Quality Characteristics and Antioxidant Activity of Cream Soup Supplemented with Freeze-Dried Tomato Powder

Abstract

In this study, cream soup was prepared by adding 10 to 30% of freeze-dried tomato powder to wheat flour, and then determining its quality characteristics, bioactive compound contents, and antioxidant activity. Moisture, crude protein, and crude fat contents of soups prepared with varying amounts of tomato powder were not significantly different from cream soup made without tomato powder (the control). The ash contents of soups ranged from 0.38∼ 0.69% and increased according to the amount of tomato powder added whereas soup pH decreased and acidity increased on adding tomato powder. Soup viscosity was highest for the control and decreased on adding tomato powder. The brightness of cream soup decreased in proportion to the amount of tomato powder added, and redness and yellowness increased. Total polyphenol, total flavonoid and carotenoid contents and antioxidant activity also increased in proportion to the amount of tomato powder added. These results show that adding tomato powder at 10∼30% by weight to the wheat flour used to prepare cream soup can increase bioactive substance contents and antioxidant activity.