Innovative Nonthermal Technologies

Abstract

Due to the high amount of biologically active compounds, basil is one of the most popular herbs. However, several outbreaks have been reported in the world due to the consumption of basil contaminated with different food pathogens. The aim of this study is to apply nonthermal and ecologically friendly approach based on photosensitization for microbial control of basil which was naturally contaminated with mesophils and inoculated with thermoresistant food pathogen Listeria monocytogenes 56Ly. The obtained data indicate that soaking the basil in 1.5·10-4 M chlorophyllin (Chl) for 15 min and illumination with light for 15 min at 405 nm significantly reduced total aerobic microorganisms on basil by 1.3 log CFU/g, and thermoresistant L. monocytogenes 56Ly from 6.1 log CFU/g in control to 4.5 log CFU/g in the treated samples. It is important to note that this treatment had no impact on enzymatic activity of polyphenol oxidase and pectinesterase. Results obtained in this study support the idea that photosensitization technique with its high selectivity, antimicrobial efficiency and nonthermal nature can serve in the future for the development of safe nonthermal and environmentally friendly preservation technology for different fruits and vegetables.

In the Right Light: Photodynamic Inactivation of Microorganisms Using a LED-Based Illumination Device Tailored for the Antimicrobial Application

“…Sodium Magnesium Chlorophyllin is a water-soluble derivative of natural chlorophyll, and holds approval as food additive E140. Due to its excellent biocompatibility, CHL has been successfully applied for the Photodynamic Decontamination of food [27,28], as well as the photodynamic killing of bacterial plant pathogens [5]. As expected, due to the lack of cationic moieties that interact with the cell wall/membrane of Gram-bacteria [6], CHL is not phototoxic against Gram-bacteria without cell-wall permeabilizing agents.…”

Chlorophylls as Natural Bioactive Compounds Existing in Food By-Products: A Critical Review

“…Paskeviciute et al (2019) used chlorophyllin to reduce the microbial load in basil. They reported that soaking the basil in chlorophyllin and exposing it to light at 405 nm could be a method to increase the safety and shelf life basil [ 82 ].…”

Microbial inactivation by photodynamic treatment

“…The use of natural PS grows as the demand for natural products increases, following the recent desires of consumers. Some examples of PSs obtained from nature are hypericin (Hyp), coumarins, furocoumarins, chlorophyllin (Chl), curcumin, and riboflavin (vitamin B2) (Bonifácio et al, 2018;Maisch et al, 2014;Otieno et al, 2020;Paskeviciute et al, 2019). The Hyp extract is a natural pigment obtained from the plant traditionally known as St John's wort (Hypericum perforatum) widely used as natural PS and considered one of the most powerful PS in nature (Lukšiene & Zukauskas, 2009).…”

“…curcumin (Corrêa et al, 2020;Tao et al, 2019;Temba et al, 2019;Tosati et al, 2018) and chlorophyllin (Josewin et al, 2018;Paskeviciute et al, 2018;Paskeviciute et al, 2019;.…”

“…At both storage temperatures, a fluence of 1,210 J/cm 2 (405 nm; LED) and 5,356 J/cm 2 (460 nm; LED) reached a reduction in cell viability of 3 log CFU/cm 2 of L. monocytogenes in both cases whereas the Salmonella cell viability was reduced by 1.1 and 3 log CFU/cm 2 for each wavelength, respectively (Josewin et al, 2018). Two aPDT studies were conducted at similar conditions of photosensitization with Chl at 150 µM and fluence of 3 J/cm 2 , with cherry tomatoes (Paskeviciute et al, 2018) and basil (Paskeviciute et al, 2019). The viability of B. cereus and L. monocytogenes, artificially inoculated on the surface of cherry tomatoes, was reduced by 1.5 and 1.6 log CFU/mL, respectively (Paskeviciute et al, 2018).…”