Impact of the increased thermal processing on retinol equivalent values of paprika oleoresins

Processing of pepper fruits (Capsicum annuum L.) to produce their oleoresins includes an extraction stage with organic solvent that extract the lipophilic content of raw material, and a desolventizing step that removes the organic solvent employed initially. This process subjects components of the product to a heating stress, what may generates degradation of the carotenoid fraction that provides this product its colouring capacity, and nutritional content. Food legislation tends to limit the use of organic solvents and diminish the residue limit levels allowed in the end product. Different paprika oleoresins were subjected to thermal degradation and evolution of the provitamin A carotenoids, P-carotene and P-cryptoxanthin was followed. Two reaction pathways were detected during thermal process: isomerization and degradation with different contributions to the provitamin A value of the sample. Increasing values of temperature applied to oleoresins (conditions that may be necessary to obtain an end-product with lower residue solvent levels) show that stability of carotenoids in paprika oleoresins, is good enough to suffer a prolonged heating process avoiding changes in the RE values. (c) 2004 Elsevier Ltd. All rights reserved.