The ubiquitous presence of hydrolases in foodstuffs and their propensity to liberate short-chain acids (<C14) which have low odour and aroma thresholds, from the tasteless tryacylglycerol components means that this is an extremely important mechanism of introducing sensory alteration in food. Moreover, the fact that microorganisms also use hydrolases for food digestion means that also these will be actively involved in changing food properties. Changes due to hydrolysis may range from extremely desirable such as the soapy notes imparted upon blue cheeses by hydrolases originating from the mould, to extremely unpleasant high butyric notes in butter and lauric acidity in coconut oil.

In commonly used vegetable oils, the polyunsaturated C18 acids which are much better substrates than the tryacylglycerols from which they originate, will, when liberated by hydrolysis, readily be oxidised into very odoriferous compounds.

In fruits and vegetables and especially when tissues are sliced or homogenised during processing, oxidation and lypolysis will generally be very quick. Free acids are responsible for off flavours and enhanced oxidability. Also, enzymatic hydrolysis of a small amount of the acyl lipids present can not be avoided during disintegration of oil seeds, a characteristic which makes further processing mandatory for separation and/or denaturation of those enzymes.

Lipid hydrolysis is catalysed by some hydrolases, whose action and specificities differ. In particular, lipases will hydrolyse triacylglycerol and related moieties when emulsified and other hydrolases are specific for polar lipids.