Biofortification (Se): Does it increase the content of phenolic compounds in virgin olive oil (VOO)?

PLoS One. 2017 Apr 27;12(4):e0176580. doi: 10.1371/journal.pone.0176580. eCollection 2017.

Abstract

Extra-Virgin Olive Oil (EVOO) is a fundamental component of the Mediterranean diet and it may contain several anti-oxidant substances, such as phenols. Previous research has shown that this food may be enriched in phenols by spraying a sodium-selenate solution (100 mg L-1 Se) onto the crop canopy before flowering. The aim of this research was to evaluate the effect of this Se-fertilization before flowering (cv. Leccino) on the phenolic profile of EVOOs, and test to what extent such effects depend on the weather pattern, as observed in two contrasting experimental seasons (2013 and 2014). Results showed that Se-fertilisation enriched EVOOs both in selenium (up to 120 μg kg-1) and in phenols (up to 401 mg kg-1). This latter enrichment was related to an increase in PAL (L-Phenylalanine Ammonia-Lyase) activities and it was largely independent on the climatic pattern. Considering the phenolic profile, oleacein, ligustroside, aglycone and oleocanthal were the most affected compounds and were increased by 57, 50 and 32%, respectively. All these compounds, especially oleacein, have been shown to exert a relevant anti-oxidant activity, contributing both to the shelf-life of EVOOs and to positive effects on human health. It is suggested that Se-fertilisation of olive trees before flowering may be an interesting practice, particularly with poor cultivars and cold and rainy weather patterns, which would normally lead to the production of EVOOs with unfavourable phenolic profile.

MeSH terms

  • Antioxidants / metabolism*
  • Fertilizers
  • Food, Fortified*
  • Olive Oil / chemistry*
  • Phenols / metabolism*
  • Selenic Acid / pharmacology*

Substances

  • Antioxidants
  • Fertilizers
  • Olive Oil
  • Phenols
  • Selenic Acid

Grants and funding

The study was kindly supported by the "Fondazione Cassa di Risparmio di Perugia" (Italy), Project: "Selenolivo", project code: 2015.0347.021, Scientific and Technological Research to PP DB MS. The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.