Efecto del injerto en las propiedades antioxidantes del tomate (Solanum lycopersicum L.)

The use of grafted plants in vegetable crop production is now being expanded greatly. However, few data are available on the nutritional composition of grafted vegetables with emphasis on antioxidant properties. Therefore, the major objective of this study was to evaluate antioxidant components of tomatoes influenced by grafting technique. The tomato plants were grown in a greenhouse located at Kriz˘evci, Croatia. The cultivars ‘Efialto’, ‘Heman’, and ‘Maxifort’ were used as rootstocks, while ‘Tamaris’ was used as scion. Grafting resulted in increase of number of marketable fruits per plant by 30%. Content of total vitamin C and total phenolics significantly decreased after grafting. The concentration of total extractable phenolics in tomatoes ranged from 287.1 to 977.4 mg gallic acid equivalents (GAE) kg–1 fresh weight, whereas lycopene content ranged from 11.44 to 60.99 mg kg–1 fresh weight. Antioxidant activities determined by 1,1-diphenyl-2 picrylhydrazyl (DPPH) method of grafts were significantly different compared to their respective rootstocks. The overall results showed that tomato grafting on suitable rootstocks has positive effects on the cultivation performance, but decreases nutritional quality of tomatoes. En la producción de cultivos hortícolas se está expandiendo actualmente de forma considerable el uso de plantas injertadas. Sin embargo, hay pocos datos disponibles sobre la composición nutricional de las hortícolas injertadas, especialmente sobre sus propiedades antioxidantes. El principal objetivo de este estudio fue evaluar los componentes antioxidantes de tomates influenciados por la técnica de injerto. Se cultivaron plantas de tomate en un invernadero de Kriz˘evcii, Croacia. Se utilizaron como portainjertos los cultivares ‘Efialto’, ‘Heman’, y ‘Maxifort’, mientras que ‘Tamaris’ fue utilizado como injerto. El resultado del injerto fue un aumento del 30% en el número de frutos comerciales por planta, mientras que el contenido de vitamina C y de fenoles totales disminuyó significativamente. La concentración del total de fenoles extraíbles en los tomates varió entre 287,1 y 977,4 mg de equivalentes de ácido gálico (GAE) por kilo sobre la base de peso fresco, mientras que el contenido de licopeno varió desde 11,44 hasta 60,99 mg kg–1 de peso fresco. Las actividades antioxidantes determinadas por el método DPPH (2,2-difenil-1-picrilhidrazilo) de los injertos fueron significativamente diferentes respecto de sus respectivos patrones. Los resultados globales muestran que el injerto de tomate sobre patrones adecuados tiene efectos positivos sobre el rendimiento de cultivo, pero la calidad nutricional de los frutos disminuye

QSAR STUDY OF ANTIOXIDANT AND VASODILATATORY ACTIVITY OF PHENOLIC ACIDS

Phenolic acids are aromatic secondary plant metabolites that are widely spread throughout the plant kingdom. The recent interest in phenolic acids comes from their potential protective role against oxidative damage diseases (coronary heart disease, stroke, and cancers) [1]. In order to explain the contribution of various structure-related parameters on biological activities of nine phenolic acids, antioxidative [Ferric Reducing Antioxidant Power (FRAP/mol L-1), Trolox Equivalent Antioxidant Capacity (TEAC/mol L-1)] and vasodilatatory activities were correlated with “two-dimensional” (2D) topological indices, “three-dimensional” (3D) molecular descriptors, calculated physicochemical parameters and variable indicators of the number and position of hydroxyl groups on the phenyl ring. The best diparametric QSAR model for the prediction of FRAP was obtained with Topological Polar Surface Area (TPSA) and mean distance degree deviation (MDDD) (r2 = 0.950; F = 60.93). A statistically significant model for the prediction of TEAC values was obtained with two GETAWAY descriptors, R7p i HATS3e (r2 = 0.955; F = 64.00). The best model for vasodilatatory activity was obtained by multiple regression with TPSA and GETAWAY descriptor R+3(u) (r2 = 0.916; F = 32.76). The results of the QSAR study have shown that biological activity of phenolic acids largely depends on hydrophylicity, electronegativity, polarizability, size and the shape of molecules. References: [1] R J Robbins, 2003, J. Agric. Food Chem. 51 2866-288

The effect of grafting on the antioxidant properties of tomato (Solanum lycopersicum L.)

The use of grafted plants in vegetable crop production is now being expanded greatly. However, few data are available on the nutritional composition of grafted vegetables with emphasis on antioxidant properties. Therefore, the major objective of this study was to evaluate antioxidant components of tomatoes influenced by grafting technique. The tomato plants were grown in a greenhouse located at Kriz?evci, Croatia. The cultivars �Efialto�, �Heman�, and �Maxifort� were used as rootstocks, while �Tamaris� was used as scion. Grafting resulted in increase of number of marketable fruits per plant by 30%. Content of total vitamin C and total phenolics significantly decreased after grafting. The concentration of total extractable phenolics in tomatoes ranged from 287.1 to 977.4 mg gallic acid equivalents (GAE) kg�1 fresh weight, whereas lycopene content ranged from 11.44 to 60.99 mg kg�1 fresh weight. Antioxidant activities determined by 1,1-diphenyl-2 picrylhydrazyl (DPPH) method of grafts were significantly different compared to their respective rootstocks. The overall results showed that tomato grafting on suitable rootstocks has positive effects on the cultivation performance, but decreases nutritional quality of tomatoes