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Potential of Nisin and Newly Discovered Bacteriocins as Preservatives for Pasteurised Milk النص الكامل
2024
Getrude Okiko | Ivan Sugrue | Fredrick O. Ogutu | Paul Ross
Spoilage of pasteurized milk is mainly caused by the presence of organisms that either survive pasteurization (psychrotolerant spore-formers) or re-contaminate milk in the processing environment (post-pasteurisation contaminants). Pasteurization of bovine milk by heat treating at 72°C for 15-30 seconds ensures milk quality without impairing its organoleptic and nutritional status and extends shelf life to 12-14 days at refrigeration temperatures. Nisin A is a class I bacteriocin known to inhibit gram positive bacteria and approved by the European Food and Safety Authority as a food preservative. It is commercially available as Nisaplin®, which contains a concentration of 2.5% w/w of nisin. This study examined the effect of Nisaplin® at different concentrations on spoilage of refrigerated commercial whole pasteurized milk over a period of 59 days. At a high concentration of 4 mgml-1, Nisaplin® reduced the total bacterial count below the limit of detection in the milk, and inhibition was visible for at least 14 days at 4°C. Previously isolated milk spoilage bacteria were identified using 16s rRNA gene sequencing and utilised as target indicators for bacteriocin production. Lactobacillus delbrueckii ssp. bulgaricus LMG6901, Microbacterium lacticum, and Pseudomonas aeruginosa were utilised as indicator strains in a screen of milk spoilage organisms for bacteriocin production. This resulted in identifying the putative bacteriocin producer Carnobacterium divergens, a lactic acid bacterium active against L. bulgaricus. The study concludes that Nisaplin® is effective in the reduction of microbial load and its effectiveness could be increased when combined with other preservative methods thus forming an extra hurdle in the milk.
اظهر المزيد [+] اقل [-]On The Pros and Cons of Using Excel for Regression Analysis النص الكامل
2024
Sencer Buzrul
Excel is a useful and powerful software for simple regression analysis without any programming skills and that is why, it is widely preferred by the undergraduate students from various areas such as chemistry, biology and agriculture as well as many engineering disciplines such as chemical engineering, food engineering and bioengineering. Parameter values and coefficient of determination (R2) can be easily obtained together with the graphical representation for those models exist in Excel such as linear and exponential models. It is also possible to visually examine the model fit and experimental data together on the same graph. For linear models (linear in parameters) Excel Add-In Data Analysis-Regression tool creates a summary output, and parameter estimates, parameter uncertainties, adjusted R2 (R2adj) and root mean square error (RMSE) values can be found even for the models that do not exist in Excel. For nonlinear models (nonlinear in parameters) Excel Add-In Solver tool can be used to obtain parameter estimates (but not uncertainties), and R2, R2adj and RMSE can be calculated manually. Despite these advantages, there are some shortcomings of Excel for regression analysis. For linear models with no-intercept Excel reports the incorrect and overoptimistic R2 and also reports incorrect and overpessimistic R2adj. Excel has also some nonlinear models such as exponential and power models in it; however, Excel computes linear parameter estimates for those nonlinear models and again optimistic R2 is calculated. This paper aims (i) to show these inaccuracies with their reasons by using published data, (ii) how to obtain the correct results, (iii) to warn the instructors who would use Excel for regression analysis in class. Excel users (instructors, students, professionals in any field) should be aware of the pitfalls when using Excel for regression.
اظهر المزيد [+] اقل [-]İskenderun Bölgesinde Kendiliğinden Yetişen Frenk İnciri (Opuntia ficus-barbarica A.Berger) Meyve ve Kabuklarının Biyoaktif Bileşenlerinin Araştırılması النص الكامل
2024
Fatma Ergün
Küresel ısınma nedeniyle su gereksiniminin düşük ve yapısında değerli bileşenlerin bulunduğu bitkisel gıdalara olan ilgi giderek artmaktadır. Bu çalışmada, frenk inciri (Opuntia ficus-barbarica A.Berger) meyve (M) ve kabuklarının (K) toplam fenolik, flavonoid madde miktarları ve antioksidan aktiviteleri değerlendirilmiştir. Bu amaçla öncelikle numuneler metanol ile ekstrakte edilmiştir. Metanol ekstraktlarında fenolik miktarları K’da 835,66±21,12 mg GAE/100 g, M’de 760,66±17,61 mg GAE/100 g; toplam flavonoid madde miktarları K’da 222,00±4,35 µg KE/g ve M’de 204,76±0,87 µg KE/g olarak belirlenmiştir. Antioksidan aktivite, serbest radikal giderme aktivitesi (DPPH) ve Bakır (II) indirgeme kapasitesi (CUPRAC) yöntemleriyle değerlendirilmiş, indirgeme kapasitesi M’de 40,93±1,46 µg TE/mL ekstrak ve K’da 80,11±2,03 µg TE/mL ekstrak olarak hesaplanmıştır. Meyve ve kabuk ekstraklarının IC50 değerleri hesaplanmış ve standart BHT (Bütil hidroksi toluen) ile karşılaştırıldığında en yakın değerin K’da olduğu görülmüştür. Sonuçlar, frenk inciri meyve ve kabuklarının önemli miktarda biyoaktif bileşen içerdiğini ve yüksek antioksidan aktiviteye sahip olduğunu göstermiştir. Bu çalışma, geleneksel olarak halk hekimliğinde kullanılan frenk incirinin sağlığı teşvik eden bir gıda bileşeni veya doğal antioksidan kaynağı olarak potansiyelini ortaya koymaktadır.
اظهر المزيد [+] اقل [-]Domates ve Hıyar Örneklerinde Element İçeriğinin ve Pestisit Kalıntılarının Araştırılması: Tekirdağ (Türkiye) ve Mamuşa (Kosova) Örneği النص الكامل
2024
Serap Duraklı Velioğlu | Kadir Gürbüz Güner | Zana Sahiti Mehmeti | Özgür Sağlam | Hasan Murat Velioğlu
Bu çalışmanın amacı, Mamuşa (Kosova) ve Tekirdağ’da yetiştirilen domates ve hıyarlarda yaygın olarak kullanılan bazı pestisitlerin kalıntılarının ve bazı toksik metallerin varlığının araştırılmasıdır. Çalışma kapsamında Tekirdağ ve Mamuşa’dan toplanan 21 domates ve 17 hıyar numunesinde pestisit kalıntı ve element analizleri gerçekleştirilmiştir. Pestisit etken maddeleri olarak abamectin, acetamiprid, carbendazim, chlorpyrifos methyl, imidacloprid, metaflumizone, propineb ve indoxacarb seçilmiştir. Elemental analizde ise bazı toksik metaller dahil 26 elementin taraması yapılmıştır. İncelenen örneklerin hiçbirisinde maksimum kalıntı limiti (MRL) üzerinde pestisit kalıntısı saptanmamıştır. Acetamiprid domateste 16 örnekte (0,25-267 µg kg-1), hıyarda 10 örnekte (0,30-202 µg kg-1), imidacloprid sadece domateste 5 örnekte (4,38-8,83 µg kg-1), indoxocarb domateste bir örnekte (21,80 µg kg-1), propineb Mamuşa’dan toplanan tüm hıyar örneklerinde (187-1090 µg kg-1) tespit edilmiştir. Elemental analiz sonuçları incelendiğinde kalay domateste 9 örnekte (10,3-12,8 mg kg-1), hıyarda 2 örnekte (10,9-13,4 mg kg-1), nikel sadece Tekirdağ’dan toplanan birer domates (14,7 mg kg-1) ve hıyar (11,3 mg kg-1) örneğinde tespit edilmiştir. Alüminyum ise analizi yapılan 3 hıyar örneğinde (10,0-36,1 mg.kg-1) tespit edilmiştir. Örneklerin hiçbirinde kurşun, kadmiyum ve civaya rastlanmaması olumlu bir durumdur. İncelenen örneklerde tespit edilen kalıntıların insan sağlığı için risk oluşturacak düzeyde olmadığı ifade edilebilir. Ancak tarımsal üretimde kullanılan su, gübre ve pestisitlerin son üründe kalıntı bırakma potansiyeline sahip olduğunu gösteren örnekler olması, üreticileri iyi tarım uygulamalarını sürdürmeye teşvik etmelidir.
اظهر المزيد [+] اقل [-]Investigation of Important Park Features that Encourage Park Visiting, Physical Activity and Social Interaction Among Teenagers with the Case of Ihlamur Park النص الكامل
2024
Sertaç Güngör | Sabriye Özer | Murat Seyhan
Today, the rapid increase in urbanization and the concentration of population density in urban centers have increased the need for individuals to be in touch with nature. In this context, urban use areas such as urban parks play an important role in meeting the physical and social needs of teenagers. Parks are not only spaces that encourage physical activity, but also spaces that increase social interaction, strengthen community ties and support physical activities. Ihlamur Park in Konya is an important living space where teenagers show great interest, offering various activities and social opportunities. However, detailed information on the purposes for which teenagers use the park and which features of the park encourage this use has not been fully identified. The aim of this study is to examine the purposes of the use of Ihlamur Park by teenagers and to identify the features of the park that encourage physical activity and social interaction. For the research, 116 teenagers were surveyed face-to-face on the basis of the law on the protection of personal data and voluntary participation of park users by visiting the area on random days on weekdays and weekends. The survey was carried out with the approval of the Ethics Committee of Selçuk University, Faculty of Architecture and Design. By determining the level of use of teenagers, it is the preparation of a resource that park users can reach. The research also provides a comprehensive evaluation to understand the park usage habits and motivations of teenagers, and in this context, it has contributed to the development of recommendations for the design and management of parks. Thus, the importance of park features that allow teenagers to lead a more active life and increase their social interactions is emphasized.
اظهر المزيد [+] اقل [-]Impact of Foliar-Applied Essential Oils on Growth, Yield and Quality of Potato (Solanum tuberosum L.) النص الكامل
2024
Arif Şanlı | Fatma Zehra Ok
In this study, effects of sage (Salvia officinalis L.), oregano (Origanum onites L.), rosemary (Rosmarinus officinalis L.), dill (Anethum graveolens L.), cumin (Cuminum cyminum L.), fennel (Foeniculum vulgare var. dulce L.) and Turkish pickling herb (Echinophora tenuifolia L. subsp. sibthorpiana (Guss.)) essential oils applied to plant leaves at different doses on potato growth, tuber yield and quality were investigated. Essential oils were applied to the upper parts of the plant by spraying at doses of 300, 600, 900 and 1200 ppm three times at 15-day intervals, starting 15 days after the completion of emergence. The number of tubers and tuber yield per plant, marketable and total tuber yield, chlorophyll content, starch content, reducing and total sugar content parameters were examined. The effects of essential oil applications on tuber yield and quality were found to be statistically significant, and this effect varied according to application doses. Compared to the control, essential oil applications increased the marketable tuber yield by approximately 38% (300 ppm rosemary essential oil) and the total tuber yield by up to 28% (600 ppm rosemary essential oil). However, rosemary and oregano oils caused phytotoxicity and reduced tuber yield when applied in high doses. Except for sage and oregano, other essential oils positively affected chlorophyll synthesis. Essential oil applications reduced the accumulation of reducing sugar, which negatively affects tuber quality, and the lowest reducing sugar contents were detected in tubers to which fennel and oregano essential oils were applied. In the study, it was understood that tuber yield in potatoes could be increased significantly with the applications of 300 and 600 ppm rosemary essential oil and 300 ppm cumin essential oil.
اظهر المزيد [+] اقل [-]Efforts to Reduce Carbon Footprint of Dokuz Eylül University Tınaztepe Campus in İzmir, Türkiye النص الكامل
2024
Elif Duyuşen Kokulu | Eylül Ceren Özyürek
Current study intends to find out the carbon footprint of Dokuz Eylül University's Tınaztepe Campus and comprehensively assess its environmental impact in the process. The study provides a detailed analysis of carbon emissions resulting from the campus’s energy consumption, transportation, water usage, and other sources. Based on these analyses, the total CO2 emmission of the campus has been determined, taking into account the carbon sequestration capacity of the university's forested area. Calculations performed using the IPCC Tier 1 Model estimate that Tınaztepe Campus's total annual carbon footprint is 2,458.44 tons of CO2. Additionally, the annual carbon footprint per capita has been calculated as 0.059 tons of carbon footprint. According to the findings, the largest portion of carbon emissions is from natural gas consumption, while the smallest is from water consumption. In light of this data, various strategic recommendations have been developed to reduce the campus’s carbon footprint. These recommendations include measures such as increasing energy efficiency, adopting more sustainable transportation methods, and reducing water consumption. The results of this study provide valuable insights for universities to consider when developing sustainability policies.
اظهر المزيد [+] اقل [-]Determination of the Current Situation of Konya Ihlamur Park According to the Physical Activity and Social Interaction Actions of Elderly Individuals, which are the Reasons for Park Use النص الكامل
2024
Sertaç Güngör | Zehra Çelik
Parks and public open green spaces are open spaces for all segments of the society. These places, which are important recreation areas, enable the elderly to renew themselves, to breathe a little in the open air, to be alone with nature even in the city. These opportunities provided by parks are utilised by elderly users. Today, the population of elderly individuals is increasing day by day due to the slowdown in population growth rate. In this study, it is aimed to determine the park usage purposes of the elderly and important park features that encourage physical activity and social interaction. Within the scope of the research, 96 elderly individuals were interviewed with 96 elderly individuals within the scope of face-to-face survey study by going to the park at random times on weekdays and weekends on a voluntary basis by using the questionnaire form prepared for revealing the user profile of individuals aged 40 and over in Ihlamur Park in Selçuklu District, determining the preference times of the park, determining the duration and times of park use, determining the reasons for park preference and selection, and evaluating park user satisfaction and expectations. The findings show that parks are an important social area for elderly people in the same age group with their seating areas, walking paths, simple fitness equipment, as they create a gathering area for elderly people in the same age group, and therefore, parks require careful planning and implementation in the design, management and use of parks and should contain a large amount of space for socialization. In line with these findings, it will be possible for elderly people to benefit more from parks and have a more enjoyable time with landscape designs that provide socialization opportunities for elderly users. Thus, elderly individuals will be able to develop a sense of belonging for the park.
اظهر المزيد [+] اقل [-]The Effects of Nanoemulsion Film Coatings Containing Essential Oils on the Storage Quality of Sugar Beets (Beta vulgaris L.) النص الكامل
2024
Fatma Zehra Ok | Arif Şanlı
This study was carried out under controlled conditions to determine the effects of chitosan-based nanoemulsion film coating formulations, formed using different essential oils, on storage quality of sugar beet roots during storage period. In the study, roots of Conviso Smart (KWS) sugar beet variety were coated with nanoemulsion film formulations containing thyme (Thymus vulgaris), clove (Szygium aromaticum), ginger (Zingiber officinale) and tea tree (Melaleuca alternifolia) essential oils doses of 250, 500 and 1000 ppm immediately after harvest. The roots were stored in plastic cases under controlled conditions (+ 8-10°C, 85-90% relative humidity) for 90 days. Weight loss in beet roots was determined at 30-day intervals from the start of the storage period, and at the end of the storage period, firmness, dry matter ratio, brix value, polar sugar, reducing sugar, alpha amino nitrogen and glycine betaine contents and fungal infection developments in beet roots were also evaluated. The film coating applications significantly affected postharvest weight and quality losses in sugar beet roots. The applications significantly reduced roots weight loss during storage compared to the control. Although the polar sugar ratios were higher in film coated roots compared to the control, alpha-amino nitrogen, glycine betaine, and reducing sugar contents showed significant decreases. White mold and green mold infections on the roots were significantly decreased, especially with high dose film coating applications. The highest dry matter ratio, brix values and firmness were obtained from film coatings containing 1000 ppm cinnamon and thyme essential oils. While polar sugar ratio was higher in root which film coated compared to the control, alpha amino nitrogen, glycine betaine and reducing sugar contents showed significant decreases. White mold and green mold infections developing on root showed significant decreases especially with film coating applications applied at high doses. The study concluded that coating sugar beet roots with nanoemulsion film formulations containing essential oils can significantly reduce, weight and quality losses, as well as fungal disease development, during the storage period.
اظهر المزيد [+] اقل [-]In vitro Antifungal Effects of Various Essential Oils against Aspergillus Crown Rot of Peanut النص الكامل
2024
Merve Oğuz | Yusuf Gümüş | Soner Soylu
Synthetic fungicides that combat plant pathogenic fungi can enhance crop yields, ensuring stable crop production and market quality. However, the increase in the use of fungicides may cause to development of fungicide-resistant pathogen strains and the accumulation of fungicide residues in the food chain above safe limits. This situation underscores the need for improved fungal disease management through alternatives to synthetic fungicides. These alternatives include plant-derived compounds such as essential oils and extracts. Essential oils are known to be potent antifungal compounds against both human and plant pathogens. Aspergillus niger is a toxin-producing fungal disease agent that causes Aspergillus crown rot in peanuts. In this study, the antifungal activities of nine different essential oils from Foeniculum vulgare, Lippia citriodora, Origanum majorana, Origanum minutiflorum, Origanum onites, Origanum syriacum, Origanum vulgare, Salvia aramiensis and Thymus syriacus plants were evaluated against A. niger under in vitro conditions by using disc diffusion test. Among the nine essential oils tested, the highest antifungal activities were displayed by O. vulgare essential oil (with an inhibition zone diameter of 49.33 mm) which was followed by T. syriacus, O. onites, O. syriacum and O. minutiflorum essential oils (48.67, 47.00, 46.33 and 43.33 mm, respectively). The essential oils of F. vulgare, L. citriodora, and O. majorana showed relatively lower antifungal effects. The essential oil of S. aramiensis did not show antifungal effect against pathogen. The results indicated that plant essential oils could be valuable in promoting research aimed at developing new antifungal agent(s) for fungal disease management. However, further studies are needed to optimize the in vivo application conditions of essential oils against A. niger.
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