From Source to Utilization: A Review of Influencing Factors and Safety Assessment for High-Value Utilization of Sweet Potato (Ipomoea batatas L.) Leaves

Sweet potato leaves (SPLs), with an annual production of millions of tons, are rich in polyphenols and other bioactive components, yet remain largely discarded or underutilized. This review proposes, for the first time, a “source–process–safety” full-chain cascade framework that elucidates three key aspects: how upstream factors (genotype and harvest period) predetermine raw material quality baselines; how midstream processing mediates the balance between activity retention and flavor improvement; and how downstream applications are subject to the decisive thresholds of heavy metal safety and regulatory compliance. Collectively, this framework provides a theoretical foundation and practical guidance for the high-value utilization of sweet potato leaves.