Combating saffron fraud: a systematic review of adulteration practices, detection technologies, recommendations and challenges.

Saffron, the world's most valuable spice, faces pervasive threats from food fraud, compromising its authenticity, economic value, and consumer safety. This systematic review synthesizes evidence from 23 studies to evaluate the prevalence, methods, impacts, and detection strategies of saffron adulteration. Following PRISMA guidelines, peer-reviewed articles from PubMed, Scopus, and ScienceDirect (2015-2025) were analyzed. Findings reveal that 20-30% of commercial saffron is adulterated globally, though with significant regional disparities (e.g., 3.5% in regulated EU markets vs. 60% in India), driven by economic incentives and regulatory gaps. Common fraudulent practices include substitution with safflower, marigold, or turmeric; dilution with extraneous plant materials; and the addition of hazardous synthetic dyes such as Sudan compounds and auramine-O. Advanced detection technologies including DNA barcoding, spectroscopy, hyperspectral imaging, and machine learning demonstrate high accuracy but face barriers in cost, accessibility, and real-world applicability. Health risks, such as exposure to carcinogenic dyes, and economic losses for legitimate producers underscore the urgency of addressing supply chain vulnerabilities. The review highlights fragmented regulatory frameworks and emphasizes the need for harmonized ISO standards, blockchain-enabled traceability, and consumer education to combat fraud. Emerging portable tools, such as smartphone-based spectroscopy and AI-driven platforms, offer promising solutions for on-site authentication.