Encapsulation as a Carrier System to Enrich Foods with Antioxidants

Abstract

Antioxidants can be well defined as substances that when present in low concentration with respect to a susceptible substrate, in the food or in the human body, significantly delay or inhibit the subtract oxidation. In the case of foods, it is one of the major causes of chemical spoilage, resulting in rancidity and/or deterioration of the nutritional quality, color, flavor, texture and safety of foods. It is estimated that half of the world?s fruit and vegetable crops are lost due to postharvest deteriorative reactions (Antolovich et al. 2002). Lipids occur in almost all foodstuffs, and most of them (more than 90%) are in the form of triacylglycerols, which are esters of fatty acids and glycerol. Two major components involved in lipid oxidation are unsaturated fatty acids and oxygen. Oxidative degradation of lipids may be initiated by active oxygen and related species which are more active than triplet oxygen molecules present in air, as well as by exogenous agents (UV, ionization radiation, heat) (Yanishlieva-Maslarova 2001). In many food products, it is suitable to add mixtures of antioxidants which usually have higher activities than single compounds, and which guarantee that the limits for single compounds have not been exceeded. Physical mixture of the selected antioxidants is not always possible, so encapsulation of the compounds, together or in a separate form could be the solution to solve these practical situations. On the other side, there is a trend towards a healthier way of living, which includes a growing awareness by consumers of what they eat and what benefits certain ingredients have in maintaining good health. Preventing illness by diet is a unique opportunity for innovative so-called functional foods. Existing and new ingredients need to be incorporated into food systems, in which they slowly degrade and lose their activity, or become hazardous, by oxidation reactions. Ingredients can also react with components present in the food system, which may limit bioavailability, or change the color or taste of a product. In many cases, microencapsulation can be used to overcome these challenges (Schrooyen, Meer, and Kruif 2001).In this sense, research on and the application of polyphenols, have recently attracted great interest in the functional foods, nutraceutical and pharmaceutical industries, due to their potential health benefits to humans. However, the effectiveness of polyphenols depends on preserving the stability, bioactivity and bioavailability of the active ingredients. The unpleasant taste of most phenolic compounds also limits their application. The utilization of encapsulated polyphenols, instead of free compounds, can effectively alleviate these deficiencies (Fang and Bhandari 2010). For many nutritional supplements, formulation and route of administration have a great effect on both these parameters. Food nanotechnology, involving the utilization of nanocarrier systems to stabilize the bioactive molecules against a range of environmental and chemical changes as well as to improve their bioavailability, presents exciting opportunities for nutritional supplement industries (Tavano et al. 2014). Microencapsulation has been defined as the technology of packaging solid, liquid and gaseous materials in small capsules that release their contents at controlled rates over prolonged periods of time (Champagne and Fustier 2007). There are various types of encapsulation technologies that can be employed in the food industry, including spray drying, coacervation, entrapment, inclusion complexation, cocrystallization, freeze drying, yeast encapsulation, emulsion surfactant micelles, nanospheres, nanoparticles, nanoemulsions, liposomes, and niosomes. However, specific studies on the interaction of encapsulating material with the antioxidant, as well as the measurement of the stability of the encapsulated antioxidant are mandatory for each case study, so, generalization should be avoid.