Impact of biodynamic viticulture on the occurrence of fungi and mycotoxins, antioxidant activity, volatile and phenolic profile of Chardonnay grapes

Abstract

This study evaluated the impact of biodynamic viticulture compared to the conventional technique regarding to the quality parameters of Chardonnay grapes. Grapes from conventional and biodynamic cultivation presented similar physicochemical characteristics (aw, pH, hardness, weight and color). The fungi occurrence was higher in conventional (52%) than biodynamic grapes (46%). A. carbonarius isolates from conventional cultivation produced higher levels of OTA, N-formyl OTα amide, OTB and OTC (38.5, 24.3, 24.1 and 24.5 μg g−1) than those from biodynamic cultivation (9.8, 10.5, 9.6 and 8.5 μg g−1), respectively. However, no mycotoxins were detected in the grapes from both viticulture practices. Sixteen volatile compounds associated to pleasant aromas were found at higher levels in the biodynamic grapes than in conventional ones, as 2-hexen-1-ol, benzaldehyde, ethyl butanoate and dihydroactinidolide, which impart a fruity odor. Higher levels of some phenolic compounds, as quercetin glucuronide (180.1 and 100.9 mg kg−1), procyanidin B1 (193 and 156.0 mg kg−1), epicatechin (160.6 and 122.0 mg kg−1), p-coumaric acid (18.6 and 17.1 mg kg−1), caftaric acid (58.6 and 32.9 mg kg−1), and catechin (9.6 and 7.0 mg kg−1), were also found in biodynamic, respectively. The antioxidant capacity of biodynamic grapes against ABTS•+, H2O2, and ROO• was 18, 5 and 48% higher than that of conventional grapes, respectively. Therefore, the biodynamic practice provides grapes with similar or even superior quality to those of conventional cultivation, in addition to being a safe and sustainable option.