Nutritional, rheological, and sensory evaluation of tomato ketchup with increased content of natural fibres made from fresh tomato pomace

Abstract

The aim of this study was to upgrade the tomato pomace by its conversion into a value added product—ketchup with increased content of natural fibre and optimal sensory properties, produced using standard processing equipment. Fresh tomato pomace was homogenized with other ingredients (water, sugar, salt, vinegar, glucose syrup, xanthan gum, guar gum) at 30 °C, then heated at 60 °C, packed and pasteurized. The end of process was determined according to Bostwick consistency value. Chemical composition, colour and rheological properties were measured at six production steps. Ketchup with increased nutritional value was compared with five commercial products in terms of colour, rheological and sensory properties. Tomato ketchup with increased content of natural fibre contained 3.18 g/100 g of total dietary fibre. Although the rheological properties of ketchup with increased fibre content depend mostly on total solids and insoluble particles content, they remained in the limits of standard tomato products. The obtained results are encouraging in terms of the applied technological process since it resulted in a product with sensory properties more similar to fresh or slightly processed tomato. Flavour, viscosity and colour of ketchup with increased nutritional value could be modified to meet the demands of consumers from different markets.