Chemical profiles of five minor olive oil varieties grown in central Tunisia

The aim of the present investigation is to discriminate five minor Tunisian olive cultivars (Hor Kesra, Sredki, Chladmi, Betsijina and Aloui) by studying their sterol and phenol compositions. This is the first study of the chemical composition of virgin olive oils (VOO) from these cultivars. The majority of analytical parameters presented statistically significant differences (P < 0.01). The examined varieties produce excellent oils with a chemical composition within the regulatory limits and an appreciable amount of natural antioxidants. Our results showed that Betsijina oil was characterized by high mean values of total phenols (1400 mg kg−1) and oxidative stability (113 h). VOOs studied demonstrate that the differences in phenols (min: 253–max: 1400 mg kg−1), tocopherol (139–402 mg kg−1), sterols (1039–1567 mg kg−1), triterpene dialcohols (19.1–32.4 mg kg−1) and triacylglycerols profiles may be explained by genetic factors. Results of PCA and HCA analyses show a good discrimination between varieties according to phenol, triacylglycerol and sterol data. These components seem to be an effective tool to discriminate between the varieties.