Response surface methodology and UPLC-QTOF-MSE analysis of phenolic compounds from grapefruit (Citrus x paradisi) by-products as novel ingredients for new antioxidant packaging

The present work reports an experimental study on the optimization of phenolic compounds extraction from Citrus x paradisi peels and the development of active packaging. Response surface methodology (RSM) was applied to investigate the effect of microwave-assisted extraction (MAE) for the recovery of total phenolic compounds (TPC). The TPC in the optimized extract were 31.10 mg gallic acid equivalent/100 g of dry weight (mg GAE/100 g dw) with strong antioxidant capacity. The bioactive compounds in the optimized extract were determined by ultrahigh performance liquid chromatography coupled to quadrupole time-of-flight with high energy mass spectrometry (ILPLC-QTOE-MSE). Forty-five compounds were detected and qualified. The optimized extract obtained by MAE was used as an active antioxidant in multilayer food packaging films. The multilayer low-density polyethylene (LDPE)/polyethylene terephthalate (PET) containing 10% of MAE optimized extract provided the most antioxidant power acting as a free radical scavenger.

Automated summary

This study optimized the extraction of phenolic compounds from Citrus x paradisi peels and developed active packaging with strong antioxidant properties. Ultrahigh performance liquid chromatography was used to identify 45 bioactive compounds in the extract. The multilayer LDPE/PET film containing 10% of the optimized extract showed the most effective antioxidant capacity as a free radical scavenger.