Mina Dzhivoderova-Zarcheva1, Kremena Nikovska2 and Kamelia Dimova3
1 University of Food Technologies, Department of Technology Tobacco, Sugar, Vegetable and Essential Oils, Technological Faculty, 4002 Plovdiv, Bulgaria
2 University of Food Technologies, Department of Catering and Tourism, Faculty of Economics, 4002 Plovdiv, Bulgaria
3 University of Food Technologies, Department of Food Preservation and Refrigeration Technology, Technological Faculty, 4002 Plovdiv, Bulgaria
Dzhivoderova-Zarcheva, M., Nikovska, K. & Dimova, K. (2021). Rheological and structural properties of tomato ketchup as affected by the addition of native and modified starches. Bulg. J. Agric. Sci., 27 (1), 220–226
It was investigated to determine the effect of several modified and/or native starches like a thickening agent, at levels of 5% on the rheological properties, consistency and syneresis of tomato ketchups. Two ketchup model systems: A (without tomato paste) and B (with tomato paste), were analyzed. Тhe model systems A and B were non-Newtonian fluids, and their viscosity variations were closely. In general, corn starches exhibited lower Bostwick values than potato starches, especially when native corn starch was applied. With higher value of Bostwick consistency was the system A with Acetylated distarch phosphate from potato starch – 8.50±0.43 сm and with lower was the system A with Acetylated distarch adipate from waxy maze starch + Native corn starch (1:1) (ADA-WMS+NCS) аnd Native corn starch (NCS) – 1.00±0.05 сm. Addition of tomato paste significantly affected the consistency and the syneresis resistancy of the systems. The highest value of the separated liquid (in %) for system B was the sample with ADP-PS (13.01±0.65%), аnd the lowest – the sample with NCS (1.77±0.09%). On the basis of these results, the most suitable for the production of ketchup tomato and in order to reduce also the modified starch, it can be used the acetylated distarch adipate from waxy corn and native corn starch in equal proportions or only native starch.