A Comprehensive Review of Saffron Nanoemulsion Production Methods and Applications

Saffron (Crocus sativus L.), one of the world’s most valuable spices, is widely recognized for its distinctive color, aroma, flavor, and diverse biological activities. Its major bioactive constituents, particularly crocins, crocetin, picrocrocin, and safranal, have demonstrated antioxidant, anti-inflammatory, neuroprotective, antimicrobial, and other promising activities. However, the practical application of saffron bioactives is constrained by their susceptibility to degradation, limited stability during processing and storage, and, for some compounds, poor aqueous solubility and bioavailability. Nanoemulsion-based and related nanoencapsulation systems have therefore been investigated to improve dispersion, protection, stability, and delivery. This review examines high- and low-energy approaches used to formulate saffron-containing nanoemulsions and compares them with other nanocarrier systems when these are directly relevant to saffron bioactive delivery. The literature was organized by production mechanism, carrier type, application, and level of experimental evidence, with particular attention to formulation parameters, physicochemical performance, stability, release, biological effects, food applications, and scale-up limitations. Recent primary studies, reviews, and relevant patent literature were considered to identify technological advances and remaining gaps. Overall, the evidence supports nanoencapsulation as a promising strategy, but the strength of evidence varies substantially among food, pharmaceutical, and preclinical applications, and claims of improved bioavailability, targeted delivery, safety, or clinical efficacy should be interpreted according to the experimental model used.