How is raspberry ketone produced — natural extraction, chemical synthesis, or biotech?

How is raspberry ketone produced — natural extraction, chemical synthesis, or biotech?
Natural raspberry ketone extraction is commercially impractical — berries contain only 1-4 mg per kilogram. Most commercial material is synthetic. Traditional routes start from petrochemical p-hydroxybenzaldehyde and acetone, or use natural anethole with fermentation-derived acetone for a 'natural-identical' label. Recent patents show improved processes: Fudan University's method uses natural anisaldehyde and acetone via Claisen-Schmidt condensation, enzymatic reduction, and demethylation, achieving ~85% yield in a continuous flow. Jiangxi Kaiyuan's route uses 2,6-di-tert-butylphenol with butenone for para-selective alkylation, then removes tert-butyl groups for high purity. Biotech alternatives, including cell-free cascades converting L-tyrosine to raspberry ketone, have reached 61 mg/L — still far below industrial needs. Cost remains the key driver for choosing among these routes.