“Processor” means any person who performs any of the functions of processing strawberries within California. When a processor is a corporation, all of the directors and officers of the corporation in their capacity as individuals shall be included, and any liability for failure to collect or make payment of assessments for which a corporate processor may be subject pursuant to this chapter shall include identical liability upon each individual director or officer of the corporation. It does not, however, include a retailer, except a retailer who purchases or acquires from, or processes on behalf of, any producer, strawberries that were not previously subject to assessment by the commission.