Phenolic contents and in vitro antioxidant activity of four commonly consumed nuts in Algeria

This study was carried out to determine the phenolic contents and the antioxidant activity of four nuts with different solvent extract. Total phenolic compounds, flavonoids, and proanthocyanidin were quantified. Antioxidant activity was evaluated by various in vitro tests, including ferric reducing power, phosphomolybdenum method assay, and free radical scavenging activity. The results showed that the total phenolic contents varied between 0.30 g GAE/100 g (peanuts) and 1.65 g GAE/100 g (walnuts); the flavonoid contents varied between 0.17 g QE/100 g (peanuts) and 0.41 g QE/100 g (hazelnut). The phenolic contents of four nut extracts exhibit potent antioxidant activity. Indeed, walnuts were the richest in total phenolic content and demonstrated the highest potential for overall antioxidant capacity using ferric reducing power assay (FRP), phosphomolybdenum method assay, and free radical scavenging activity (FRSA). Phenolic amounts positively correlated with antioxidant activity tested

Optimisation of microencapsulation efficiency of propolis phenolic compounds by double emulsion method using response surface methodology

Abstract The aim of this study was to optimise the microencapsulation efficiency of propolis phenolic compounds by double emulsion solvent evaporation technique (W 1 /O/W 2 ). The solvent/sample ratio and the polymer and surfactant concentration parameters were optimised using response surface methodology (RSM) through Box–Behnken Design (BBD). For each parameter studied, total phenolic content encapsulation efficiency (TPCEE), free radical scavenging activity (DPPH), and ferric reducing antioxidant power (FRAP) were evaluated. The results showed that the optimal parameters were: 31.60 mg mL −1 for sample/solvent ratio, 606.28 mg mL −1 for poly(ε-caprolactone) (PCL) concentrations, and 2.05 g mL −1 for poly(vinyl alcohol) (PVA) concentration. The optimum values obtained were: 84.62% for encapsulation efficiency of phenolic content, 51.89% for DPPH, and 48,733 mg Trolox Equivalent/100 g dry weight for FRAP. The experimental checking of results revealed the validity of elaborated models and their suitability for the prediction of both responses. The developed mathematical models have expressed a high level of significance through RSM optimisation processes for phenolic antioxidants of propolis

Effect of microencapsulation conditions on phenolic compounds and antioxidant activity of propolis using double emulsion solvent evaporation approach

The aim of this work was to microencapsulate propolis phenolic compounds using polycaprolactone as wall material by double emulsion solvent evaporation (w 1 /o/w 2) . Microencapsulation experiments were carried out by investigating the effect of sample/solvent ratio (10–100 mg mL −1 ), poly(ε-caprolactone) (PCL) concentrations (200–1,000 mg mL −1 ), poly(vinyl alcohol) (PVA) concentrations (0.5–2.5 g mL −1 ), and stirring speed (200–1,000 r.p.m.) on the microencapsulation efficiency of total phenolic content (TPC%) and antioxidant activity of propolis. The best microencapsulation conditions were selected according to the total phenolic amount and their antioxidant activity. Experimental results showed that all microencapsulation conditions had significant effects ( P < 0.05) on total phenolic content and antioxidant activities. The best conditions were: 30 mg mL −1 , 600 mg mL −1 , 2 g mL −1 , and 400 r.p.m. for sample/solvent ratio, PCL concentrations, PVA concentrations, and stirring speed, respectively, with values of 86.98 ± 0.03% for phenolic encapsulation efficiency, 53.81 ± 0.50% for free radical scavenging activity (DPPH), and 45,480 Trolox equivalent, mg TE/100 g dry weight for ferric reducing antioxidant power (FRAP). Under all encapsulation conditions, a significant positive correlation was observed between ferric reducing antioxidant power, free radical scavenging activity, and phenolic content