RO (reverse osmosis) Tomato Paste(2)
— The advantage of the RO (reverse osmosisi) tomato paste process
With changes in lifestyle and eating habits, there has been an increase in the demand for tomato products of better sensory quality and attributes such as colour, aroma, flavour and texture need to be consistent to retain market share and reputation. Alternative lower temperature concentration processes should be used to preserve the colour, aroma, flavour and taste characteristics in the final concentrates. Reverse osmosis concentration processes requiring less energy than TVE (thermal vacuum evaporation) processes, can also concentrate without causing drastic changes to the sensory properties of colour, flavour and aroma in the end quality of processed tomato products. Other advantages of reverse osmosis include, lower labor/operating costs (no boiler system required since no steam is used), increased recovery/product yield, lower energy requirements, cold sterilization for cold packing, minimum waste production and possible by-product recovery.
Tomato pastes prepared by reverse osmosis concentration were compared with commercial pastes prepared by TVE (thermal vacuum evaporation) processes.
RO tomato paste had a brighter red colour and were preferred over the duller red colour of commercial pastes. It was due to the lower temperatures used during the reverse osmosis concentration processing and manufacture of these pastes. The lower processing temperatures resulted in reduced pigment discolouration and browning compound formation as reflected in the lower HMF levels in the final pastes compared to the commercial pastes.
The aroma of RO tomato paste was also noted as superior to and preferred over the aromas of commercial pastes. The overall superiority in aroma of RO tomato paste is most probably due to the reduced loss of volatile components associated with the lower heat processes used during the manufacture of these pastes, hence giving them an
advantage over current commercial pastes.
The texture of the tomato pastes usually can be correlated with and discussed in terms of consistency. The consistency value of RO tomato paste was higher than commercial pastes.
The flavour of RO tomato paste was significantly different from and preferred more than the flavour of commercial pastes.
The colour of the pizzas made with RO tomato pastes were significantly different to and preferred over the colour of the pizzas made with commercial pastes.
Tomato pastes prepared by the new processing strategy using reverse osmosis and membrane technology had better colour, flavour and aroma than current leading commercial brands of tomato paste.