Fruits of Capsicum annuum L. are largely used in both food and pharmaceutical sectors due to the presence of beneficial nutritional and healthy components. Capsaicinoids, have showed to exert strong physiological and pharmacological properties including the ability to decrease the cholesterol levels and to affect fat metabolism while they are responsible for the peculiar taste of the hot pepper and for that fruits are largely used in oil-based dressings and sauces. Limited is until now the knowledge about the activity and the technological functionality of the bioactive compounds of peppers and in particular of the more hydrophobic ones.
Aim of this work was the evaluation of the technological functionality of the lipophylic fraction of driedpepper fruitsin oil and o/w emulsified systems.
The overall lipophyclic fraction of peppers was extracted in sunflower oil using different pepper:oil ratio. The composition (capsaicinoids and carotenoids) of the extracted oils was determined along with their antioxidant activity, interfacial properties and emulsifying ability. O/w emulsions (Tween 20,f:0.20) were prepared with the liphophylic extracted pepper oil and accelerated shelf-life conditions were used to test oxidative and physical stability of both oil and emulsions.
The lipophylic fraction in the extracted oil resulted composed mainly by carotenoids and capsaicinoids whose concentration depends on the pepper:oil ratio used during the extraction.
A decrease of the interfacial tension occurred in the pepper lipophylic compounds enriched-oil that could be implied in the correspondent improved emulsifying capacity. The effect on both properties was not proportional to the extracted compounds content, likely due to competition phenomena of the more surface active lipophylic compounds at the oil-water interface.
Upon storage, the lipophylic bioactive compounds didn’t affect the formation of hydroperoxides in respect to the reference oil, while a delay in development of the secondary products occurred and attributed to a H× donor ability.
Knowledge gained from this research could be used to design food and pharmaceutical products made with peppers extracts with improved health and stability.
Prof. Paola Pittia ppittia@unite.it
