اثر غنی‌سازی آرد گندم با آرد کنجد بر ویژگی‌های آرد، خمیر و نان‌های سنگک و بربری

در پژوهش حاضر، اثر غنی‌سازی آرد گندم با آرد کنجد در نسبت‌های صفر، 5، 10 و 15 درصد بر ویژگی‌های آرد، خمیر و نان‌های سنگک و بربری بررسی شد. نتایج نشان داد که با افزایش میزان آرد کنجد، مقدار خاکستر و پروتئین آرد افزایش یافت، اما مقادیر رطوبت و گلوتن مرطوب کاهش پیدا کرد. به‌علاوه، شاخص‌های فارینوگرافی خمیر نظیر جذب آب و پایداری کاهش داشت، اما زمان گسترش و درجه نرم شدن خمیر افزایش یافت که بیانگر ضعیف شدن شبکه گلوتنی خمیر بود. نتایج اکستنسوگرافی نیز نشان داد که با افزایش میزان آرد کنجد، شاخص مقاومت به کشش نسبت به کشش‌پذیری کاهش پیدا کرد. بررسی نتایج ارزیابی سفتی بافت و رنگ نان‌ها نشان داد که افزودن آرد کنجد سبب کاهش سفتی بافت شد ولی اثر معنی‌داری بر شاخص‌های رنگی نان‌ها(l*, a* , b*)  نداشت. به‌علاوه ترکیب اسیدهای چرب نان‌ها نیز بهبود پیدا کرد. در نهایت در ارزیابی حسی، نان‌های سنگک و بربری به‌ترتیب حاوی 10 و 5 درصد آرد کنجد، بیشترین امتیاز پذیرش کلی را به‌دست آوردند.

effect of wheat flour fortification with sesame flour on properties of sangak and barbari flour, dough and bread

1]introduction: bread is an important staple food widely consumed all over the world including iran. the consumption of traditional breads in iran, including barbari, sangak, taftoon and lavash, is steadily increasing because of its convenience and being a ready-to-eat food product normally consumed at breakfast, lunch and dinner. hence, fortification of several types of bread with other cereals, pseudo cereals, legumes and oil seeds flours, has received considerable attention. sesame, although referred to as “seed of immortality” and “queen of oilseeds” is considered as a rich food as it has a high nutritive quality. apart from being a prominent oilseed (45-50%), sesame seeds are a rich source of protein (18–40%). also, sesame was reported as a rich source of vitamins and minerals. therefore, in the current study, the effect of wheat flour fortification with sesame flour at the ratio of 0, 5, 10 and 15 % on flour, dough, sangak and barbari samples properties was evaluated. material and methods: proximate analysis of flour samples (sesame, wheat and composite flour samples) including acid value, moisture, ash, protein and wet gluten contents of the flour samples were determined according to the aacc methods. water absorption, dough development time, dough stability time, degree of softening and the ratio between resistance to extension and extensibility (r/e), of prepared dough samples were determined according to aacc 21-54 and aacc 10-54 standard methods. after 2 h of bread baking the crust color parameters (l*, a* and b*) were determined using the hunter–lab color flex colorimeter (hunter associated lab, inc., reston, va, usa). crumb hardness was also measured 2 h after baking using a texture analyzer (texture analyzer, brookfield, ct3, usa). the organoleptic characteristics (taste, aroma, color, texture and overall acceptability) of the prepared bread samples were evaluated by 15 trained panelists familiar with the traditional bread usually consumed, using 5-point hedonic scale (5 = like extremely, 1 =dislike extremely) test. the data was analyzed by one way analysis of variance (anova). a multiple comparison procedure was performed by duncan’s new multiple range test using spss software. significance of the difference was defined as p <0.05. results and discussion: according to the results obtained from flour samples analysis, sesame flour contained higher amounts of protein, lipid and ash and low amount of moisture and gluten than wheat flour. furthermore, with increasing the amount of sesame flour, ash and protein contents of flour samples were increased, but their moisture and gluten contents were decreased. furthermore, farinograph parameters including water absorption and stability were decreased, but dough development time and degree of softening were increased with increasing the amount of sesame flour in the formulation. the results of extensograph test also, showed the r/e ratio, which indicates dough stability during fermentation, was decreased when the sesame flour content increased. therefore, the addition of sesame flour induced to weaken the gluten network formation in dough samples. the qualitative characteristics results of bread samples showed that addition of sesame flour to bread formulation tends to decrease crumb hardness and had no effect on color attributes (l*, a* and b*). sensory evaluation results showed the higher total acceptability of sangak and barbari bread samples containing 10 and 5 % of sesame flour, respectively. in these ratios the color and texture of bread samples were also similar to related control bread samples. according to the results obtained in the current study and based on the functional properties of sesame flour (rich source of oil, protein, minerals, vitamins and antioxidant compounds) that reported by several previous studies, addition of 5 and 10 % of sesame flour in large scale production of barbari and sangak breads is recommended. due to the high consumption of sangak and barbari breads in iran, fortification of these breads can be effective in providing the daily needs of several nutrients.