Multiobjective response and chemometric approaches to enhance the phytochemicals and biological activities of beetroot leaves: an unexploited organic waste

Abstract

Research on medicinal plants is developing each day due to inborn phytochemicals, which can encourage the progress of novel drugs. Most plant-based phytochemicals have valuable effects on well-being. Among them, beetroot leaves (BL) are known for their therapeutic properties. Here, three solvents, namely, acetonitrile, ethanol, and water, and their combinations were developed for BL extraction and simultaneous assessment of phytochemical compounds and antioxidant and antifoodborne pathogen bacteria activities. By using the augmented simplex-centroid mixture design, 40.40% acetonitrile diluted in water at 38.74% and ethanol at 20.86% favored the recovery of 49.28 mg GAE/mL (total phenolic content (TPC)) and 0.314 mg QE/mL (total flavonoid content (TFC)), respectively. Acetonitrile diluted in water at 50% guarantees the best antioxidant activity, whereas the optimal predicted mixture for the highest antibacterial activity matches 24.58, 50.17, and 25.25% of acetonitrile, ethanol, and water, respectively. These extraction conditions ensured inhibition of Staphylococcus aureus , Salmonella enterica , and Escherichia coli , respectively, at 0.402, 0.497, and 0.207 mg/mL. Under optimized conditions, at three concentrations of BL, minimal inhibitory concentration (MIC), 2 × MIC, and 4 × MIC, a linear model was employed to investigate the inhibition behavior against the three tested bacteria. The early logarithmic growth phase of these bacteria illustrated the bactericidal effect of optimized extracted BL with a logarithmic growth phase inferior to 6 h. Therefore, BL extract at 4 × MIC, which corresponds to 1.608, 1.988, and 0.828 mg/mL, was more efficient against S. aureus , S. enterica , and E. coli.

Disclosing the Functional Potency of Three Oxygenated Monoterpenes in Combating Microbial Pathogenesis: From Targeting Virulence Factors to Chicken Meat Preservation

“…Then, 10 μL of cell suspension of the studied microorganism was added to a final inoculum concentration of 10 6 colony-forming unit (CFU)/mL and incubated overnight at 37 °C. A volume of 25 µL of thiazolyl blue tetrazolium bromide (MTT) at 0.5 mg/mL was added to the wells and incubated at room temperature for 30 min [ 24 ].…”

“…For each test, the L, E, and C compounds were deposited into the respective well to perform a two-fold serial dilution from the original sample with a final volume of 100 µL per well. Then, 10 µL of cell suspension of the studied microorganism was added to a final inoculum concentration of 10 6 colony-forming unit (CFU)/mL and incubated overnight at 37 • C. A volume of 25 µL of thiazolyl blue tetrazolium bromide (MTT) at 0.5 mg/mL was added to the wells and incubated at room temperature for 30 min [24].…”

“…Therefore, the untreated samples overpassed the limits of the shelf life (6.7 log CFU/g for APC and PTC and 2 log CFU/g for EC) declared by the Association of French Normalization Organization Regulation (AFNOR), indicating that the chicken meat became unfit for consumption [67]. However, APC, PTC, and EC growth rates significantly (p < 0.05) decreased in treated samples owing to the addition of the L/E/C mixture at different concentrations (16,24, and 32 µg/mL). Interestingly, 2-L/E/C (at 32 µg/mL) displayed better antibacterial activity than the BHT.…”

Effect of Extraction Solvent on Total Phenol Content, Total Flavonoid Content, and Antioxidant Activity of Euphorbia resinifiera O. Berg

“…The lowest activity was shown by the distilled water extract of Euphorbia resinifiera (Figure13). 24 Notwithstanding the extraction method, the aqueous-methanol (70%) remains the best solvent for extracting polyphenols and flavonoids. Also,the extracts of this solvent show the best free radical scavenging activity, followed by methanol distilled water.The same observations were reported by Lapornik et al, 20 who showed that the low content of phenolic compounds inaqueous extracts might be due to the absence of oxidases.…”

Agro-Food Waste: Harnessing the Potential Significance of Natural Biofilm Inhibitors

“…10 Few studies were found about beet leaves, as a by-product, reporting their bioactive compounds content and therapeutic applications. 37 The ethanolic extract of beet leaves was shown to have anti-quorum-sensing activity using the bio-monitor strain of Chromobacterium violaceum which secretes the violacein pigment. A 50% decrease in violacein production was observed without change in the cell viability confirming its ability to block the cellular interaction and signaling without inhibiting the cell growth.…”