Beef trimmings may be prepared from any portion of the carcass which yields product that meets end item requirements. All objectionable materials listed in the material requirements shall be removed. Ground product is not permitted. Unless, otherwise specified by the purchaser, trimmings derived from automatic deboning machines and advance lean retrieval systems shall be excluded. The purchaser may specify that the trimmings meet the IMPS microbial requirements for ground beef as specified within the IMPS QAP.