Bioguided design of new black truffle (Tuber aestivum Vittad.) product enriched with herbs and spices

Abstract Black truffle (Tuber aestivum Vittad.) is one of the most appreciated and one of the most expensive European truffles. The intention of our study was to create a truffle–based product (truffles, extra virgin olive oil, rosemary, red paprika, cayenne pepper) by bioguded design – a novel strategy aimed to find right mixtures of ingredients to achieve enhanced biological activity of final product. Ingredients and their combinations in different ratios were evaluated in several in vitro bioassays related to antioxidant (DPPH·, NO· scavenging activity, inhibition of lipid peroxidation, reducing power – FRAP assay) and some metabolic syndrome–associated enzymes (α–amylase, α–glucosidase, pancreatic lipase) inhibitory activity. Concentration–dependent synergy/antagonism of ingredients was noticed. For the first time, it was determined that black truffles have α–amylase, α–glucosidase and pancreatic lipase inhibitory activity (IC50= 0.49, 8.54 and 1.21 mg/mL, respectively). Dominant phenolic acids in preferable combination were rosmarinic and ursolic (2.83 and 3.48 mg/g dw, respectively), while luteolin, apigenin and chrysoeriol (55.72, 22.56 and 30.75 μg/g dw, respectively) were the most abundant flavonoids. Considerable contents of proteins (405.44 mg BSAE/g dw) and polysaccharides (1.05 mmol GE/g dw) contributed to the nutritional value of final product.