Optimizing the recovery of bioactive compounds is critical for the accurate assessment of the quality of freeze-dried vegetables. In this context, Response Surface Methodology (RSM) was performed to optimize the ultrasound-assisted extraction (UAE) of phenolic compounds from freeze-dried broccoli (cv ‘Thassos’) and cauliflower (cv ‘Cercy’) florets. The influence of three process parameters, namely solvent-to-material ratio (20 to 60 mL/g), extraction time (10 to 40 min) and solvent mixture (methanol: water) composition (60 to 100% methanol) was evaluated. Multi-response optimization identified the optimal process conditions for both cultivars (composite desirability = 0.996) as a 60 mL/g ratio, 10 min extraction time and 76% methanol content. The application of the optimized extraction conditions to broccoli ‘Naxos’ and cauliflower ‘Guideline’ cultivars, confirmed the model applicability and revealed significant genotypic heterogeneity (p 0.9) correlation between TPC and ABTS for both broccoli and cauliflower, high (r = 0.78) correlation between TPC and FRAP for broccoli and moderate (r = 0.63) for cauliflower. These findings confirm that process parameter optimization is crucial for the maximum recovery of phenolic compounds from freeze-dried broccoli and cauliflower, and UAE conditions should be carefully selected to ensure accurate cultivar evaluation.
Statilko et al. (Thu,) studied this question.