[1] Department of Biochemistry and Food Chemistry,
[2] University of Turku,undefined
[3] 20014 Turku,undefined
[4] Finland e-mail: anu.johansson@utu.fi,undefined
[5] MTT Plant Production Research,undefined
[6] Horticulture,undefined
[7] 21500 Piikkiö,undefined
[8] Finland,undefined