Influence of storage upon light-induced chlorogenic acid accumulation in potato tubers (Solanum tuberosum L.).
The influence of 2 weeks and 3 months of dark storage upon light-induced chlorogenic acid accumulation within tuber tissue of four potato cultivars and upon 5-, 4-, and 3-caffeoylquinic acid concentrations within cv. King Edward was determined. Storage period significantly affected (P < 0.05) the magnitude of the light-induced chlorogenic acid response with accumulation rates 3-4 times higher in tubers exposed to light after 2 weeks compared with those placed under light after 3 months. Comparison of chlorogenic acid concentrations in controls after 2 and 3 months of dark storage indicated that tuber chlorogenic concentrations decline during prolonged cold store at 5 degrees C. Rates of accumulation in response to light were cultivar-dependent with cv. Fianna the most light-sensitive and cv. Maris Piper relatively light-insensitive. In virtually all cases exposure to sodium and fluorescent light promoted higher rates of accumulation than did exposure to high-pressure mercury light sources. Chlorogenic acid values steadily increased over 15 days of illumination with, in the majority of cases, no indication of cessation. Light exposure increased 5-, 4-, and 3-caffeoylquinic acid accumulation rates in cv. King Edward. Irrespective of storage period and light source, ratios of 5-:4-:3-caffeoylquinic acid were ca. 85:15:0 at day 0 and 52:42:6 by day 15.
Percival
G C
GC
Department of Plant Biology, Scottish Agricultural College, Auchincruive, United Kingdom. G.Percival@au.sac.ac.uk
Baird
L
L
D002726:Chlorogenic Acid / Q000031:analogs & derivatives / Q000032:analysis / Q000378:metabolism*; D003624:Darkness; D005519:Food Preservation; D008027:Light; D011198:Solanum tuberosum / Q000378:metabolism* / Q000528:radiation effects; D013045:Species Specificity; D013997:Time Factors
D002726:Chlorogenic Acid