Physicochemical and techno-functional evaluation of native Mexican fruit by-products for their application in industry

Abstract

In recent years it has been observed that consumers are more aware of the food intake that can bring more benefits to their health or that can reduce the risk of suffering from various diseases (cardiovascular, diabetes, cancer, among others). In Mexico there are a large number of unknown native fruits that potentially have a preventive effect on these diseases. These fruits are rich in multiple nutrients, among which it could be highlighted the content of fiber, protein, vitamins and minerals. In fact, recent studies have shown that these fruits also contain a large number of bioactive compounds such as phenolic compounds, carotenoids, flavonoids, anthocyanins, just to mention some. These elements are highly related to beneficial health effects since they present bioactivity as antioxidants, anticancer, antidiabetic, antimicrobial, among others. Additionally, due to the composition of native Mexican fruits, their use has been proposed for the development of techno-functional ingredients, in other words, of additives that can improve the physicochemical characteristics of foods, replacing some of the conventional chemical additives. After a long review in the literature, it was found that the representative fruits of the western zone of Mexico that could be used in this first stage are the following: aguama (Bromelia pinguin L.); nance (Byrsonima crassifolia L. Kunth); hawthorn fruit (Crataegus mexicana); ayale (Crescentia alata Kunth); black sapote (Diospyros digyna); sapodilla (Manilkara sapota (L.) Royen); xoconostle (Opuntia joconostle Weber ex Diguet); guamuchil (Pithecellobium dulce (Roxb.) Benth); papache (Randia echinocarpa); and yellow plum (Spondias mombin L.). These fruits seem to be a potential source of bioactive ingredients that combined with their nutrients can have a high impact as additives in the food industry. In addition, because they are under exploited fruits and therefore not much used, they could generate a positive impact on society. Due to the increase in food consumption, currently large amounts of food waste are generated. This food waste have proven to be rich sources of bioactive compounds, even more than fresh fruits and vegetables, therefore, the study of these fruits as by-products is proposed, that is, as those industrial waste that can still be used such as shells, bagasse, seeds, juice, peels, among others. Therefore, the separation of pulps, peels and seeds parts of each fruit is proposed to similar these by-products. Therefore, the purpose of this work is to make a physicochemical characterization, as well as the state of maturity of the selected fruits. Additionally, a characterization of the fruits by-products composition will be carried out, determining the content of soluble dietary fiber, insoluble dietary fiber, total dietary fiber, digestible carbohydrates, protein, fat, minerals, as well as the energy content of the samples. After obtaining ingredients from these fruits, a techno-functional characterization will be accomplished: water and oil retention capacity (WRC and ORC, respectively), solubility (SOL), swelling capacity (SWC), and tapping density (TD). Finally, the functional capacity measured with three different assays were studied in terms of antioxidant compounds, Folin-Ciocalteu for total phenolic content (TPC) and radical scavenging ability determination by DPPH and ABTS. These studies were achieve in order to fully characterize these ingredients and to be able to relate their nutraceutical and techno-functional properties with their composition so that, native Mexican fruits by-products powders can be used to obtain ingredients to different industries, mainly in the food industry.