This process yields pectin of around 70% esterification (or
methoxylation). To produce other types, some of the ester groups
must be hydrolysed. This is commonly carried out by the action of
acid, either before or during a prolonged extraction, in the
concentrated liquid, or in alcoholic slurry before separation and
drying. This process can produce a range of calcium reactive low
methoxyl pectins. Hydrolysis using ammonia results in the
conversion of some of the ester groups into amide groups,
producing ‘amidated low methoxyl pectins’ (May, 1990).