Zahra Sheikholeslami; Mahdi Karimi; Toktam Hejrani; Mehdi GhiafeDavoodi; Hamed Fatemian
Abstract
Introductıon: Hydrocolloids have been employed for reduction of moisture migration from the crumb to crust, added to the formulation, improved texture, prevent ice Crystallization and delay staling (Ba´rcenas et al 2003, 2004, Hager, and Arendt, 2013). However, given the importance of their role still ...
Read More
Introductıon: Hydrocolloids have been employed for reduction of moisture migration from the crumb to crust, added to the formulation, improved texture, prevent ice Crystallization and delay staling (Ba´rcenas et al 2003, 2004, Hager, and Arendt, 2013). However, given the importance of their role still trying to find new resources will continue to create the best quality. Today, researchers introduced new technologies such as modified atmosphere packaging, frozen technology and using different additives to produce bread with higher quality, longer shelf life and high nutritional value. Production of the part baked frozen bread is a method which interrupted baking process, the first stage is the crumb formation and the crust color is not developed. The aim of this study was to evaluate the effect of Ocimum Bacilicum and tragacanth at 3 levels (0, 0.3 and 0.5%) (W/W flour basis) on the quality of part-baked Barbari bread after frozen storage and re-baking.
Materials and methods: The Ocimum Bacilicum seeds were cleaned, then were firstly soaked in distilled water to obtain a water to seed ratio of 37:1 at 40˚C and pH 7. Separation of the hydrocolloid from the swollen seeds was achieved by passing the seeds through an extractor equipped with a rotating plate that scraped the gum layer on the seed surface. The extracted solution was then filtered and dried in an air forced oven at 60˚C and finally the powder was milled, sieved using a mesh 18 sifter, packed and kept at cool and dry condition (Karazhiyan et al., 2010, Sahraiyan et al., 2013). Tragacanth purchased from the local market as a tape shape after milling and sieve (70 mesh) were used. Bread prepared as part baked, freezing in -18°C and storage for 15 days, after this time samples were thawing and full baked. The test includes moisture content, specific volume, porosity, firmness, image analysis and sensory properties was measured. For Data Analysis used SPSS software and Duncan test, for mean comparisons.
Results and discusions: The results obtained from volume, texture, moisture content and sensory properties showed Tragacanth gum at 0.5 concentrations and Ocimum Bacilicum gum at 0.5 levels improved moisture content. Using tragacanth at 0.3% and Ocimum Bacilicum gums at 0.5 % concentration improved the specific volume, porosity, firmness, and sensory properties. The hydrocolloids are highly hydrophilic nature, it made hydrogen link between the water available in the system, prevent the movement of water from crumb and improved the firmness and improved the quality of bread (Manadala et al., 2008). The hydrocolloids capable to strengthen the gluten matrix surrounded cell gas as result maintenance them during part baked and frozen storage. Hydrocolloid, coalescence of gas cells as a result of expansion during the proofing step and increase the volume and porosity of bread (Shillini & Laxemi, 2007).
Conclusion: Addition of Ocimum Bacilicum and tragacanth to bread recipe improved the crumb texture of the bread that obtained from part-baking, frozen storage and re-baking. In addition, the presence of gums improved the specific volume, texture and the overall quality of the product during frozen storage, removing the negative effects of that process conditions. The Ocimum Bacilicum in comparison of tragacanth had the greater concentration effect on PBF Barbari bread on improved the quality. The interaction of tragacanth and Ocimum Bacilicum (0.3 and 0.5 %) respectively had the best result to improving the all parameters that investigated in part baked and freezing storage of Barbari bread. This study provides insights into the complexity of interactions between tragacanth and Ocimum Bacilicum as a new source of hydrocolloids and their combined influence on bread characteristics, thereby serving as a guide for future research on the other bread
