Nilgün Özdemir

Bio: Nilgün Özdemir is an academic researcher from Ondokuz Mayıs University. The author has contributed to research in topics: Aroma & Fermentation. The author has an hindex of 5, co-authored 16 publications receiving 74 citations.

Antioxidant capacity, phytochemical compounds, and volatile compounds related to aromatic property of vinegar produced from black rosehip (Rosa pimpinellifolia L.) juice

Abstract: Black rosehip (Rosa pimpinellifolia L.) is an edible fruit belonging to the large Rosaceae family. Processing this and similar fruits that have low water into vinegar generates added values. Besides, vinegar consumption has beneficial effects on human health. This study aimed to produce vinegar with enormous functional properties from the black rosehip fruits, which is disadvantaged due to its low water content, and high functional activities, and to convert from this fruit into a high value-added product. As a result, it was showed that the wine and vinegar had higher values of antioxidant activities than the juice; however, the highest values of total phenolic content, total anthocyanin content, total flavonoid content, and antioxidant activity were found in the wine. Gallic acid, catechin, ellagic acid, protocatechuic acid, and epicatechin were the most important bioactive compounds in wine and vinegar. Vitamin-C content increased significantly in the vinegar, giving a positive feature to the vinegar. Especially, the vinegar stood out in terms of volatile aroma compounds, including a total of 28 volatile compounds whose major components were 2-phenylethanol, acetic acid, octanoic acid, ethyl acetate, phenylethyl acetate, and 3-methyl-1-butanol. Also, hexyl-salicylate, 4-terpineol, and dihydro-methyl jasmonate. The present study showed the richness of black rosehip vinegar in aroma compounds and functional aspects. Black rosehip fruit was revealed to be a suitable raw material mainly for vinegar production. A new product was obtained to take advantage of the enormous antioxidant activity of black rosehip fruit, which has limited consumable and processability due to its low water content.

The effect of lactic acid bacteria and yeast usage on aroma development during tarhana fermentation

Abstract: The aim of this study was to select starter cultures by showing correlation between the volatiles and the starter cultures used during fermentation with the goal of producing a standard and desirable tarhana. This traditional fermented cereal product is produced with fermentation of a dough prepared by mixing wheat flour, yoghurt, some vegetables and spices. To understand the relationship between aroma development and certain starter cultures through both statistical and sensorial approaches, 11 tarhana dough samples were prepared using three lactic acid bacteria (Lactobacillus farciminis PFC83, Lactobacillus casei PFC90, Lactobacillus alimentarius PFC91) or two yeast (Pichia kudriavzevii PFC12, Candida humilis PFC138) strains, as mono- or co-culture. Ester and alcohol volatiles accumulated during fermentation in the tarhana dough samples with starter, triggered by the use of starter cultures. Additionally, it was noted that lactic, succinic and acetic acids were the most prevalent organic acids to be produced in the dough samples during fermentation, and a partial least squares regression analysis showed that L. alimentarius PFC91 and P. kudriavzevii PFC126 were correlated with the accumulation of esters and these organic acids. Moreover, a sensory analysis showed that tarhana dough samples prepared using the L. alimentarius PFC91 and P. kudriavzevii PFC126 strains obtained the most acceptable scores. In conclusion, this study showed a strong correlation between aroma development in tarhana and starter usage in which L. alimentarius PFC91 is co-cultured with P. kudriavzevii PFC126, contributing to the accumulation of the volatile aromatic compounds and organic acids that are responsible for desirable aromatic tarhana.

Phytochemical content, and antioxidant activity, and volatile compounds associated with the aromatic property, of the vinegar produced from rosehip fruit (Rosa canina L.)

Abstract: This study was aimed to be produced rosehip vinegar production from rosehip fruit, which has a limited usage, for the first time, and to monitor in detail the changes in bioactive compounds and volatile compounds, which affected on aroma property of it, during the rosehip vinegar production. Thus, it was aimed to contribute to the modernization of fermented foods and to produce rosehip vinegar as a healthy, aromatic and alternative product. The results showed that the rosehip vinegar had high TPC, TFC contents, and antioxidant activity. And catechin, ellagic-acid, quercetin, taxifolin, 4-hydroxy-benzoic-acid, and salicylic-acid were the important phenolic compounds in the rosehip wine and vinegar. Besides, vitamin-C content increased during the fermentation, and the highest value of vitamin-C was obtained in the rosehip vinegar. And, in the vinegar, it was displayed a total of 27 volatile compounds, the major compounds were acetic-acid, acetoin, pentanoic-acid, propionic-acid, octanoic-acid, followed by vitispirane, phenethyl-alcohol, isobutyric-acid, and 1-p-menthen-9-al. As a result, it has been thought that the rosehip fruit an adequate substrate for the production of rosehip vinegar which is a healthy and aromatic vinegar. Also, rosehip vinegar, obtained from rosehip fruit, which has a limited usage was contributed to the modernization of fermented foods.

[Coronavirus disease 2019 : More safety through compact facts and recommendantions for action]

Abstract: Das Thema „coronavirus disease 2019“ (COVID-19)mussnichtmehreingeführt werden. Es ist allgegenwärtig in einer Art und Weise, wie es sich wahrscheinlich niemand – weder innerhalb noch außerhalb der Medizin – je hätte vorstellen können. Täglich bekommen wir durch öffentliche und wissenschaftliche Medien Informationen zum Virus. Alle diese Meldungen sind selbst für medizinisches Fachpersonal schwierig einzuordnen und führen zu Unsicherheiten. Erschwerend kommt hinzu, dass mittlerweile auch Fake News ihren Weg in die sozialenMedien gefundenhabenund sich „viral“ verbreiten. Um diesen Zustrom von Informationen sinnvoll einzuordnen, relevante von weniger relevanten, irrelevanten Fakten oder gar mutwilligen Falschmeldungen zu trennenund soSicherheit bei denMitarbeiterinnen und Mitarbeitern im Gesundheitssystem zu schaffen, benötigen wir viel Zeit. Diese Zeit fehlt mittlerweile vielerorts. Mehr denn je ist es daher gerade jetzt wichtig, gut recherchierte, kompakt zusammengefasste und gutachterlich geprüfte Informationen zu dieser „neuen“Viruserkrankungzubekommen. Der Beitrag „COVID-19: update für Anästhesisten und Intensivmediziner März 2020“ von D.Thomas-Rüddel et al. bietet genau das! Er vermittelt in übersichtlicher und fundierter Weise all das, was wir aktuell über die Symptomatik, Diagnostik, Hygienemaßnahmen und Therapie der Coronaviruserkrankung wissen. Gleichzeitig weist der Beitrag auf eindrücklicheWeise darauf hin, dass diese Pandemie neben den medizinischen v. a. auch logistisch-organisatorische Herausforderungen in ungekannter Dimension mit sich bringt. Hier gilt es vorausschauend, Ressourcen zu generieren, ausreichend Schutzausrüstung zu beschaffen, Personal vorzubereiten sowie Störungen im klinischen Ablauf vorauszusehen und zu beseitigen.

The Many Faces of Kefir Fermented Dairy Products : Quality Characteristics, Flavour Chemistry, Nutritional Value, Health Benefits, and Safety

Abstract: Kefir is a dairy product that can be prepared from different milk types, such as goat, buffalo, sheep, camel, or cow via microbial fermentation (inoculating milk with kefir grains). As such, kefir ...

Kefir and Its Biological Activities.

Abstract: Kefir is a fermented beverage with renowned probiotics that coexist in symbiotic association with other microorganisms in kefir grains. This beverage consumption is associated with a wide array of nutraceutical benefits, including anti-inflammatory, anti-oxidative, anti-cancer, anti-microbial, anti-diabetic, anti-hypertensive, and anti-hypercholesterolemic effects. Moreover, kefir can be adapted into different substrates which allow the production of new functional beverages to provide product diversification. Being safe and inexpensive, there is an immense global interest in kefir's nutritional potential. Due to their promising benefits, kefir and kefir-like products have a great prospect for commercialization. This manuscript reviews the therapeutic aspects of kefir to date, and potential applications of kefir products in the health and food industries, along with the limitations. The literature reviewed here demonstrates that there is a growing demand for kefir as a functional food owing to a number of health-promoting properties.

Ethnic and industrial probiotic foods and beverages: efficacy and acceptance

Abstract: Microbial fermentation is an indigenous process known to be adapted for centuries by different communities and folks for the improvement of the quality of the food. Quality enhancement of the food is mostly carried out by lactic acid fermentation and sometimes probiotic fermentation mainly for the elongation of shelf-life, nutritional value addition and improvement of the sensory property. Technological interventions have led to the commercial production of many indigenous probiotic foods and beverages. The article reviews varieties of ethnic and industrial probiotic food and their distribution throughout the globe. Also, the health perspective, the involvement of microorganisms and their impact on the development of the food product have been elucidated in the article. Moreover, bottlenecks and the direction of research and commercialization with regards to ethnic and industrial probiotic food are of crucial importance and are also discussed in this review.

Comparison of traditional and backslopping methods for kefir fermentation based on physicochemical and microbiological characteristics

Abstract: Backslopping method for large-scale production of kefir drink was established to scale up the production of kefir beverage containing original kefir microbiota. The microbiological, nutritional, physiochemical, and sensory properties of novel backslopped kefir (BK) were compared with those of traditional kefir (TK). Application of backslopping method in kefir production increased production yields by 50-folds, and the microbiological, nutritional, and physicochemical characteristics of BK were not significantly different from those of TK except the numbers of Lactobacillus kefiri and yeast, % carbohydrate, and pH. In cold storage, the number of lactic acid bacteria remained constant at 9 log CFU/mL in both TK and BK; however, yeast population increased from 4.7 to 6.5 log CFU/mL of BK, and from 4.8 to 7.5 log CFU/ml of TK (p