J. C. Miller

Antioxidant capacity, anthocyanins and total phenolics in purple-and red-fleshed potato (Solanum tuberosum L.) genotypes

Purple- and red-fleshed potatoes (Solanum tuberosum L.) were evaluated for their total anthocyanin (ACY), total phenolic (PHEN), and antioxidant capacity. The ACY and PHEN compounds were distributed throughout the tubers; however, a higher concentration was found at the stem-end than the bud-end. Although ACY and PHEN concentrations in potato peel were 0.9-to 1.6-fold higher than in potato flesh, overall contribution of the peel to ACY and PHEN contents of a potato slice was ∼20%. These observations differ from the widespread idea that phytonutrients are mostly accumulated in the peel of tubers. The ACY and PHEN contents of different purple- and red-fleshed potato genotypes ranged from 11 to 174 mg cyanidin-3-glucoside/100 g fresh weight and from 76 to 181 mg chlorogenic acid/100 g fresh weight, respectively, and were genotype and location dependent. High positive correlations between antioxidant capacity and ACY and PHEN suggest that these compounds are mainly responsible for the antioxidant capacity. These results provide useful and important information for potato breeders and researchers in order to increase the antioxidant capacity and functional value of purple- and red-fleshed potatoes for the food and nutraceutical industries.ResumenPapas (Solanum tuberosum L.) de pulpa morada y roja, se evaluaron para determinar su contenido total de antocianina (ACY), compuestos fenólicos totales (PHEN) y capacidad antioxidante. Los compuestos ACY y PHEN estuvieron distribuidos por todo el tubérculo; sin embargo, se encontró una mayor concentración en el extremo cerca del tallo que en el extremo distal. Aunque las concentraciones en la piel del tubérculo fueron de 0.9 a 1.6 veces más que en la pulpa, el aporte total del ACY y PHEN de la piel de una rodaja de papa fue de aproximadamente 20%. Estas observaciones difieren de la idea generalizada de que los fitonutrientes se acumulan mayormente en la piel de los tubérculos. El contenido de ACY y PHEN de los tubérculos de los diferentes genotipo de papa de pulpa morada y roja estuvo entre los limites de 11 a 174 mg de cianidina-3-glucósido/100 g de peso fresco y de 76 a 180 mg de ácido clorogénico/100 g de peso fresco respectivamente dependiendo del lugar y genotipo. La alta correlación positiva entre la capacidad antioxidante y ACY y PHEN sugiere que estos compuestos son principalmente responsables de la capacidad antioxidante. Estos resultados proporcionan información muy importante y útil a los mejoradores e investigadores para incrementar la capacidad antioxidante y el valor funcional de las papas de pulpa morada y roja para el consumo y las industrias nutraceúticas.

Environmental conditions influence the content and yield of anthocyanins and total phenolics in purple- and red-flesh potatoes during tuber development

Changes in content and yield of anthocyanins (ACY) and total phenolics (PHEN) during development of purple- and red-flesh potato (Solanum tuberosum L.) were studied in cultivars grown in Texas and Colorado. In both locations, the ACY and PHEN content (mg/100 g tissue) decreased with tuber growth and maturity, while tuber weight (kg), total yield (Ton ha-1) and compound yields (kg ha-1) increased. Longer days and cooler temperatures in Colorado favored about a 2.5- and 1.4-times higher ACY and PHEN content, respectively, than in Texas-grown tubers. Harvesting potatoes at later maturity stages maximized compound yields while minimizing the glycoalkaloid content. This information can be useful to potato breeders and producers in selecting appropriate growing conditions for the enhancement of natural colorant and antioxidant yields in purple- and red-flesh potatoes for the nutraceutical and food industry.ResumenSe estudiaron los cambios en el contenido y rendimiento de antocianinas (ACY) y fenolicos totales (PHEN) en cultivares de papa (Solanum tuberosum L.) de pulpa morada y roja, durante su desarrollo en Texas y Colorado. En ambas localidades, el contenido de ACY y PHEN (mg/100 g de tejido) disminuyó a medida que el tubérculo desarrolló y maduró, mientras que el peso de tubérculos (kg), el rendimiento total (Ton ha-1) y el rendimiento de compuestos fenolicos (kg ha-1) aumentaron. Los días más largos y temperaturas frías en Colorado favorecieron el contenido de ACY y PHEN en los tubérculos cosechados en 2.5 y 1.4 veces respectivamente, que aquellos obtenidos en Texas. La cosecha de tubérculos en periodos tardíos de madurez maximizó los rendimientos de compuestos fenolicos, mientras que el contenido de glicoalcaloides se minimizó. Esta información puede ser útil para mejoradores y productores de papa, con el fin de seleccionar las condiciones apropiadas de cultivo que aumenten el rendimiento de colorantes y antioxidantes, en papas de pulpa morada y roja, para su utilización en las industrias nutracéuticas y de alimentes.

GemStar russet: A potato variety with high yield, good culinary quality, excellent fresh market appearance, and resistance to common scab

GemStar Russet, derived from the cross Gem Russet x A8341-5, was released in 2004 by the USDA/ARS and the agricultural experiment stations of Idaho, Oregon, and Washington. The foliage of GemStar Russet is dark yellowish-green, spreading, with large leaves and abundant white flowers. The tubers are brown, medium to heavily russeted, oblong, with a slightly prominent eyebrow, white flesh, and indistinct pith. GemStar Russet was compared with Russet Burbank and Russet Norkotah in trials across the Pacific Northwest for yield, quality, and disease response. Except for locations in southern Idaho, in general, GemStar Russet produced slightly lower total yield than Russet Burbank, but much higher U.S. No. 1 yield. When compared with Russet Norkotah, GemStar Russet produced similar total and U.S. No. 1 yields in early harvest trials but higher total and U.S. No. 1 yields in late-harvest trials. When observed for defect problems, GemStar Russet exhibited resistance to second growth, growth cracks, and stemend discoloration, moderate resistance to blackspot and shatter bruising, but a high level of susceptibility to hollow heart. In product quality tests, GemStar Russet was rated superior to Russet Burbank for french fry quality and comparable for baked potato quality. GemStar Russet was found to be immune to PVX, resistant to common scab and powdery scab, moderately resistant to Verticillium wilt, tuber net necrosis caused by PLRV, and corky ringspot. It demonstrated susceptibility to late blight, PLRV, dry rot, soft rot, and ringrot and extreme susceptibility to PVYo. Biochemical analysis of GemStar Russet tubers showed them to be higher in protein and much higher in vitamin C than those of Russet Burbank or Russet Norkotah. Three-year average for tuber glycoalkaloid concentration was 1.5 mg 100 g−1.ResumenEn el ano 2004 el USDA/ARS y las Estaciones Experimentales Agrícolas de Idaho, Oregon y Washington liberaron la variedad GemStar Russet derivada del cruzamiento de Gem Russet x A8341-5. El follaje de GemStar Russet es amarillo verdoso oscuro, extendido, con hojas grandes y abundantes flores blancas. Los tubérculos son pardos, mediana a fuertemente rojizos, oblongos con prominencia del ojo ligeramente pronunciada, pulpa blanca y médula indistinguible. GemStar Russet ha sido comparada con Russet Burbank y Russet Norkotah en pruebas realizadas a lo largo del Pacífico nor-occidental para determinar rendimiento, calidad y respuesta a enfermedades. Con excepción de localidades del sur de Idaho, en general, GemStar Russet dio rendimientos totales ligeramente inferiores a Russet Burbank, pero mucho mayor rendimiento de US No 1. Comparado con Russet Norkotah, GemStar Russet produjo un rendimiento total similar y de US No 1 en pruebas de cosecha temprana, pero totales más altos y rendimiento de US No 1 en pruebas de cosecha tardía. Cuando se hicieron observaciones para determinar defectos, GemStar Russet exhibe resistencia a crecimiento secundario, rajaduras de crecimiento y decoloración de la base del tubérculo, resistencia moderada a mancha negra y magulladuras por golpe, pero un alto nivel de susceptibilidad al corazón vacío. En pruebas de calidad del producto GemStar Russet fue calificado como superior a Russet Burbank para papa frita y similar para papa horneada. Se encontró que GemStar Russet es inmune al virus PVX, resistente a la sarna común y sarna polvorienta, moderadamente resistente a la marchitez por Verticillium, necrosis reticulada del tubérculo causada por el virus PLRV y mancha corchosa anillada. Demostró susceptibilidad al tizón tardío, PLRV, pudrición seca, pudrición blanda y susceptibilidad extrema a PVYo. El análisis bioquímico de los tubérculos de GemStar Russet dio un alto contenido de proteína y mucho más alto de vitamina C que los de Russet Burbank o Russet Norkotah. El promedio de tres años sobre concentración de glicoalcaloides en el tubérculo fue de 1.5mg 100g-1.

Krantz: A Russet cultivar for the irrigated sands

Krantz is an oblong to slightly blocky, russet-skinned potato cultivar with medium-late maturity and a vigorous vine. It is resistant to hollow heart, has high resistance to common scab and possesses high field resistance to late blight. It is moderately resistant toVerticillium wilt, susceptible to early blight, viruses S and X, and exhibits symptoms of bacterial ring rot. Krantz is adapted to the irrigated sands, but will growth crack in heavier soils.CompendioKrantz es un cultivar de papa de forma oblonga a ligeramente adoquinada, piel escamosa, maduración medianamente tarde, y tallos vigoros. Es resistente a corazón hueco, y tiene resistencia superior tanto a costra comun como a tizón tarde en el campo. Es moderamente resistente a la marchitez por Verticillium y susceptible tanto a tizón temprano como a los “S” y “X” viruses, y muestra sintomas de pudrición anular. Krantz es adaptada a arenas regadas, pero se resquebra en suelos mas pesados.

Century russet : A high-yielding fresh market cultivar with verticillium resistance

Century Russet, a high-yielding, late-maturing variety suitable for fresh tablestock use, was jointly released in 1995 by Agricultural Experiment Stations in Oregon, Idaho, Washington, Colorado, California, and Texas and the USDA Agricultural Research Service. Extremely high yields have been observed for Century Russet in variety trials conducted in Oregon and throughout the western United States under a wide range of soil and climatic conditions. Century Russet produced 40 percent higher marketable yields than Russet Burbank and 67 percent higher marketable yields than Russet Norkotah in 11 regional trials conducted over a three-year period in sevenwestern states. Uniform tuber shape, high yields of count carton sizes, and attractive tuber appearance make Century Russet well suited for the fresh market industry. It is not recommended for chipping or processing into frozen products because of low solids and dark fry color. Century Russet is highly resistant toVerticillium wilt and consistently develops less hollow heart, brown center, and other internal defects than Russet Burbank. It requires more time between vine kill and harvest than Russet Burbank for adequate tuber maturity and skin set. Bruised Century Russet tubers are susceptible to early blight andFusarium infection.

AC Stampede Russet: a high-yielding oblong russet cultivar for the French fry and fresh market industries.

AC Stampede Russet has a maincrop maturity, and the tubers reach maximum size in western Canada in early to mid-September. The tubers are attractive with russet skin, shallow eyes, an oblong shape, and are very uniform in size. The cultivar is suitable for french fry or fresh market (count carton) production. It appears to perform best under irrigated conditions. The cultivar provides the industry with a russet-skinned, dual purpose russet cultivar with high yield, low defect levels, excellent fresh market appeal, and good storage quality for both the french fry and fresh market industries.