Ja. Singleton et Lf. Stikeleather, HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY ANALYSIS OF PEANUT PHOSPHOLIPIDS .2. EFFECT OF POSTHARVEST STRESS ON PHOSPHOLIPID-COMPOSITION, Journal of the American Oil Chemists' Society, 72(4), 1995, pp. 485-488
Peanuts are harvested in late September, and sometimes the harvest sea
son can extend through most of October. When weather patterns delay ha
rvest, the result may cause an immature crop, curing problems, rain da
mage, and freeze damage. All of the above stress situations can affect
oil quality and flavor of the peanuts by altering phospholipid compos
ition. Such changes are related to refining problems as well as flavor
problems. A new high-performance liquid chromatography (HPLC) method
was used for the analysis of phospholipids from postharvest stressed p
eanuts. The concentrations of phosphatidic acid (PA), phosphatidyletha
nolamine (PE), and phosphatidylcholine (PC) were higher in immature se
ed when compared to mature seed. A slight increase in concentration wa
s observed for phosphaltidylglycerol (PC), and a decrease in phosphati
dylinositol occurred in immature peanuts. All phospholipids increased
in concentration except PG when peanuts were cured at a high temperatu
re (40 degrees C). When peanut seeds were frozen at -16 degrees C (bef
ore curing), a significant increase in concentration was observed for
PA and PG, whereas the concentrations of PC and PE decreased to very l
ow levels when compared to the control. Where concentration permitted,
molecular species were separated on a reverse-phase column by HPLC.