On the other hand, vacuum drainage reduced the extent of
oxidation by only 12%, showing that the absence of air (or oxygen)
during the short drainage period is not sufficient to retard oxidative
degradation significantly. As a consequence, this difference resulted
in minimal reduction in the values of total colour difference,
viscosity and polar compounds. Changes in fatty acid composition
were more pronounced in the case of atmospheric drainage. There
was no significant difference in tocols content in the case of vacuum
and atmospheric drainage over the frying period, although a
significantly higher value was observed in the case of the former
in the initial two days of frying.