You can create a custom validator to handle this.
new FormControl(field.fieldValue || '', [Validators.required, this.noWhitespaceValidator])
Add noWhitespaceValidator method to your component
public noWhitespaceValidator(control: FormControl) {
return (control.value || '').trim().length? null : { 'whitespace': true };
}
and in the HTML
<div *ngIf="yourForm.hasError('whitespace')">Please enter valid data</div>