## 3 Results and Discussion
### Total Polyphenol Content (TPC)  
The findings of this investigation indicate that negatively charged clarifiers have a greater impact on polyphenol retention compared to their positively charged counterparts. Statistical comparisons indicate significant differences (\(p<0.05\)) in polyphenol preservation across treatments. The findings confirm that polyphenol retention was optimal when both clarifier types were applied at medium concentrations (MM), whereas increasing protein levels (MH, HH) resulted in excessive polyphenol removal, reducing the overall antioxidant benefits of the juice (Figure 4). The best-performing samples were GL-MM and KF-MM, which retained the highest polyphenol content. In comparison with the control sample, no significant differences in polyphenol content were observed in the following samples: KF-MM (\(p=0.999\)), KF-HM (\(p=0.998\)), GE-MM (\(p=0.134\)), GL-HH (\(p=1.000\)), GL-HM (0.072), GF-MM (0.337), SE-MM (0.967), SE-HH (0.110), SE-MH (1.000), SE-HM (0.134), SL-MH (\(p=0.665\)), SL-HM (1.000), SF-MH (1.000). The remaining combinations all resulted in significantly higher polyphenol concentrations.  
The efficacy of three plant-clarifying agents, red lentil, green lentil, and green pea protein, was investigated in the clarification of apple juice at concentrations ranging from 60 to 900 mg/L. Gelatin-bentonite treatment was used as a control at the same concentration. The results showed that the 300 mg/L concentration was the best treatment for all agents and, at this concentration, red lentil showed the highest clarification efficiency in terms of both flocculation and sedimentation. Regarding TPC content, the lowest value was for the juice treated with the red lentil agent (266 mgGAE/mL) while the values were higher for the green lentil and green pea agents (295 mg GAE/mL). The effect of red lentil protein was similar to that of the gelatin-bentonite-treated sample in terms of clarification efficiency  
Figure 3: The effect of clarifying agents on the antioxidant capacity (FRAP) of apple juice. MM (medium protein dosage and medium mineral dosage), HM (high protein dosage and medium mineral dosage), MH (medium protein dosage and high mineral dosage). E (gelatin), L (LittoFresh Liquid—plant-based protein), F (FloaClair—plant-based protein). Each value is expressed as mean \(\pm\) standard deviation. The type of mineral-based agent had a significant effect (F(2;101) = 4.194; \(p<0.05\)). The type of protein-based clarification agent had a significant effect (F(2;101) = 62.427; \(p<0.001\)). The types of clarification agents had no significant effect (F(4;101) = 2.261; \(p=0.068\)). The presence of different letters indicates that the groups in question are significantly different. Lower-case letter: comparison of proteins at fixed mineral clarification agents and concentrations.  
and TPC. This study proposed red lentil protein as a promising alternative to commercial fining agents in the fruit juice industry [16].  
In the case of pomegranate juice, compared to natural sedimentation (keeping the juice at 2 \({}^{\circ}\)C for 16 h), protein-based fining agents were found to be more effective in reducing total phenolic content and the number of hydrolyzable tannins that cause turbidity [41]. The process is based on the fact that proteins can form water-insoluble complexes with polyphenols through different mechanisms of action. The main mechanisms observed are electrostatic interactions between positively charged proteins and negatively charged phenolic compounds [42].