Whenever the commissioner of agriculture, markets, and food has reasonable grounds to believe that a licensee has violated any of the provisions of this subdivision or any rule adopted hereunder, he may suspend the license of such licensee forthwith for a period not to exceed 30 days. Upon such suspension the commissioner of agriculture, markets, and food shall notify the licensee thereof and the grounds therefor, and shall set a time and place for hearing. If upon hearing it shall appear that such provisions or rules have been violated, said license shall be revoked; otherwise it shall be reinstated.