| Abstract
| - The influence of physicochemical conditions on the phospholipase D (PLD) activity of subcellularpreparations of sweet corn (Zea mays L. cv. Peaches and Cream) kernels has been studied. Themicrosomal, mitochondrial, and cytosolic preparations of corn kernels possessed PLD activity albeitat varying proportions. The microsomal and cytosolic PLD activities were stimulated 2-fold between5 and 15 °C. Ethanol had varying modulatory effects on PLD activity. By contrast, acetaldehydewas a potent inhibitor of PLD. As well, a naturally occurring C6 aldehyde such as hexanal and analcohol such as hexanol inhibited PLD activity efficiently. Divalent cations such as calcium chlorideand magnesium chloride stimulated PLD activity at micromolar levels. Monovalent cations such asKCl and NaCl did not appear to affect PLD activity. Partial purification of PLD from the microsomal,mitochondrial, and cytosolic fractions separately revealed four major isoforms with relative molecularmasses of 200, 140−150, 102−108, and 60−66 kDa. The importance of PLD in the maintenance ofprocessed food quality is discussed. Keywords: Chilling; membrane; phospholipase D; processing; sweet corn kernels
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