Seasonal and yearly variation of total polyphenols, total anthocyanins and ellagic acid in different clones of cloudberry (Rubus chamaemorus L.) 2018. Anne Linn Hykkerud1, Eivind Uleberg, Espen Hansen, Marieke Vervoort, Jørgen Mølmann, Inger Martinussen Journal of Applied Botany and Food Quality 91, 96 – 102 (2018)
Scientists in Norway have done more than any others in cultivating the cloudberry, Rubus chamaemorus. A lot of research on field cultivation as well as cultivar selection have been done in that country. This study continues that research and studies the levels of two phytonutrients: ellagic acid (the most abundant in cloudberry) and total anthocyanin. They examined the content of the berries in four clones, ‘Fjordgull’, ‘Fjellgull’, ‘102’ and ‘306’ growing in Tromsø 69°39’N 18°57’E.
Interestingly the anthocyanin which are found in small quantities, varied significantly by the seasonal weather patterns. Anthocyanin levels were greatest in cool seasons and lowest when the weather was hot. They also were highest at the beginning of harvest season and lowest at the end and differed also with cultivar. The most important chemical, ellagic acid did not show the same variation with the seasons. Instead, the biggest factor was genetics. The four cultivars tested showed significantly different levels of this chemical, and those levels also varied by year and by harvest time. Berries lose ellagic acid content life harvested after in the season.
The authors concluded that there is a lot that can be done to select for clones of cloudberry with higher levels of these phytonutrients. It also shows how nutrient levels can change drastically from season to season and even within a single season. Lessons for berry pickers? Pick early in the season. 2018. Rubus chamaemorus