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Öğe Assessment of powder flow, functional and microbiological characteristics of ozone-treated skim milk powder(Elsevier Sci Ltd, 2021) Sert, Durmus; Mercan, EminThe influence of ozone treatment (OT) of skim milk powder (SMP) on functional, physicochemical characteristics, powder flow behaviours and microbiological quality was evaluated. SMP was ozone treated for 0 (control), 30, 60, 90 or 120 min. Particle size parameters of samples were not affected by OT. OT increased dispersibility and foaming capacity, but decreased wettability time. The cohesion index of samples ranged from 11.98 to 18.34, with higher treatment times decreasing it. OT significantly decreased the tendency for caking and cohesion, as well as compaction characteristics, and increased the flow stability of ozone-treated samples compared with control. OT could be effective for improving SMP flow behaviours in terms of caking, cohesion, and compaction. OT for 120 min decreased the count of all analysed microorganisms to under the detection limit. Inactivation of microorganisms and improving functional and powder flow characteristics by OT may have applications in dairy powder processing and food safety. (c) 2021 Elsevier Ltd. All rights reserved.Öğe Butter production from ozone-treated cream: Effects on characteristics of physicochemical, microbiological, thermal and oxidative stability(Elsevier, 2020) Sert, Durmus; Mercan, Emin; Kara, UmmugulsumThe goal of this research was to investigate the effects of the ozone treatment (OT) to raw cream on the physicochemical, microbiological, thermal, and oxidative properties of butter. For this purpose, butter samples were produced from raw cream, which was ozone-treated for 5 (OT-5), 15 (OT-15), 30 (OT-30), and 60 (OT-60) min. The control sample was also produced from non-ozonated raw cream. OT increased firmness, consistency, and fat particle size values of cream. The firmness of butter was between 97 and 380 N. Average fat particle size of samples (D[3.2]) ranged from 22.1 to 30.2 mu m, in which OT decreased it. A monomodal fat particle size distribution was determined in all-butter samples. OT decreased b value (yellowness) of butter, and the lowest value was determined in OT-60. The induction time of butter changed from 1.04 (OT-60) - 32.9 h (control). Two melting peaks were determined in butter samples at 14.2-14.6 and 32.3-33 degrees C. Ozonation for 60 min caused 2.01 log reduction in Staphylococci. Above 15 min, OT completely inactivated Salmonella and yeast-mould. Coliform was not detected in OT-30 and OT-60. The results showed that OT resulted in higher microbiological quality in butter from raw cream.Öğe Characterisation of physicochemical, microbiological, thermal, oxidation properties and fatty acid composition of butter produced from thermosonicated cream(Elsevier Sci Ltd, 2020) Sert, Durmus; Mercan, EminThe effects of thermosonication of cream on physicochemical, microbiological, thermal, oxidation properties and fatty acid composition of butter were determined. Butter samples were produced from cream thermosonicated (TS) for 5, 10, or 15 min and from raw (R) and pasteurised (P) cream as controls. Thermosonication decreased moisture content, water activity, and pH of samples when compared with control groups. Mean particle size (D [3.2]) values of TS samples were lower than the R and P samples. Thermosonication improved spreadability compared with that of butter from pasteurised cream. Oxidative stability (induction time) of TS samples was lower than R, but higher than P. Two melting peaks were determined; in all samples, the T-onset of the first peak ranged from 11.39 to 11.93 degrees C, and the Tpeak was between 14.01 and 14.14 degrees C. Thermosonication significantly reduced total bacteria count and can improve spreadability, oxidative stability, and microbial safety of butter samples. (C) 2020 Elsevier Ltd. All rights reserved.Öğe Characterization of lactic acid bacteria from yogurt-like product fermented with pine cone and determination of their role on physicochemical, textural and microbiological properties of product(Elsevier, 2017) Sert, Durmus; Mercan, Emin; Dertli, EnesThe aim of this study was to understand how pine cone (PC) addition could acidify the milk and result in the production of yogurt. For this purpose, yogurts were produced with three different pine cones which were classified according to collection period; PC-1 (October), PC-2 (November) and PC-3 (December). Physicochemical, textural and microbiological properties were determined as quality criteria on the yogurt samples. Importantly, Lactic Acid Bacteria (LAB) were isolated and identified from yogurt samples. 26 of 80 yogurt isolates were identified. The incubation time of yogurts until the pH reached 4.6-4.7 was similar to 3.5-4 h at 45 degrees C. Textural properties of yogurt PC-3 increased as compared to PC-1 and PC-2 which was found to be related with high LAB numbers in PC-3. Similarly, the highest dry matter, water holding capacity, acidity values were determined in the yogurt PC-3 whereas PC-1 had the lowest values. The lowest pH value was found in yogurt PC-3 related to LAB counts. Lactobacillus spp. and Streptococcus spp. counts of yogurts ranged between 5.95-6.82 and 6.32-6.99 log cfuig, respectively. Also, LAB species were identified as Streptococcus thermophilus and Lactobacillus plantarum in all yogurt samples showing that pine cones somehow harbour the yogurt starters. (C) 2016 Elsevier Ltd. All rights reserved.Öğe Determination of powder flow properties of skim milk powder produced from high-pressure homogenization treated milk concentrates during storage(Elsevier, 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 Development of buffalo milk ice-cream by high pressure-homogenisation of mix: Physicochemical, textural and microstructural characterisation(Elsevier, 2021) Sert, Durmus; Mercan, Emin; Kilinc, MehmetThis study aimed to determine the physicochemical, textural, and microstructural characteristics of buffalo milk ice cream produced from high-pressure homogenisation (HPH) treated ice cream mix. Ice cream mix was subjected to 0 (control), 30, 60, 90, 120, or 150 MPa. HPH increased the firmness and consistency value of mixes, whereas it decreased cohesiveness and index of viscosity values. Also, HPH improved the lightness, redness, and yellowness of the mix. The mean particle size of HPH-treated mix samples was lower than the control, except HPH-150. The hardness of ice cream samples was between 14.30 and 77.81 N, in which HPH increased hardness value with the increasing pressure. The overrun of ice cream samples ranged from 19.93 to 45.15%, and HPH decreased it. HPH significantly improved resistance to melting in the ice cream. Scanning electron microscopy images revealed that HPH reduced the size of air bubbles. HPH at 150 MPa resulted in a foamy structure in the ice cream. HPH can alter the hardness, microstructure, and melting characteristics of buffalo milk ice cream. Products with improved properties may be developed by further modifying the formulation and processing parameters.Öğe Development of gelatine-based edible film by addition of whey powders with different demineralisation ratios: Physicochemical, thermal, mechanical and microstructural characterisation(Wiley, 2021) Sert, Durmus; Ucok, Gamze; Kara, Ummugulsum; Mercan, EminThe effects of using whey powders with different demineralisation rates on the physicochemical, thermal, mechanical, and microstructural properties of gelatine-based edible films were investigated. Films were produced from film-forming solutions (FFS) containing whey powder (WP) and 50, 70 and 90% demineralised whey powder (50DWP, 70DWP, 90DWP). The addition of whey powders increased the pH and particle size values of FFS. The zeta potential decreased significantly in the WP sample and gradually reduced depending on the demineralisation rate in the DWP samples. The addition of whey powders partially increased the density of the films. WP addition reduced the hydrophobicity of the film, while the addition of DWPs did not cause any change. The addition of whey powders decreased the L* and a* values of the films while increasing the b* values. Control was the most transparent, while 70DWP and 90DWP films had higher opacity. WP films had the most uniform and smooth surface. The highest degradation temperature (269.64 degrees C) was observed in the control sample. The weight loss of the control was 95%, whereas those of WP and DWP samples were 88-89%. WP addition reduced the tensile strength and increased the elasticity of the films.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 Effect of ultrasonic treatment on reduction of Esherichia coli ATCC 25922 and egg quality parameters in experimentally contaminated hens' shell eggs(Wiley, 2013) Sert, Durmus; Aygun, Ali; Torlak, Emrah; Mercan, EminBackround In this study, hen eggs which were experimentally contaminated with Esherichia coli ATCC 25922 were used. Contaminated eggs were washed statically (S5 to S30; 0 kHz) and by ultrasonic waves (U5 to U30; 35 kHz) for given applications of time (5, 15 and 30 min), then the eggs were stored at 22 degrees C for 14 days. Results Depending on the time of ultrasonic application, a significant increase in egg shell strength (P < 0.01) was recorded. The highest value of the Haugh unit (67.93, 1 day) was observed on the eggs which were washed by ultrasonic waves. Yolk width values of ultrasonic washed eggs diminished. E. coli was completely removed by 30 min of ultrasonic application. During storage E. coli growth was not detected on the eggs which were washed by ultrasonic waves except the eggs in U5 group (2.04 log CFU eggshell(-1)) on the first day of storage. Conclusion Depending on the time of ultrasonic application a significant increase in egg quality parameters (shell strength, albumen height, Haugh units, and yolk height) were observed. The application of ultrasound led to a significant reduction in E. coli numbers on egg shells. (c) 2013 Society of Chemical IndustryÖğe Effects of churning with different concentrations of ozonated water on particle size, texture, oxidation, melting and microbiological characteristics of butter(Elsevier Sci Ltd, 2020) Sert, Durmus; Mercan, EminThe effects of churning with different concentrations of ozonated water (OW) on fat particle size, texture, oxidation, melting and microbiological characteristics of butter from raw cream were investigated. For this purpose, butter samples were produced by churning with ozonated waters at concentrations of 0 (control), 0.15 (OW-15), 0.20 (OW-20), 0.25 (OW-25) and 0.30 (OW-30) mg L-1. Churning with OW increased the lightness and redness value of samples and decreased yellowness. Firmness value of samples ranged from 126.86 to 347.46 N, with an increase with ozone concentration. Mean fat particle size (D[4.3]) value of samples decreased with higher ozone concentration in churning water. OW reduced the oxidative stability of samples. Microbial reductions by churning with ozonated water ranged from 0.07 to 1.59 log. Microbiological analysis results showed that ozone treatment improved the microbial safety of butter samples produced from raw cream. (C) 2020 Elsevier Ltd. All rights reserved.Öğe Effects of milk somatic cell counts on some physicochemical and functional characteristics of skim and whole milk powders(Elsevier Science Inc, 2016) Sert, Durmus; Mercan, Emin; Aydemir, Serdar; Civelek, MustafaThe aim of this work vas to study the influence of milk somatic cell count (SCC) levels on spray-dried milk powders. For this reason, 3 cow milks with different SCC (<300,000, 300,000700,000, >700,000 SCC/mL) were processed into skim (SNIP) and whole milk powder (WMP). The effect of SCC on the physicochemical and functional characteristics of the milk powders and textural properties of set-type yogurts produced from reconstituted milk powders with different SCC was evaluated. A crucial difference was rioted between milk powders depending on different SCC. Protein values and ash content of powder samples decreased correlatively with increasing SCC. The hydroxymethylfurfural content of SNIP was higher than WMP. We noted an increase in hydroxymethylfurfural content of both SMP and WMP depending on elevated SCC. Solubility index of SMP and WMP was 1.280 to 1.632 and 0.940 to 1.208 mL, respectively; with increasing SCC, solubility index was affected adversely. The highest foam stability was determined in SMP containing >700,000 SCC. Bulk density of SNIP and WMP was between 0.682 and 0.708 and 0.660 to 0.685 g/cm(3), respectively. An increase was observed in scorched particle of both SMP and WMP depending on increasing SCC. We found significant differences in particle size distribution of milk powders produced from milk with SCC at different levels. Although WMP had more uniform and big particle structure, SMP had more specific area. A negative correlation was noted between yogurt texture and SCC. Results indicate that milk SCC has negative influences on milk powder quality.Öğe Effects of ozone treatment to milk and whey concentrates on degradation of antibiotics and aflatoxin and physicochemical and microbiological characteristics(Elsevier, 2021) Sert, Durmus; Mercan, EminThe aim of this study was to investigate the effects of the ozone treatment (OT) to milk concentrate (MC) and whey concentrate (WC) on the physicochemical and textural properties, as well as, on the microbial, antibiotic, and aflatoxin content. For that purpose, OT was applied to MC and WC samples 0 (control), 5, 10, 15, 30, or 60 min. OT (60 min) achieved 18.9 and 9.9% degradation of aflatoxin M1 in MC and WC, respectively. OT caused degradation of beta-lactam, and tetracycline in concentrates. Volume mean diameter of MC was increased by OT, those of WC was decreased. The firmness and consistency values of ozone-treated concentrates were lower than the control groups. OT decreased the cohesivity of MC. OT increased the lightness of samples, while it decreased yellowness. In MC and WC samples, OT was effective in reducing the microbial load. The degradation of antibiotics and aflatoxin, and reducing the microbial load of concentrates by OT are crucial for human health and the processing of dairy products.Öğe High-pressure homogenisation of sheep milk ice cream mix: Physicochemical and microbiological characterisation(Elsevier, 2021) Sert, Durmus; Mercan, EminThe effect of high-pressure homogenisation (HPH) treatment (0, 25, 50, 75, or 100 MPa) of mix on the physicochemical, textural, and microbiological characteristics of sheep milk ice cream was determined. Textural properties of the mix were not affected by HPH. However, HPH increased L*, a*, and b* values of the mix. In HPH-treated mix samples, the mean particle diameter was lower compared with the control. The hardness value of ice cream changed from 43.0 to 58.1 N, and HPH increased it depending on the increasing pressure. The highest overrun (58.3%) was determined in control, whereas the lowest overrun (35.8) was found in HPH-100. Melting time and first dripping time were increased depending on the increasing pressure of HPH, while HPH decreased the melting rate. HPH treatment of mix significantly reduced the microbial loads of ice cream samples. Consequently, HPH treatment can enhance the hardness, melting, and microbiological properties of ice cream from sheep milk.Öğe Impact of exopolysaccharide production on functional properties of some Lactobacillus salivarius strains(Springer, 2015) Mercan, Emin; Ispirli, Humeyra; Sert, Durmus; Yilmaz, Mustafa Tahsin; Dertli, EnesThe aim of this work was to characterize functional properties of Lactobacillus salivarius strains isolated from chicken feces. Detection of genes responsible for exopolysaccharide (EPS) production revealed that all strains harbored a dextransucrase gene, but p-gtf gene was only detected in strain E4. Analysis of EPS production levels showed significant alterations among strains tested. Biofilm formation was found to be medium composition dependant, and there was a negative correlation with biofilm formation and EPS production. Autoaggregation properties and coaggregation of L. salivarius strains with chicken pathogens were appeared to be specific at strain level. An increment in bacterial adhesion to chicken gut explants was observed in L. salivarius strains with the reduction in EPS production levels. This study showed that strain-specific properties can determine the functional properties of L. salivarius strains, and the interference of these properties might be crucial for final selection of these strains for technological purposes.Öğe Impact of high-pressure homogenisation of milk on physicochemical, microbiological, and textural characteristics of sheep milk yoghurt(Elsevier Sci Ltd, 2023) Sert, Durmus; Mercan, Emin; Tanrikulu, MehmetYoghurt samples were produced from sheep milk that was high-pressure homogenisation (HPH) treated at 0 (control), 30, 50, 70 and 100 MPa. Depending on the acidification kinetic parameters, HPH treatment increased the acidification rate and shortened the fermentation time. HPH-treated samples had lower pH, increased water holding capacity, decreased syneresis, decreased particle size and higher acetalde-hyde content than the control. At 0 and 14 days of storage, the tyrosine value of HPH-treated samples was higher than the control. Although HPH resulted in higher L* and a* values, it caused lower b* values in yoghurt samples. Up to 30 MPa, HPH increased firmness and consistency; however, these were decreased above 50 MPa. During storage, Streptococcus thermophilus and Lactobacillus bulgaricus counts ranged from 6.12 to 8.20 log cfu g-1 and 5.70 to 8.96 log cfu g-1, respectively. Depending on the increasing pressure, HPH caused higher S. thermophilus and L. bulgaricus counts.& COPY; 2023 Elsevier Ltd. All rights reserved.Öğe The impact of ozone treatment on whey concentrate on the flow behaviour, functional and microbiological characteristics of whey powder(Elsevier Sci Ltd, 2022) Sert, Durmus; Mercan, EminThe impact of ozone treatment (OT) for 0 (control) 30, 60, 90 and 120 min to whey concentrate (WC) on powder flow, physicochemical, functional, and microbiological characteristics of whey powders (WPs) was examined. OT decreased the cohesiveness of WC, whereas the firmness, consistency and index of viscosity were not affected. OT caused higher L* and b* values in WP and improved the solubility and foaming capacity, but decreased foaming stability and bulk density. OT increased the mean particle size of WP samples depending on the treatment time. Higher treatment time of OT resulted in a lower cohesion index. OT decreased caking ability of WP samples and increased flow stability. Compaction coefficient and cohesion index depending on increasing test speed, were generally reduced with higher OT. Overall, powder flow analyses revealed that OT of WC resulted in improved flow behaviour of WP. The microbial load of WP was reduced using OT.(c) 2022 Elsevier Ltd. All rights reserved.Öğe Microbiological, physicochemical, textural characteristics and oxidative stability of butter produced from high-pressure homogenisation treated cream at different pressures(Elsevier Sci Ltd, 2020) Sert, Durmus; Mercan, EminMicrobiological, physicochemical, and textural characteristics, and oxidative stability was investigated of butter produced from raw cream treated with high-pressure homogenisation (HPH) at 0 (control), 10, 20, 30, 50, or 70 MPa. HPH treatment of cream increased lightness and decreased yellowness of butter. Firmness of all butter samples was between 97 (control) and 380 N (70 MPa). HPH decreased the spreadability of butter dependent on increasing pressure. A monomodal fat particle size distribution was determined in all butter samples; D[3.2] ranged from 25.25 to 125.5 mu m and HPH decreased average particle size compared with the control. The induction time of butter ranged from 27.40 (control) to 39.61 h (70 MPa). Above 50 MPa, Salmonella, and yeast and moulds were completely inactivated whilst coliforms and staphylococci were not detected in butter from HPH treated cream at 70 MPa, indicating that HPH can improve the microbial quality of butter produced from raw cream. (C) 2020 Elsevier Ltd. All rights reserved.Öğe Powder flow behaviour, functional characteristics and microstructure of whole milk powder produced from cow and buffalo milk mixtures(Elsevier Sci Ltd, 2022) Sert, Durmus; Mercan, Emin; Kilinc, MehmetThe effects of cow and buffalo milk mixtures on powder flow behaviour, functional characteristics and microstructure of whole milk powder was investigated. Milk powder was produced from 100% cow milk (G1), 100% buffalo milk (G2), 75% cow/25% buffalo milk (G3), 50% cow/50% buffalo milk (G4) and 25% cow/75% buffalo milk (G5). A higher proportion of buffalo milk increased the hydroxymethylfurfural, thiobarbituric acid reactive substances and free fatty acid contents in powders, but decreased dis-persibility and wettability. The lowest and highest mean particle size values were obtained in G3 and G2 samples. Milk powder containing a higher level of buffalo milk increased caking ability and compaction coefficients of milk powder. All samples had remarkably cohesive characteristics. A higher proportion of cow milk can improve the flow behaviour of milk powder containing cow and buffalo milk mixtures in terms of caking, cohesion, and powder speed flow dependency.(c) 2022 Elsevier Ltd. All rights reserved.Öğe Processing of skim milk powder made using sonicated milk concentrates: A study of physicochemical, functional, powder flow and microbiological characteristics(Elsevier Sci Ltd, 2021) Sert, Durmus; Mercan, Emin; Dinkul, Muhsin; Aydemir, SerdarThe impact of sonication treatment (0, 5, 15, 30, and 60 min) of skim milk concentrates on physicochemical, functional, powder flow behaviour, and microbiological properties of milk powders was investigated. Sonication resulted in higher firmness and consistency of concentrates with increasing treatment time. In milk powders, higher L* and a* values were observed in sonicated samples. D[4,3] parameter of milk powders was between 8.1 and 255.0 mu m, and sonication for 60 min decreased this value. Sonication significantly decreased the caking, cohesion, and compaction properties of samples. The flow stability of sonicated samples was higher than that of the control. Sonication can result in improved flow characteristics of milk powders in terms of caking, cohesion, and compaction. These observations could relate to effects of sonication on casein micelle, whey proteins denaturation, whey/whey or casein/whey aggregation. Sonication of milk concentrates was also effective in reducing the microbial counts of milk powders. (C) 2021 Elsevier Ltd. All rights reserved.Öğe Production and characterisation of goat milk powder made from sonicated whole milk concentrates(Elsevier Sci Ltd, 2022) Sert, Durmus; Mercan, EminIn the present study, goat milk powder (GMP) was produced from sonicated whole milk concentrates for 0e60 min. The physicochemical, functional, and microbiological properties and powder flow behaviours of the GMP samples were determined. Sonication decreased firmness and consistency values of milk concentrate with the increased treatment time. L* value of the sonicated GMPs was higher than that of the control. The bulk density of samples was between 0.681 and 0.736 g cm(-3), increased by sonication. However, sonication resulted in lower wettability, dispersibility, and foaming capacity. The D [3,2] value of GMPs ranged from 21.9 to 31.1 mm, increased by sonication. Sonication caused reduced cohesion and caking properties of GMPs compared with the control. Also, lower compaction levels at different flow rates were determined in the sonicated samples. In general, powder flow analyses showed that sonication improved GMP flow behaviour. Sonicated samples had reduced microbial load compared with the control. (C)& nbsp;2022 Elsevier Ltd. All rights reserved.
