Determination of amygdalin in apple seeds, fresh apples and processed apple juices.

Cyanogenic glycosides are natural plant toxicants. Action by endogenous plant enzymes can release hydrogen cyanide causing potential toxicity issues for animals including humans. We have quantified amygdalin in seeds from different apple varieties, determined the effects of processing on the amygdalin content of apple juice and quantified amygdalin in commercially-available apple juices. Amygdalin contents of seeds from fifteen varieties of apples ranged from 1 mg g(-1) to 4 mg g(-1). The amygdalin content of commercially-available apple juice was low, ranging from 0.01 to 0.04 mg ml(-1) for pressed apple juice and 0.001-0.007 mg ml(-1) for long-life apple juice. Processing led to juice with low amygdalin content, ranging from 0.01 mg ml(-1) to 0.08 mg ml(-1). The results presented show that the amygdalin contents of commercially-available apple juices are unlikely to present health problems to consumers.

Development and application of an enzyme-linked immunosorbent assay (ELISA) for the quantification of amygdalin, a cyanogenic glycoside, in food.

Amygdalin is a member of the cyanogenic glycoside group of plant secondary metabolites capable of generating hydrogen cyanide under certain conditions. As a consequence, the cyanogenic glycosides have been associated with incidents of acute and subacute food poisoning. Specific antibodies were raised against an amygdalin-bovine serum albumin immunogen synthesized using a novel approach. The antibodies were used in a microtitration plate enzyme-linked immunosorbent assay (ELISA) for the quantification, for the first time, of amygdalin in commercially available foods. Correlation of results with high-performance liquid chromatography was very high (r = 0.983). The limit of detection of the immunoassay was 200 ± 0.05 pg mL(-1), and the 50% inhibitory concentration of amygdalin was 50 ± 0.02 ng mL(-1), making the ELISA particularly sensitive.

Amygdalin content of seeds, kernels and food products commercially-available in the UK.

Cyanogenic glycosides are a large group of secondary metabolites that are widely distributed in the plant kingdom, including many plants that are commonly consumed by humans. The diverse chemical nature of cyanogenic glycosides means that extraction and analysis of individual compounds can be difficult. In addition, degradation can be rapid under appropriate conditions. Amygdalin is one of the cyanogenic glycosides found, for example, in apples, apricots and almonds. We have developed and applied a high performance liquid chromatographic procedure for amygdalin quantification to investigate extraction efficiency and to determine levels in a range of commercially-available foods for the first time. Our results show that seed from Rosaceae species contained relatively high amounts (range 0.1-17.5 mg g(-1)) of amygdalin compared to seed from non-Rosaceae species (range 0.01-0.2 mg g(-1)). The amygdalin content of processed food products was very low.