Effects of boiling and oil or vinegar on pickled jurubeba (<i>Solanum paniculatum</i> L.) fruit

Abstract

Jurubeba fruit, raw and thermally processed for different periods of time, were preserved in soybean oil or vinegar and evaluated for physical characteristics, phytochemicals, antioxidant capacity and polyamines. The loss of green color in many vegetables after cooking is a frequent problem that affects the quality of pickled foods, and chlorophyll content is a relevant parameter to assess the quality. Data showed that a 20 min cooking treatment maintained the best fruit quality and no change in the chlorophyll content occurred. The thermal processing caused no increase in the carotenoid and flavonoid content as compared to the raw fruits, but caused an increase in the phenol content. At a cooking time of about 10 min, the antioxidant capacity increased. Cooking time did not cause significant differences in the content of isoorientin, rutin and caffeic acid. Spermine and spermidine contents were lower after 20 min of boiling. Jurubeba that was preserved in vinegar showed a lower pH and putrescine level, regardless of the cooking time used, whereas the use of oil caused an increase in carotenoids and antioxidant capacity.

Key words: Thermal processing, antioxidants, polyamines, phytochemicals, Solanaceae.