An Optimized Alternative for Phenolic Compound-Extraction of Strawberry Bagasse Agro-Industrial Residues

Abstract

The optimum extraction conditions for highest recovery of total phenolics content and antioxidant capacities were analyzed for strawberry (Fragaria ananassa) using response surface methodology. Phenolic compounds have been used in food technological processes, and thus it can contribute to the prevention of some degenerative diseases and used as antioxidant or antimicrobial. The assessment of the concentration of total phenolics, as well as their capacity to scavenge ABTS and the antioxidant capacity, determined by the modified DPPH method, were investigated based on distinct combinations of time, temperature, and solvents concentration. It was investigated that the optimum condition for getting the highest antioxidant yield was obtained under water-acetone (80:20, v/v) at 36 ºC and 36 min. We have found that the maximum yield of total phenolic was 1707.66 ± 38.43 (mg GAE/100 g), preserving the antioxidant capacity which was measured by using DPPH and ABTS assays, showing an EC50 of 1085.20 ± 32 (g fruit/g of DPPH) and 66.67 ± 2.4 (μM trolox/g fruit) respectively. This method is also easier and cheaper than other methods to perform polyphenols extractions since does not require expensive reagents or high quantities of organic solvents.

Extraction of Isoflavones, Alpha-Hydroxy Acids, and Allantoin from Soybean Leaves—Optimization by a Mixture Design of the Experimental Method

“…In turn, pure alcohol or a mixture of EtOH or propanediol exhibited a low phenol extraction ability. The obtained results are in accordance with the data presented by Felix et al [18] who indicated that pure H2O extracted 5-fold and 3-fold higher amounts of phenolic compounds from Fragaria ananassa compared to pure EtOH or an H2O:EtOH (50:50, v/v) mixture, respectively. Similarly, a high ability of H2O for phenolic compound extraction was shown in peppermint [52].…”

“…This phenomenon was expected since isoflavones display free-radical scavenging potential [14]. At the same time, both the allantoin and alpha-hydroxy acids did not exhibit a positive correlation with the scavenging of ABTS (Table 3), which is in accordance with previous reports [18,50]. However, alpha-hydroxy acids are considered antioxidant molecules since they are capable of oxidation inhibition and the suppression of free-radical formation [14], while allantoin exhibits the induction of antioxidant enzyme activity [51].…”

“…The yield of a single compound extraction process strictly depends on the physical and chemical properties of extrahents. Here, a three-solvent system was used containing EtOH, H 2 O, and propanediol, which present different dipolar moments of 1.69 D, 1.85 D, and 2.52 D, respectively [18,39]. Additionally, the surface tensions (EtOH: 22.3; H 2 O: 71.9; propanediol: 47.8 J•m −2 ) and contact angles (EtOH: 18.8; H 2 O: 85.6; propanediol: 81.3 • at 0 ms) (data not published) varied significantly between the solvents.…”

“…Solvents are crucial factors in the metabolite extraction efficiency in plants [16]. These compounds vary significantly in their solubility properties; thus, the selection of an appropriate solvent mixture brings several difficulties, including proper solvent composition and the proportion chosen [16][17][18]. In this context, the design of experiment (DoE) approach for mixture composition optimization is considered a valuable tool for increasing the extraction efficiency by solvent composition optimization [19,20].…”