الفهرس 
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Abstract
Wheat is the most important grain crop in Egypt and grains are, in turn, the most important crop group. Wheat represents almost 10 percent of the total value of agricultural production and about 20 % of all agricultural imports. Wheat is an extensively cultivated food crop and forms an important staple food in many countries. The wheat kernel or caryopsis can be roughly divided into 3 parts: the endosperm, the germ, and multiple histological outer layers (that is, outer and inner pericarp, seed coat, and nucellar epidermis), commonly denominated as botanical bran.
Bread is a staple food in many parts of the world and varies widely in its formulation. Flour is the most important and basic ingredient in bread making. Generally, bread is mainly prepared from wheat flour. To improve the nutritional profile of wheat bread, substitution of wheat flour with other flour, such as barley .The base of Ancient Egyptians diet depended mainly upon bread, thus it has been used as food for all Egyptians wealthy and poor and was consumed at every meal, and no meal was considered complete without them. Bread as made from wheat grains consisting mainly of starch, proteins, traces of vitamins and minerals it played an important role in the ancient Egyptians life, economy and religious cult rituals.
Enzymes are biological catalysts which are an indispensible component of biological reactions .Amylases are important hydrolyses enzymes which have been widely used since many decades. Types of amylase, α-amylase (E.C.3.2.1.1) is a hydrolyses enzyme that catalyses the hydrolysis of internal α-1, 4-glycosidic linkages in starch to yield products like glucose and maltose .Sources of α-Amylase can be isolated from plants, animals or microorganisms. The enzyme has been isolated from barley and rice plants
The development of baking technology is a phenomenon that has had a great impact on the food industry, and has increased the acceptance of food by the consumers .The use of different additives such as oxidants to improve the quality of bread is nowadays common practice .Potassium bromated , ascorbic acid, azodicarbonamide are some of the examples of oxidizing agents.
The main objective of the present study is to investigate and determine the effect of alpha amylase and ascorbic acid with different levels on quality of pan bread.
Specific objective are to:-
1. Determine the effect of α-amylase and ascorbic acid in combination on texture quality of Ban Bread.
2. Determine the ability of enzyme and ascorbic acid to delay the staling processes upon storage for different periods of time
(2 weeks).
3. Evaluate the overall quality of the treated dough and the final product.
4. Investigate the nutritive value of the final product.
Materials and Methods
A. Materials:
• Wheat flour ”Triticum aestivum L.” (72% extraction) was obtained from Agriculture Research Center, Giza, Egypt.
• Alpha amylase and ascorbic acid Were obtained from Cairo Company for Chemical Trading, Cairo, Egypt
• Ingredients (yeast, salt and sugar) for bread preparation were purchased from the local market, Cairo, Egypt.
B. Methods:
1- Preparation of pan bread (unfortified and fortified with different additives):
Preparation of pan bread products was be prepared according to the recipe and procedures of Food Technology Research Center. Using different level of alpha amylase and ascorbic acid with constant bread recipe and was be added as shown in Table (1), different additives were added each individually and combination as a mixture , then left to fermented for (1h) at 30° C., punched ,molded , fermented again for (30 minutes ) at 30° C , and baked for 40-44minutes . In an oven at 200 °C .