RESUMO
The objective of this article was to combine tea polyphenols, gallic acid, and cinnamon essential oil to construct a natural extract-complex microemulsion system (NMs) with good antibacterial activity, antioxidant activity, and stability, as well as low irritation. NMs were characterized by particle size distribution, electrical conductivity, and light transmittance. The stability, as well as the antimicrobial, antioxidant, irritation, and antimicrobial mechanisms, of NMs were also studied. The results showed that NMs had a significant antimicrobial function against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Candida albicans and Aspergillus brasiliensis. The minimum inhibitory concentrations were 156 µg/mL, 62.5 µg/mL, 125 µg/mL, 250 µg/mL, and 125 µg/mL, respectively. Through the cell membrane permeability test and growth curve test of bacteria and fungi, we concluded that the NMs' mechanism of action on bacteria and fungi could be interpreted as NMs mainly altering the permeability of cell membranes to inhibit the growth of bacteria and fungi. The results of this study have important implications for utilizing plant extracts as natural preservatives for food and cosmetics.
RESUMO
In this paper, ultrasonic cellulase extraction (UCE) was applied to extract polyphenols from passion fruit. The extraction conditions for total phenol content (TPC) and antioxidant activity were optimized using response surface methodology (RSM) coupled with a Box-Behnken design (BBD). The results showed that the liquid-to-solid ratio (X2) was the most significant single factor and had a positive effect on all responses. The ANOVA analysis indicated quadratic models fitted well as TPC with R2 = 0.903, DPPH scavenging activity with R2 = 0.979, and ABTS scavenging activity with R2 = 0.981. The optimal extraction parameters of passion fruit were as follows: pH value of 5 at 30 °C for extraction temperature, 50:1 (w/v) liquid-to-solid ratio with extraction time for 47 min, the experimental values were found matched with those predicted. Infrared spectroscopy suggested that the extract contained the structure of polyphenols. Furthermore, three main polyphenols were identified and quantified by HPLC. The results showed the content of phenolic compounds and antioxidant activity of the optimized UCE were 1.5~2 times higher than that determined by the single extraction method and the Soxhlet extraction method, which indicates UCE is a competitive and effective extraction technique for natural passion fruit polyphenols.
Assuntos
Antioxidantes/isolamento & purificação , Passiflora/química , Extratos Vegetais/química , Polifenóis/isolamento & purificação , Antioxidantes/química , Celulase/química , Cromatografia Líquida de Alta Pressão , Polifenóis/química , UltrassomRESUMO
Chinese herbal pieces are a key factor to protecting the quality of the clinical efficacy of traditional Chinese medicine (TCM), and it is one of the basic elements of ensuring the quality of TCM and people's usage safety. However, Chinese herbal pieces has massive problem such as adulteration and counterfeit, dyeing and weighting, pesticide residues, heavy metals in excess of the standards, and all the issues are repeated excessive in the clinic treatment. These issues impacted sound development of production, management and use of TCM, but also brings common people hidden trouble for the clinical safety of medication. Protect and improve the quality of the Chinese herbal pieces demand that continue improve quality system, in-depth scientific research, and strengthen self-discipline and other factors. So it is fundamentally to ensure good quality of Chinese herbal pieces with the color, taste and shape by systematic supervision to it from the source, production, management and research, with strengthened implementation and en- forcement of the "3G".