Antioxidantes naturais para aplicação em alimentos

Abstract

The growing interest in replacing synthetic antioxidants with natural antioxidants in foods has spurred research on plant sources, characterization of raw materials and identification of new antioxidant compounds. To make this substitution viable, it is important to know the stability of these compounds in foods in the face of the processing they can undergo before ingestion and to know how these compounds can be affected from obtaining them to the consumer's table. These compounds are used to prevent oxidation in food and are not only a concern for the food industry, but also for consumers who demand additives that do not cause undesirable health effects. In this study, a bibliographic review of studies that evaluated sources and ways of obtaining natural antioxidants and how they behaved during processing and storage when applied to foods was made. Most studies found in the literature evaluated sources of antioxidant of plant origin, with phenolic compounds being the most relevant class with antioxidant activity. Concentration and substances identified with antioxidant activity varied according to the plant used, the form of preparation and preparation of its extracts, methods for evaluating antioxidant capacity, methods of extracting the compounds as well as their variables such as time, temperature and solvent. Extraction methods may be by conventional extraction with organic solvents and supercritical extraction. In the first case it may be efficient in some cases, but it becomes an environmental problem due to the waste that is generated during the use of toxic substances. Already supercritical extraction provides good extraction yield and preserves antioxidant properties, but is a method with high cost of operation. Studies have shown that the replacement of synthetic antioxidants with natural ones presents satisfactory results, although in some cases synthetic antioxidants still showed better results than natural ones, in this case, association of natural antioxidants with synthetic antioxidants can be adopted in order to decrease the concentration of synthetics in food, meeting the popular search for foods as natural as possible. Finally, total or partial substitution is possible in some cases, but studies have yet to be performed to improve the standardization of sample preparation, extraction and food application, thus improving the comparison between the antioxidant compounds obtained in the research.