Chemical characterization of Sicilian dried nopal [Opuntia ficus-indica (L.) Mill.]

Sicilian dried nopal (Opuntia ficus-indica L.) was for the first time chemically characterized in relation to the cultivar (i.e., Sanguigna, Surfarina and Muscaredda) and the pruning season (i.e., January-February and June-July 2019). To this purpose, a variety of analytical techniques were employed for elucidating its proximate composition, fatty acid composition, sugars, element fingerprint, and single polyphenols. Sicilian nopal was rich in dietary fiber (44.11-49.55%), inorganic elements -such as Ca (4780.31-5041.47 mg/100 g) and K (4899.25-6612.95 mg/100 g)- phenolic acids (4.10-5.3 g/Kg) and flavonoids (3.80-4.85 g/Kg), including the characteristic kaempferol-3-O-rutinoside and isorhamnetin-3-O-rutinoside. It was also a good source of carbohydrates, with predominant monosaccharides such as glucose (9.30-12.00 g/100 g) and galacturonic acid (6.16-7.90 g/100 g) and demonstrated to be low in fat (0.76-2.46%). In particular, its fatty acid composition was characterized by the predominance of short and long chain fatty acids, such as caprylic acid (3.48-7.65%), linoleic (20.81-24.27%) and linolenic acids (11.02-16.83%). Additionally, obtained results pointed out that macro- and micronutrients were affected by both cultivar and pruning season, however, the influence of the pruning season being more pronounced. Such variability should be taken into account when evaluating the employment of Sicilian nopal in food and nutraceutical areas.