and Bifidobacterium bifidum ATCC 29521) in butter on microbiological counts, sensory characteristics, chemical characteristics and free fatty acid (FFA) composition during storage for 60 days were investigated. The butter samples produced with B. bifidum ATCC 29521 maintained the probiotic characteristics, in that the level of viable cells of the probiotic was >106 cfu g-1 until 30 days of storage. The highest scores in sensory assessment were obtained on the first day of storage. FFAs, including C2:0, C6:0, C14:0 and C18:1, were affected significantly by storage period and by the adjunct cultures, however conjugated linoleic acid and C18:2 were not affected by storage period and the use of probiotic adjunct culture.