Investigation on the effect of different additives (enzymes, gums and improvers) on rheological properties of frozen dough and bread

Bread is one of the most popular item consume in the world and Iran. Daily bread Using, 400 to 500 g provide the total energy used by the body. Bread has short shelf life, because after baked immediately, occurred physical and chemical changing lost quality, and not consumption. This leads to production high volume of waste and economic losses. From the 21st century have been introduced the frozen technology of bakery products In order to improve the shelf life of bread, quality, increase nutritional value, great product, available it at any time of the day. Given the above this study aim to investigate the effects of amylase and lipase in 3 levels, 250 and 350 ppm and gum and xanthenes guar at 3 concentrations of 0, 0.4, 0.8 g acid ascorbic three levels (0, 75 and 150ppm), Datum three levels (0.03 and 0.5%) and glycerol at three levels (0, 0.5 and 1%) to improve the rheological and sensory properties of semi-volume part baked frozen Barbari bread. Barbari bread prepared with formulations commonly, bread cooked as part baked then packed in polyethylene bags, and transferred to chest freezer with a f - 18 ° C for 15 day, then thawing and full baked at 260° C for 10 min. after full baked measured the moisture content, water activity, volume, porosity, texture properties, color index and sensory characteristics. This experiment were performed in design factorial and according to the frequency of treatment done in 2 repeated. The result given from tests showed Guar gum at 0.4 levels, the amylase enzyme in 0.07, lipase at 0.05, 0.5% glycerol, 75 ppm ascorbic acid and a second level of DATEM to improve all parameters were measured. The independent and interactive effects of guar gum and amylase was higher than to improve all parameters. In the second phase Xanthenes gum replaced guar and measured the effect of it in independently and in combination with optimal concentration of lipase and amylase given past phase. In all parameters measured, and compared with guar, xanthenes gum at 0.4 concentration at independent effect improve the quality and increase the volume, In contrast, the effect of guar have been better on color and sensory properties.