Antioxidant content and colour level in different varieties of red pepper (Capsicum annuum L.) affected by plant-leaf Ti4+ spray and processing

Seasoning paprika is, economically, one of the most important vegetable spices and some of the factors that most likely determine its quality may be red colour and antioxidation capacity. This study was carried out to evaluate the varietal influence on the colour levers and on the most effective biological bioantioxidants: ascorbic acid and a-tocopherol. The variations induced during the drying and grinding operations were also determined and the effect of a biological activity inductor (Ti4+-ascorbate) on the composition of these quality parameters in both the fresh and the dried fruit pericarp was analysed. An important decrease of all the parameters studied was observed during processing, especially on the ascorbic acid content (about 75%), red colour (14-58%), and on the level of cr-tocopherol (25-30%). Red colour retention in paprika was strongly related to the total bioantioxidant diminution. All the compounds studied were increased when two leaf Ti4+ treatments were applied to plants during the crop cycle, but there was some important varietal differences in the intensity of the response.