Browsing by Autor "Yvan Larondelle"

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Glucosinolates in isaño (<i>Tropaeolum tuberosum</i>) tubers: qualitative and quantitative content and changes after maturity
(Wiley, 2004) Rodrigo Ramallo; Jean‐Paul Wathelet; Éric Le Boulengé; Elizabeth Aparecida Ferraz da Silva Torres; M. Marlier; Jean‐François Ledent; Augusto Guidi; Yvan Larondelle
Abstract Six varieties of isaño ( Tropaeolum tuberosum ), an Andean edible tuber, were analysed. The aim was to characterise qualitatively and quantitatively their content of glucosinolates and to determine concentration changes of these compounds upon delayed harvest. Additionally, exploratory assays were carried out on the effect of postharvest cold storage of the tubers as well as of a drying process imposed on blanched tuber slices. Only one glucosinolate ( p ‐methoxybenzyl glucosinolate) was found in the six domestic varieties analysed. Its concentration varied between 36.5 and 90.0 µmol g −1 dry matter. This range is relatively high when compared with other edible glucosinolate‐containing vegetables. ‘Dark’ coloured tuber varieties showed higher levels than ‘light’ coloured tuber varieties at normal harvest time. Of the two varieties on which the effect of delayed harvest was studied, one showed increasing and then decreasing changes until 44 days after maturity, while the other did not show any significant change with time. Postharvest cold stored samples showed similar changes to tubers kept in soil, and glucosinolate levels in dried blanched tubers did not differ significantly from those in fresh samples. Taken together, the data indicate that the glucosinolate content of isaño is highly dependent on both the variety and the time of harvest. These parameters should be taken into account when considering isaño as a promising food source with medicinal properties for humans and animals, but also with possible adverse biological effects, all related to the presence of glucosinolates. Copyright © 2004 Society of Chemical Industry
Glycoalkaloids in potato tubers: the effect of variety and drought stress on the ?-solanine and ?-chaconine contents of potatoes
(Wiley, 2000) Liliana Bejarano; Éric Mignolet; Andr� Devaux; Nelly Espinola; Enrique Carrasco; Yvan Larondelle
Six varieties of Solanum tuberosum L potato grown in the Bolivian highlands under drought stress, with and without irrigation, were analysed for their content of glycoalkaloids (GAs). The plant material consisted of three drought-tolerant varieties from a local breeding programme (PROINPA), Potosina, Chapaquita and Pampeña, and three control cultivated varieties, Malcacho, Sani Imilla and Desiree, either susceptible or relatively tolerant to drought. α-Solanine and α-chaconine were quantified in both the peel and flesh of the tubers. A significant increase in GA concentration (α-solanine + α-chaconine) was observed under drought stress conditions in most varieties; average concentration increases of 43 and 50% were registered in the improved and control cultivars respectively. In all tested cultivars, however, the GA concentration remained lower than the recommended food safety level (200 mg kg−1 fresh tubers). It ranged from 52.4 to 100 mg kg−1 fresh tubers in the improved cultivars and from 55.6 to 122.3 mg kg−1 fresh tubers in the controls. In the improved and control varieties the α-solanine content averaged 42.6 and 35.4% of the total potato GAs respectively and was not significantly affected by drought stress, except in Desiree. In all conditions the peel contained the greatest proportion of total GAs. The hybrid variety Pampeña (new drought-tolerant variety) contained the lowest amounts of GAs, which were lower than those of the control varieties, with and without irrigation. © 2000 Society of Chemical Industry
Glycoalkaloids in potato tubers: the effect of variety and drought stress on the α‐solanine and α‐chaconine contents of potatoes
(Wiley, 2000) Liliana Bejarano; Éric Mignolet; A. Devaux; Nelly Espinola; Enrique R. Carrasco; Yvan Larondelle
Six varieties of Solanum tuberosum L potato grown in the Bolivian highlands under drought stress, with and without irrigation, were analysed for their content of glycoalkaloids (GAs). The plant material consisted of three drought-tolerant varieties from a local breeding programme (PROINPA), Potosina, Chapaquita and Pampeña, and three control cultivated varieties, Malcacho, Sani Imilla and Desiree, either susceptible or relatively tolerant to drought. α-Solanine and α-chaconine were quantified in both the peel and flesh of the tubers. A significant increase in GA concentration (α-solanine + α-chaconine) was observed under drought stress conditions in most varieties; average concentration increases of 43 and 50% were registered in the improved and control cultivars respectively. In all tested cultivars, however, the GA concentration remained lower than the recommended food safety level (200 mg kg−1 fresh tubers). It ranged from 52.4 to 100 mg kg−1 fresh tubers in the improved cultivars and from 55.6 to 122.3 mg kg−1 fresh tubers in the controls. In the improved and control varieties the α-solanine content averaged 42.6 and 35.4% of the total potato GAs respectively and was not significantly affected by drought stress, except in Desiree. In all conditions the peel contained the greatest proportion of total GAs. The hybrid variety Pampeña (new drought-tolerant variety) contained the lowest amounts of GAs, which were lower than those of the control varieties, with and without irrigation. © 2000 Society of Chemical Industry
Seis Cultivares Potenciales de Papa con Resistencia al Tizón Tardío (Phytophthora infestans) en Bolivia
(2016) Enrique Carrasco; Nelson Estrada; Julio Gabriel; Gonzalo Alfaro; Yvan Larondelle
El tizón tardío de la papa (Phytophthora infestans) es un problema serio en casi todas las zonas paperas de Bolivia. Esta enfermedad es causante de severas pérdidas en el cultivo de papa, llegando hasta un 100% si no se aplica ninguna medida de control. Por tanto para un control efectivo del tizón tardío de la papa se requieren numerosas aplicaciones de fungicidas, llegando en algunos casos a más de 10 durante el ciclo de cultivo. Ante este problema el Programa de Investigación de la Papa (PROINPA), ha venido seleccionando durante cinco años clones con resistencia a esta enfermedad provenientes del Centro Internacional de la Papa (CIP) y del Instituto Colombiano Agropecuario (ICA). Por evaluaciones anuales de una población inicial aproximada de 300 clones, se seleccionaron clones por su resistencia al tizón, altos rendimientos y buenos atributos agronómicos. Para evaluar eldaño por tizón tardío se usó la escala internacional propuesta por el CIP (1 = 0% daño a 9 = 97-100% daño), que sirvió para calcular el AUDPC (Área Bajo la Curva de Progreso de Phytophthora infestans), que conjuntamente al rendimiento y la calidad culinaria determinaron la selección de seis clones para su entrega como cultivares potenciales, con la activa participación de agricultores y técnicos de las zonas donde fueron conducidos los ensayos. Además se determinaron contenido de nutrientes y de glicoalcaloides de los seis cultivares potenciales, cultivados en dos regiones similares. Se analizó el nivel de glicoalcaloides de la variedad Robusta bajo dos condiciones de cultivo contrastadas.Aceptado para publicación: mayo de 1997