Stability of health-related compounds in plant foods through the application of non thermal processes

A significant number of compounds found in plant-based foods exhibits health-promoting biological functions. Over the past decades, food research has shed light on the basic science of the degradative processes that account for losses of these compounds. Indeed, temperature/time conditions have been shown to play a determinant role when aiming at preserving the bioactive potential of raw products. The deleterious effect of certain thermal treatments on antioxidant compounds has been reported. Lately, a number of alternative technologies allowing low temperature processing have emerged and many research efforts have been put towards their development and optimisation. It is known that the concentration and biological activity of most health-related compounds is dramatically reduced as thermal treatment intensity increases. Nonetheless, both extrinsic and intrinsic factors such as oxygen, light, pH, and the presence of certain enzymes, can also induce changes in the bioactive constituents of foods. The susceptibility of each compound to these conditions needs to be considered when aiming at evaluating the effect of processing. Generally, non thermal technologies presented in this review allow preserving most food bioactive compounds, such as vitamins, phenolics, carotenoids and organosulfur compounds. Different results can be obtained, though, depending on the food matrix because the presence of antagonistic agents may substantially compromise the stability of health-promoting compounds through storage. Recent published work provides examples to illustrate the ability of non thermal food preservation technologies for keeping the bioactive properties of plant foods and, at the same time, show limitations of each technology regarding the preservation of health-related compounds.