GENOTYPIC VARIATION IN NUTRITIONAL AND ANTIOXIDANT PROFILE AMONG ICEBERG LETTUCE CULTIVARS

Regular consumption of fruits and vegetables is associated with reduced risk of chronic diseases and improvement of cognitive health. Lettuce (Lactuca sativa L.) is a major salad food, which is widely grown and consumed worldwide. Cultivars-specific information on bioactive composition of crisphead subtype iceberg remains scarce. The present study aimed to profile the nutrition and antioxidant composition of seven new cultivars of iceberg ('Equinos', 'Ice Castle', 'Metalia', 'Num 189', 'Silvinas', 'Ombrinas' and 'Vanguardia'). The head fresh mass of the iceberg cultivars ranged from 485 to 801 g per plant, with the highest values recorded in 'Num 189' and 'Vanguardia'. Across cultivars, K was the predominant macronutrient and was followed by Ca. The highest nitrate content was recorded in 'Equinos' and 'Umbrinas', whereas the lowest value was observed in 'Metalia'. The hydrophilic (HAA) and lipophylic antioxidant activities (LAA) of the selected iceberg cultivars ranged from 4.9 to 13.0 mmol ascorbic acid 100 g(-1) dw, and from 6.8 to 12.5 mmol Trolox 100 g(-1) dw, respectively. Chicoric acid was the main phenolic acid present in all cultivars, followed by chlorogenic acid and caffeoyl tartaric acid. The highest HAA, LAA, caffeoyl tartaric acid, chicoric acid and total phenolic content were observed in 'Num 189', whereas an opposite trend was recorded for chlorogenic acid. The current findings will improve knowledge of the compositional variation among iceberg cultivars and assist growers in selecting cultivars combining optimal yield with high nutritional value.