Detection of internal defects in onion bulbs by means of single-point and scanning laser Doppler vibrometry

The number of onion consignments which are rejected or downgraded due to the incidence internal defects is a continuing problem for wholesalers and growers. Defects may only be up 4% level, but result in entire lot being lost sale. Destructive quality control testing causes waste, so that there need alternative non-invasive assessment. aim current research was demonstrate whether could detected using Laser Doppler vibrometry (LDV). Several trials, with different types sensors levels defect severity were conducted. Both scanning single-point LDV employed order develop suitable measurement method evaluate defects. It necessary measure resonant frequency at neck equator bulbs segregate rot (Botrytis allii) bacterial rot, respectively, not differentiate sprouting double hearted from sound onions. In conclusion, it possible non-destructively identify 5% area affected (visible after cutting). would calibrate cultivars origins, if technique implemented on commercial sorting line.