Bitterness, odor properties and volatile compounds of virgin olive oil with phospholipids addition

Abstract

Bitter hydrophilic phenolic compounds contained in virgin olive oil (VOO) beneficially affect human health. However, consumers mostly do not tolerate oils with a pronounced bitter taste (bitterness index K 225 ≥ 0.360) and this could limit their consumption. The possibility of bitterness attenuation of quite bitter VOO ( K 225 = 0.501) by the addition of granular soy lecithin, as a source of phospholipids, up to the levels present in seed oils (2.5–30 g/kg), was evaluated by sensory difference tests. Statistically significant differences were found starting from 5 g/kg of added phospholipids ( p ≤ 0.05). Phospholipids addition caused a significant decrease of the total concentration of 20 volatiles determined by HS-SPME–GC analysis (slope 0.056; r = −0.9962), and the most influenced among them was E-2-hexenal (slope 0.048; r = −0.9975). Results of quantitative descriptive sensory analysis showed that the addition of phospholipids in a range from 5 to 10 g/kg slightly reduced olive fruity and green odor notes, significantly increased sweetness and decreased bitterness. The significant changes of overall sensory quality grading were not found between pure VOO and samples enriched with phospholipids. Thus, in the context of functional food formulation, addition of phospholipids could be proposed as a procedure useful for bitterness attenuation of VOO.