Effect of some aromatic plants and their essential oils on pan bread quality /
تأثير إضافة بعض النباتات العطرية وزيوتها على جودة خبز القوالب
Hanaa Ahmed Ragaei Mohamed ; Supervised Yahia Ibrahim Sallam , Ahmed Salama Elleithy , Safaa Ezzat Ali
- Cairo : Hanaa Ahmed Ragaei Mohamed , 2019
- 110 P. : charts , facsimiles ; 25cm
Thesis (Ph.D.) - Cairo University - Faculty of Agriculture - Department of Food Science Technology
Ajwain (TrachyspermumammiL.) seeds and thyme (Thymus vlugaris) powders and their essential oils as natural food preservative agents were studied. Ajwain seeds and thyme leaves yielded of 2.8 and 1.1% (on dry weight basis) essential oils. Thymol (35.80 - 38.07 %), þ-cymene (34.76 - 26.33%) and -terpinene (19.20 - 8.11%) were identified as major constituents of ajwain and thyme essential oil, respectively. The total phenolic contents of aqueous extracts of ajwain and thyme were 8.77 and 25.28 mg GAE/g dry mater, respectively. Meanwhile, total flavonoid contents were 6.55 and 80.00 QE/g dry mater, respectively. The essential oils of ajwain and thyme revealed antioxidant activity where, IC50 was 30.44 and 28.31 g/ml. Ajwain essential oil was more effective against A. niger than thyme essential oil. Meanwhile, S. cerevisiae was more sensitive against thyme than ajwain. Rheological studies showed that an increase in replacement level led to an increase in water absorption of wheat flour 72% extract and a decrease in dough stability. Ajwain and thyme powders were used to replace 2, 4 and 6% of pan bread wheat flour and their essential oils were incorporated at 200l/4g sunflower oil. all samples were acceptable by panelists. except, at level of 6%. Specific volume of pan bread samples was decreased with increasing substitutes level. Sample containing 4% thyme (T4) recorded the lowest specific volume. Crumb color was significantly affected (p<.05), since increasing replacement level gradually increased darkness, and decreased yellowness