Nutritional and Antioxidant Properties of the White Desert Truffle Tirmania nivea (Zubaidi)

Abstract

Tirmania nivea (Pezizaceae) is a desert truffle which inhabits arid and semiarid alkaline soils in many countries of the Middle East and around the Mediterranean basin. A precious food commodity, it is nutritious, rich in protein, carbohydrate, and fiber. The very limited available scientific literature indicates that T. nivea possesses antioxidant properties comparable to those found in other higher fungi (truffles and mushrooms) and superior to many antioxidant-rich foods. This chapter summarizes findings using several methods to estimate the antioxidant–antiradical activities (i.e., FRAP, DPPH, ABTS-TEAC, FC). Total antioxidant capacity, total reducing power, metal-chelating ability, and anti-lipid peroxidation are reported. Antioxidant constituents were also evaluated. Many of the findings are presented for the first time. Samples of T. nivea from different sources/origins exhibit variable but high antioxidant activity in all methods used. Phenolic compounds, free and bound, are present at relatively high levels and contribute significantly towards the antioxidant properties of T. nivea. Condensed tannins are present in appreciable levels. Ascorbic acid and carotenoids play a minor role in the antioxidant activity of T. nivea due to their low concentration. T. nivea contains primary and secondary antioxidants that exert their capacity through several mechanisms including direct radical scavenging and transition metal chelating. Ecological importance of the antioxidant activity of T. nivea is also discussed.