Poster Session 6 Submission ID: 798
IN-VITRO GLYCEMIC INDEX DETERMINATION OF SOURDOUGH BREADS PREPARED BY USING SOURDOUGHS COLLECTED FROM DIFFERENT REGIONS OF TURKEY 1
2
EZGI ŞENOL , MUSTAFA YAMAN , M. ZEKI DURAK
1
ABSTRACT Bread is of great importance for diet of Turkish people. Especially white bread is one of the most consumed foods with its high glycemic index (GI). As known, white sourdough bread or sourdough bread containing different rate of dietary fibers has lower GI than white bread. The aim of this study was to collect traditional sourdough samples from different regions of Turkey and determine the GI of sourdough breads made from these sourdoughs. For this purpose, 5 different traditional sourdoughs were obtained: 4 different homemade white sourdoughs (Oğuzlu (O), Kastamonu (K), Lüleburgaz (L), Afyon/ Bolvadin 2 (B2)) and 1 commercial whole wheat sourdough, Safranbolu Yıldız Fırını (SYF). Sourdough breads were prepared using the dough of these samples with their own flour and long timed-cold fermentation (18h). Then GI values of the prepared sourdough breads were evaluated by using an in vitro method based on Goni–assay calculating the GI by measuring rate of starch digestion. A similar glycemic response was observed for sourdough breads except whole wheat sourdough bread. O, K, L, B2, SYF had GI of 50.05±0.3, 51.8±1.65, 50±0.5, 51±0.5 and 46.5 ±0.5, respectively. Compared to the control (White bread, GI: 70), the GI of sourdough breads was found low (<55). There was no significant difference among the GI values of white sourdough breads collected from different regions. The difference of SYF was thought to stem from dieatary fiber. There was a negative correlation between the GI value and sourdough - dietary fiber. According the results, the ability of breads to lower GI was affected by sourdough, dieatry fiber and long timed-cold fermentation.
KEYWORDS in vitro glycemic index, sourdough, dietary fiber, fermentation temperature
Corresponding Author: M. ZEKİ DURAK, mzdurak@yildiz.edu.tr 1 YILDIZ TEKNİK ÜNİVERSİTESİ 2 İSTANBU ZAİM ÜNİVERSİTESİ
891