Browsing by Author "Akpinar A."
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Item The volatile compounds, free fatty acid composition and microbiological properties of sepet cheese packaged with different modified atmosphere conditions; [Farklı modifiye atmosfer koşulları ıle paketlenen sepet peynirinin aroma bileşenleri, serbest yağ asitleri kompozisyonu ve mikrobiyolojik özellikleri](Veteriner Fakultesi Dergisi, 2017) Akpinar A.; Yerlikaya O.; Kinik Ö.; Kahraman C.; Korel F.; Uysal H.R.The objective of this present study was to investigate traditional sepet cheese samples which were packaged with different modified atmosphere conditions (MAP). The volatile compounds, free fatty acid composition and microbiological properties of Sepet cheeses were analyzed on 1., 45., 90. and 180. day of the storage period at +4°C. In packaking of cheese, three different modified atmosphere packaging conditions were tried. These cheeses were packaged into polystyrene packages that include 100% N2 (N), 80% N2 + 20% CO2 (NC), 100% CO2 (C). In accordance with volatile compounds of sepet cheese samples, it was shown that control cheese sample was different from MAP samples in terms of aroma fractions. MAP samples showed variability in preservation of aroma fractions. When fatty acid composition during the storage period was researched, it was found that there was a significant difference in all samples. When microbiological properties were investigated statistically, it was determined that there was not a significant difference in samples during storage. In general, it could be said that sepet cheeses that were packaged in different modified conditions protected their specialities better. © 2017, Veteriner Fakultesi Dergisi.Item Physicochemical and sensory characteristics of winter yoghurt produced from mixtures of cow’s and goat’s milk; [İnek ve keçi sütü karışımlarından üretilen kış yoğurtlarının fizikokimyasal ve duyusal karakteristikleri](Ankara University, 2017) Kesenkaş H.; Karagözlü C.; Yerlikaya O.; Özer E.; Akpinar A.; Akbulut N.Winter yoghurt is one of the most popular dairy products in Van and Hatay region of Turkey. It is made of different kinds of milk, and known as “cooked yoghurt” or “salted yoghurt” due to its high solids content and long shelf life. In this study, two different concentration methods were used to produce traditional winter yoghurt. Some physical (firmness and cohesiveness, L-, a- and b- values), chemical (total solid, fat, protein, pH, lactic acid, salt) and sensory analyses (color, odor, consistent and flavor) were made to determine the effect of production methods and storage on winter yoghurt samples at the 1st, 30th, 60th and 90th days. Significant differences were found between sensory, rheological properties and color values of winter yoghurts however no significant differences were found between physicochemical properties of the samples. Especially, winter yoghurts produced from 100% goat milk were the more appreciated samples. © Ankara Üniversitesi Ziraat Fakültesi.Item Production of set-type yoghurt using Enterococcus faecium and Enterococcus durans strains with probiotic potential as starter adjuncts(Blackwell Publishing Ltd, 2020) Akpinar A.; Saygili D.; Yerlikaya O.The study investigated the potential use of Enterococcus faecium and E.durans strains as adjunct cultures in the production of set-type probiotic yoghurt. There were significant changes and differences in the pH, titratable acidity, textural properties and microbiological properties of the products containing adjunct culture during the storage period (P < 0.05), whereas there were no statistically significant differences between the sensory properties (P > 0.05). In conclusion, the use of Enterococcus species that have known probiotic properties as the adjunct culture in yoghurt production can also positively affect the physical, chemical and rheological properties in addition to its positive effects to the functional properties by increasing the viable probiotic bacterial counts. © 2020 Society of Dairy TechnologyItem Incorporation of Propionibacterium shermanii subsp. freudenreichii in probiotic dairy drink production: physicochemical, rheological, microbiological and sensorial properties(Blackwell Publishing Ltd, 2020) Yerlikaya O.; Akpinar A.; Saygili D.; Karagozlu N.The aim of this study was to investigate the use of Propionibacterium shermanii subsp. freudenreichii as a combined culture with Lactobacillus acidophilus (AP), Bifidobacterium animalis subsp. lactis (BP), Lactobacillus casei (CP) and Lactobacillus rhamnosus (RP) in probiotic dairy drink production. Although Propionibacterium spp. is used for many purposes including biopreservative and adjunct culture, in this study, probiotic dairy drinks containing P. freudenreichii were evaluated in terms of their physicochemical, rheological, microbiological and sensory properties. The results of the study showed that P. freudenreichii can also be suitable for the production of probiotic drinks and that there are no adverse effects on the product characteristics. © 2019 Society of Dairy TechnologyItem Analysis of some physicochemical, rheological, sensorial properties, and probiotic viability of fermented milks containing Enterococcus faecium and Enterococcus durans strains(Blackwell Publishing Ltd, 2020) Yerlikaya O.; Akpinar A.; Saygili D.The aim of this research was to observe the combined usability of Enterococcus faecium and Enterococcus durans strains, which are resistant to adverse environmental conditions, together with commercial probiotic starters in the production of probiotic fermented milk. Accordingly, eight different probiotic fermented milks were produced; AF:Lactobacillus acidophilus + Enterococcus faecium, BF:Bifidobacterium animalis subsp. lactis + Enterococcus faecium, CF:Lactobacillus casei + Enterococcus faecium, RF:Lactobacillus rhamnosus + Enterococcus faecium, AD:Lactobacillus acidophilus + Enterococcus durans, BD:Bifidobacterium animalis subsp. lactis + Enterococcus durans, CD:Lactobacillus casei + Enterococcus durans, RD:Lactobacillus rhamnosus + Enterococcus durans. As a result of the data obtained in the study, it was found that fermented dairy products containing Enterococcus faecium and Enterococcus durans had no negative effects on the physicochemical, rheological properties and probiotic viability, and positively affected the sensory properties of the samples. The viscosity and hardness values of probiotic fermented milk produced by combining with E. durans were higher than by combining with E. faecium and serum separation was not occurred. Also, probiotic bacteria viability was higher than 7 log cfu/ml level at the end of the storage period. Practical applications: Enterococci are found naturally in the human intestinal microbiota and are highly resistant to adverse environmental conditions. Enterococcus strains that produce antimicrobial peptides such as enterocin were found to be able to effectively inhibit the development of many food pathogens when they are added to some foods including cheese. They are microbial additives that are thought to be used in many foods to improve food safety. The bacteriocin called enterocin could act as natural bio-preservatives in foods. This study will guide the use of Enterococcus species as bio-preservative in foods such as dairy products and the possibility of the continuation of probiotic viability. © 2020 Wiley Periodicals LLC.Item Some potential beneficial properties of Lacticaseibacillus paracasei subsp. paracasei and Leuconostoc mesenteroides strains originating from raw milk and kefir grains(John Wiley and Sons Inc, 2021) Akpinar A.; Yerlikaya O.In this study, some potential beneficial properties and probiotic characteristics of Lacticaseibacillus paracasei subsp. paracasei and Leuconostoc mesenteroides strains were investigated in 48 isolates, which were isolated from raw cow's and sheep's milk and kefir grains. The study aimed to determine the antimicrobial properties, antibiotic resistance profiles, antioxidant properties, proteolytic activities, bile salt resistance levels, and bile salt deconjugation activities of L. paracasei and Leu. mesenteroides strains. L. paracasei strains showed a higher antimicrobial activity profile than Leu. mesenteroides strains. L. paracasei strains were not sensitive to novobiocin (5 µg) and bacitracin (10 µg), while Leu. mesenteroides ZT8 showed resistance only to polymyxin B (300 µg). L. paracasei strains showed higher antioxidant activity compared to Leu. mesenteroides strains. L. paracasei SMM1 strain showed strong growth in the presence of 0.25% bile salt, whereas Leu. mesenteroides ZT8 and Leu. mesenteroides ZX3 showed poor growth. Neither L. paracasei nor Leu. mesenteroides strains were able to develop at 0.5%–1% bile salt concentration. Bile salt deconjugation ability was lower in Leu. mesenteroides strains, and Leu. mesenteroides ZT8 produced deconjugation from taurodeoxycholic acid. It was remarkable that Leu. mesenteroides strains showed higher proteolytic activity. Leu. mesenteroides ZT8 strain showed the highest hydrophobicity. Evaluating the obtained results, it was seen that the characteristics of Leu. mesenteroides and L. paracasei strains differed according to the source and strain from which they were isolated. It was determined that both types were suitable for industrial use. Novelty impact statement: Isolation and identification of Lacticaseibacillus paracasei subsp. paracasei and Leuconostoc mesenteroides strains derived from raw milks and kefir grains. Biochemical properties of dairy orgin L. paracasei and Leu. mesenteroides strains. Probiotic potential of L. paracasei and Leu. mesenteroides strains isolated from dairy environment. © 2021 Wiley Periodicals LLC.Item The effect of various herbs and packaging material on antioxidant activity and colour parameters of whey (Lor) cheese(John Wiley and Sons Inc, 2021) Akan E.; Yerlikaya O.; Akpinar A.; Karagozlu C.; Kinik O.; Uysal H.R.This study aimed to research the effects of some herbs and the packaging material on total phenolic compound content and the antioxidant activity of Lor cheeses. The total phenolic content and antioxidant activity of Lor cheeses containing only black cumin were found to be significantly lower than cheeses containing black cumin and rosemary or black cumin and thyme (P < 0.05). 2,2-azino-di-(3-ethylbenzothialozine- sulfonic acid) (ABTS) and Cupric Ion Reducing Antioxidant Capacity (CUPRAC) methods were found to be more reliable than the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method in evaluating the antioxidant activity of herbs added to Lor cheeses. It has been observed that the packaging material effects the antioxidant activity of the samples differently during the storage. © 2021 Society of Dairy TechnologyItem The Effects of Grape, pomegranate, Sesame Seed Powder and Their Oils on Probiotic Ice Cream: Total phenolic contents, antioxidant activity and probiotic viability(Elsevier Ltd, 2021) Akca S.; Akpinar A.The present study aimed to produce probiotic ice cream, containing Lactobacillus rhamnosus and Bifidobacterium animalis subps. lactis BB12 as the starter cultures, by adding vegetable seed pulp powder (sesame, pomegranate seed, and grape seed) and oils of these seeds to the ice cream mixtures and to examine the effects of these additions on pH, acidity, total phenolic content, flavonoid content, antioxidant capacity and the probiotic viability of Lactobacillus rhamnosus and Bifidobacterium animalis subps. lactis BB12 in ice cream samples stored at −20 °C for 90 days. Total phenolic content, flavonoid content, and antioxidant capacity were evaluated on the first and last day of the storage. Vegetable seed powders and oils did not affect the pH and acidity values of the ice cream samples. The pulp powders and oils used contributed to preserving the viability of probiotic bacteria during storage. Among the seed pulp powders, the grape seed had the highest phenolic content and antioxidant activity. Especially, ice creams containing grape seed powder, grape seed powder + seed oil, and pomegranate seed powder promoted the development of probiotic microorganisms in these ice cream samples due to the high phenolic components and antioxidant activity. The total phenolic content and antioxidant activity of seed powders and oils were parallel to the total phenolic content and antioxidant activity of ice creams produced using these powders and oils. It can be concluded that grape seed powder and its oil can be used as a natural ingredient to develop a novel ice cream with high nutritional antioxidant activity. © 2021Item Evaluation of antimicrobial activity and antibiotic susceptibility profiles of lactobacillus delbrueckii subsp. Bulgaricus and streptococcus thermophilus strains isolated from commercial yoghurt starter cultures(Sociedade Brasileira de Ciencia e Tecnologia de Alimentos, SBCTA, 2021) Yerlikaya O.; Saygili D.; Akpinar A.This research investigated the antimicrobial activity and antibiotic susceptibilities of nine Lactobacillus delbrueckii subsp. bulgaricus strains and nine Streptococcus thermophilus strains isolated from commercial yoghurt cultures. The antimicrobial activities of overnight culture strains against Bacillus cereus CECT 131, Bacillus subtilis ATCC 6633, Campylobacter jejuni NCTC 11351, Candida albicans ATCC 14053, Enterobacter aerogenes ATCC 13048, Escherichia coli ATCC 25922, Listeria monocytogenes ATCC 7644, Pseudomonas aeruginosa ATCC 9027, Salmonella typhimurium ATCC 14028 and Staphylococcus aureus ATCC 12600 were investigated using the disc diffusion method. The antibiotic resistance/susceptibility profiles of the strains were determined using antibiotic discs, which included ampicillin (10µg), ampicillin (25µg), bacitracin (10µg), clindamycin (2µg), clindamycin (10µg), erythromycin (10µg), erythromycin (15µg), gentamicin (10µg), gentamicin (120µg), nalidixic acid (30µ), neomycin (10µg), novobiocin (5µg), oxacillin (1µg), penicillin (10units), streptomycin (25µg), streptomycin (300µg), tetracycline (30µg) and vancomycin (30µg). The results of the study showed that while the Streptococcus thermophilus strain SY8, Lactobacillus bulgaricus strains LY6, LY8, LY9 and LY10 showed antimicrobial activity for all test microorganisms, Streptococcus thermophilus SY5 strains showed the weakest antimicrobial effect. All the Lactobacillus bulgaricus and Streptococcus thermophilus strains were resistant to oxacillin (1μg) and nalidixic acid (30μg). Indeed, the highest antibiotic susceptibility was seen with antibiotics such as ampicillin (25μg), clindamycin (10μg) and erythromycin (15μg). © 2021, Sociedade Brasileira de Ciencia e Tecnologia de Alimentos, SBCTA. All rights reserved.Item An application of selected enterococci using Bifidobacterium animalis subsp. lactis BB-12 in set-style probiotic yoghurt-like products(Elsevier Ltd, 2021) Yerlikaya O.; Saygili D.; Akpinar A.The present study aimed to develop a novel dairy product by combining Bifidobacterium lactis subsp. lactis BB-12® with proven probiotic properties with Enterococcus faecium K67E3 and Enterococcus durans K63E1, which possess potential probiotic properties. Physicochemical, textural and viscosity properties, microbiological, and sensorial attributes of set-style probiotic yoghurt-like products were analysed during the storage at 4 °C for 21 days. The starter culture type had an effect (p < 0.05) on physicochemical, textural and viscosity properties of probiotic yoghurt-like products. High probiotic viability was determined in all samples except for the LD sample containing a combination of Bifidobacterium animalis subsp. lactis BB-12® and Enterococcus durans K63E1. The use of starter culture combination containing Streptococcus thermophilus, Bifidobacterium animalis subsp. lactis BB-12® and Enterococcus durans K63E1 (TLD) in the probiotic yoghurt-like product yielded better textural parameters, apparent viscosity, and improved sensory attributes. Although Enterococcus genera are not thought to be completely safe for use in human food so far, as a result of the research findings, it would be of interest for the dairy industry in the development of novel probiotic dairy products. © 2021 Elsevier LtdItem The effect of packaging materials on physicochemical, microbiological, and sensorial properties of Turkish whey (Lor) cheese with some plants(John Wiley and Sons Inc, 2022) Akpinar A.; Yerlikaya O.; Akan E.; Karagozlu C.; Kinik O.; Uysal H.R.In this study, 2% black cumin, 1% black cumin (Nigella damascena L–Damascus black cumin), 1% rosemary (Rosemarinus officinalis), and 1% black cumin and 1% thyme (Origanum onites L.–Izmir thyme) were added to whey cheese with a short shelf life and cheese samples stored in different packaging materials (goat-skin bags and artificial casing). pH levels and titratable acidity, degree of proteolysis, microbiological, and sensory attributes of the samples were examined. In 20 days of storage, the pH values of whey cheese with black cumin stored in goat-skin bags were statistically higher (ranged 6.34–5.30) than other samples (ranged 6.32–4.10). Proteolytic activity values were higher (0.34–0.58 mg/ml serine) in cheese samples containing black cumin and thyme in both packaging materials (p <.05). After 30 days of storage, black cumin and thyme-added cheese packaged in goat-skin bags have the highest Lactobacillus spp. count (8.64 log CFU/g), while cheese containing black cumin and thyme (6.32 log CFU/g) filled into an artificial casing has the least. Based on the results of sensory analysis, the samples containing black cumin were generally more preferred while cheese with rosemary had the lowest sensory scores. In conclusion, the difference in packaging materials has a significant effect on the physicochemical and microbiology properties and proteolytic activity of whey cheese produced by adding different plants. However, the sensory properties of whey cheese are influenced by the plants used rather than the differences in packaging materials. Novelty impact statement: Turkish whey (Lor) cheese is food with limited storage time and rapid microbial spoilage. Black cumin, rosemary, and thyme were added to whey cheese. Black cumin, rosemary, and thyme have been added to whey cheese and this limited storage period has been tried to be extended. In addition, the effects of goat-skin and artificial casing packages on physicochemical and sensory properties were investigated. © 2022 Wiley Periodicals LLC.Item The effect of using different yeast species on the composition of carbohydrates and volatile aroma compounds in kefir drinks(Elsevier Ltd, 2023) Saygili D.; Yerlikaya O.; Akpinar A.Kefir is a fermented dairy product known for its high content of lactic acid bacteria and various types of yeast. The yeast microorganisms present in kefir cultures play a crucial role in shaping the distinctive characteristics of kefir. This study aimed to investigate the impact of different yeast species commonly used in industrial kefir production on the carbohydrate and volatile aroma components of kefir during the storage period. To this end, kefir cultures with various yeast species, including Debaryomyces hansenii (DH), Kluyveromyces marxianus (KM), Candida colliculosa (CC), Yarrowia lipolytica (YL), Saccharomyces bouardii (SB), Saccharomyces cerevisiae (SC), Kluyveromyces lactis (KL), and Geotricum candidum (GC), were prepared and utilized in kefir production. The study findings revealed significant effects of different yeast species on the composition of carbohydrate and volatile aroma components in kefir (p < 0.05), with Klyveromyces spp. having particularly notable effects. It was observed that kefir drinks containing ethanol exhibited negligible lactose content, while their ethanol content was high. Kefir drinks containing minimal Klyveromyces marxianus contained glucose and galactose, whereas those containing Yarrowia lipolitica exhibited the lowest ethanol content. © 2023 Elsevier LtdItem Microbiological aspects and challenges of whey powders – I thermoduric, thermophilic and spore-forming bacteria(John Wiley and Sons Inc, 2023) Hebishy E.; Yerlikaya O.; Mahony J.; Akpinar A.; Saygili D.For dairy processors, spoilage and pathogenic spore-forming bacteria are key sources of concern, not only due to their ability to remain dormant in a desiccated state in powders and to survive heat treatments, but also their ability to form biofilms in the vegetative state that lead to contamination of foods. These include members of the genera Bacillus, Geobacillus, Anoxybacillus, Brevibacillus, Paenibacillus and Clostridium, many of which are associated with food poisoning and spoilage. Here, we review the common bacterial species that form spores in whey powders and their sources and provide insights into their risks and strategies to control them. © 2023 The Authors. International Journal of Dairy Technology published by John Wiley & Sons Ltd on behalf of Society of Dairy Technology.Item Health benefits and risks of fermented foods—the PIMENTO initiative(Frontiers Media SA, 2024) Todorovic S.; Akpinar A.; Assunção R.; Bär C.; Bavaro S.L.; Berkel Kasikci M.; Domínguez-Soberanes J.; Capozzi V.; Cotter P.D.; Doo E.-H.; Gündüz Ergün B.; Guzel M.; Harsa H.S.; Hastaoglu E.; Humblot C.; Hyseni B.; Hosoglu M.I.; Issa A.; Karakaş-Budak B.; Karakaya S.; Kesenkas H.; Keyvan E.; Künili I.E.; Kütt M.-L.; Laranjo M.; Louis S.; Mantzouridou F.T.; Matalas A.; Mayo B.; Mojsova S.; Mukherjee A.; Nikolaou A.; Ortakci F.; Paveljšek D.; Perrone G.; Pertziger E.; Santa D.; Sar T.; Savary-Auzeloux I.; Schwab C.; Starowicz M.; Stojanović M.; Syrpas M.; Tamang J.P.; Yerlikaya O.; Yilmaz B.; Malagon-Rojas J.; Salminen S.; Frias J.; Chassard C.; Vergères G.Worldwide, fermented foods (FF) are recognized as healthy and safe. Despite the rapid increase of research papers, there is a lack of systematic evaluation of the health benefits and risks of FF. The COST Action CA20128 “Promoting innovation of fermented foods” (PIMENTO) aims to provide a comprehensive assessment on the available evidence by compiling a set of 16 reviews. Seven reviews will cover clinical and biological endpoints associated with major health indicators across several organ systems, including the cardiovascular, gastrointestinal, neurological, immune, and skeletal systems. Nine reviews will address broader biological questions associated with FF including bioactive compounds and vitamin production, nutrient bioavailability and bioaccessibility, the role of FF in healthy diets and personalized nutrition, food safety, regulatory practices, and finally, the health properties of novel and ethnic FF. For each outcome assessed in the reviews, an innovative approach will be adopted based on EFSA’s published guidance for health claim submissions. In particular, each review will be composed of three parts: (1) a systematic review of available human studies; (2) a non-systematic review of the mechanism of action related to the clinical endpoints measured by the human studies identified in part 1; and (3) a non-systematic review of the characterization of the FF investigated in the human studies identified in part 1. The evidence and research gaps derived from the reviews will be summarized and published in the form of a strategic road map that will pave the way for future research on FF. Copyright © 2024 Todorovic, Akpinar, Assunção, Bär, Bavaro, Berkel Kasikci, Domínguez-Soberanes, Capozzi, Cotter, Doo, Gündüz Ergün, Guzel, Harsa, Hastaoglu, Humblot, Hyseni, Hosoglu, Issa, Karakaş-Budak, Karakaya, Kesenkas, Keyvan, Künili, Kütt, Laranjo, Louis, Mantzouridou, Matalas, Mayo, Mojsova, Mukherjee, Nikolaou, Ortakci, Paveljšek, Perrone, Pertziger, Santa, Sar, Savary-Auzeloux, Schwab, Starowicz, Stojanović, Syrpas, Tamang, Yerlikaya, Yilmaz, Malagon-Rojas, Salminen, Frias, Chassard and Vergères.Item Microbiological aspects and challenges of dairy powders – II: Biofilm/biofouling(John Wiley and Sons Inc, 2024) Hebishy E.; Yerlikaya O.; Reen F.J.; Mahony J.; Akpinar A.; Saygili D.; Datta N.Biofilms generated during production of dairy/whey powders can cause contamination, spoilage and equipment failures, posing a significant challenge in the agri-food sector. Factors including temperature, protein composition, equipment structures and surface topography influence biofilm formation and resistance to cleaning and sanitation. Several species of bacteria are well adapted to these challenges, posing the most pressing concerns of dairy whey process. Despite efforts to improve cleaning-in-place strategies, bacteria persist in difficult-to-clean areas. This review provides insights into bacterial biofouling in dairy protein powders, highlighting the mechanism of biofilm formation, predominant bacterial genera, critical processing steps and strategies to manage biofilm formation during the manufacturing process. © 2024 The Authors. International Journal of Dairy Technology published by John Wiley & Sons Ltd on behalf of Society of Dairy Technology.Item Production of plant-based fermented beverages using probiotic starter cultures and Propionibacterium spp.(Elsevier Ltd, 2024) Gungor G.; Akpinar A.; Yerlikaya O.The popularity and demand for cow's milk substitutes has increased in recent years. Plant-derived beverages appear to be among the most important substitutes for cow's milk. By breaking down legumes, grains and nuts and homogenizing them with water, liquids similar to cow's milk in terms of appearance, taste and shelf life are used in the production of different beverages and fermented foods. This study aimed to produce vegan beverages by fermenting soy, almond, and coconut beverages with probiotic starter cultures and Propionibacterium spp. Physicochemical, microbiological, and sensory properties of the produced plant-based fermented beverages were examined during storage. Whereas the use of various nondairy beverages in the production of probiotic beverages affects the acidity, color (L* a* and b*), serum separation, water holding capacity, and viscosity values (p < 0.05), microbiological analysis showed that probiotic (Bifidobacterium BB-12®) viability during storage was protected and the counts of Propionibacterium spp. increased. It was observed that plant beverage type did not affect the viability of Propionibacterium spp. and probiotics (p > 0.05). Additionally, whereas the fermented coconut beverage was liked the most, the fermented soy beverage was liked the least. © 2024 Elsevier Ltd