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Öğe Changes in volatile composition, proteolysis and textural and sensory properties of white-brined cheese: effects of ripening temperature and adjunct culture(Springer France, 2014) Sahingil, Didem; Hayaloglu, Ali A.; Simsek, Osman; Ozer, BarbarosThe effects of ripening temperature and adjunct cultures (Lactobacillus helveticus and Lactobacillus casei) on the volatile compounds and sensory and textural properties of white-brined cheese were investigated. Three batches of cheese were produced: cheese Awas inoculated with only cheese starter culture (Lactococcus lactis subsp. lactis plus Lactococcus lactis subsp. cremoris), cheese B was inoculated with cheese starter culture plus Lactobacillus helveticus and cheese C was inoculated with cheese starter culture plus Lactobacillus casei. Cheeses were ripened at 6 or 12 degrees C and analyzed at 30-day intervals up to 120 days of ripening. The use of adjunct culture and ripening temperature significantly influenced the pH and proteolysis of cheeses (P< 0.05). Acids, ketones and alcohols were found at high levels in all three cheeses. Volatiles were significantly influenced by the use of the adjunct cultures, ageing and to some extent ripening temperature (P< 0.05). Textural parameters of the cheeses were significantly affected by the adjunct culture during ripening (P< 0.05). The sensory scores of the cheese samples decreased during the ripening period. An age-related bitterness was detected by the panellists in 90 or 120-day-old cheeses with added adjunct cultures. In conclusion, the use of adjunct culture and ripening at 12 degrees C enhanced the volatile composition and changed the texture profiles of the cheeses.Öğe Changes of proteolysis and angiotensin-I converting enzyme-inhibitory activity in white-brined cheese as affected by adjunct culture and ripening temperature(Cambridge Univ Press, 2014) Sahingil, Didem; Hayaloglu, Ali A.; Kirmaci, Huseyin A.; Ozer, Barbaros; Simsek, OsmanThe effects of use of adjunct cultures (Lactobacillus helveticus and Lb. casei) and ripening temperatures (6 or 12 degrees C) on proteolysis and angiotensin-I converting enzyme (ACE)-inhibitory activity in white-brined cheeses were investigated during 120 d ripening. Proteolysis was monitored by urea-polyacrylamide gel electrophoresis (urea-PAGE) and reversed phase-HPLC (RP-HPLC) of water-insoluble and -soluble fractions of the cheeses, respectively. Urea-PAGE patterns of the samples revealed that the intensities of the bands representing casein fractions decreased in the experimental cheeses, being more pronounced in the cheeses made with adjunct cultures. Similarly, peptide profiles and the concentrations of individual and total free amino acids were influenced by both the adjunct cultures and ripening temperatures. The ACE-inhibitory activity of the water-soluble extracts of the cheeses were higher in the cheeses made using adjunct cultures (especially Lb. helveticus) and ripened at 12 degrees C. The ACE-inhibitory activity did not decrease during ripening. The contribution of Lb. helveticus to the development of proteolysis and ACE-inhibitory peptide activities were higher than that of Lb. casei. To conclude, the use of Lb. helveticus as adjunct culture in white-brined cheese and ripening at 12 degrees C would be recommended to obtain white-brined cheese with high ACE-I-inhibitory peptides activity and higher levels of preoteolysis.Öğe Characterization of Antimicrobial Peptide Fraction Producing Lactobacillus spp. Based on LC/MS-MS and Determination of ACE-inhibitory Activity in Kefir(Galenos Publ House, 2022) Atalay, Merve; Sahingil, DidemIn the present study, bioactive properties such as ACE-I activity and antimicrobial activity of kefir using different Lactobacillus (Lactobacillus delbrueckii ssp. bulgaricus ATCC 11842, Lactobacillus helveticus ATCC 15009 and Lactobacillus plantarum ATCC 14917) on some pathogen and Gram-positive bacteria during 28 day-storage periods was investigated and proteolysis (RP-HPLC peptide profiles, RP-HPLC amino acid profiles) were studied. The antimicrobial activity was investigated in kefir extract and separated peptide fractions (<3 kDa, named F2) which were characterized by LC-MS/MS and precursor and product ions were determined. Antimicrobial activity has been observed against pathogenic bacteria such as Escherichia coli (E. coli) in all samples. But the results revealed that the F2 fraction separated from kefir manufactured using Lactobacillus had a stronger antibacterial effect than control samples. It was determined that the F2 fraction has antimicrobial activity against S. aureus, S. warneri 95052 and S. hominis. The ACE-I activity of samples A, B, C and K were 76.47%, 84.95%, 87.33% and 85.57%, respectively. In the kefir using Lactobacillus has increase of ACE-I activity and was significant (P<0.01). In this study, it was concluded that the using of adjunct Lactobacillus contributed to the functional value of kefir.Öğe A comparative study of compositional, antioxidant capacity, ACE-inhibition activity, RP-HPLC peptide profile and volatile compounds of herbal artisanal cheeses(Elsevier Sci Ltd, 2020) Sulejmani, Erhan; Sahingil, Didem; Hayaloglu, Ali AdnanThe effect of aromatic herbs on the RP-HPLC peptide profile, angiotensin l-converting enzyme-inhibitory (ACE-i) activity, antioxidant capacity and volatile compounds in artisanal cheeses was investigated. Three representative artisanal cheeses (white brined, beaten and Kashkaval cheeses) were produced using aromatic herbs (Mentha longifolia, Origanum vulgare, Thymus longicaulis, Alium sativum, Petroselinum crispum, Capsicum annuum). Compared with control group, herbal cheeses (except white cheese with garlic and parsley) revealed a significant increase in antioxidant activity. The highest ACE-i activity was noticed in 60 days of ripening with a mean value of 98.72% in goat beaten cheese and 97.78% in Kashkaval cheese enriched with peppers. One hundred and one volatile compounds, mainly acids, esters and alcohols, were identified in significantly higher amounts in cheeses made with herbs and contributed to the development of the overall aroma perception. (C) 2020 Elsevier Ltd. All rights reserved.Öğe Effect of blends of camel chymosin and microbial rennet (Rhizomucor miehei) on chemical composition, proteolysis and residual coagulant activity in Iranian Ultrafiltered White cheese(Springer India, 2019) Soltani, Mostafa; Sahingil, Didem; Gokce, Yasemin; Hayaloglu, Ali A.Iranian Ultrafiltered White cheese was produced by using different blends of coagulants (100:0, 75:25, 50:50, 25:75 and 0:100; Rhizomucor miehei and camel chymosin, respectively) and ripened for 90days. The effect of different combinations of these coagulants on chemical composition, proteolysis and residual coagulant activity of the cheeses were studied. The results showed that pH, fat-in-dry matter, salt-in-dry matter and protein contents of the cheeses were significantly influenced by type and concentration of the coagulants. The difference between proteolytic activities of the two coagulants resulted in different levels of proteolysis in the cheeses. A direct relationship was determined between using higher concentrations of R. miehei and increasing the hydrolysis of (s1)-casein in the cheeses, during ripening. The residual coagulant activity was influenced by the type and concentration of the coagulant as well. In conclusion, R. miehei provided a higher level of proteolysis and residual coagulant activity compared with camel chymosin.Öğe Floral authentication of some monofloral honeys based on volatile composition and physicochemical parameters(Springer, 2022) Yildiz, Oktay; Gurkan, Hacer; Sahingil, Didem; Degirmenci, Atiye; Kemal, Mehtap Er; Kolayli, Sevgi; Hayaloglu, Ali AdnanTwenty four honey samples of eight distinct botanical origins obtained from different regions of Turkey were analyzed in this study. Various physicochemical (glucose and fructose content, color, diastase activity, electrical conductivity, optical rotation, moisture and proline content), biochemical (total phenolic content, total flavonoid content, FRAP antioxidant capacity and DPPH radical scavenging activity) and volatile analytical methods were used for floral authentication of the honeys. Identification of 103 volatile compounds from different chemical classes was carried out using SPME/GC/MS. The availability of physicochemical and volatile identification methods, instead of melissopalynology which is dependent on the researcher's ability and judgment regarding honey classification, was investigated. The results were statistically processed, and principal component analysis (PCA) was applied. The first two principal components explained 98.10% of the total variance, and the PCA produced eight different groups rhododendron, chestnut, lavandula, astragalus, chaste tree, polyfloral, oak, and pine honeys, each corresponding to a distinct botanical origin. Polyfloral honeys formed a cluster, although those samples were rather widespread. The studied honeys exhibited specific volatile compounds and biochemical properties which may be capable of use as floral markers.Öğe GC/MS-Olfactometric Characterization of the Volatile Compounds, Determination Antimicrobial and Antioxidant Activity of Essential Oil from Flowers of Calendula (Calendula officinalis L.)(Taylor & Francis Ltd, 2019) Sahingil, DidemCalendula officinalis is a member of the richest family of flowering plants, Asteraceae. In this study, the volatile profile of C. officinalis flowers obtained from the Marmara region was determined using SPME-GC/MS-O technique. Antimicrobial effects of essential oil in the C. officinalis flowers against Gram negative and Gram positive bacteria and yeast were determined by disc diffusion method (0.6 mm disc diameter). Six different concentrations (10-200 mu g/mu L) were studied for the determination of minimum inhibitory concentration. 22 aroma active compounds were identified in the sample of the GC/MS-Olfactometer. Antimicrobial activity was tested against both Gram negative and Gram positive bacteria using essential oil of C. officinalis flowers. As a result, it was found that essential oils of C. officinalis flower had high antimicrobial activity. A total of 21 main essential oils were found in C. officinalis flowers.Öğe Influence of using different ratios of small ruminants (ovine and caprine) milk on compositional and proteolytic changes during ripening of raw milk lighvan cheese(Elsevier Sci Ltd, 2024) Soltani, Mostafa; Saremnezhad, Solmaz; Kanmaz, Hilal; Tekin, Ali; Gokce, Yasemin; Kaya, Busra; Sahingil, DidemLighvan cheese was manufactured using different ratios of ovine and caprine milk (100:0, 75:25, 50:50, 25:75, 0:100) and ripened for 90 days. Chemical composition, proteolysis level, total and individual levels of free amino acids, texture and residual coagulant activity were analysed during ripening. Significant decreases in pH and moisture content and significant increases in texture parameters, residual coagulant activity, soluble nitrogen fractions, fat, and protein contents were determined in the cheese manufactured using higher ratios of ovine milk (P <0.05). Differences in gel electrophoresis and RP-HPLC peptide profiles of the cheeses were seen. Leu and Phe were detected as predominant free amino acids in the cheeses during ripening. In conclusion, besides the cheese manufactured using ovine milk alone, the lighvan cheeses made with ovine and caprine milk in the ratios of 75:25 and 50:50 can be introduced as the preferred cheeses because of having proper proteolysis indices and semi-hard texture. (c) 2023 Elsevier Ltd. All rights reserved.Öğe Rheological and physicochemical properties of apricot kernel cream-An innovative cream-like product(Wiley, 2021) Sahingil, Didem; Hayaloglu, Ali AdnanPhysicochemical and rheological characteristics of apricot kernel milk cream (AMC) were tested and compared with cow's milk cream (CMC) during 60 days of storage. The dry matter content was 64.03% and 61.35% in CMC and AMC samples, respectively. Color values (L* and a*) for the samples were unchanged during storage. For antioxidant activity, the sample of AMC has a stronger ABTS* radical scavenging capacity than the CMC; that is, the ABTS* values were 76.74 and 114.39 mg/L for CMC and AMC, respectively (p < .05). Loss modulus (G '') values were lower in samples than storage modulus (G ') indicating that all cream samples had a hard, viscoelastic-like behavior. This study can provide useful information for producers to distinguish apricot kernel creams by their basic compositional properties and their rheological properties. Based on the data found in this study, it is predicted that apricot kernel cream can be produced as a new product for vegetarian people nutrients. Novelty impact statement Apricot seed cream, which is plant-based product, gave similar rheological properties like regular milk cream. Results provide a useful guide for producers to distinguish apricot seed creams based on their overall rheological properties. It is seen that the cream with apricot seeds can be produced as a new product especially for vegan nutrition.
