A Sydney woman awarded $151,000 after slipping on a grape in a Woolworths supermarket has lost her case on appeal.

Colleen McQuillan had successfully sued the supermarket giant after falling over in the fruit and vegetable section at Leichhardt in November 2012.

But the NSW Court of Appeal on Monday upheld Woolworths' appeal and dismissed Ms McQuillan's claim, finding the company had not been negligent over the grape which the three judges said had been of an unknown colour.

In their judgment, the three appeal judges said Ms McQuillan had slipped on the grape and fallen soon after the supermarket opened at 10am on Sunday, November 25, 2012.

The judges said the NSW District Court judge who awarded Ms McQuillan $151,000 over the fall found that the grape's presence on the floor near the banana stand was more likely to have occurred before the store opened when grapes were taken from the cool room and placed on the display table.

In reaching this conclusion, the District Court judge had rejected three other possibilities: the grape was missed by the overnight cleaners; the grape was dropped by a customer after the store opened; or the grape had been caught up in a black safety mat on the floor and was dislodged when the mat was removed by two meat department staff.

''His Honour found that if someone had been on duty in the produce section they would have identified the risk, based on the training given and the warning signs to be on the lookout for grapes on the floor,'' the appeal judges said.

''His Honour concluded that the grape constituted a slip hazard and was the cause of Ms McQuillan's fall.''

Woolworths denied negligence, breaching its duty of care or that staff had failed to keep a proper lookout for grapes on the floor, and the appeal judges agreed.

They found there was no evidence of any activities by Woolworths staff before 10am likely to have dislodged a single grape; the grape was unlikely to have been on the floor before 10am; and staff looking for grapes on the floor could have been impeded by customers, trolleys and baskets before Ms McQuillan fell.