Sürdürülebilir Yeşil Kampüs Koleksiyonu / Sustainable Green Campus Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7755
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Master Thesis Effects of Preharvest and Postharvest Treatments on Quality Characteristics of Grapes(Izmir Institute of Technology, 2016) Konuk, Dilara; Korel, Figen; Korel, Figen; 03.08. Department of Food Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyGray mold, caused by Botrytis cinerea, is the most important disease which causes major quality and quantity losses in preharvest period and postharvest storage of grapes. Grapes are commonly treated with sulfurdioxide (SO2) to control decay caused by Botrytis cinerea both in vineyard and during storage. However, there is need for natural alternatives to replace SO2 because of many considerations related with sulfite residues, emergence of B.cinerea resistant strains, hazards for human and environment, negative effects on quality characteristics and sustainability, and certification for organic grapes. In this study, the effects of alginate solution with or without (w/wo) vanillin as preharvest spray and postharvest edible coating on quality, safety and biochemical properties of grapes from Semillon Blanc, Alphonse Lavalleé and Razaki cultivars were investigated. Soluble solid content, pH, titratable acidity, total phenolic content, antioxidant activity, yeast-mold counts, lactic acid content, color, and firmness were determined at the day of preharvest treatment, at harvest and during 35 days of storage at 4±2°C. In addition, sensory evaluation of grapes coated w/wo vanillin were also performed using hedonic scale test. Alginate treatments w/wo vanillin were effective in preventing weight, soluble solids, acidity, and firmness losses. Incorporation of vanillin into alginate coating provided significant reduction in yeast-mold growth. Moreover, phenolic content and antioxidant activity of grapes treated with alginate coating incorporating vanillin were higher than others during postharvest storage. In sensory evaluation, appearance was ranked as the highest for alginate coating wo vanillin. As a conclusion, alginate solution enriched with vanillin could be a natural alternative of synthetic fungicides to prevent deteriorations and enhance quality of grapes.Master Thesis Structural Changes of Gliadins During Sourdough Fermentation as a Promissing Approach To Gluten-Free Diet(Izmir Institute of Technology, 2010) Kömen, Gökçen; Harsa, Hayriye Şebnem; Harsa, Hayriye Şebnem; 03.08. Department of Food Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyGluten intolerance, celiac disease, is an autoimmune disease caused by the ingestion of gluten proteins and the only treatment is the strict gluten-free diet which results in a mucosal recovery. At this point, the variety, availability and low price of gluten-free products on the market are of great importance. Sourdough is a traditional fermented semi-product that contains lactic acid bacteria (LAB). LAB are capable of metabolizing proteins and peptides with their proteolytic enzymes. It is predicted that gluten proteins are able to be hydrolyzed with the help of this proteolytic mechanisms and also by the wheat proteolytic enzymes. the help of this proteolytic mechanisms and also by the wheat proteolytic enzymes. gliadins involved in gluten intolerance during sourdough fermentation with selected LAB. First, sourdough fermentation with selected Lactobacillus strains was accomplished. As a control, dough with no inoculation and chemically acidified dough were prepared. During 48 h of fermentation, changes in pH, acidity, LAB concentration and free amino nitrogen content were investigated. SDS-PAGE, 2-D electrophoresis and RP-HPLC were applied to prolamins extracted from each sourdough sample taken at definite time intervals. The results showed that the inoculated LAB adapted to the dough environment and as they grew, a decrease in pH, and an increase in acidity and free amino nitrogen were observed. According to SDS-PAGE, 2-D electrophoresis and RP-HPLC results, some modifications in the protein patterns were observed in the inoculated doughs. The same alterations occurred in control and chemically acidified doughs, but not as fast as inoculated ones.