Aproveitamento de compostos fenólicos de bio resíduos de diferentes variedades de casca de kiwi

Abstract

Fruits are recognized as having very significant levels of biologically active substances recognized for their health benefits. Kiwis are an example of fruits with excellent properties which has been justifying the increase of its consumption and the consequent generation of tons of waste that are not properly harnessed. Thus, the objective of this work was to compare two varieties of kiwi: Actinidia deliciosa cv. “Hayward” (green kiwi) and Actinidia spp. (red kiwi) regarding the nutritional value of their pulps, but also the chemical composition and bioactivities of each pulp and peel. The nutritional assessment revealed that pulps have a high water content and low amount of ash, protein and carbohydrates. Both pulps presented a prevalence of polyunsaturated fatty acids, with linoleic acid as the major one. The peels of both varieties revelaed the highest total tocopherols content, presenting three of the tocopherol isoforms (α, γ, and δ). These byproducts also presented the highest concentration of phenolic compounds, especially the green kiwi peel. In turn, only the red kiwi pulp presented an anthocyanin (cyanidin-3-O-sambubioside), which is responsible for its interior colour. In general, the peels exhibited the highest antioxidant activity and the green kiwi peel showed cytotoxicity against all tested tumoral cell lines, and anti-inflammatory activity, which could be related to its higher content in phenolic compounds. Thus, these kiwi components currently underutilized may be indicated as a source of natural functionalizing ingredients with several benefits for human health.