Impact of ozonation process on the texture parameters, antioxidant activity and organo-leptic properties of highbush blueberry and apple jams

Abstract

The comparison of jams prepared from blueberry fruit and apples subjected to the ozonation process with the ozone atmosphere concentrated from 1 ppm during 5 minutes for apples as well as from 10 and 100 ppm for blueberry fruits during 30 minutes showed the below observations:

1) Prior ozonation of highbush blueberries and apples has no significant effect on the sensory properties of the prepared jams except when using the highest dose of ozone (100 ppm).

2) Prior ozonation of blueberry and apple fruits has a significant, but ambiguous and dependent on the measured parameter, effect on the texture determined using the standard TPA test (hardness, destructive force, compressive work, adhesiveness, elasticity, gumminess), with the indication to increase the hardness and size of derivatives.

3) Prior ozonation of blueberry fruit and apples significantly contributes to the antioxidant activity of blueberry jams and the content of polyphenols in apple jams.

4) The assessed sensory parameters and textures as well as antioxidant activity and polyphenol content in ready-made jams greatly depend on the sort of fruit used.

Blueberry and apple fruits were treated with mixed air and ozone at the same. Ozone was generated by corona discharges at concentrations of 1, 10 and 100 ppm for 5 minutes on apples constituting as a major batch and 30 minutes on blueberries as the main input material. The jams were subjected to organoleptic evaluation on the basis of selected sensory characteristics such as: colour, aroma, taste, consistency, spreadability, texture. The texture of the jam was assessed with the following parameters: hardness, destructive force, compressive work, adhesiveness, elasticity, gumminess. Moreover, there were also conducted biochemical analyzes of antioxidant activity using the DPPH method (as the equivalent of Trolox per 100 g of fruit) and the amount of polyphenols using the Folin-Ciocialteu method as the equivalent of gallic acid (mg of GAE per 100 g of fruit).