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Öğe Acceleration of proteolysis, flavour development and enhanced bioactivity in a model cheese using Kuflu cheese slurry: An optimisation study(Elsevier Sci Ltd, 2023) Boran, O. S.; Sulejmani, E.; Hayaloglu, A. A.This study aimed to use Kuflu (a mould-ripened cheese) cheese slurry to accelerate ripening, improve biological activity and flavour development in a model cheese in terms of proteolysis and volatile compounds. Response surface methodology (RSM) was employed for the model cheese to determine higher proteolysis and volatile development level during ripening as a function of Kuflu cheese slurry addition level (0-5 %), salt concentration (1-3 %) and ripening temperature (5-15 C-?). The highest aminopeptidase activities (0.140 and 0.187 OD/g per hour) were determined in 15-day-old samples containing 3 % and 5 % Kuflu cheese slurry, respectively. Also, the use of Kuflu cheese slurry, regardless of ripening, caused an increase in ABTS(*+) antioxidants, angiotensin-converting enzyme (ACE)-inhibition activity and volatile compounds in model cheeses. The sensory evalua-tion indicated that the use of 3 % (w/w) Kuflu cheese slurry, storage temperature 10 ?C for 15 days provided better flavour, odour, texture, colour, appearance and overall acceptability. In conclusion, using Kuflu cheese slurry for model cheese production enhanced the level of proteolysis and volatile flavour composition with shortened ripening time.Öğe ACE-inhibitory activities of peptide fractions (<3 kDa) and identification of peptide sequence by MALDI-ToF-MS in model cheeses incorporating different Lactobacillus species(Academic Press Inc Elsevier Science, 2022) Sahingil, D.; Gokce, Y.; Celikbicak, O.; Hayaloglu, A. A.In this study, the effects of five adjunct lactobacilli on the formation of angiotensin-converting enzyme inhibitory (ACE-i) peptides in model cheeses were investigated. A total of seven peptide fractions (less than 3 kDa) were obtained by means of a fraction collector coupled with a HPLC system. ACE-i activity and peptide sequence analysis of the seven fractions were determined by RP-HPLC and then MALDI-ToF-MS techniques, respectively. Peptides produced from alpha s1- and kappa-caseins had higher amounts compared to those produced by other caseins. There were considerable differences between the fractions in terms of peptide sequences and ACE-i activities. In general, the peptide fraction containing Lactobacillus delbrueckii ssp. bulgaricus exhibited a higher level of ACE-i activity (79.56%) than the other samples. The next highest ACE-i activity was determined in the cheese containing L. plantarum and significant differences were observed between the ACE-i activities of the fractions. The highest ACE-i activity was identified in fractions including f1 (51.39%) for L. casei, f6 (33.49%) for L. helveticus, f4 (46.62%) for L. helveticus DPC4571 and f1 (47.96%) for cheese containing non-adjunct culture. In conclusion, use of lactobacilli as an adjunct in model cheese increased the peptide types and amounts and also ACE-i activity.Öğe An alternative plant-based fermented milk with kefir culture using apricot (Prunus armeniaca L.) seed extract: Changes in texture, volatiles and bioactivity during storage(Elsevier Sci Ltd, 2022) Uruc, K.; Tekin, A.; Sahingil, D.; Hayaloglu, A. A.The aim of the study was to produce kefir from apricot seed extract (ASE) as an alternative functional dairy food for vegans and lactose-intolerant people, the elderly, people with cardiovascular disease and diabetes. Kefir was produced by using cow's milk (100%, as control) and 100% ASE, and cow's milk was mixed with 25%, 50% and 75% (v/v) with ASE for kefir production and the resultant kefir samples were stored at 4 degrees C for 21 days. In proportion to the level of ASE, more yellowish color, lower viscosity, firmness, consistency and TPA values were developed. Additionally, a higher syneresis was observed in kefir samples with increasing levels of ASE. Angiotensin-converting enzyme-inhibitory (ACE-i) and antioxidant activities increased with the increasing levels of ASE used in the kefir production. The levels of individual free amino acids significantly changed by use of ASE and some amino acids including Gln, Gly and Arg dramatically increased, while others decreased by increasing levels of the ASE. Relatively lower levels of gamma-amino butyric acid (GABA) were observed in the samples when compared to the free amino acids, and its concentration decreased by increasing levels of the ASE. The counts for yeasts, lactobacilli and lactococci increased with addition of ASE. Qualitative and quantitative differences were seen in volatile composition of kefir with the addition of ASE and acceptable sensory scores were obtained for all samples during storage. Concentrations of carboxylic acids decreased with increasing levels of ASE in kefir formula; however, the levels of alcohols and aldehydes increased. In conclusion, ASE can be considered in the formulation of fermented milk products or used purely in the production of plant-based fermented non-dairy beverages.Öğe Changes in volatile composition and sensory properties of Iranian ultrafiltered white cheese as affected by blends of Rhizomucor miehei protease or camel chymosin(Elsevier Science Inc, 2016) Soltani, M.; Sahingil, D.; Gokce, Y.; Hayaloglu, A. A.The effect of using various combinations of Rhizomucor miehei protease and camel chymosin (100:0, 75:25, 50:50, 25:75, and 0:100, respectively) on volatile composition and sensory scores in Iranian ultrafiltered white cheese was studied during 90 d of ripening. A solid-phase microextraction-gas chromatography-mass spectrometric method was used for determining the volatile compounds of the cheeses. Forty compounds including esters (12), acids (6), ketones (9), alcohols (3), and miscellaneous compounds (10) were identified. The main classes of volatile components in the cheeses are esters, miscellaneous compounds, and ketones. The type and concentration of the coagulants influenced both volatile composition and sensory scores of the cheeses. Principal component analysis separated the cheeses based on the use of 2 coagulants in various combinations and ripening time. The cheeses produced using higher concentrations of R. miehei were separately located on the plot compared with the cheeses produced using higher concentrations of camel chymosin. Sensory evaluation of the cheeses showed that, in general, the cheeses produced using higher concentrations of camel chymosin received higher body and texture and odor and flavor scores than the cheese produced using higher concentrations of R. miehei. In conclusion, 2 combinations of R. miehei and camel chymosin (75:25 and 25:75, respectively) can be successfully used for the production of Iranian ultrafiltered white cheese, considering the results of volatile composition and sensory analysis.Öğe Characterization of the chemistry, biochemistry and volatile profile of Kuflu cheese, a mould-ripened variety(Elsevier Science Bv, 2008) Hayaloglu, A. A.; Brechany, E. Y.; Deegan, K. C.; MeSweeney, P. L. H.The chemistry, biochemistry and volatile compounds of Kuflu cheese, a Turkish mould-ripened variety were studied. A total of 29 samples were analysed and the titratable acidity, moisture, salt-in-moisture, fat-in-dry matter and total protein contents (as mean values) were 0.96%, 49.97%, 7.49%, 12.18% and 37.84%, respectively, and the pH of the cheeses was 6.29. Indices of proteolysis (i.e., the levels of pH 4.6- and trichloroacetic acid-soluble nitrogen) were high; however, these values were lower than those of other Blue cheeses probably due to proportionally higher levels of total nitrogen and salt-in-moisture in Kuflu cheese samples. Urea-polyacrylamide gel electrophoresis of the pH 4.6-insoluble fractions of the cheeses showed that both alpha(s1)- and beta-caseins were extensively degraded, but beta-casein was less degraded than alpha(s1)-casein. RP-HPLC peptide profiles of the pH 4.6-soluble fractions from Kuflu cheeses showed that some minor quantitative differences were found between the samples, while peptide profiles of the samples were qualitatively similar. One hundred and thirty-eight compounds were identified in the volatile fractions of Kuflu cheese by gas chromatography-mass spectrometry (GC-MS) using a solid-phase microextraction technique. Ketones and alcohols were the principal class of volatile components in Kuflu cheeses, and terpenes and sulphur compounds were found at substantial levels in the majority of the samples, but aldehydes and lactones were present at low levels. The RP-HPLC and GC-MS data were analysed by principal component analysis based on their peptide and volatile profiles, respectively. Kuflu cheeses obtained from different markets had some differences in terms of chemical composition, proteolysis and patterns of aroma compounds. (c) 2007 Swiss Society of Food Science and Technology. Published by Elsevier Ltd. All rights reserved.Öğe Characterizing volatile compounds and proteolysis in Gokceada artisanal goat cheese(Elsevier, 2013) Hayaloglu, A. A.; Yasar, K.; Tolu, C.; Sahingil, D.The objective of the study was to determine the gross composition, proteolysis and volatile compounds in Gokceada goat cheese and to provide initial information on its manufacturing and ripening processes. Gokceada goat cheese is traditionally manufactured from raw goat milk in Gokceada (Imbros) island, Canakkale, Turkey. In the present study, 23 commercial samples were characterized. Urea-polyacrylamide gel electrophoresis of the water-insoluble fractions showed that both alpha(s)- and beta-caseins were extensively decomposed, but beta-casein was less degraded compared to alpha(s)-casein. RP-HPLC of peptide profiles in the water-soluble fractions demonstrated qualitative and quantitative differences among the samples. Sixty volatile compounds were identified by SPME/GC-MS technique with alcohols and esters as the principal class of volatile components in the cheeses. In general, relatively large variability in gross composition and concentration of volatile aroma was found, which probably reflects lack of standardization in the production of the cheese. (C) 2013 Elsevier B.V. All rights reserved.Öğe Determination of the effects of proteolysis-based changes by adjunct lactobacilli on the bioactivity (ACE-inhibitory and antioxidant activities) of cheese: a model cheese study(Springer India, 2024) Sahingil, D.; Gokce, Y.; Hayaloglu, A. A.Bioactive properties, proteolysis and microbiology of model cheeses with and without adjunct lactobacilli (Lactobacillus helveticus, Lactiplantibacillus plantarum, Lactobacillus bulgaricus and L. casei) were studied during 120 days of storage at 8 or 16 C-degrees. Bioactive properties were observed in peptide fractions (< 3 kDa, 3-10 kDa, < 10 kDa) separated using ultrafiltration membranes. Antioxidant activity of these fractions was determined by radical scavenging assays as ABTS [2, 2 ' -azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)]. Angiotensin-converting enzyme-inhibitory (ACE-i) activity (% and IC50) and peptide profiles of 70% ethanol-soluble and -insoluble fractions were determined by RP-HPLC. Use of lactobacilli as an adjunct culture significantly changed the RP-HPLC peptide profiles of the cheeses; however, slight changes were observed in the patterns of urea-polyacrylamide gel electrophoresis. Fractions smaller than 3 kDa had higher ACE-i and antioxidant activities for all cheese samples. In conclusion, this study indicates that the addition of lactobacilli as an adjunct culture contributed to the formation of bioactive compounds in the model cheeses and also changed the proteolysis levels.Öğe Effect of maceration duration on physicochemical characteristics, organic acid, phenolic compounds and antioxidant activity of red wine from Vitis vinifera L. Karaoglan(Springer India, 2016) Kocabey, N.; Yilmaztekin, M.; Hayaloglu, A. A.Effects of different maceration times (5, 10 and 15 days) on composition, phenolic compounds and antioxidant activities of red wines made from the Vitis vinifera L. Karaoglan grown in Malatya were investigated. Maceration duration changed some chemical constituents and color of Karaoglan red wines. A linear relationship was observed between antioxidant activity of wine and maceration duration. Major organic acid was tartaric acid which was at the highest concentration in wine macerated for 10 days. A total of 25 phenolic compounds was determined in wine samples. Within these phenolics; procyanidin B2, trans-caftaric acid, gallic acid, trans-caffeic acid, (+) catechin, (-) epicatechin and quercetin-3-O-glucoside were the most abundant phenolics regardless of maceration duration. In general, extended maceration duration resulted in increase in the concentration of phenolic compounds, reflecting the antioxidant activities of wine. In conclusion, the highest concentrations of total and individual phenolic compounds as well as antioxidant activities were found in wines macerated for 15 days.Öğe The effect of pungency perception and personality traits on consumer's preferences from various regions of Turkiye for cig kofte, a traditional Turkish food(Elsevier, 2022) Boran, O. S.; Omac, B.; Gokce, Y.; Hayaloglu, A. A.The aim of this study was to test whether personality traits influenced liking and choice of pungent foods such as cig kofte for Turkish population. In addition, we explored the role of demographic variables (gender and regions of Turkiye) and various concentration of capsaicin in cig kofte on the relation between personality traits and the frequency of annual cig kofte intake and liking of a spicy meal. Data of 316 participants from different region of Turkiye (47% women and 53% men) were examined. Participants were categorized for demographics, region, and personality traits (sensitivity seeking (AISS), sensitivity to reward (SR) and sensitivity to punishment (SP). They tasted cig kofte including various concentrations of capsaicin (trans-8-methyl-N-vanillyl-6-nonenamide; 50, 75, 100, and 150 mu M) and then evaluated liking and perceived intensity in it.A significant positive correlation was found between the liking of a spicy meal and frequency of annual cig kofte intake. Although a significant negative correlation was observed between the liking of a spicy meal and each concentration of capsaicin in cig kofte, no correlation was seen between the frequency of annual cig kofte intake and each concentration of capsaicin. In addition, the liking of a spicy meal was only associated with a personality trait, AISS, but the frequency of annual cig kofte intake was related to personality traits, AISS and SR. Besides, the relations between the frequency of annual cig kofte intake, liking of a spicy meal, personality traits (AISS, SR, and SP) and various concentration of capsaicin were influenced by both gender and region. Finally, no clear relationship was observed between liking and perceived intensity in cig kofte.Öğe EFFECT OF SINGLE STRAINS OF LACTOCOCCI ON MANUFACTURE AND CHEMICAL QUALITY OF FRESH BEYAZ PEYNIR, TURKISH WHITE-BRINED CHEESE(Akademiai Kiado Zrt, 2008) Hayaloglu, A. A.; Guven, M.Beyaz peynir, Turkish white-brined cheese, was produced with six different strains of Lactococcus and ripened at 6-8 degrees C. Two of these were Lc. lactis subsp. lactis UC317 and NCDO763, while four of them were Lc. lactis subsp. cremoris SK11, HP, Wg2 and AM2. To determine their performance in manufacture of Beyaz cheesemaking, the activity of six different strains of Lactococcus were monitored during cheese production by determining the curd acidity. Also, their proteolytic and lipolytic activities were tested by determining nitrogen fractions and free fatty acid contents, respectively, after 3 days of ripening. These cheeses made with each strain of Lactococcus did not differ significantly in pH decline during cheesemaking. The gross compositions of the fresh cheeses were found to be similar; however, the cheeses made with HP and Wg2 had the lowest and highest levels of salt-in-moisture content, respectively. Water-soluble nitrogen, 12% trichloroacetic acid soluble nitrogen, total free amino acid and total free fatty acid contents were significantly influenced by using different strains of lactococci in manufacture of Beyaz peynir. All strains, except for Wg2 and AM2, gave a satisfactory result in chemical quality of the cheese; however, some differences were observed.Öğe Effect of various blends of camel chymosin and microbial rennet (Rhizomucor miehei) on microstructure and rheological properties of Iranian UF White cheese(Elsevier, 2016) Soltani, M.; Boran, O. S.; Hayaloglu, A. A.Various blends of milk coagulants Rhizomucor miehei protease and camel chymosin were mixed at levels of 100:0, 75:25, 50:50, 25:75 and 0:100, respectively and used in the manufacture of Iranian ultrafiltered (UF) White cheese. Effect of different blends of these coagulants on microstructure and rheological properties of Iranian UF White cheese were studied during 90 days of ripening. The results showed that both microstructure and rheology of the cheeses were influenced by type and concentration of these coagulant blends due to their different proteolytic activities. Use of high concentrations of camel chymosin resulted in a more compact protein network and firmer structure in the cheeses. Increasing levels of camel chymosin in the coagulant blends increased the storage (G') and loss (G '') moduli and decreased loss tangent (8) in the cheeses. In conclusion, increasing levels of camel chymosin provided less protein breakdown and more solid-like viscoelastic structure in UF cheeses. (C) 2016 Elsevier Ltd. All rights reserved.Öğe Effects of blends of camel and calf chymosin on proteolysis, residual coagulant activity, microstructure, and sensory characteristics of Beyaz peynir(Elsevier Science Inc, 2019) Gumus, P.; Hayaloglu, A. A.Beyaz peynir, a white brined cheese, was manufactured using different blends of camel chymosin (100, 75, 50, 25, and 0%) with calf chymosin and ripened for 90 d. The purpose of this study was to determine the best mixture of coagulant for Beyaz peynir, in terms of proteolysis, texture, and melting characteristics. The cheeses were evaluated in terms of chemical composition, levels of proteolysis, total free amino acids, texture, meltability, residual coagulant activity, microstructure, and sensory properties during 90 d of ripening. Differences in the gross chemical composition were statistically significant for all types of cheeses. Levels of proteolysis were highly dependent on the blends of the coagulants. Higher proteolysis was observed in cheeses that used a higher ratio of calf chymosin. Differences in urea-PAGE and peptide profiles of each cheese were observed as well. Meltability values proportionally increased with the higher increasing levels of calf chymosin in the blend formula. These coagulants had a slight effect on the microstructure of cheeses. The cheese made with camel chymosin had a harder texture than calf chymosin cheese, and hardness values of all cheese samples decreased during ripening. The cheeses with a high ratio of calf chymosin had higher residual enzyme activity than those made with camel chymosin. No significant difference in sensory properties was observed among the cheeses. In conclusion, cheeses made with a high level of calf chymosin had a higher level of proteolysis, residual coagulant activity, and meltability. The cheeses also had a softer texture than cheeses made with a high content of camel chymosin. Camel chymosin may be used as a coagulant alone if low or limited levels of proteolysis are desired in cheese.Öğe Effects of breed and lactation stage on melting behaviour of milk fat determined by differential scanning calorimeter(Springer India, 2008) Koytepe, A.; Allpaslan, M.; Hayaloglu, A. A.Three dairy cow breeds ('Holstein', 'Simmental', and 'Jersey') of Turkey were selected for evaluation of melting behavior of their milk fat during various stages of lactation i.e., early lactation (1st month), mid lactation (5th month) and late lactation (10th month)]. The melting behaviour of milk fat was determined by using a differential scanning calorimeter. Milk fat of 'Holstein' cow had lower melting point (MP) than those of 'Jersey' and 'Simmental' cows. 'Simmental' and 'Jersey' milk fat with low NIP did not differ (p>0.05) from other breeds. Milk fats of 'Holstein' and 'Jersey' cows have lower mid MP fractions than milk fats from 'Simmental' cows. Milk fats in the late lactation had higher MP than early lactation (1st month) and mid lactation. NIP were higher levels at the late lactation period in all breeds. The 'Simmental' cows' milk fat contained significantly higher melting fractions than 'Holstein' and 'Jersey' breeds' milk fat. Results showed that the melting profiles of milk fat obtained from 3 different dairy breeds were different during lactation and differential scanning calorimeter technique can be satisfactorily used for determining the melting behaviour of milk fat.Öğe Effects of Wild-Type Starter Culture (Artisanal Strains) on Volatile Profile of Urfa Cheese Made from Ewe Milk(Taylor & Francis Inc, 2015) Kirmaci, H. A.; Hayaloglu, A. A.; Ozer, H. B.; Atasoy, A. F.; Levent, O.In the present study, the development of volatile flavor compounds in sheep's milk Urfa cheese made by using three different combinations of wild-type strains including Lactococcus lactis subsp. lactis 1B4, Lactococcus garvieae IMAU 50157, Enterococcus faecium ATCC 19434, Enterococcus durans IMAU 60200, and Enterococcus faecalis KLDSO.034 was investigated over 180 days. Three batches of cheese were made using above strains as follows: Cheese A (strains ATCC 19434+1B4+IMAU 50157); Cheese B (strains IMAU 60200+ATCC 19434+1B4); Cheese C (strains KLDSO.034+ IMAU 60200+ ATCC 19434+1B4+ IMAU 50157). The fourth batch was produced from raw sheep's milk as control (Cheese D). The volatile compounds were identified using a gas chromatography/mass spectrometry system combined with solid-phase microextraction. In total, 70 volatile compounds were recovered from the cheeses including 10 alcohols (mainly ethanol, 2-methyl-1-propanol, 3-methyl-1-propanol), 20 aldehydes and ketones (mainly 2-pentanone, 2-heptanone), 11 esters (mainly ethyl acetate), 10 acids (mainly acetic acid, 2-hydroxy-4-methyl pentanoic acid), 6 terpenes (mainly alpha-pinene), and 13 miscellaneous compounds (mainly 3,7-dimethyl-1,6-octadiene). While total aldehydes concentration in the control cheese was higher than those made from combinations of wild-type strains (Cheeses A to C), the concentration of alcohols was lower in the former sample. Regarding other volatile compounds there was no clear differences between the cheeses. Results showed that strain combination A or C (Cheese A or C, respectively) could be employed in the manufacture of Urfa cheese made from pasteurized sheep's milk. However, to reach a fair judgement on the proper strain combination for Urfa cheese, aroma profile (i.e., active compounds) released by the strains should be laid open in detail.Öğe Enrichment of antioxidant activity, phenolic compounds, volatile composition and sensory properties of yogurt with rosehip (Rosa canina L.) fortification(Elsevier, 2022) Sahingil, D.; Hayaloglu, A. A.Total phenolic content, pH, color, total antioxidant activity and volatile compounds in yogurt fortified [5-20%] with rosehip (Rosa canina L.) were identified in the present study. Rosehip addition caused a proportional increase in the levels of total phenolics. Fifty-three volatile compounds were identified using the gas chromatographic method, and the major volatiles were carboxylic acids including acetic, butanoic, hexanoic and octanoic acids. After sensory evaluation, yogurt with 20% rosehip pulp added scored highest for overall acceptability. The use of rosehip pulp positively contributed to quality parameters such as water holding capacity, antioxidant capacity and phenolic contents, and contributed to volatile profile and sensory attributes of yogurt. Consuming yogurt with rosehip pulp could provide prebiotics for probiotic bacteria and contribute to the antioxidant activity of yogurt. Furthermore, it may enhance polyphenols with the potential to exert synergistic effects on human health.Öğe Evaluation of volatiles, phenolic compounds and antioxidant activities of rose hip (Rosa L.) fruits in Turkey(Elsevier Science Bv, 2014) Demir, N.; Yildiz, O.; Alpaslan, M.; Hayaloglu, A. A.Five different rose hip (Rosa L) species including Rosa canina, Rosa dumalis, Rosa gallica, Rosa dumalis subsp.boissieri and Rosa hirtissima grown in Turkey are studied. Phenolic compounds, organic acids, sugar and volatile compounds of five different species of rose hips are studied. Total phenolic contents of the rose hip fruits were significantly influenced by species and the levels of total flavonoid and tartaric esters were almost identical in the samples. Antioxidant activities and antiradical scavenging capacities of the extracts were high levels in all rose hip species. It is noticeable that organic acid and sugar contents of the fruits were highly dependence of species and the high levels of ascorbic acid were characteristic. In total, eighteen different phenolic compounds were identified in rose hip species by RP-HPLC-DAD method and, in particular, R. dumalis subsp. boissiericontained different phenolic compounds. Gallic acid, catechin, procyanidin-B2 and hydroxycinnamic acid derivatives (chlorogenic, t-caffeic, p-coumaric, ferrulic and sinapic acids) were principal for all rose hip species. A total of 52 volatile compounds were identified in rose hip species by SPME/GC-MS and it was characterized by abundance of alcohols and aldehydes with also some monoterpenes and sesquiterpenes. (C) 2014 Elsevier Ltd. All rights reserved.Öğe Evolution of proteolysis in Urfa cheese made from ewe's milk by wild type starter culture systems(Elsevier Science Bv, 2014) Kirmaci, H. A.; Hayaloglu, A. A.; Ozer, H. B.; Atasoy, A. F.; Turkoglu, H.The evolution of proteolysis in Urfa cheese made from ewe's milk by using various combinations of wild-type strains of Lactococcus lactis (strain 1B4), Lactococcus garvieae (strain IMAU 50157), Enterococcus faecalis (strain KLDSO.0341),Enterococcus faecium (strain ATCC 19434) and Entero coccus durans (strain IMAU 60200) was monitored for 180 days. The strains used in the study were isolated from traditional raw ewe's milk Urfa cheese and characterized by phenotypic and genotypic studies previously. Three different combinations of the strains were employed in the manufacture of cheeses from pasteurized milk. These are: cheese A (strains 1B4 + ATCC 19434 + IMAU 50157), cheese B (strains 1B4 + IMAU 60200+ ATCC 1934) and cheese C (strains ATCC 19434 + 1B4 + IMAU 50157 + IMAU 60200 + KLDSO.0341). The control cheese (cheese D) was produced from raw ewe's milk without starter culture. Proteolysis in the cheeses was evaluated using urea-PAGE of pH 4.6-insoluble and RP-HPLC of both 70% ethanol-insoluble (EtOH-i) and ethanol-soluble (EtOH-s) nitrogen fractions. The variations in water soluble nitrogen (WSN) and trichloroacetic acid-soluble nitrogen (TCA-SN) were also monitored during ripening as well as gross compositions of the cheeses. Results indicated that the degradation of casein fractions were faster in the cheeses A, B and C than the control. The peptide profiles of 70% EtOH-i and EtOH-s nitrogen of the cheeses A, B and C were close to each other but far more extensive than the control cheese. The proteolytic capacities of the strains employed in the cheeses A, B and C were superior to that of raw milk flora. To conclude, any of the combinations of the wild-type strains could be used in the production of Urfa cheese from pasteurized ewe's milk, as long as the safe use of enterococcal strains is assured. (C) 2014 Elsevier B.V. All rights reserved.Öğe Influence of brine immersion and vacuum packaging on the chemistry, biochemistry, and microstructure of Mihalic cheese made using sheep's milk during ripening(Springer France, 2012) Hayaloglu, A. A.; Bansal, N.; McSweeney, P. L. H.Due to practical and hygienic uses in storage and marketing, cheese maker preference for the use of vacuum packaging instead of the brining method has increased significantly in recent years. The objective of the paper was to study and compare the chemistry, biochemistry, and microstructure of Mihalic cheeses ripened in vacuum packaging or under brine over 360 days. Proteolysis in Mihalic cheese was quite low (e.g., pH 4.6 soluble nitrogen was lower than 15%, as a percentage of the total nitrogen, and alpha (s1)-casein was slower in comparison to other brined cheeses) due to its high salt-in-moisture and low moisture contents. Urea-PAGE patterns of the pH 4.6 insoluble fractions of the cheeses showed different degradation patterns of alpha(s1)-casein in cheeses of different ages. However, beta-casein was relatively resistant to hydrolysis. Packaging the cheese in polyethylene bags significantly increased the levels of pH 4.6 soluble nitrogen, 12% trichloroacetic acid-soluble nitrogen, and free amino acids compared to the cheeses ripened in brine. The total concentrations of free amino acids (FAA) in cheeses increased after 120 days of ripening, and Glu, Val, Leu, Lys, and Phe were the most abundant FAA in the cheeses. Higher levels of these AAs were found in the cheeses ripened in polyethylene bags. The peptide profiles by reversed-phase high-performance liquid chromatography of 70% (v/v) ethanol-soluble and ethanol-insoluble fractions of the pH 4.6 soluble fraction of the cheeses revealed that slight differences were found in the levels of some peptides between cheeses. Majority of the volatile compounds were present at higher concentrations in vacuum-packaged cheeses than in those ripened in brines. The images obtained by scanning electron microscopy of the cheeses ripened in polyethylene bags were clearly different (the protein matrix was more compact) from those of brine-ripened cheeses. The cheese ripened in vacuum packaging was completely different in terms of chemical composition, proteolysis, volatile composition, and microstructure. It was concluded that the vacuum packaging may be useful to maintain the chemical and biochemical qualities of Mihalic cheese, and it is also an easy practice during ripening.Öğe Influence of goat breeds and starter culture systems on gross composition and proteolysis in Gokceada goat cheese during ripening(Elsevier, 2013) Hayaloglu, A. A.; Tolu, C.; Yasar, K.Milk from two different breeds (Gokceada and Turkish Saanen) and three different starter culture systems (starter-free, mesophilic and thermophilic cultures) were used in the manufacture of Gokceada goat cheeses. Milk from the two breeds differed in dry matter, protein, fat and ash contents. These differences were reflected on the yield and chemical composition of the cheese. The pH values and soluble nitrogen fractions (in water, 12% trichloroacetic acid, and 5% phosphotungstic acid) were significantly influenced by the starter culture systems, but not the types of milk. The degradation of alpha(s)-caseins and its degradation products sharply increased after 60 days of ripening, especially in the cheese made using mesophilic starters. Greater changes were observed in RP-HPLC peptide profiles of the cheeses made using mesophilic starter cultures during ripening; however, the breed has minor effect on peptide profile. In conclusions, cheeses made using mesophilic starter culture exhibited different proteolysis patterns during ripening and the milk from Gokceada breed increased the gross composition parameters and cheese yield. (C) 2013 Elsevier B.V. All rights reserved.Öğe Influence of purple basil (Ocimum basilicum L.) extract and essential oil on hyperlipidemia and oxidative stress in rats fed high-cholesterol diet(Elsevier, 2021) Gokce, Y.; Kanmaz, H.; Er, B.; Sahin, K.; Hayaloglu, A. A.The aim of this study was to investigate and compare the effects of purple basil methanolic extract and essential oil on serum lipid profiles in rats fed a high cholesterol diet. Feeding a high-cholesterol diet increased serum lipid profiles, leptin, hepatic triglyceride, cholesterol levels, malondialdehyde concentrations, fatty acid synthase (FAS), liver X receptors (LXRs), ATP-citrate lyase (ACLY), and sterol regulatory element-binding proteins (SREBP-1c) expression in the liver in rats. The extract and essential oil reduced serum triglycerides by 28.2%, 30.7%, and total cholesterol by 21.7% and 14.5%, respectively. The applications did not return the aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities to their normal levels. Extract and feno-fibrate administration decreased serum leptin levels by 17.5% and 27.5%, respectively. The extract reduced hepatic triglyceride by 16.4% and total cholesterol by 22.1%. Fenofibrate reduced the triglyceride and hepatic total cholesterol by 25.5% and 46.3%, respectively. The decrease in MDA levels was 34.6% in those treated with the extract, and less in those who were applied essential oil. Expression of fatty acid synthase (FAS), liver X receptors (LXRs), ATP-citrate lyase (ACLY), and sterol regulatory element-binding proteins (SREBP-1c) in the liver decreased by 20.9%, 15.4%, 20.7% and 16.9%, respectively, when the extract was administered. For those treated with essential oil, the decline was 9.9%, 13.6%, 10.2%, and 12.5%. It decreased by 38.1%, 56.8%, 21.7% and 40.8% in those administered fenofibrate. The ABTS and DPPH based antioxidant activities and total phenolic contents of the extract were 67.83%, 86.98% and 57.94 +/- 0.39 mg Gallic acid equivalent (GAE), respectively. The results reveal that methanolic extract of purple basil may contain hypolipidemic and antioxidant substances and its protective effect on the liver.
