Application of Native and Modified Canna Starches as Thickening agent in Tomato sauces

Abstract

Native canna starch and its derivatives (hydroxypropyl canna starch with molar substitution of 0.11 and acetylated canna starch with degree of substitution of 0.08) together with the other two starches, i.e., cassava and commercial-modified starches, were evaluated as thickening and phase stabilizing agents in tomato sauce; a commercial tomato sauce was used as a reference. Viscosities of tomato sauces containing all types of starches at a concentration of 1.5% (w/w) were lower than that of the commercial sauce (initial viscosity = 2757 cP). Viscosities of the sauces added with 3.0% (w/w) of native canna, acetylated canna, hydroxypropyl canna, commercial-modified, and cassava starches were 1644, 5118, 5490, 9015 and 3855 cP and decreased to 1443, 4641, 3903, 5403 and 2745 cP, respectively, when kept at room temperature for 8 weeks. Tomato sauces added with native canna starch had the highest percentage of serum loss (41-57%); this was followed by the souces added with acetylated canna and commercial-modified starches (medium loss, 15-22%), and hydroxypropyl canna and cassava starches (low loss, 1-8%), whereas the serum loss of the commercial tomato sauce kept under the same condition was around 15-18%. Tomato sauces with hydroxypropyl canna starch exhibited smooth and homogeneous texture without observable water separation. Based on the three main criteria, namely, viscosity, serum loss and textural appearance as well as total solid content, pH, acidity, reducing sugar content and color, it could be concluded that hydroxypropyl canna starch has high potential for being used as thickening agent in tomato sauce.