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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 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 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 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 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.Öğe Optimization of proteolysis and angiotensin converting enzyme inhibition activity in a model cheese using response surface methodology(Elsevier Science Bv, 2019) Sahingil, D.; Gokce, Y.; Yuceer, M.; Hayaloglu, A. A.Adjunct cultures including lactobacilli play important role in cheese proteolysis and bioactivity including Angiotensin Converting Enzyme (ACE)-inhibition and antioxidant activity. Four species of lactobacilli was used in the manufacture of model cheese and these were salted at different levels and the resultant cheeses were ripened at different time and temperature to understand the effect of salting and ripening conditions. The effects of the use of various of lactobacilli (Lactobacillus casei, Lb. helveticus, Lb. delbrueckii ssp. bulgaricus and Lb. plantarum), salt concentrations (1, 2, 3, 4 and 5%), ripening times (1, 30, 60, 90 and 120 days) and temperatures (5, 10, 15 and 20 degrees C) were investigated. The experiments were designed to determine the optimal salt concentration, ripening times and temperatures for optimal proteolysis, the highest levels of ACE-inhibition and antioxidant activity. The highest level of proteolysis and ACE-inhibiting activity in the model cheese was observed when ripening temperatures were between 8 and 16 degrees C, salt concentration at 2.5-3.0% and with a ripening period of about 60 days. The use of each lactobacilli contributed to the proteolysis in different manner; for example, ACE-inhibiting activity and antioxidant activity in the model cheese.
