Browsing by Author "GÜRBÜZ, OZAN"

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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-1332-2019
Spirulina 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.
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-6424-2021
The 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.
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-2088-2021
In 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.
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-1744-2024
The 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%.
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-1332-2019
Probiotic 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.
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-1332-2019
Anthocyanins 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.
Profile phenolic compounds in spanish-style and traditional brine black olives (′Gemlik′ Cv.) provided from different regions of Turkiye
(MDPI, 2023-08-01) Demir, Cansu; Yıldız, Elif; Gürbüz, Ozan; Demir, Cansu; YILDIZ, ELİF; GÜRBÜZ, OZAN; Bursa Uludağ Üniversitesi/Fen Bilimleri Enstitüsü; Bursa Uludağ Üniversitesi/Keles Meslek Yüksekokulu/Gıda İşleme Bölümü; Bursa Uludağ Üniversitesi/Ziraat Fakültesi/Gıda Mühendisliği Bölümü; 0000-0002-4084-3972; 0000-0003-1356-9012; 0000-0001-7871-1628; AAG-6424-2021; GLT-7125-2022; HJZ-6819-2023
The aim of this study was to evaluate the effect of growing regions and processing methods on the composition and the quantity of phenolic compounds in ' Gemlik ' variety table olives. Two different processing methods, Spanish- style and traditional brine (naturally processed) olives, were used in the processing of ' Gemlik ' table olives. According to the data obtained in this study, the highest concentrations of phenolic compounds were observed for 3-hydroxytyrosol (4.58-168.21 mg/kg), followed by 4-hydroxyphenyl ( 0.76-97.58 mg/kg), luteolin 7-glucoside (0.32-58.64 mg/kg), tyrosol (1.57-47.24 mg/kg), and luteolin (0.17-53.56 mg/kg) in overall samples. The highest quantity of phenolic compounds was determined in raw olives, and the lowest phenolic compound content was determined in Spanish-style processed olives. Table olives which are produced by the natural process were observed to contain higher concentrations of phenolic compounds compared with the olives, which are produced in the Spanish style. In this sense, statistical results showed that region and processing methods have significant impacts on the phenolic compounds of table olives.