Enzymatic hydrolysis of kaempferol 3-O-(2‴-O-sinapoyl-β-sophoroside), the key bitter compound of rapeseed (Brassica napus L.) protein isolate.

Background: The use of rapeseed protein for human nutrition is primarily limited by its strong bitterness, which is why the key bitter compound, kaempferol 3-O-(2‴-O-sinapoyl-β-sophoroside), is enzymatically degraded.

Results: Mass spectrometry analyses of an extract from an untreated rapeseed protein isolate gave three signals for m/z 815 [M-H]. The predominant compound among the three compounds was confirmed as kaempferol-3-O-(2‴-O-sinapoyl-β-sophoroside).