Bioactive Perilla frutescens hydrodistillation residue extract as antioxidant and anti-melanosis preservatives for whiteleg shrimp

• New insights into the solid residue of essential oil hydrodistillation. • 14 biocompounds in the P. frutescens extract (PE-E) were identified by HPLC-MS. • The extract reduced melanosis and microbes over 8 days at 1–3°C. • PF-E-2 extract (0.25% w/v) showed preservation comparable to SMS during storage. • The PE-E’s strong preservation is due to its high polyphenol and flavonoid content. Turning the solid residue of essential oil hydrodistillation into a reusable source, discovering its composition and bioactivities for anti-oxidative and anti-melanosis applications in seafood preservation has revealed promising and significant insights that previous studies have not. Perilla frutescens (PF-E) residue extracts showed the greatest antioxidant and tyrosinase inhibition activities, which is ascribed to their abundant polyphenols and flavonoids determined by total phenolic content (TPC), total flavonoid content (TFC), Fourier-transform infrared (FT-IR) spectroscopy, and high-performance liquid chromatography-mass spectrometry (HPLC-MS) analyses. Afterward, PF-E-2 extract at a concentration of 0.25% ( w / v ) showed better inhibitory effect on melanosis development in whiteleg shrimp ( Litopenaeus vannamei) than 0.1% ( w / v ) concentration, performed equivalently to 0.5% ( w / v ) concentration and commercial preservative sodium metabisulfite (SMS, 1.25% w / v ) during 12-h refrigerated preservation of shrimp, and was selected as the most suitable concentration for long-term preservation. Noticeably, variations in melanosis development, pH, lipid peroxidation, microorganisms, nitrogen-based contents, and stiffness in shrimps treated with the PF-E-2 extract were no statistical difference from that of the SMS-treated during eight-day preservation at 1−3°C ( p > 0.05). These findings potentiate using PF-E as an economical and effectively benignant alternative to SMS in refrigerated storage of whiteleg shrimps.