Carotenoides microemulsionados: estratégia para enriquecimento de matriz alimentar aquosa

Abstract

Carotenoids are fat-soluble natural pigments, many of them with intense color, which are synthesized by plants and microorganisms. Nutritionally, they are among the most important minority components of foods, as they act as antioxidants and some are precursors of vitamin A. However, these compounds are chemically unstable, requiring strategies to increase their stability in products to which they are added. Therefore, the study aimed to develop microemulsions containing carotenoids and to evaluate the possibilities of this system for application in an aqueous food matrix. The first study contains a bibliographical review of information about the most recent techniques for protecting and applying carotenoids in food matrices, especially focused on the use of nanotechnology. It appears that studies on release systems for the use of carotenoids in foods are recent, with emphasis on their application in yogurts; therefore, more research is needed to expand their application in different food matrices. The second and third study, experiments were related to the development of microemulsions of the (O/W) type incorporating β-carotene (synthetic) and annatto (Bixa orellana) in clarified apple juice. These studies reported the evaluation of some properties (antioxidants, rheological and structural) and product stability (by storage time, centrifugation and thermal conditions), as well as evaluating the microbiological behavior of clarified apple juice microemulsified with carotenoids during 21 days of refrigerated storage, and the different sensory attributes in acceptance of the product by consumers. The developed product presented optical clarity, more intense color, isotropic characteristics, stability under heating, Newtonian behavior and hydrodynamic radius in the order of nanometers; however, with asymmetric and polydisperse droplets, and, in addition, low values of zeta potential and mobility. The sample of apple juice clarified with β-carotene and Tween 20 microemulsion showed little fungal development within 21 days of storage, in addition, no development of lactic acid bacteria was observed within 14 days of refrigerated storage. Sensory, the apple was the most noticeable descriptor in the temporal dominance of sensations (TDS) test. Furthermore, the results indicated a preference for formulations with a lower percentage of Tween 20, regardless of the type of carotenoid source used, and a purchasing trend was observed for the sample of clarified apple juice added with annatto in the form of a microemulsion. Finally, the present work represents an innovation in this field of study due to the limited descriptions in the literature on the application of the microemulsion system (O/W) aiming at the enrichment of carotenoids in aqueous food matrices.