Person: YILDIZ, ELİF
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YILDIZ
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ELİF
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Publication Characterization of fruit vinegars via bioactive and organic acid profile using chemometrics(Mdpi, 2023-10-01) Yıldız, Elif; YILDIZ, ELİF; Bursa Uludağ Üniversitesi/Keleş Meslek Yüksekokulu.; 0000-0003-1356-9012; AAG-6424-2021Vinegar has been known as a traditional remedy since ancient times. In addition to being used as a flavoring and aroma enhancer in world cuisines, it has attracted more and more attention due to its bioactive potential and health properties. Although the most common use is apple cider vinegar together with grape vinegar, vinegar produced from red fruits has come to the fore due to their health purposes. Rosehip, pomegranate, fig, guelder-rose, blackberry, raspberry, and blueberry vinegars were evaluated regarding the organic acid content, phenolic compound content, and bioactive potential to assess their health potential and associated contents. Acetic acid, citric acid, succinic acid, and malic acid were determined as prominent organic acids in the vinegar samples. In contrast, gallic acid, vanillic acid, protocatechuic acid, and ferulic acid were dominant regarding phenolic compounds. Raspberry, guelder-rose, and pomegranate vinegars came forth regarding their bioactive content and potential. The discriminative parameters of the vinegar samples were pH, total acidity, dL-isocitric acid, gallic acid, and hydroxybenzoic acid. Fruit vinegars were determined to have a notable bioactive content compared to apple and grape vinegars. The use of these vulnerable bioactive materials in vinegar fermentation could provide an effective way for nutrition and raw material resourcing.Publication Antioxidant and anti-diabetic properties of spirulina platensis produced in Turkey(Soc Brasileira Ciencia Tecnologia Alimentos, 2021-07-01) Güldaş, Metin; Ziyanok-Demirtaş, Sedef; Şahan, Yasemin; Yıldız, Elif; Gürbüz, Ozan; GÜLDAŞ, METİN; ZİYANOK DEMİRTAŞ, SEDEF; ŞAHAN, YASEMİN; YILDIZ, ELİF; GÜRBÜZ, OZAN; Bursa Uludağ Üniversitesi/Sağlık Bilimleri Fakültesi/Beslenme ve Diyetetik Bölümü; Bursa Uludağ Üniversitesi/Fen-Edebiyat Fakültesi/Biyoloji Bölümü; Bursa Uludağ Üniversitesi/Ziraat Fakültesi/Gıda Mühendisliği Bölümü; 0000-0002-5187-9380; 0000-0003-3878-3808; 0000-0003-1356-9012; 0000-0001-7871-1628; ABE-6748-2020; GLT-7125-2022; AAG-6424-2021; AAH-4272-2021; U-1332-2019Spirulina produced in Turkey has a high antioxidant capacity determined by the three common methods (ABTS, CUPRAC, and DPPH). The major phenolics found in Spirulina were acacetin (53.62%) and pinocembrin (41.28%). The bio-accessibility values of the phenolic compounds in Spirulina were approximately 60%. PUFas are the significant antioxidant compounds to prevent lipid peroxidation. Spirulina has been found to reduce blood sugar and oxidative stress due probably to the high amount of omega-6 PUFA. By the treatment of Spirulina, the levels of antioxidant enzymes (GSH-Px and SOD) were increased 240 and 60% in the healthy rats, while 19 and 59% in the diabetics. In diabetic rats fed with Spirulina, glucose, triglyceride, total cholesterol levels in blood and malondialdehyde content in body tissues were decreased by 20, 31, 22 and up to 56%, respectively. In-vitro and in-vivo tests have shown that Spirulina has anti-hyperglycaemic, anti-hyperlipidaemia and antioxidative effects on diabetic rats.Publication Impact of coffee silverskin on in-vitro viability of kefir culture during storage(Croatian Dairy Union, 2022-01-01) Değirmencioğlu, Nurcan; Özmen-Togay, Sine; GÜLDAŞ, METİN; ÖZMEN TOĞAY, SİNE; Gülkün, Günnur; YILDIZ, ELİF; Yıldız, Elif; Sahan, Yasemin; ŞAHAN, YASEMİN; Gürbüz, Ozan; GÜRBÜZ, OZAN; Bursa Uludağ Üniversitesi/Ziraat Fakültesi; Bursa Uludağ Üniversitesi/Sağlık Bilimleri Fakültesi; Bursa Uludağ Üniversitesi/Keleş Meslek Yüksekokulu.; 0000-0002-5187-9380; 0000-0003-1356-9012; 0000-0001-7871-1628; GLT-7125-2022; AAG-6424-2021; U-1332-2019Probiotic dairy products must contain a certain level of live probiotic microorganisms at the time of consumption. The number of live microorganisms in kefir culture, which is a mixture of different microorganisms, may change during storage due to various factors. In this study, the effects of adding a novel ingredient coffee bean membrane (CSS-coffee silverskin), on the viability of microorganisms contained in kefir culture were investigated. For this purpose, CSS obtained from 2 different coffee varieties (Arabica and Robusta) was added to kefir samples at 3 different concentrations (0.5, 0.75 and 1.0 %) at the beginning of fermentation. It was observed that especially the addition of CSS belonging to the Robusta variety significantly increased the viability of lactic acid bacteria (lactobacilli and lactococci) which accounted for 88-94.10 % and 82.37-92.44 % respectively. During the storage period of 28 days at 4 degrees C; it could be observed that kefir enrichment with CSS of both coffee varieties increased the viability of lactobacilli and lactococci after in-vitro digestion, depending on the rate of supplementation. Number of yeasts was decreased during the storage.Publication Oxidative stress and antioxidants-a critical review on in vitro antioxidant assays(Mdpi, 2022-12-01) Kotha, Raghavendhar R. R.; Tareq, Fakir Shahidullah; Luthria, Devanand L. L.; Yıldız, Elif; YILDIZ, ELİF; Bursa Uludağ Üniversitesi/Keleş Meslek Yüksek Okulu.; 0000-0003-1356-9012; AAG-6424-2021Antioxidants have been widely studied in the fields of biology, medicine, food, and nutrition sciences. There has been extensive work on developing assays for foods and biological systems. The scientific communities have well-accepted the effectiveness of endogenous antioxidants generated in the body. However, the health efficacy and the possible action of exogenous dietary antioxidants are still questionable. This may be attributed to several factors, including a lack of basic understanding of the interaction of exogenous antioxidants in the body, the lack of agreement of the different antioxidant assays, and the lack of specificity of the assays, which leads to an inability to relate specific dietary antioxidants to health outcomes. Hence, there is significant doubt regarding the relationship between dietary antioxidants to human health. In this review, we documented the variations in the current methodologies, their mechanisms, and the highly varying values for six common food substrates (fruits, vegetables, processed foods, grains, legumes, milk, and dairy-related products). Finally, we discuss the strengths and weaknesses of the antioxidant assays and examine the challenges in correlating the antioxidant activity of foods to human health.Publication Effect of drying methods and pre-treatments on bioactive potential of persimmon ( diospyros kaki l.)(Springer, 2023-12-28) Yıldız, Elif; YILDIZ, ELİF; Yılmaz, Aslıhan; YILMAZ, ASLIHAN; Gürbü, Ozan; Alibaş, İlknur; ALİBAŞ, İLKNUR; GÜRBÜZ, OZAN; Bursa Uludağ Üniversitesi/Ziraat Fakültesi/Gıda Mühendisliği Bölümü.; Bursa Uludağ Üniversitesi/Ziraat Fakültesi/Biyoistatistik Mühendisliği Bölümü.; 0000-0003-1356-9012; 0000-0002-4913-905X; 0000-0002-1898-8390; AAY-2088-2021In this research, persimmon samples (sliced, pureed) were dehydrated by convective (50 and 100 degrees C) and microwave (100 W) drying techniques with different pre-treatment combinations of sugar addition (25%) and blanching (100 degrees C, 5 min). Each pre-treatment consisting of sugar addition, slicing, and blanching resulted in a significant increase in color parameters compared to unpretreated samples. Color parameters measured at low drying temperatures were lower than high ones. Also, 100 W dried samples were higher in total anthocyanin content, and the pureed samples were 24.80% higher than sliced ones. The bioactive potential was evaluated regarding extractable, hydrolysable, and bioaccessible phenolic fractions by total phenolic content and ABTS (2,2 '-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid), DPPH (2,2-diphenyl-1-picrylhydrazyl) and CUPRAC (Cupric Reducing Antioxidant Capacity) antioxidant capacity assays. (i) 50 degrees C drying prevailed on drying at 100 degrees C and 100 W, especially in terms of extractable phenolic fractions and bioaccessible phenolic fractions; (ii) Sliced samples were higher for EPF and BPF, while pureed ones were higher in hydrolysable phenolic fractions; (iii) Blanched samples were relatively higher than unblanched ones in total phenolic content. For antioxidant capacity assays, extractable phenolic fractions were higher in blanched samples and bioaccessible phenolic fractions in unblanched ones (TEAC(ABTS), TEAC(CUPRAC)). (iv) Sugar addition negatively affected the bioactive potential in persimmon samples; no-sugar-added samples were higher, especially in bioaccessible phenolic fractions (p < 0.01; Total phenolic content, TEAC(ABTS,) TEAC(CUPRAC)). (v) The CUPRAC assay was the most appropriate method due to providing a view of more statistical distinction by picturing the same potential.Publication Effects of honey enrichment with Spirulina platensis on phenolics, bioaccessibility, antioxidant capacity and fatty acids(Elsevier, 2021-09-12) Güldaş, Metin; Gürbüz, Ozan; Çakmak, İbrahim; Yıldız, Elif; Şen, Hasan; GÜLDAŞ, METİN; GÜRBÜZ, OZAN; ÇAKMAK, İBRAHİM; YILDIZ, ELİF; Bursa Uludağ Üniversitesi/Sağlık Bilimleri Fakültesi/Beslenme ve Diyetetik Bölümü.; Bursa Uludağ Üniversitesi/Ziraat Fakültesi/Gıda Mühendisliği Bölümü.; Bursa Uludağ Üniversitesi/Ziraat Fakültesi/Zootekni Bilimleri Bölümü.; Bursa Uludağ Üniversitesi/Arıcılığı Geliştirme Uygulama ve Araştırma Merkezi.; Bursa Uludağ Üniversitesi/Keles Meslek Yüksekokulu/Gıda Teknolojisi Bölümü.; 0000-0002-5187-9380; 0000-0001-7871-1628; 0000-0003-1356-9012; GLT-7125-2022; AAG-6424-2021; U-1332-2019; KFC-1744-2024The honeybees have been fed by Spirulina platensis extract and algal honey with green color produced by the bees naturally was obtained the first time in order to enhance its medicinal properties, mainly antioxidant properties. Antioxidant capacity, bioaccessibility of phenolics, hydrolysable and extractable phenolics, sugar, phenolic and fatty acid profiles were determined in the Spirulina honey. Total phenolic content of the Spirulina honey was 14.37 mg GAE/100g and increased 28.53% with Spirulina enrichment. Antioxidant capacities of the Spirulina honey were determined as 6.31, 5.85 and 3.66 mu mol Trolox/g by ABTS, CUPRAC and DPPH methods in bioaccessible extracts. No significant difference was observed between control and Spirulina honey samples in terms of bioaccessibility of the total phenolics (p <= 0.01). Among the detected phenolic compounds (15 phenolics), acacetin (48.55%) and pinocembrine (47.13%) were the highest. Total phenolic content of the honey can be enriched up to 20% by feeding of the honey bees with 10% of Spirulina. Saccharose content in Spirulina honey was lower than the control honey as 4.42%.Publication Use of coffee silverskin to improve the functional properties of cookies(Springer India, 2019-06-01) GÖÇMEN, DUYGU; ŞAHAN, YASEMİN; YILDIZ, ELİF; Yıldız, Elif; Coşkun, Meral; Aroufai, Idriss Amit; Bursa Uludağ Üniversitesi/Ziraat Fakültesi/Gıda Mühendisliği Bölümü.; 0000-0003-1356-9012; AAG-6424-2021; ABE-6748-2020; KDP-3344-2024The purpose of this study was to determine the suitability of coffee silverskin (CSS) supplementation to enhance phenolic content and antioxidant capacity of cookies. Cookie samples were prepared with partial replacement of wheat flour by CSS (2.5, 5.0, and 7.5%). Spread ratios were found lower in all cookies with CSS than in control. Cookies became darker with increasing levels of CSS. This is due to the fact that CSS has a dark color like cocoa. CSS supplementation had improved functional quality of cookies by increasing phenolic contents, antioxidant capacities, and in vitro bioaccessibilities of them. According to the sensory evaluation, all samples with CSS received 6 and above scores (6: like slightly, 7: like moderately) for all attributes from the panelists. The results demonstrated that CSS supplementation have a good potential for developing functional and acceptable cookies and similar bakery products.Publication Phenolics, antioxidant capacity and bioaccessibility of kombucha tea(Amer Chemical Soc, 2019-03-31) Değirmencioğlu, Nurcan; Yıldız, Elif; Şahan, Yasemin; Güldaş, Metin; Gürbüz, Ozan; YILDIZ, ELİF; ŞAHAN, YASEMİN; Bursa Uludağ Üniversitesi/Fen Bilimleri Enstitüsü/Gıda Mühendisliği Bölümü.; 0000-0003-3457-251X ; 0000-0003-1356-9012 ; AAG-6424-2021; ABE-6748-2020Publication Obesity-associated pathways of anthocyanins(Soc Brasileira Ciencia Tecnologia Alimentos, 2021-06-01) ; Yıldız, Elif; YILDIZ, ELİF; Ellergerzen, Pinar; Guldas, Metin; GÜLDAŞ, METİN; Acar, Asli Gul; ACAR, ASLI GÜL; Gurbuz, Ozan; GÜRBÜZ, OZAN; Bursa Uludağ Üniversitesi/Ziraat Fakültesi.; Bursa Uludağ Üniversitesi/Tıp Fakültesi/İmmunoloji Anabilim Dalı.; 0000-0003-1356-9012; 0000-0002-5187-9380; 0000-0001-7871-1628; GLT-7125-2022; AAG-6424-2021; U-1332-2019Anthocyanins have a great potential for human health, as a sub-group of phenolic compounds. Interactions of anthocyanin involved in digestion and thus in obesity consist of inhibition of pancreatic lipase, regulation of lipolysis and lipogenesis, activation of an activated protein kinase enzyme, controlling of digestion hormones (leptin, insulin, ghrelin, cholecystokinin, GIP, GLP-1). Anthocyanins are the compounds that can control metabolic syndrome and obesity by ameliorating lipid metabolism, increasing energy expenditure, suppressing food intake and inhibiting lipid absorption. In addition, the interactions with other compounds during the processing and/or in the intestinal canal can change their absorption capability and bioavailability. Activation of mitogen-activated protein kinase and cyclooxygenase (COX) enzymes, inflammatory cytokines signaling, free-radical scavenging activity are among the primary functions of anthocyanins playing role in the basic metabolic pathways. Anthocyanins also interact with gut microbiota that plays a role in many metabolic pathways. In the review, the effects of anthocyanins on the obesity-associated mechanisms in the metabolism are considered and summarized under the light of recent researches.Publication Antioxidant and bioaccessibility characteristics of functional fruit and vegetable honeys produced by innovative method(Elsevier, 2022-05-04) Demircan, H.; Tosunoğlu, H.; Çavus, Filiz; Şen, H.; Oral, Rasim Alper; Güldaş, Metin; GÜLDAŞ, METİN; Çakmak, İbrahim; ÇAKMAK, İBRAHİM; YILDIZ, ELİF; Gürbüz, Ozan; GÜRBÜZ, OZAN; Bursa Uludağ Üniversitesi/Sağlık Bilimleri Fakültesi.; Bursa Uludağ Üniversitesi/Ziraat Fakültesi/Gıda Mühendisliği Bölümü.; Bursa Uludağ Üniversitesi/Keleş Meslek Yüksekokulu.; 0000-0002-5187-9380; 0000-0003-3375-8777; 0000-0001-7530-7478; 0000-0003-1356-9012; 0000-0001-7871-1628; 0000-0003-1694-0104; U-1332-2019; AAK-4760-2020; GLT-7125-2022; AAG-6424-2021The functional fruit and vegetable honeys were produced by the natural bee feeding method with pomegranate, orange and black carrot concentrates. The natural enrichment method did not cause any negative effects on the quality criteria questioned in the standards such as moisture, pH, free acidity and HMF (Hydroxymethylfurfuraldehyde) content and the quality of the functional honeys obtained was high. Parallel to TPC contents, the antioxidant values of the honeys were increased 5.00-31.50, 16.09-53.96 and 21.18-39.72% by enrichment of orange, pomegranate, and black carrot concentrates. Gallic acid in pomegranate honey (14.52%) and chlorogenic acid in black carrot honey (27.01%) were determined as antioxidant components increased by enrichment. The enrichment process also led to an increase in the bioaccessibility characteristics. The increased antioxidant activity of functional honeys (DPPH) was verified by a high negative correlation value (R =-0.9103) and decreasing IC50 ratios in the opposite direction.