Effect of pedoclimatic variables on analytical and organoleptic characteristics in olive fruit and virgin olive oil

Abstract

Due to the expansion of olive oil cultivation around the world and the increasing effects of climate change, Olea europaea (L:) cultivation must deal with ever higher temperatures and drought conditions, with productivity and virgin olive oil (VOO) quality issues. At the same time the demand for premium quality products with high nutraceutical value, chemical and organoleptic characteristics related to specific areas of cultivation is steadily rising. Within this framework a deep knowledge of the olive variety with regards to environment interaction is necessary to achieve VOO production and qualitative standards required by the market. Rainfed adult olives (cv Bosana) cultivated in five typical areas of north and central Sardinia (Italy) were the subject of a three-year study, with the aim to investigate the influence of pedoclimatic variability on olive and olive oil characteristics. Physical and chemical attributes of fruits (morphometric features, firmness, pH, titratable acidity, sugar content, moisture, and oil yield) and VOO (fatty acid and sensory profile) were analysed at harvest and related to monthly weather data (precipitation, maximum, average, and minimum temperatures) of the whole fruit development period and soil composition. Monthly maximum temperatures were the most relevant variables. However, the role of each meteorologic variable was specific per olive and olive oil parameters and their relevance varied according to the period of the season. An emblematic example is that the maximum temperatures during summer months reduced oil yield and improved oleic acid concentration, but during the following months, the same variable exerted an opposite effect. This suggests the presence of a maximum temperature threshold in the olive fruits, for lipogenesis processes. Meteoclimatic conditions during maturation were the principal element responsible for VOO sensory profile: high precipitation and low thermal amplitude promoted an attribute’s intensities.