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

Effect of in vitro gastrointestinal digestion on antioxidant potential of three prickly pear variety extracts

The aim of this study was to evaluate the effect of in vitro gastrointestinal digestion on the phenolic amounts and their antioxidant potential of three prickly pear variety extracts. The total phenolic compounds (phenolic, flavonoid, and proanthocyanidin) contents were assessed as well as their antioxidant activities (total antioxidant capacity, ferric reducing power, and DPPH free radical scavenging activity) were evaluated before and after digestion. Our results showed that before digestion, the yellow variety possesses high phenolic and proanthocyanidin contents with values of 3176±18 mg GAE/100 g and 90.3±9.8 mg CE/100 g, respectively. However, the red variety has high flavonoids content with a value of 1638±6 mg QE/100 g. Antioxidant activities showed similar trend that phenolic compounds. During the digestion, the antioxidant potential of digested extracts decreased significantly (P<0.001) compared to undigested ones. Hence, this potential increased significantly (P<0.01) from the oral to the intestinal phases. The statistical analysis revealed a moderate correlation between phenolic compounds and antioxidant activity. Hence, IVGID affects the antioxidant potential of extracts, but pH and enzymatic changes do not affect their gut bioaccessibility

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

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

Evaluation of the antimicrobial potential of digested and undigested carob phenolic extracts: Impact on selected gut microbiota

Carob pulp is a natural source of polyphenols, which have been shown to possess health benefits. These compounds play a crucial role in initiating, shaping, and modulating the gut microbiota. The objective of this study was to evaluate the impact of carob pulp phenolic extracts on nine specific groups of human gut microbiota before and after in vitro gastrointestinal digestion. The effects of pure gallic and coumaric acids were also tested. The results showed that the treated phenolic compounds exhibited inhibitory effects on the growth of most pathogenic bacteria. Gallic acid, in particular, demonstrated the most potent antimicrobial effect on Listeria monocytogenes , reducing its growth to below 5%. Staphylococcus aureus and Escherichia coli showed a growth reduction of up to 10%. Furthermore, both phenolic acids, before and after digestion, led to a slight reduction in E. coli O157:H7 numbers. Probiotic bacteria experienced minimal decrease following exposure to phenolic extracts. However, the growth of Lactobacillus casei ssp . rhamnosus was significantly inhibited by almost 50%. Interestingly, the in vitro digestion process exhibited a stronger antibacterial effect against pathogenic bacteria compared to probiotic bacteria. These results highlight the potential of carob phenolic extracts in modulating the intestinal microbiota, thereby offering interesting prospects for the development of diet-based health strategies