Influence of cut number on qualitative traits in different cultivars of sweet basil

In Italy basil (Ocimum basilicum L.) is mainly used to make a sauce called “pesto” and in order to produce this sauce industrially, the cultivated basil is cut several times during the growing cycle. This study was conducted to evaluate the effect of three cuts timing (CT1, CT2 and CT3) on biomass productivity, oil content and chemical composition of three basil cultivars (CV1, CV2 and CV3) in order to check the most suitable techniques to produce high quality pesto sauce. The production of the cultivars differed, with CV3 giving the lowest production (15.3 t ha-1), whereas CV1 and CV2 were not significantly different with quantities over 18 t ha-1. The essential oil content in CV1 differed from CV2, with 14.95 and 11.89 L ha-1 for each cut respectively. However, the highest oil content (%) was recorded in CV3 with values 7.4% and 17.0% higher than CV1 and CV2 respectively. The highest antioxidant activity (AOA) was recorded in CV3 with almost 20000 mg Fe2+E kg-1 fw followed by CV2 and CV1, where values did not exceed 7500 mg Fe2+E kg-1 fw. In terms of cuts, the AOA increased from CT1 to CT2 (+62.4%), then decreased in CT3. Among phenolics, rosmarinic acid was the most important from a quantitative point of view and was higher in CV3 with more than 1000 mg kg-1 fw, followed by CV2 and CV1. It increased from CT1 to CT2 (+74.8%) to decrease again in CT3 (-36.7%). The most relevant content of caffeic and ferulic acid was observed in CV3 and also in CT3 due to the high stress caused by cuts. Consequently, within the same crop cycle, basil could offer several options to the producer. The first two cuts are suitable for fresh consumption and industrial food processing, CT3 for essential oils extraction for cosmetic and pharmaceutical industries.