Influence of the site altitude on strawberry phenolic composition and quality.

• The effect of altitude on strawberry phenolics and quality was evaluated in two years.
• Anthocyanins concentration and antioxidant activity correlate negatively with altitude.
• Strawberry acidity and sugar content were not affected by altitude.
• Year-to year climatic variation contribute to the final quality of strawberries at different altitude.

Altitude is associated to general climatic trends, such as temperature reduction, increasing radiation under a cloudless sky, decreasing atmospheric pressure and other environmental changes. Against this background, there is a limited knowledge on the effects of these climatic changes along the altitudinal range on quality characteristics of fruits such as strawberry. Thus, this research aimed to characterize the quality of Elsanta strawberries samples, harvested at altitudes ranging from 900 to 1.500 m above sea level, during two consecutive years (2011 and 2012). Strawberry samples were collected once from the four cultivation sites located at 900 m, 1.100 m, 1.200 m and 1.500 m above sea level in each year, when the yield per pick was the highest. Anthocyanins concentration correlated negatively with the increase of altitude in both years (R = −0.55; p ≤ 0,01). Consistently, the strawberry antioxidant potential, measured with an electrochemical method, was lower in fruits grown at higher altitude (36% less when fruits from 900 and 1.500 m asl were compared). Strawberries collected at 1.500 m asl presented an higher average fruit weight, whereas other physico-chemical parameters such as soluble solids and titratable acidity did not change according to the altitude. This research consistently confirm the role of altitude as effective factor on the phenolic synthesis and final accumulation in strawberry fruits, as well as on their antioxidant activity.