JWSS - Journal of Water and Soil Science

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The quality of Iranian breads has intensively decreased during recent years due to socio-economic factors and poor quality of flour. The purpose of this study is to investigate the effects of mono- and diglycerides and ascorbic acid as improvers on Iranian bread (Taftoon) quality. Three wheat type flours (Ghods, Mahdavi and Roshan wheat varieties produced in Isfahan region) were used. The effects of ascorbic acid at three levels (20, 40 and 60 ppm flour basis) and esters of mono- and diglycerides at three levels (0.5, 1.0 and 1.5 percent) on the dough baking and bread quality were measured. The Taftoon bread was baked in a semi-traditional oven.

 Loaves of bread were scored after baking and also on the first and second days of storage at room temperature. Analysis of variances indicated that ascorbic acid and mono- and diglycerides have significant effects on the improvement of the rheological properties of dough. However, ascorbic acid had higher effects than mono- and diglycerides. The results of the tests showed that dough resistance to mixing and tensile stress increased with addition of the improvers. Both improvers used in this experiment have an anti-stabling effect on bread. However, the ascorbic acid effect is much less than that of mono- and diglyceride. The low concentration of 0.5 percent of mono- and diglyceride and 60 ppm of ascorbic acid with flours of moderate protein contents (10-11%) resulted in good quality Taftoon bread with good organoleptic and tearing qualities after two days.

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Baking is obviously one of the most important stages of bread production. Baking time and oven temperature have greatest effects on bread quality. The aim of this study was to investigate the effect of baking time and temperature on bread quality and its shelf life. In this study, the effect of three rates of oven temperature (top and under bread surface) and baking time levels on bread quality and its shelf life was investigated. Baking temperature and time were 300 and 280 °C for 3 minutes and 20 seconds, 300 and 350 °C for 2 minutes and 30 seconds and 350 and 380 °C for 2 minutes respectively. Soluble starch and staling factors of the samples were measured. The data was statistically analyzed by complete randomized design and comparison was made between the means via Duncan,s multiple range test at 5% level. The results showed that the bread baked in various time–temperature conditions were different in moisture content. The bread baked at lower temperature and longer time had the lowest moisture. Also, the result showed that the amount of soluble starch increased by increasing the baking time and decreasing the baking temperature. The bread baked in various baking conditions showed significant differences in staling rates. Lower baking time and higher baking temperature caused the lowest bread staling rates.