Glycoalkaloid concentration of potato tubers following continuous illumination

Abstract

The total glycoalkaloid concentration of dormant (non-sprouted) and sprouted potato tubers cv Pentland Hawk was measured following 13 days continuous illumination (250 pmol m -' s-photosynthetically active radiation) using high-performance liquid chromatography. Comparisons were made of the influence of three sources of illumination : high-pressure mercury, high-pressure sodium and fluorescent tube type warm white. Glycoalkaloid concentrations in both dormant and sprouted tubers increased over 13 days illumination regardless of the form of illumination used. Glycoalkaloid concentrations accumulated with time in dormant and sprouted tubers exposed to sodium and fluorescent light but fluctuated in those exposed to mercury light. Dormant tubers were more sensitive to illumination than sprouted tubers regardless of light souce. Fluorescent light was associated with maximum glycoalkaloid synthesis in dormant tubers; while sodium light enhanced glycoalkaloid synthesis in sprouted tubers to the greatest extent. Mercury light weakly elicited glycoalkaloid synthesis in both sets of tubers. Exposure of dormant tubers to continuous light altered the ratio of a-chaconine to a-solanine irrespective of illumination source.

Glycoalkaloid Concentration of Potato Tubers Following Exposure to Daylight

“…Since potatoes are inevitably exposed to light (daylight, fluorescent and incandescent) and wounding (chipping, slicing) in the processing and marketing chain, stimulation of glycoalkaloids presents a major hazard to food safety. Recent studies, however, have shown that glycoalkaloid concentrations failed to increase significantly in cv Desiree and Pentland Hawk after exposure to fluorescent-and mercury-derived radiation respectively (Percival et al 1993(Percival et al , 1994 Results 59 J Sci Food Agric 0022-5142/96/$0! ).00 Q 1996 SCI.…”

Quantification of Light-Induced Glycoalkaloids, .ALPHA.-Solanine and .ALPHA.-Chaconine, in Four Potato Cultivars (Solanum tuberosum L.) Distributed in Japan by LC/MS

“…It has been reported that these glycoalkaloids show acute toxicity (Jellema et al, 1980;McMillan & Thompson, 1980), chronic toxicity (Mun et al, 1975;Keeler et al, 1976), and have a bitter taste (Sinden & Deahl, 1976;Woolfe, 1987). The intrinsic glycoalkaloid content in tubers of commercial potato cultivars is low due to selection in breeding, but the content may increase in response to environmental stress conditions, such as light (Friedman, 1997;Griffiths et al, 1994;Kozukue et al, 1993;Maga, 1980;Percival & Dixon, 1994;Percival, 1999;Sinden et al, 1984;Woolfe, 1987), frost and hail damage, and wounding during harvesting or postharvest handling (Woolfe, 1987). Among these stress conditions, the stimulation of glycoalkaloid accumulation with light exposure is a major problem for farmers, packers, suppliers, and vendors of potato (Percival & Dixon, 1994).…”

“…The intrinsic glycoalkaloid content in tubers of commercial potato cultivars is low due to selection in breeding, but the content may increase in response to environmental stress conditions, such as light (Friedman, 1997;Griffiths et al, 1994;Kozukue et al, 1993;Maga, 1980;Percival & Dixon, 1994;Percival, 1999;Sinden et al, 1984;Woolfe, 1987), frost and hail damage, and wounding during harvesting or postharvest handling (Woolfe, 1987). Among these stress conditions, the stimulation of glycoalkaloid accumulation with light exposure is a major problem for farmers, packers, suppliers, and vendors of potato (Percival & Dixon, 1994). This is because potato is exposed to various lights and illuminations, such as daylight, fluorescent light, and incandescent light, during harvest, transport, and marketing.…”

“…Quantitative analyses of glycoalkaloids have been carried out by gas chromatography (Gelder, 1985;Lawson et al, 1992), immunoassays (Plhak & Sporns, 1992), and HPLC (Dao & Friedman, 1996;Griffiths et al, 1998;Kozukue et al, 1987;Percival & Dixon, 1994;Saito et al, 1990;Sotelo & Serrano, 2000). HPLC with a UV detector is now the most widely used apparatus for the analysis of oe-solanine and oe-chaconine due to its high data reproducibility, ease of operation, and relatively low cost.…”

Light-induced glycoalkaloid accumulation of potato tubers (Solanum tuberosum L)

“…Although the effect of light as a positive elicitor of glycoalkaloid synthesis in potato tubers is well recognised, 11±13 further studies have shown that rates of glycoalkaloid accumulation were signi®cantly reduced in cvs Desiree and Pentland Hawk after exposure to¯uorescent and mercury light respectively. 10,14 Whether this response occurs in other genotypes remains unknown. Use of alternative light sources may offer a technique to markedly reduce glycoalkaloid synthesis in potato tubers during marketing and sale and thus improve consumer safety.…”