Akademik Veri Yönetim Sistemi
Tezin Türü: Yüksek Lisans
Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Gıda Mühendisliği Bölümü, Türkiye
Tezin Onay Tarihi: 2012
Öğrenci: CEYDA AKHAN
Danışman: HAMİ ALPAS
Özet:High Hydrostatic Pressure (HHP) application, alone or in combination with refrigeration, ambient or moderate heating temperatures; inactivates pathogenic and spoilage microorganisms and conserves the product „„freshness‟‟ with fewer changes when compared to conventional food preservation processes. During handling and frozen storage, quality deterioration of seafood brings the risk of contamination, quality loss and a potential threat to food safety and human health. In this respect, the aim of this study was to determine the effect of HHP on quality factors and shelf life of anchovy (Engraulis encrasicolus) and haddock (Gadus merlangus euxinus) under different pressure, temperature and time combinations. Due to their high perishability and easy availability in Turkey, anchovy (Engraulis encrasicolus) and haddock (Gadus merlangus euxinus) samples were chosen and pressurized with HHP at 200, 300 and 400 MPa, at 5, 10 and 15 °C for 5 and 15 min. According to the results of physical and chemical analysis which were performed to HHP treated fish samples; such as color (L*, a*, b* and ΔE), trimethylamine nitrogen (TMA-N), and 2-thiobarbituric acid (TBA); best HHP combinations were selected for shelf life analysis as 200 MPa, 5 °C for 5 min for anchovy; both 200 MPa, 5 °C for 5 min and 400 MPa, 15°C for 5 min for haddock. In order to determine the effect of HHP on the shelf life, untreated and HHP treated samples were stored at refrigeration temperature (4 °C) for 15 days. Every each day, sensory, color (L*, a*, b* and ΔE), pH, trimethylamine-nitrogen (TMA-N), thiobarbituric acid (TBA), total volatile basic-nitrogen (TVB-N) and total plate count (TPC) analysis including statistical analysis (ANOVA) were monitored for untreated and treated samples during 15 days at refrigeration temperature (4 °C). Considering the rejection limits for consumption, effect of HHP to shelf life was evaluated. When all conclusions were combined, the shelf life extension was determined averagely as 9 days for pressurized anchovies (200 MPa 5 °C for 5 min) when stored at 4 °C. Also for haddock, shelf life was extended to 13 days and 15 days when samples pressurized with 200 MPa at 5 °C for 5 min and 400 MPa at 15 °C for 5 min, respectively; since all control samples of anchovy and haddock became unacceptable within 3 days.