Abstract
Pollen-food allergy syndrome (PFAS) associated with birch and alder pollinosis is becoming a problem in Japan, therefore,
it is necessary to find apple cultivars in which Mal d 1, a major PFAS allergen component, is expressed at low levels. Relative
quantification of Mal d 1 mRNA in 28 Japanese apple cultivars was performed, and several cultivars with low Mal d 1 expression
were identified. As it is the protein and not mRNA that is the allergen, it was necessary to ascertain protein levels. To do this, an
ELISA test was constructed for the quantification of Mal d 1 protein levels in apples cultivated in the Nagano prefecture. Mal d 1
extraction solutions were compared, and extraction efficiency was shown to be optimal with minimal sample variation when a
composition of 1 mol/L sucrose, 2% polyvinylpolypyrrolidone (PVPP), 2 mmol/L EDTA, and 1 mmol/L diethyldithiocarbamic acid
was used. Using this approach, Mal d 1 extraction and quantification were performed on 26 apple cultivars from Nagano prefecture.
Of the cultivars tested, 24 were significantly lower in Mal d 1 protein than Sun fuji apples. These low Mal d 1 protein expression
cultivars are proposed candidates for producing low-allergenic Japanese apples.
