A comparative study on sequential green hybrid techniques (ultrasonication, microwave and high shear homogenization) for the extraction of date seed bioactive compounds and its application as an additive for shelf-life extension of Oreochromis niloticus

What if the secret to fresher fish lies in the humble date seed? A new study shows that green extraction techniques can unlock powerful antioxidants from this waste product, extending the shelf life of Nile tilapia.

Date seeds are often discarded, but they are packed with bioactive compounds. Researchers explored five polyol-based deep eutectic solvents (P-DESs) combined with green extraction methods—microwave, high-shear homogenization, and ultrasound—to recover these valuable polyphenolics.

Using response surface methodology, they optimized each technique. Among the solvents, choline chloride: ethylene glycol (ChCl:Eg) proved most effective. Microwave-assisted extraction (MAE) came out on top, followed by homogenization and ultrasound. But the real magic happened when techniques were combined.

Hybrid methods, especially binary combinations like ultrasound-microwave (UMAE) and homogenization-microwave (HMAE), boosted total phenolic content by 52% and 49% respectively, compared to single methods. The extracts also showed antimicrobial activity, with minimum inhibitory and bactericidal concentrations as low as 40% and 20%.

Finally, the MAE extract was applied to Oreochromis niloticus stored at 4°C for 10 days. It effectively inhibited microbial growth, offering a natural way to extend shelf life and reduce food waste.

Key Points

• ChCl:Eg solvent best for date seed polyphenols
• Hybrid UMAE and HMAE boost phenolics by 52% and 49%
• Extract inhibits microbes in tilapia for 10 days