COMPOSICI????N QU????MICA DE CULTIVARES LOCALES DE CASTA????AS DE TENERIFE: I. COMPOSICI????N QUIMICA Y CONTENIDO DE ANTIOXIDANTES CHEMICAL COMPOSITION OF LOCAL CHESTNUT CULTIVARS IN TENERIFE ISLAND: I. CHEMICAL COMPOSITION AND ANTIOXIDANT CONTENT

摘要

Resumen The effect of peeling methods and storage conditions on unstable physicochemical parameters was studied. Losses of moisture, ascorbic acid, and phenolic compounds with hand peeled were lower than with heat peeled using microwave. A decrease of moisture, ascorbic acid and phenolic compounds was found after 60 days in refrigeration of whole chestnut, and only 3 days in refrigeration of previously homogenized chestnut. The weight and edible portion, moisture, starch, Brix degree, total dietary fiber and non-soluble fiber, protein, ash, pH, acidity, ascorbic acid and total phenolic compounds, were determined in samples from 21 local cultivars in Tenerife island. Chestnut is mainly constituted by starch and sugars, and contributes considerably to the intake of antioxidant compounds such as ascorbic acid and phenolic compounds, as well as fiber and minerals. Significant differences in mean values of the physicochemical parameters were observed among the varieties of chestnuts analyzed. Besides, important differences in the mean values of moisture, starch, Brix degree, different fractions of fiber and phenolic compounds were found according to the zone and municipality of the island. Se estudi???3 el efecto de los m????todos de pelado y condiciones de conservaci???3n de las casta???±as sobre par????metros fisicoqu???-micos inestables. Se observaron p????rdidas m???-nimas de humedad, ????cido asc???3rbico y compuestos fen???3licos cuando se realiz???3 el pelado manual en comparaci???3n con el pelado por calor usando microondas. Se constat???3 un descenso de humedad, ????cido asc???3rbico y compuestos fen???3licos en casta???±as que fueron conservadas a temperatura de refrigeraci???3n durante 60 d???-as y despu????s de tres d???-as de refrigeraci???3n de muestras de casta???±as previamente trituradas y homogeneizadas. Se determinaron los siguientes par????metros fisicoqu???-micos: peso y porci???3n comestible, humedad, almid???3n, o Brix, fibra alimentaria total e insoluble, prote???-nas, cenizas, pH, acidez, ????cido asc???3rbico y compuestos fen???3licos totales en 40 muestras correspondientes a 21 cultivares locales de casta???±as de la isla de Tenerife. La casta???±a est???? constituida principalmente por almid???3n y az???ocares aportando una cantidad considerable de compuestos antioxidantes tales como ????cido asc???3rbico y compuestos fen???3licos, adem????s de fibra y minerales. Se observaron diferencias significativas en los valores promedio de los par????metros fisicoqu???-micos analizados entre los cultivares. Asimismo, se encontraron diferencias importantes entre los valores promedio de humedad, almid???3n, o Brix, diferentes fracciones de fibra y compuestos fen???3licos en casta???±as en funci???3n del municipio y zona de la isla. Palabras clave: Islas Canarias, Castanea sativa, porci???3n comestible, pelado, o Brix, fibra, prote???-na, ceniza, pH, acidez