The effects of grinding, soaking and cooking on the degradation of amygdalin of bitter apricot seeds

More than 650 metric tonnes of bitter apricot seeds are produced in Turkey per year as a by-product from the fruit canning industry. The seeds contain the toxic cyanogenic glycoside amygdalin in amounts up to around 150 μmol/g fresh weight. The effect of grinding, soaking and cooking on the degradation of amygdalin to prunasin, benzaldehyde cyanohydrin and HCN, has been studied, as has the release of these cyanides into the soaking water. Analysis for total cyanogenic potential (TCP), cyanogenic glycosides and non-glycosidic cyanogens were thus made on a number of differently processed seed batches. The parameters were: particle size, soaking time and temperature, the presence of a natural microflora, and the duration of cooking. Great reductions were obtained for all three values measured, i.e. from the initial TCP of 85 μmol/g and down to around 2–4μmol/g. However, none of the products obtained were considered safe for human consumption, i.e. a further microbiological detoxification must be added.