Agronomic and quality traits of different snake melon (Cucumis melo var. flexuosus) breeding lines and hybrids grown in Tunisia

none6noneIlahy R, Tlili I, Siddiqui MW, Montefusco A, Hdider C, Lenucci MSIlahy, R; Tlili, I; Siddiqui, Mw; Montefusco, A; Hdider, C; Lenucci, M

Effect of the stage of maturity on the antioxidant content and antioxidant activity of high-pigment tomato cultivars grown in Italy

Lycopene has attracted much interest during the last few years because of its antioxidant activity against free radicals, suggesting protective roles in reducing the risk of several chronic diseases. Therefore, tomato cultivars, with increased lycopene content have been developed. However, a detailed assessment of their nutritional value remains scarce in literature. In this study, the effect of the stage of maturity on the antioxidant content and activity of six high-lycopene tomato cultivars (‘Lyco 1’, ‘Lyco 2’, ‘HLY 02’, ‘HLY 13’, ‘HLY 18’ and ‘Kalvert’) and one ordinary (‘Donald’) was determined. The pattern of change in lycopene and β-carotene was similar in all tomato cultivars, although quantitatively higher in high-lycopene tomatoes. In those cultivars, lycopene and β-carotene were respectively 1.68- to 3.7-fold and 2.11- to 2.48-fold higher during ripening compared to ‘Donald’. The lipophilic antioxidant activity was well correlated to the lycopene and β-carotene contents. The pattern of change in total phenolic, flavonoid and total vitamin C was cultivars dependent. At the red ripe stage, ‘HLY 13’ showed the highest total vitamin C and flavonoid contents. However, ‘HLY 02’ showed the highest total phenolic content. The hydrophilic antioxidant activity was only well correlated to the phenolic and flavonoid contents

Bioactive compounds and antioxidant activities of different watermelon (Citrullus lanatus (Thunb.) Mansfeld) cultivars as affected by fruit sampling area

This investigation reports the variability of antioxidant components and antioxidant activities of six watermelon cultivars (cvs) (four commercial cvs Aramis, Crimson Sweet, Dumara, Giza, and two new selections P503 and P403 produced by the National Agricultural Research Institute of Tunisia) as influenced by sampling area. All cvs were simultaneously grown in an open-field and subjected to identical horticultural practices in order to minimize the effects of environmental conditions and maximize those related to genotype. Significant differences were found between watermelon cvs for lycopene, phenolics, flavonoids, ascorbic acid (AsA), dehydroascorbic acid (DHA) and total vitamin C (AsA + DHA) contents, as well as in the antioxidant activity of their hydrophilic and lipophilic fractions. P503 cv showed the highest lycopene and flavonoid contents. Crimson Sweet and Giza cvs showed the highest HAA and LAA when TEAC was used as assay method, while the highest HAA and LAA were detected in Giza and Dumara cvs and in P503 cv, respectively, when FRAP assay was used. This study demonstrates that the amount of each specific antioxidant, as well as the HAA and LAA, were both influenced by genotype and sampling area, emphasizing the need to evaluate watermelon biodiversity in order to improve its nutritional value

Effect of growing season on some qualitative and functional attributes of different potato genotypes

Potato (Solanum tuberosum L.) is a staple food widely consumed in Tunisia and a source of nutrients beneficial for human health. The tubers are, indeed, important source of vitamins, minerals, and bioactive compounds, including carotenoids, polyphenols, and flavonoids. However, data regarding the functional quality of potato varieties grown and consumed in Tunisia are very scarce. For this reason, two field trials were conducted to focus on the effect of the growing season on the functional quality of four potato genotypes (Selena, El Beidha, Naima, and CL07F172.5): a first autumnal trial in Teboulba, Monastir (September 2015–February 2016), which is the late cropping season (LCS) and a second summer cropping season (SCS) in El ksour, El Kef region at an altitude > 1000 m (July 2015–October 2015). Total carotenoids, total phenolics, and flavonoids contents, as well as the hydrophilic radical scavenging activity and lipophilic radical scavenging activity (LRSA) were determined. The obtained results confirmed the importance of potato tubers as a source of bioactive compounds. All quality traits varied significantly among varieties and cropping seasons. Tubers grown under colder weather conditions (LCS: minimum and maximum averages temperatures and relative humidity (RH) ranging between 14.25 and 22.55°C and 25.46% and 83.07%, respectively) accumulated the highest total vitamin C content and exhibited the highest LRSA values. However, temperature and warmer growing conditions (SCS: minimum and maximum averages temperatures and RH ranging between 19.74 and 34.22°C and 35.46% and 87.51%, respectively) probably enhanced the synthesis and accumulation of total carotenoids, total phenolics, and total flavonoids, associated with higher LRSA values