The effects of high hydrostatic pressure (HHP) treatment on shelf life and quality parameters of conventionally produced boza

---

Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Gıda Mühendisliği Bölümü, Türkiye

Tezin Onay Tarihi: 2014

Öğrenci: NURAN NİSA ILGAZ

Danışman: HAMİ ALPAS

Özet:

Nowadays, fermented products constitute an important part of the ready to eat products all around the world. A traditional fermented beverage Boza is produced with different formulations and techniques in different countries. Boza is mostly produced and consumed during winter in Turkey due to high energy and nutritional value. Traditionally produced Boza with no thermal process applications is sold in market, therefore, has a short shelf life even kept refrigerated. The aim of this study is to investigate effect of HHP treatment (150, 250, 350MPa; 5°C; 5 minutes) on the keeping parameters of Boza. Viscosity, pH, titratable acidity and total mesophilic aerobic count and total yeast and mold count were investigated to be compared with the control. HHP combination of 350MPa at 5°C for 5 minutes was sufficient to decrease the bacterial load around 3.0 log cycles and all combinations of HHP treatment were effective on total destruction of yeast and mold. Also, HHP treatment at 350MPa at 5°C for 5 minutes had little impact on pH change during storage. All combinations of HHP treatments showed little differences for viscosity and titratable acidity.