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Öğe The Antioxidant Activity of Rose hip Marmalade Yogurt(Selçuk Üniversitesi, 2015) Alzamara, Rola Mohammad; Akin, NihatIn this study, the highest antioxidant Rose hip marmalade was added before fermentation in different concentration (5%, 10% and 15%) to yogurt (set Rose hip marmalade yogurt). The antioxidant activity and the phenolic compounds content of Rose hip marmalade yogurt determined and comparing with plain yogurt during 21 days of cold storage. The Rose hip marmalade enhanced the radical scavenging activity of yogurt. where the significant decreases of antioxidant activity and phenolic compounds content occurred during cold storage period, Rose hip marmalade yogurt remained more rich in antioxidant and phenolic compounds comparing with plain yogurt.Öğe Determination of functional characteristics, presence of virulence factors and antibiotic resistance of enterococci isolated from Turkish White-Cheese(ELSEVIER SCIENCE BV, 2016) Akin, Nihat; Dertli, Enes; Ispirli, Humeyra; Yuvasen, Ayse; Akaya, Zuhal[Abstract not Available]Öğe Determination of powder flow properties of skim milk powder produced from high-pressure homogenization treated milk concentrates during storage(ELSEVIER SCIENCE BV, 2018) Mercan, Emin; Sert, Durmus; Akin, NihatThe aim of this study was to determine effects of high-pressure homogenization (HPH) treatment to milk concentrates on powder flow properties of skim milk powders (SMP). For this purpose, SMP samples were produced from skim milk concentrates which were HPH treated at 0 (control), 50, 100 and 150 MPa. SMP samples were stored 180 days at 20 and 40 degrees C and caking, cohesion and powder flow speed dependency test (PFSD) were performed using a Powder Flow Analyzer. HPH treatment decreased cohesion and caking properties of SMPs. At the 0. day, cake strength of SMPs from HPH treated concentrates varied from 0.43-2.70 mN.m, whereas cake strength of SMP-0(control) was 8.20 mN.m. Cohesion index (CI) of samples ranged from 6.80-15.74 nun during storage. Based on CI, SMPs from HPH treated concentrates showed free and easy flowing flow behavior during storage at 20 and 40 degrees C. In addition, cohesion index at four speeds indicated that SMP from HPH treated concentrates were more flowable at even lower flow speeds then SMP-0. PFSD test verified that all SMP samples showed more free-flowing characteristics with increasing flow speeds. Flow stability of samples ranged from 0.95-1.15 and also flow stability of SMP-0 increased during storage at both 20 and 40 degrees C. The results revealed that HPH treatment to milk concentrates could improve powder flow properties of skim milk powders.Öğe Effect of different levels of pine honey addition on physicochemical, microbiological and sensory properties of set-type yoghurt(WILEY, 2017) Mercan, Emin; Akin, NihatIn this study, the effects of different levels of pine honey addition (3%, 5% and 7% w/v) to the yoghurt milk on starter bacteria, physicochemical and sensory characteristics of set-type yoghurts during the storage were investigated. Antioxidant activity and total phenolic content of yoghurts with added honey increased compared to control yoghurt. There was a significant increase in water-holding capacity (WHC), viscosity, total solids, redness (a*) and yellowness (b*) values of the yoghurt samples with the addition of honey at higher concentrations, whereas water activity (aw), pH and luminosity (L*) values decreased. Viscosity and WHC of the yoghurts increased during the storage.Öğe Effect of high-pressure homogenisation on viscosity, particle size and microbiological characteristics of skim and whole milk concentrates(ELSEVIER SCI LTD, 2018) Mercan, Emin; Sert, Durmus; Akin, NihatEffect of high-pressure (HPH) homogenisation on milk concentrates were studied. Skim and whole milk concentrates were homogenised at 0-150 and 0-40 MPa, respectively, and viscosity, particle size measurement, microbiological and colour characteristics determined. Up to a pressure of 120 MPa, viscosity of HPH-treated skim milk concentrates (SMC) was proportional to HPH pressure and was lower than that of the control (0 MPa). With whole milk concentrates (WMC), HPH decreased viscosity up to a pressure of 20 MPa; above 30 MPa viscosity increased. According to a power law model, both skim and whole milk concentrates showed shear-thinning flow behaviour. HPH at pressures above 120 MPa completely inactivated the microbial load of SMC. Up to a pressure of 50 MPa, HPH decreased the mean particle size (D [3,2]) of SMC; an increasing trend of D [3,2] was observed above 70 MPa. Except at 40 MPa, HPH decreased D [3,2] values of WMC samples. (C) 2018 Elsevier Ltd. All rights reserved.Öğe The effect of milk type and heat treatment on physicochemical and microbiological properties of Tulum cheese whey(M H SCHAPER GMBH CO KG, 2013) Sert, Durmus; Akin, NihatIn this study, Tulum cheese produced by using cow, sheep, goat milk and mixtures of them and physicochemical and microbiological properties of these cheeses whey were analyzed. Two different methods were used in the cheese production. In the first method, traditional production type was used; for this reason, raw milk wasn't heated. In the second method, heat treated milk (60 +/- 2 degrees C 10 min.) was used. Dry matter was determined to be less in whey of cheeses produced from heat treated milk. It was determined that there were increases in fat losses with whey in cheeses that were produced from sheep and goat milk. Lowest protein content in dry matter was determined to be in whey of heat treated cow-sheep milks (50:50). Color values of whey significantly varied according to heat treatments among milk groups. The highest yeast-mold number was determined in whey of cheeses produced from raw sheep's milk. Lactococci count in whey varied between 2.38-6.35 log cfu/g in mesophilic flora, between 4.26-5.70 log cfu/g in termophilic flora. The lowest enterococci count was found in whey of cheeses made of cow milk.Öğe The effects of carbon dioxide addition to cheese milk on the microbiological properties of Turkish White brined cheese(WILEY-BLACKWELL, 2012) Dertli, Enes; Sert, Durmus; Akin, NihatThis study invest0igated the effect of CO2 added to achieve three pH levels: pH 6.1, pH 6.2 and pH 6.3 for treatments X, Y, Z, respectively, on some microbiological properties of Turkish White (TW) brined cheese. For each pH, four batches of cheese were produced from: raw milk with no added carbon dioxide (UR), raw milk with carbon dioxide (TR), pasteurised milk with no carbon dioxide addition (UP) and pasteurised milk with carbon dioxide addition (TP). The microbiological analysis of TW brined cheeses was carried out for 90 days of maturation period. Total aerobic mesophilic bacteria, mesophilic lactic acid bacteria, yeasts and moulds and coliform group were determined in control and CO2 treatment groups. Mesophilic bacteria count was determined as 5.14, 5.29, 5.67 log cfu/g for pH 6.1, 6.2 and 6.3, respectively, in CO2-treated raw milk cheeses. Yeasts and moulds reduction increased significantly by applying CO2 (P < 0.01). For TW cheese samples, the most significant microbial inactivation was detected at sample groups of pH 6.1.Öğe The Effects of Probiotic Cultures on Quality Characteristics of Ice Cream(IGI GLOBAL, 2018) Akin, Nihat; Ozturk, Hale InciThe manufacturing design and probiotic strain that are used in ice cream production affect sensorial, nutritional, and physicochemical properties of ice cream. Therefore, it is possible to produce better quality products or to develop existing methods by considering the effects of probiotic cultures on these properties of ice cream. The International Dairy Federation has recommended that probiotic products contain at least 107 CFU/g of viable probiotic strain before consumption, so that the therapeutic value of a probiotic product can be associated with the viability of these bacteria. The nutritional value of probiotic ice cream is related not only to the dietary components it contains, but also to the maintaining of the viability and the activity of the probiotic bacteria. This chapter provides information on the viability of probiotic strains during ice cream processing and storage. Furthermore, the effects of probiotic cultures on sensory and physicochemical properties of ice cream are also discussed.Öğe The effects of starter culture on chemical composition, microbiological and sensory characteristics of Turkish kasar cheese during ripening(BLACKWELL PUBLISHING, 2007) Sert, Durmus; Ayar, Ahmet; Akin, NihatKasar cheese samples were produced from raw milk and starter culture- added pasteurized milk. Chemical, microbiological and organoleptic properties of kasar cheeses were analysed at certain times during the ripening periods ( on the 1st, 7th, 15th, 30th, 60th, 90th days). Generally, chemical parameters were not affected by starter culture. The pH, ripening index, water- soluble nitrogen and non- protein nitrogen did not show significant differences between the cheese samples. The addition of starter affected the microbiological quality of the cheeses. Starter culture- added kasar cheeses contained low levels of total aerobic mesophilic bacteria, moulds and yeasts, and coliforms, and achieved higher organoleptic scores than those of cheeses made from raw milk. The starter cultures contributed to acidity and microbial quality of the cheese. Kasar cheese samples were produced from raw milk and starter culture-added pasteurized milk. Chemical, microbiological and organoleptic properties of kasar cheeses were analysed at certain times during the ripening periods (on the 1st, 7th, 15th, 30th, 60th, 90th days). Generally, chemical parameters were not affected by starter culture. The pH, ripening index, water-soluble nitrogen and non-protein nitrogen did not show significant differences between the cheese samples. The addition of starter affected the microbiological quality of the cheeses. Starter culture-added kasar cheeses contained low levels of total aerobic mesophilic bacteria, moulds and yeasts, and coliforms, and achieved higher organoleptic scores than those of cheeses made from raw milk. The starter cultures contributed to acidity and microbial quality of the cheese.Öğe Effects of sunflower honey on the physicochemical, microbiological and sensory characteristics in set type yoghurt during refrigerated storage(WILEY-BLACKWELL PUBLISHING, INC, 2011) Sert, Durmus; Akin, Nihat; Dertli, EnesThe primary purpose of this research was to monitor the influence of sunflower honey addition (2%, 4% and 6% w/v) to yoghurt milk on survival of the microbial flora of yoghurt and the physicochemical and sensory characteristics during refrigerated storage for 4 weeks. The water activity decreased according to the addition of honey with higher concentrations in the storage period (4 degrees C). At the end of fermentation, pH values of yoghurt samples ranged between 4.33 (without honey) and 4.52 (addition of honey with 6%). The highest water holding capacity, consistency and the lowest brightness values were determined in the groups produced with 6% honey addition. The water holding capacity and a* (redness) values of the honey incorporated yoghurt samples increased during storage. Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus values of the yoghurt with honey increased compared with the control group samples (P < 0.01). Addition of honey to yoghurt milk has affected the vitality of the characteristics starters in the incubation and storage time of the yoghurt samples (P < 0.01). Optimum sweetness was obtained with the samples containing 4% honey level.Öğe Fortification of set-type yoghurts with Elaeagnus angustifolia L. flours: Effects on physicochemical, textural, and microstructural characteristics(ELSEVIER SCIENCE BV, 2018) Ozturk, Hale Inci; Aydin, Sumeyye; Sozeri, Didem; Demirci, Talha; Sert, Durmus; Akin, NihatThe effect of peeled oleaster (Elaeagnus angustifolia L.) flour (PO) and unpeeled oleaster flour (UPO) in different levels (1% and 2%) on the quality parameters of set type yoghurt was investigated throughout 28 days of storage. Acidification kinetics, water holding capacity, syneresis level, textural characteristics and microstructure were firstly measured. Additionally, influence of oleaster flours on DPPH and ABTS(+) radical scavenging activity and total phenolic content of yoghurt samples was also assessed. Besides, all the products were subjected to sensorial preference test. Enrichment with 2% PO and UPO reduced fermentation time by 31 and 37 min, respectively. Addition of PO and UPO increased cohesiveness and the viscosity index, furthermore, syneresis decreased. Oleaster supplementation to yoghurt significantly increased scavenging activities of DPPH and ABTS radicals and the highest activities were determined in yoghurts fortified with 2% UPO. The results demonstrated that yoghurt with reduced syneresis, improved functional properties, and enhanced some textural characteristics can be achieved by a 2% UPO addition. Also, surprisingly yoghurts containing 2% UPO had similar consumer overall preference scores comparing to plain yoghurt.Öğe Impact of Cooking pH Values on the Textural and Chemical Properties for Processed Cheeses with/without the Use of Traditional Village Cheese during Storage(KOREAN SOC FOOD SCIENCE ANIMAL RESOURCES, 2019) Bulut-Solak, Birsen; Akin, NihatProcessed cheeses (PCs) were made under varying cooking pH values (5.3, 5.4, 5.5, and 5.6) using a processed cheese cooker. Along with emulsifying salts (2.5%), distilled water, NaCl (2%) and a colouring agent under these cooking pH values, the PC samples made with either 100% fresh curd and rennet casein coded processed cheese control (PCC) as control or similar to 70% fresh curd-similar to 30% traditional village cheese coded processed cheese with village cheese (PCv). The main aim of this study was to determine the effect of the varying cooking pH values on the textural properties for the PCv samples compared with the control sample during 90 days of storage. Chemical and textural properties of all PC samples were investigated over time. The chemical compositions of the PC samples (dry matter and ash) increased at d 90 of storage significantly, due to 1-d ripening of all PC samples at ambient temperature in terms of the manufacturing protocol of the cheese. The textural properties of the PC samples were altered by the varying cooking pH values. It may propose that the interactions of the proteins at the cooking pH values during processing and biochemical mechanisms in the cheese systems could likely affect the texture of the PC samples over time. Hardness, gumminess and chewiness values of all PC samples also increased over time (p<0.05). This study is also to give some knowledge on the design of PC manufacture to cheese makers, and a marketing opportunity to local cheese makers who individually make a traditional village cheese in Turkey.Öğe Production of functional probiotic ice creams with white and dark blue fruits of Myrtus communis: The comparison of the prebiotic potentials on Lactobacillus casei 431 and functional characteristics(ELSEVIER SCIENCE BV, 2018) Ozturk, Hale Inci; Demirci, Talha; Akin, NihatIn the present study, dark blue (BM) and white (WM) Myrtus communis (M. communis) pulps were added to probiotic goat milk ice cream formulations containing Lactobacillus casei (L. casei) 431 to evaluate prebiotic potentials of BM and WM fruits on L. casel 431. Additionally, the effects of storage and freezing process on viable L. casei 431 counts, total phenolic content (TPC) and antioxidant activity were examined. According to the results, it was determined that the BM and WM fruits had prebiotic potentials on L. casei 431. The freezing process of mixes reduced the counts of L. casei 431 by about 0.80-1.32 log CFU g(-1) and this strain maintained high viability throughout the storage. After freezing process, TPC values of ice cream samples containing WM and BM fruits increased by 5.00 and 8.50 mg GAE 100 g(-1), respectively. No alteration was detected in antioxidant activity during the storage.Öğe The trace metal levels in milk and dairy products consumed in middle Anatolia-Turkey(SPRINGER, 2009) Ayar, Ahmet; Sert, Durmus; Akin, NihatIn this study, aluminium (Al), lead (Pb), cadmium (Cd), selenium (Se) and arsenic (As) contents in milk and different dairy product samples were measured. Pb, Cd, As, Al and Se contents in the milk and different dairy products ranged from 0.054 mg/kg (milk powder)-1.100 mg/kg (Ka angstrom ar cheese), 0.009 mg/kg (whey powder and yogurt)-0.051 mg/kg (Tulum cheese), 0.010 mg/kg (whey powder)-0.146 mg/kg (butter), 2.848 mg/kg (ice cream)-8.778 (drained yogurt) and n.d. (ice cream, milk and whey powder, yogurt, ayran and Lor cheese)-0.434 mg/kg (Tulum cheese), respectively. The 75% of White and Ka angstrom ar cheeses, 50% of Lor and 12.5% of Tulum cheese samples contained higher Pb according to the legal limits established by the Turkish Food Codex and European Communities regulation and 12.5% of Tulum cheese sample contained Cd. It was concluded that Pb contents of milk and dairy products from this region might be highly hazardous to human.
