الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
The production of juices and concentrates of the largest and most important food industries in Egypt. The consume concentrates throughout the year after retrieval is both oranges and tomatoes of the most important agricultural crops spread cultivated in Egypt, where it is a source of many important nutrients such as ascorbic acid and beta-carotene and lycopene so they consume commercially around the world, either fresh or in the food industry. This research aims to study the physicochemical and microbiological properties as well as sensory evaluation of some juices and their concentrates manufactured in Egyptian, which consume larger quantities in the Egyptian market. The physicochemical properties changes in some constituents for example, moisture content, sugar content, acidity, pH value, color index, pectin fraction, ascorbic acid content and ash contents of both orange and tomato juices and their concentrates were analyzed in fresh juices and concentrates, then after storage at -18°C for 6 months. On the other hand, the physicochemical properties changes were analyzed after the preheating on 65°C for tomato juices and 80°C for orange juices. The physicochemical changes after sterilization at 105°C was investigated for tomato concentrates. The percentage of total bacterial counts, lactic acid bacteria, yeasts & molds and coliform group absences were analyzed in fresh juices and concentrates, then after storage at -18°C for 6 months. The sensory attributes of juices prepared from stored concentrates of orange and tomato recorded less sensory quality for color, taste, odor, texture and overall acceptability when compared to fresh juices.