Master Degree / Yüksek Lisans Tezleri
Permanent URI for this collectionhttps://hdl.handle.net/11147/3008
Browse
5 results
Search Results
Master Thesis Development of mixed fruit snack having high phenolic and protein contents using freeze-dried fruits and nutritional ingredients(01. Izmir Institute of Technology, 2024) Köse, Günce; Korel, FigenGünümüz koşulları, bireylerin pratik ve hızlı tüketim ihtiyaçlarını arttırmış, bu doğrultuda paketli gıdaların tüketimi yaygınlaşmıştır. Kolay taşınabilir, paketli gıdalar atıştırmalık olarak adlandırılmaktadır. Atıştırmalık ürünler, günümüzde tüketicilerin sıklıkla tercih ettiği gıdalardır. Bu çalışmada, üç farklı meyve kullanılarak, protein içeriği, antioksidan aktivitesi ve toplam fenolik içeriği yüksek, alternatiflerine göre daha sağlıklı atıştırmalık geliştirilmesi amaçlanmıştır. Bu çalışma kapsamında karpuz, çilek ve avokado meyveleri dondurularak kurutulmuş ve dondurularak elde edilen tozlara kabak çekirdeği, çörek otu, keten tohumu ve zencefil gibi fonksiyonel bileşenlerle birleştirilerek bir hamur elde edilmiştir. Bu hamurlar, hava fritözünde pişirilmiş ve meyve atıştırmalıkları elde edilmiştir. Bu meyve atıştırmalıklarının kimyasal, fiziksel, mikrobiyolojik ve duyusal özellikleri araştırılmıştır. Designmax atıştırmalığındaki meyve oranları, değerlendirilen üç yanıt için en yüksek sonuçları elde etmek üzere seçilmiştir. Analiz bulguları, Designmax meyve atıştırmalığının protein içeriği açısından diğer meyve atıştırmalıklarına göre daha yüksek bir değer sunmuştur. Avokado atıştırmalığı, yüksek yağ içeriğine sahip olması sebebiyle diğer atıştırmalıklara kıyasla (neredeyse 4 kat daha yüksek) yağ içeriğine sahiptir. Karpuz atıştırmalığının karbonhidrat içeriği diğer alternatiflerinden daha yüksek olmasına rağmen, çilek ve meyve-karışımı atıştırmalıklarıyla arasında anlamlı fark olmadığı saptanmıştır. Doku profili analizinin sonuçlarına göre, çilek atıştırmalığı sertlik, esneklik, yapışkanlık, çiğnenebilirlik ve sakızımsılık parametreleri açısından en yüksek değerleri göstermiştir. Mikrobiyolojik analizler, meyve atıştırmalıkları örneklerinde maya, küf ve toplam canlı üremesi olmadığını ortaya koymuş ve bu da ürünlerin mikrobiyolojik açıdan güvenliğini doğrulamıştır. Duyusal değerlendirmede, atıştırmalıklara karpuz ve çileğin dahil edilmesinin tüketici tercihlerini olumlu yönde etkilediğini, avokado ve çörek otunun dahil edilmesinin ise tüketici kabul edilebilirliği üzerinde olumsuz bir etkiye sahip olduğunu belirlemiştir.Master Thesis Development of Strained Yogurt Ice Cream With Aronia and Hydrolyzed Collagen(01. Izmir Institute of Technology, 2024) Güler, Sevda; Korel, FigenYogurt ice cream, made using yogurt cultures Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus, is integrated with freezing technology, and it is a healthy food that creates cooling effect on consumers. In this study, it was aimed to obtain strained yogurt ice cream that would allow consumption of hydrolyzed collagen and aronia together. Different concentrations of collagen were added to samples with and without aronia. Different amounts of stevia were also added to selected sample due to its antioxidant activity. The quality of the ice creams in the study were evaluated by analyses as follows; dry matter, protein, fat, ash, carbohydrates, pH, color, viscosity, overrun, melting rate, antioxidant activity, coliform and lactic acid bacteria counts, and sensory analyses. While aronia decreased pH, collagen increased pH; adding stevia did not cause any significant change on pH. A correct proportion was observed between the viscosity and fat content of formulations. Samples were examined for antioxidant activity by DPPH and total phenolic content analyses. According to DPPH analysis results, sample B containing 20g of aronia had highest antioxidant activity. According to total phenolic content analysis, sample F containing 20g of aronia and 2.5g of hydrolyzed collagen had the highest total phenolic content. After the antioxidant activity was evaluated, stevia was added as a sweetener to sample E, which contained 1g of hydrolyzed collagen. According to sensory analysis results, sample E1 containing 20g of aronia, 1g of collagen and 0.006g of stevia was the most liked yogurt ice cream in terms of taste.Master Thesis Development of a Functional Snack(01. Izmir Institute of Technology, 2023) Maşa, Zeynep Tuğba; Korel, Figen; Sezgin, EfeNowadays, with the increasing animal food prices, many people in our country are malnourished because they cannot get the necessary protein in their bodies. Additionally, with the Corona virus, which entered our lives in 2019, many people had to struggle with various mental disorders. Although we have left behind the pandemic period, negative emotional states such as depression and unhappiness are still observed in many people today. In this direction, vegetables rich in protein were investigated and used in developing functional snacks. In this study, vegetable chips dough was prepared with 40% pea flour content 15, 17.5, 20, 22.5, and 25% radish, 20, 22.5, 25, 27.5, and 30% zucchini, and 10, 12.5, 15, 17.5, and 20% pumpkin seeds. Each vegetable chip mix was cooked at 50°C, 55°C, and 60°C with the aid of a tray dryer. The proximate analyses (moisture, ash, fat and protein), chemical analyses (antioxidant activity and total phenolic content), physical analyses (color and texture) and sensory analysis were carried out. Mixture design was created with the help of MINITAB 16.0 (Minitab Inc., State College, PA, USA) program, the results of the analyses were evaluated statistically. Based on the design, it was decided to bake thirteen different mixtures at three different temperatures and to perform all the analyzes mentioned above. As a result of the evaluation of all analyses results, the optimized sample was determined as the vegetable chips sample with 40% pea flour, 22.5% zucchini, 25% radish, and 12.5% pumpkin seeds baked at 60°C. The vegetable chips, with this mixture, were baked at 50°C, 55°C and 60°C in the a tray dryer, and in addition to all analyses, sensory analysis and antioxidant activity analysis for all samples baked at 50°C, 55°C and 60°C were conducted. The sample baked at 60°C was the most liked sample.Master Thesis Investigation of Microwave Processing for Pasteurization of Vegan Milk Products(01. Izmir Institute of Technology, 2021) Erol, Büşra; Korel, Figen; Erdoğdu, FerruhIn this study microwave processing was applied for the pasteurization of three different vegan milk products (almond, soy, and oat milk). For microwave process, 360 Watt power applied for 38 seconds. Also, results were compared with conventional thermal treatment which was carried out in a water bath at 70 ℃ during come-up times and 30 seconds holding time. For three vegan milk products, dielectric properties were investigated at different temperature values. After the treatments, important quality properties such as color, pH, particle size distribution and zeta potential values were evaluated. After all treatments, more than 5- log reduction of Salmonella Enteritidis was observed in three vegan milk products. Dielectric properties generally were significantly changed with temperature and frequency (p <0.05). Color differences of vegan milk samples were not perceptible or perceptible through close observation. The pH values generally were not affected by the heat treatments for soy and oat milk (p >0.05). Only there is a significant increase in the almond milk pH value with the heat treatments (p <0.05). Only soy milk's zeta potential values were significantly affected by the different processes (p <0.05). However, microwave pasteurized samples gave the closest value to untreated samples. Also holding process affected the stability of the oat milk. Particle size diameters were changed after the different processes. According to the results, the holding process is not required for the conventional pasteurization at 70 ℃. Microwave heating could be a promising new pasteurization method for vegan milk.Master Thesis Effects of Yeast Species on Quality Characteristics of Fermented Turkish Sausages(01. Izmir Institute of Technology, 2012) Büyüktaş, Duygu; Korel, FigenIn this study, the effects of yeast species in combination with starter cultures on the chemical, physical, microbiological, organoleptic and aroma characteristics of fermented Turkish sausages (sucuk) during processing and storage were investigated. Debaryomyces hansenii and Yarrowia lipolytica were used as yeast species. During processing a decrease in moisture content and water activity and an increase in protein and fat contents were determined. The pH values of sausage samples decreased while titratable acidity values increased during ripening. Thiobarbituric acid values of samples having Y.lipolytica in combination with starter cultures increased during ripening and decreased during storage. Non-protein nitrogen contents of sausage samples showed an increase during processing while protein solubility of all samples decreased during ripening and storage. Moreover, addition of yeast species did not show any difference in protein solubility. According to sodium dodecyl sulfate-polyacrylamide gel electrophoresis profiles, sarcoplasmic and myofibrillar proteins were not affected by the addition of yeast species. Addition of yeast species did not have any important effect on the color of sausage samples during fermentation and ripening. Total aerobic mesophilic bacteria and lactic acid bacteria counts increased, but Enterobacteriaceae and yeast counts decreased in all samples. Moreover, micrococci/staphylococci counts decreased in all samples. It was determined that an important part of the volatile fraction in all sausage samples is composed of terpenes. Samples having Y.lipolytica in combination with starter cultures had the lowest lipid oxidation derived volatile compounds. According to the sensory analysis, samples having yeast species had the highest overall acceptability scores.