Determination of oligomeric procyanidins in avocado pulp and its by-products

Avocado (Persea Americana Mill.) is a tropical and subtropical fruit native to southern Mexico and, nowadays, it is grown in America, Australia, South Africa and Spain. Avocado is mainly consumed as fresh fruit; however, efforts are being undertaken to expand the range of avocado value-added products available such as guacamole and avocado oil. The manufacture of avocado based products produce considerable amounts of waste that are a source of bioactive compounds. Because of that, the aim of this work was to investigate the oligomeric procyanidins content by normal phase chromatography coupled to fluorimeter detector and mass spectrometry (NP-HPLC-FLD-MS) in avocado pulp, peel and seed. The avocado fruit consists of numerous varieties around the world, but ‘Hass’ variety is one of the most important in the international market. Samples of ‘Hass’ variety of avocado were collected in the Tropical Coast of Granada in Motril. The samples analyzed were fresh and overripe avocados. NP-HPLC-FLD-MS permitted the identification of thirteen procyanidin oligomers plus the polymers in avocado peel and skin. Only four oligomers and the polymers were reported in avocado pulp. Moreover, A and B-type procyanidins were detected in avocado peel and seed. Interestingly, procyanidins are mostly localized in avocado peels and seeds; instead, avocado pulp displayed the lowest procyanidins content. Overripe samples showed higher amounts of procyanidins in all parts, compared to fresh samples. Hence, results from the present study highlight remarkable technological applications of avocado waste extracts as natural food ingredients or nutraceuticals in the design of healthy products.