Angular Option field change value

<mat-select [(ngModel)]="model.workRightType" formControlName="workrighttype" (change)="onWorkRightChange($event)" placeholder="Engagement Type">
<mat-option *ngFor="let item of workRightTypes" [value]="item.value">       
  {{ item.title}}
  </mat-option>
  </mat-select>     
</mat-form-field>

onWorkRightChange(event){   
this.selectedWorkRight = event.value;       
}