Improved Sensory Quality and Antioxidant Capacity of Wheat Bread Supplemented with the Desert Truffle Terfezia boudieri Flour

Abstract

The effects of Terfezia boudieri supplementation in the range from 1 to 5% in wheat bread were evaluated in order to obtain a nutritionally increased product. The truffle powder used to enrich the bread showed relatively high levels of soluble dietary fiber (SDF, 0.435 µg·g⁻¹ DW), insoluble dietary fiber (IDF, 0.149 µg·g⁻¹ DW) and also a significant polyphenol content of 21.0 mg·g⁻¹ DW. Liquid chromatography – electrospray ionization – tandem mass spectrometry analysis of the truffle ethanolic extract allowed the identification of the phenolic compounds quinic acid, gallic acid, luteolin-7-o-glucoside, apigenin-7-o-glucoside, kaempherol, cirsiliol, and acacetin that are associated with the several health benefits and primarily responsible for the observed high antioxidant activity. The high quantity of truffle powder used for bread preparation was responsible for the increased phenolic content and antioxidant capacity of the final product. Moreover, Terfezia boudieri powder showed two important technological potentialities, a water binding capacity (0.459 µg·g⁻¹ of water/DW) and a fat absorption capacity (0.237 µg of fats/DW). Compared to the control bread, the highest percentage of T. boudieri powder addition (5%) in bread formulation led to a considerable presence of phenolics and flavonoids (266 mg GAE·kg⁻¹ and 207 mg GAE·kg⁻¹ respectively) and a high antioxidant activity. The supplementation with 3% of truffle powder was shown to optimize the nutritional quality of bread while obtaining the highest score in a sensory acceptability test.

Keywords:

• Antioxidants
• high-performance liquid chromatography (HPLC)
• phenolics
• red truffle
• sensory analysis
• Terfezia boudieri

Acknowledgments

This work did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors