Abstract
Curing of Sebago potatoes for 10 days at 25°C prior to common storage at 5°C, reduced the responsiveness of tubers to photoinduced glycoalkaloid synthesis. Continuous illumination with 15 and 25-Watt incandescent light for 10 days increased glycoalkaloid content of peelings (12–14% of tuber weight) in uncured potatoes by a factor of 3.2 and 2.8, respectively, while the corresponding factor for cured tubers was only 1.8 for both lights. The peeled tuber portion (86–88% of tuber weight) had negligible amounts of glycoalkaloids, averaging about 1 mg per 100 g of fresh weight. The rise of glycoalkaloid levels in peels of uncured tubers was nearly linear to 164.7 mg/100g (15W light) with no indication of levelling off. In peels of cured tubers, the rise began only after the 4th day of light exposure with an apparent maximum and levelling off at 94.7 mg or approximately 43% lower than the final TGA levels in uncured tubers.
Resumen
Al someter papas de la variedad Sebago a un proceso de curación por 10 días a 25°C antes de almacenar a 5°C, produjo una reducción en la sintesis fotoinducida de glicoalcaloides.
La iluminación continua por 10 días con luz incandescente de 15 y 25 watts aumentó el contenido de glicoalcaloides de la cáscara (12–14% del peso del tubérculo) en papas no sometidas previamente a curación, siendo este aumento de 3.2 y 2.8 veces, respectivamente. En papas con curación este aumento fue sólo 1.8 veces en ambos regímenes de luz. La parte sin cáscara (86–88% del peso del tubérculo) mostró cantidades insignificantes de glicoalcaloides y que en promedio fue elrededor de 1mg. por 100 gr de peso junco. E1 nivel de glicoalcaloides en la cáscara de los tubérculos no sometidos a curación incrementó en forma aproximadamente lineal en 164.7 mg/100 g (15 watt) sin indicación de alcanzar estabilización. En cáscaras de tubérculos curados, el incrementó empezó solo después del cuarto día de exposición a la luz alcanzando un nivel máximo y estabilizándose a un nivel de 94.7 mg o aproximadamente 43% menos que el nivel final de TGA en tubérculos no sometidos a curación.
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Research supported by Agriculture Canada grant, Ottawa, Ontario.
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Zitnak, A. Photoinduction of glycoalkaloids in cured potatoes. American Potato Journal 58, 415–421 (1981). https://doi.org/10.1007/BF02852953
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DOI: https://doi.org/10.1007/BF02852953