Towards better microbial safety of fresh produce: Chlorophyllin-based photosensitization for microbial control of foodborne pathogens on cherry tomatoes

Antimicrobial activity of octyl gallate nanoemulsion combined with photodynamic technology and its effect on food preservation

Photodynamic inactivation, as a safe and effective antimicrobial technology that does not damage the organoleptic properties of the food itself, decreases the use of preservatives and is gradually gaining attention in the food industry. This study selected octyl gallate (OG) as an antimicrobial photosensitizer with eucalyptus oil as the oil phase and prepared it as an octyl gallate nanoemulsion (OG-NE) to ensure the delivery of the photosensitizer. Escherichia coli and Staphylococcus aureus inactivation with the OG-NE combined with photodynamic technology, as well as the effect on the quality of food products, was investigated. The results showed the successful preparation and homogeneous distribution of the OG-NE with an encapsulation rate of 85.18 %. The OG-NE's ability to produce single oxygen (1O2) was significantly higher, as shown by 1O2 production. The OG-NE combined photodynamic technique confirmed the effectiveness of microbial removal, demonstrating a significant increase in reactive oxygen species (ROS) and the permeability of the cell membrane. The effect of the OG-NE combined photodynamic technology on perch (microbiology, pH, whiteness, water holding capacity, TVB-N and TBA) and litchi (weight loss, titratable acid and sugar content) preservation was assessed. Food preservation experiments revealed that the OG-NE combined photodynamic technology exhibited a positive effect on food quality. The results indicated that the combination of the OG-NE and photodynamic technology provided a new alternative strategy for the food industry in antimicrobial and preservation.

Food additives as photosensitizers: A systematic review and narrative synthesis

Photosensitizers are the key molecules determining the efficacy of anti-microbial photodynamic inactivation. However, photosensitizers for clinical use frequently fail to satisfy safety standards required by the food industry. A variety of strategies could be employed to address these issues i.e. focusing on photosensitizers with high efficiency (>3-log decrease in CFU), on food additives with minimal effects on food qualities (taste, texture, appearance, or nutrients), and also approved photosensitizers by regulatory authorities. This review summarizes 48 relevant studies that reported on the photodynamic activities of approved food additives. We report food additives with favorable photosensitive properties, which are capable of producing reactive oxygen species upon exposure to light at appropriate wavelengths, thereby inactivating various foodborne pathogens with great promise for food sterilization. The information presented in this systematic review may provide practical insights for implementation of photodynamic inactivation in industrial settings and encourage future development of food-grade photosensitizers for food sterilization.

Photodynamic bactericidal nanomaterials in food packaging: From principle to application

Compared to traditional preservatives, photodynamic inactivation (PDI) offers a promising bactericidal approach due to its nontoxic nature and low propensity for microbial resistance. In this paper, we initially investigate the principles and antibacterial mechanisms underlying PDI. We then review factors influencing PDI's germicidal efficacy in food preservation. Furthermore, we delve into the application potential of PDI nanomaterials, such as quantum dots, titanium dioxide, and graphene, in packaging and films. Special attention is given to the impact of PDI treatment on food quality and the potential for microbial tolerance development. Last, we discuss the migration and safety of PDI nanomaterials. The chemical basis of PDI involves the generation of reactive oxygen species through the activation of endogenous or exogenous photosensitizers. Its primary antibacterial mechanisms encompass the disruption of cell membranes, impairment of cellular functions, and inhibition of quorum sensing. The multi-target action of PDI significantly reduces the likelihood of resistance development. PDI has great potential for application in the field of antibacterial packaging. The information contained in this paper will provide effective reference for the design of new antibacterial packaging.

Photodynamic Inactivation in agriculture: combating fungal phytopathogens resistant to conventional treatment

Botrytis cinerea is a severe threat in agriculture, as it can infect over 200 different crop species with gray mold affecting food yields and quality. The conventional treatment using fungicides lead to emerging resistance over the past decades. Here, we introduce Photodynamic Inactivation (PDI) as a strategy to combat B. cinerea infections, independent of fungicide resistance. PDI uses photoactive compounds, which upon illumination create reactive oxygen species toxic for killing target organisms. This study focuses on different formulations of sodium-magnesium-chlorophyllin (Chl, food additive E140) as photoactive compound in combination with EDTA disodium salt dihydrate (Na2EDTA) as cell-wall permeabilizer and a surfactant. In an in vitro experiment, three different photosensitizers (PS) with varying Chl and Na2EDTA concentrations were tested against five B. cinerea strains with different resistance mechanisms. We showed that all B. cinerea mycelial spheres of all tested strains were eradicated with concentrations as low as 224 µM Chl and 3.076 mM Na2EDTA (LED illumination with main wavelength of 395 nm, radiant exposure 106 J cm-2). To further test PDI as a Botrytis treatment strategy in agriculture a greenhouse trial was performed on B. cinerea infected bell pepper plants (Capsicum annum L). Two different rates (560 or 1120 g Ha-1) of PS formulation (0.204 M Chl and 1.279 M Na2EDTA) and a combination of PS formulation with 0.05% of the surfactant BRIJ L4 (560 g Ha-1) were applied weekly for 4 weeks by spray application. Foliar lesions, percentage of leaves affected, percentage of leaf area diseased and AUDPC were significantly reduced, while percentage of marketable plants were increased by all treatments compared to a water treated control, however, did not statistically differ from each other. No phytotoxicity was observed in any treatment. These results add to the proposition of employing PDI with the naturally sourced PS Chl in agricultural settings aimed at controlling B. cinerea disease. This approach seems to be effective regardless of the evolving resistance mechanisms observed in response to conventional antifungal treatments.

Radical species generating technologies for decontamination of Listeria species in food: a recent review report

Foodborne illnesses occur due to the contamination of fresh, frozen, or processed food products by some pathogens. Among several pathogens responsible for the illnesses, Listeria monocytogenes is one of the lethal bacteria that endangers public health. Several preexisting and novel technologies, especially non-thermal technologies are being studied for their antimicrobial effects, particularly toward L. monocytogenes. Some noteworthy emerging technologies include ultraviolet (UV) or light-emitting diode (LED), pulsed light, cold plasma, and ozonation. These technologies are gaining popularity since no heat is employed and undesirable deterioration of food quality, especially texture, and taste is devoided. This review aims to summarize the most recent advances in non-thermal processing technologies and their effect on inactivating L. monocytogenes in food products and on sanitizing packaging materials. These technologies use varying mechanisms, such as photoinactivation, photosensitization, disruption of bacterial membrane and cytoplasm, etc. This review can help food processing industries select the appropriate processing techniques for optimal benefits, in which the structural integrity of food can be preserved while simultaneously destroying L. monocytogenes present in foods. To eliminate Listeria spp., different technologies possess varying mechanisms such as rupturing the cell wall, formation of pyrimidine dimers in the DNA through photochemical effect, excitation of endogenous porphyrins by photosensitizers, generating reactive species, causing leakage of cellular contents and oxidizing proteins and lipids. These technologies provide an alternative to heat-based sterilization technologies and further development is still required to minimize the drawbacks associated with some technologies.

Photodynamic Inactivation of Staphylococcus aureus Using Aloe-emodin as Photosensitizer

Aloe-emodin (AE) is a natural compound with photodynamic properties. The aim of this study was to investigate the inhibitory effect of AE-mediated photodynamic inactivation (PDI) on Staphylococcus aureus (S. aureus). The bacteriostatic efficiency under different photodynamic conditions and photosensitizing mechanism was studied in detail. The results showed that AE-mediated PDI exhibited a typical concentration and time-dependent characteristics. In terms of bactericidal mechanism, disruption of membrane integrity and increase of cell membrane permeability was observed. Type II reaction was assumed as the main photochemical reaction involved in AE-mediated PDI as evidenced by the action of different ROS quenching agents. Furthermore, AE-mediated PDI decreased the bacterial survival in freshly squeezed apple juice and maintained its quality. The combination of blue light and AE enlarged the application of AE as an effective natural photosensitizer suitable for a food system.

Chlorophyllin-Based 405 nm Light Photodynamic Improved Fresh-Cut Pakchoi Quality at Postharvest and Inhibited the Formation of Biofilm

The aim of this study was to evaluate the effect of chlorophyllin-based photodynamic inactivation (Chl-PDI) on biofilm formation and fresh-cut pakchoi quality during storage. Firstly, Chl-based PDI reduced the amount of biofilm in an in vivo experiment and inactivated the food spoilage bacteria. Antibacterial mechanism analysis indicated that the bacterial extracellular polysaccharides and extracellular proteins were vulnerable targets for attacks by the Chl-based PDI. Then, the food spoilage microorganisms (Pseudomonas reinekei and Pseudomonas palleroniana) were inoculated onto the surface of fresh-cut pakchoi. We used chlorophyllin (1 × 10⁻⁵ mol/L) and 405 nm light (22.27 J/cm² per day) to investigate the effect of Chl-based PDI treatment on fresh-cut pakchoi quality during storage. The results showed that Chl-based PDI increased the visual quality and the content of chlorophyll, VC, total soluble solids, and SOD activity and decreased the occurrence of leaf yellowing and POD activity. These suggest that Chl-based PDI can be used for the preservation of fresh-cut pakchoi and has the potential to inhibit biofilm formation of food spoilage bacteria. It is of great significance for the effective processing and traditional vegetable preservation.

Photodynamic inactivation and its application in food preservation

Food incidents caused by various foodborne pathogenic bacteria are posing a major threat to human health. The traditional thermal and chemical-based procedures applied for microbial control in the food industry cause adverse effects on food quality and bacterial resistance. As a new means of innovative sterilization technology, photodynamic inactivation (PDI) has gained significant attention due to excellent sterilization effect, environmental friendliness, safety, and low cost. This review analyses new developments in recent years for PDI systems applied to the food preservation. The fundamentals of photosensitization mechanism, the development of photosensitizers and light source selection are discussed. The application of PDI in food preservation are presented, with the main emphasis on the natural photosensitizers and its application to inactivate in vitro and in vivo microorganisms in food matrixes such as fresh vegetable, fruits, seafood, and poultry. The challenges and future research directions facing the application of this technology to food systems have been proposed. This review will provide reference for combating microbial contamination in food industry.

Assessing the photodynamic efficacy of different photosensitizer-light treatments against foodborne bacteria based on the number of absorbed photons

Increasing interests in photodynamic treatment (PDT) for food preservation require a holistic method to evaluate and compare different photosensitizer (PS)-light treatments. In this report, the absorbed photons were used as the basis to assess the antimicrobial photodynamic efficacy of two PSs, chlorophyllin sodium magnesium salt (Chl-Mg) and chlorophyllin sodium copper salt (Chl-Cu), under blue and white light against two typical foodborne pathogens, Gram-negative Escherichia coli, and Gram-positive Staphylococcus aureus. The results showed that the phototoxicity of a PS was predominantly decided by the absorbed photons rather than the characteristics of light sources. Photosensitized Chl-Mg exhibited superior antimicrobial activity as compared to that of ChlCu. The applied treatments were found to be more effective against S. aureus than E. coli. Bacterial inactivation kinetics as a function of the number of absorbed photons could be described by Weibull model with R² from 0.947-0.962, and kinetics constants D in the range of 0.202 × 10¹⁷ photons/cm²-2.409 × 10¹⁸ photons/cm². The kinetics models may find promising applications in the design, assessment, and optimization of PDT processes.

Emerging trends in the photodynamic inactivation (PDI) applied to the food decontamination

The food and drink manufacturing industry is constantly seeking for alternative sanitation and disinfection systems that may achieve the same antimicrobial efficiency of conventional chemical sanitisers and at the same time be convenient in terms of energy and water savings. A candidate technology for this purpose is the use of light in combination with photosensitisers (PS) to generate a bioactive effect against microbial agents in a process defined as photodynamic inactivation (PDI). This technology can be applied to the food processing of different food matrices to reduce the microbial load of foodborne pathogens such as bacteria, fungi, viruses and protozoa. Also, the PDI can be exploited to increase the shelf-life period of food by inactivation of spoiling microbes. This review analyses new developments in the last five years for PDI systems applied to the food decontamination from foodborne pathogens. The photosensitisation mechanisms and methods are reported to introduce the applied technology against microbial targets in food matrices. Recent blue light emitting diodes (LED) lamp systems for the PDI mediated by endogenous PS are discussed as well PDI technologies with the use of exogenous PS from plant sources such as curcumin and porphyrin-based molecules. The updated overview of the most recent developments in the PDI technology both in wavelengths and employed PS will provide further points of analysis for the advancement of the research on new competitive and effective disinfection systems in the food industry.

The effect of red and violet light emitting diode (LED) treatments on the postharvest quality and biodiversity of fresh-cut pakchoi (Brassica rapa L. Chinensis)

The effects of red and violet Light Emitting Diode (LED) irradiation on the quality changes of fresh cut pakchoi (Brassica rapa L.Chinensis), such as water migration, soluble solids, chlorophyll, ASA, shelf life, antioxidant enzyme activity and changes of biodiversity were evaluated in this study using physicochemical and high-throughput sequencing analys. The results showed that red and violet LED irradiation (15 μ mol/(m² · s)) (1) are significantly inhibited the changes of sensory evaluation, (2) increased the content of chlorophyll, ASA and antioxidant enzymes, and (3) prolonged the shelf life of pakchoi at 4 °C. Furthermore, through the using of high-throughput sequencing, aerobic plate count and the count of Pseudomonas spp., it was found that (4) red and violet LED changed the microbial community structure among samples, and inhibited the reproduction of specific spoilage organism (SSO) in fresh cut pakchoi. At the same time, compared with the traditional sterilization method, the results showed that visible light sterilization was also effective. In general, the results showed that LED treatment was an effective way to delay the senescence and maintain the quality of the pakchoi by enhancing the activity of antioxidant enzymes and regulating chlorophyll and ASA metabolism, inhibited the reproduction of SSO.

Antimicrobial Blue Light versus Pathogenic Bacteria: Mechanism, Application in the Food Industry, Hurdle Technologies and Potential Resistance

Blue light primarily exhibits antimicrobial activity through the activation of endogenous photosensitizers, which leads to the formation of reactive oxygen species that attack components of bacterial cells. Current data show that blue light is innocuous on the skin, but may inflict photo-damage to the eyes. Laboratory measurements indicate that antimicrobial blue light has minimal effects on the sensorial and nutritional properties of foods, although future research using human panels is required to ascertain these findings. Food properties also affect the efficacy of antimicrobial blue light, with attenuation or enhancement of the bactericidal activity observed in the presence of absorptive materials (for example, proteins on meats) or photosensitizers (for example, riboflavin in milk), respectively. Blue light can also be coupled with other treatments, such as polyphenols, essential oils and organic acids. While complete resistance to blue light has not been reported, isolated evidence suggests that bacterial tolerance to blue light may occur over time, especially through gene mutations, although at a slower rate than antibiotic resistance. Future studies can aim at characterizing the amount and type of intracellular photosensitizers across bacterial species and at assessing the oxygen-independent mechanism of blue light-for example, the inactivation of spoilage bacteria in vacuum-packed meats.

Understanding Escherichia coli damages after chlorophyllin-based photosensitization

Pathogenic strains of bacteria are causing various illnesses all around the world and have a major socio-economic impact. Thus, fast- and low-cost methods for the microbial control of foods are needed. One of them might be photosensitization. This study looks deeper into the mechanism of Escherichia coli damage by chlorophyllin-based photosensitization. Fluorimetric data indicate that after 15 minute incubation with chlorophyllin (Chl) (1.5 × 10^-5 M Chl) 0.73 ± 0.03 μM of this compound was associated with E. coli cell surface. After photoactivation (405 nm, 6-30 J/cm² ) significant reduction (88.2%) of bacterial viability was observed. Higher concentration of Chl (5 × 10^-4 M Chl) reduced viability of bacteria more than by 98%. Results indicated that reactive oxygen species (ROS) took place in this inactivation. Colloidal surface enhanced Raman scattering (SERS) spectroscopy was employed to detect the molecular changes in the treated bacteria. It was found that Chl-based based photosensitization triggers multiple surface structure changes in E. coli what induce lethal unrepairable damages and inactivation of pathogen.

Modelling the Inactivation and Possible Regrowth of Salmonella enterica Treated with Chlorophyllin-Chitosan Complex and Visible Light

The study focuses on predictive modelling of inactivation of Salmonella enterica after treatment with chlorophyllin-chitosan complex and visible light. Salmonella cells were incubated with chlorophyllin-chitosan complex (0.001% chlorophyllin and 0.1% chitosan) for different times (5-60 min) and then illuminated with visible light (λ=405 nm, H_e=38 J/cm²). Inactivation curves and post-treatment regrowth curves were built based on microbiological viability tests and data were fitted to ten inactivation and two regrowth models. The photoactivated complex reduced Salmonella population, which were unable to regrow. Weibull and Baranyi models were the best to describe the inactivation and regrowth kinetics respectively. In conclusion, data from the kinetic analysis and predictive modelling confirmed that photoactivated chlorophyllin-chitosan complex is a promising non-thermal approach for inactivation of Gram-negative pathogens, since no bacterial regrowth after treatment has been predicted.

An insight into curcumin-based photosensitization as a promising and green food preservation technology

Consumer awareness on the side effects of chemical preservatives has increased the demand for natural preservation technologies. An efficient and sustainable alternative to current conventional preservation techniques should guarantee food safety and retain its quality with minimal side effects. Photosensitization, utilizing light and a natural photosensitizer, has been postulated as a viable and green alternative to the current conventional preservation techniques. The potential of curcumin as a natural photosensitizer is reviewed in this paper as a practical guide to develop a safe and effective decontamination tool for industrial use. The fundamentals of the photosensitization mechanism are discussed, with the main emphasis on the natural photosensitizer, curcumin, and its application to inactivate microorganisms as well as to enhance the shelf life of foods. Photosensitization has shown promising results in inactivating a wide spectrum of microorganisms with no reported microbial resistance due to its particular lethal mode of targeting nucleic acids. Curcumin as a natural photosensitizer has recently been investigated and demonstrated efficacy in decontamination and delaying spoilage. Moreover, studies have shown the beneficial impact of an appropriate encapsulation technique to enhance the cellular uptake of photosensitizers, and therefore, the phototoxicity. Further studies relating to improved delivery of natural photosensitizers with inherent poor solubility should be conducted. Also, detailed studies on various food products are warranted to better understand the impact of encapsulation on curcumin photophysical properties, photo-driven release mechanism, and nutritional and organoleptic properties of treated foods.

Toward better microbial safety of wheat sprouts: chlorophyllin-based photosensitization of seeds

Sprouted seeds are gaining popularity worldwide due to their high nutritional value. At the same time, they are among the most highly contaminated fresh produce and have been recognized as the primary source of food-borne pathogens, such as E. coli O157 and harmful microfungi. The antifungal and antibacterial properties of chlorophyllin-based photosensitization in vitro together with successful application of this treatment for microbial control in wheat sprouts have been investigated. First, we examined the antimicrobial efficiency of chlorophyllin (Chl, 1.5 × 10-5-5 × 10-3 M) activated in vitro by visible light (405 nm, radiant exposure: 18 J cm-2) against the food-borne pathogen Escherichia coli and plant pathogen Fusarium oxysporum. Results revealed that this treatment (1.5 × 10-5 M Chl, incubation time 1 h, 405 nm, radiant exposure: 18 J cm-2) can reduce the E. coli population by 95%. Moreover, at higher chlorophyllin concentrations (5 × 10-4-5 × 10-3 M Chl), it is possible to delay the growth of F. oxysporum by 51-74%. The decontamination of wheat seeds by chlorophyllin-based photosensitization (5 × 10-4 M Chl, 405 nm, radiant exposure: 18 J cm-2) remarkably reduced the viability of surface-attached mesophilic bacteria (∼2.5log CFU g-1), E. coli (∼1.5log CFU g-1) and yeasts/fungi (∼1.5log CFU g-1). Moreover, SEM images confirmed that this treatment did not damage the grain surface microstructure. Most importantly, Chl-based photosensitization did not reduce the seed germination rate or seedling growth and had no impact on the visual qualities of sprouts. In conclusion, the chlorophyllin-based photosensitization treatment, being nonthermal, environmentally friendly and cost-effective, has huge potential for microbial control of highly contaminated germinated wheat sprouts and seeds used to produce sprouts, especially in organic farming.

Inactivation of molds on the surface of wheat sprouts by chlorophyllin-chitosan coating in the presence of visible LED-based light

The present study clearly demonstrated the significant antifungal activity of chlorophyllin-chitosan complex (Chl-CHS) after activation with visible light. This phenomenon afterwards was successfully applied for better microbial control of highly popular food- germinated wheat sprouts. Obtained results indicated that photoactivated Chl-CHS complex (0.001% Chl-0.1% CHS and 0.005% Chl-0.5% CHS, 405 nm, 76 J/cm²) considerably inhibited (83%) the growth of dominating sprout pathogenic microfungus Fusarium graminearum in vitro. Moreover, obvious delay of fungus growth by 4 days after treatment was observed. The efficiency of antifungal treatment strongly depended on used Chl-CHS complex concentration. The coating of wheat grains with Chl-CHS (0.005% Chl-0.5% CHS) and illumination with visible light (405 nm; 76 J/cm²) inactivated the molds on the surface of grains by 79%. It is important to note, that no grain surface microstructure damage observed by SEM imaging have been found. No inhibiting effects on seed germination process, viability, average weight of grains, length of seedlings and content of chlorophyll a and chlorophyll b in the seedlings or eventually visual quality after Chl-CHS coating of grains and illumination with visible light have been observed. In conclusion, chlorophyllin-chitosan coating in the concert with visible light has great potential as cost-effective, environmentally friendly and sustainable strategy for better microbial control of highly contaminated sprouts.

How protoporphyrinogen IX oxidase inhibitors and transgenesis contribute to elucidate plant tetrapyrrole pathway

Several families of herbicides, especially diphenyl ether (DPE) and pyrimidinedione, target the plant tetrapyrrole biosynthesis pathways and in particular one key enzyme, protoporphyrinogen IX oxidase (PPO). When plants are treated with DPE or pyrimidinedione, an accumulation of protoporphyrin IX, the first photosensitizer of this pathway, is observed in cytosol where it becomes very deleterious under light. Indeed these herbicides trigger plant death in two distinct ways: (i) inhibition of chlorophylls and heme syntheses and (ii) a huge accumulation of protoporphyrin IX in cytosol. Recently, a strategy based on plant transgenesis that induces deregulation of the tetrapyrrole pathway by up- or down-regulation of genes encoding enzymes, such as glutamyl-[Formula: see text]RNA reductase, porphobilinogen deaminase and PPO, has been developed. Against all expectations, only transgenic crops overexpressing PPO showed resistance to DPE and pyrimidinedione. This herbicide resistance of transgenic crops leads to the hypothesis that the overall consumption of herbicides will be reduced as previously reported for glyphosate-resistant transgenic crops. In this review, after a rapid presentation of plant tetrapyrrole biosynthesis, we show how only PPO enzyme can be the target of DPE and how transgenic crops can be further resistant not only to herbicide but also to abiotic stress such as drought or chilling. Keeping in mind that this approach is mostly prohibited in Europe, we attempt to discuss it to interest the scientific community, from plant physiologists to chemists, who work on the interface of photosensitizer optimization and agriculture.

Radioprotective properties of food colorant sodium copper chlorophyllin on human peripheral blood cells in vitro

Sodium copper chlorophyllin (CHL) is a food colorant that exhibits many beneficial properties, including potential for use in radiotherapy. Nevertheless, genotoxicity studies investigating radioprotective properties against γ-radiation on human cells are rather scarce. The aim of this study was to assess the cytotoxicity, genotoxicity and induction of malondialdehyde formation on CHL pre-treated whole blood cells after an absorbed dose of 5 Gy γ-radiation. Irradiated whole blood cells pre-treated with 100, 500, and 1000 μg/mL CHL showed less DNA-strand breaks (10.92 ± 0.74%, 10.69 ± 0.68%, and 8.81 ± 0.69%, respectively) than untreated irradiated cells (12.58 ± 0.88%). At the same time, the level of malondialdehyde was lower in CHL pre-treated samples with 100, 500, and 1000 μg/mL CHL (14.11 ± 0.43, 16.35 ± 2.82, and 13.08 ± 1.03 μmol/L, respectively) compared to untreated irradiated samples (24.11 ± 0.25 μmol/L). Regarding cytotoxicity, no changes were observed in the samples tested. Another important finding is that CHL had no cyto/genotoxic properties toward human blood cells. Taken together, since CHL had no cyto/genotoxic effects and showed good radioprotective properties in human blood cells, further studies should be conducted in order to find its possible application in radiotherapy.

Photoactivated Self-Sanitizing Chlorophyllin-Containing Coatings to Prevent Microbial Contamination in Packaged Food

Chlorophyllins are semi-synthetic porphyrins obtained from chlorophyll that—when exposed to visible light—generate radical oxygen substances with antimicrobial activity. In this work, chlorophyllins incorporated with polyethylene (PE), polyvinyl alcohol (PVOH), (hydroxypropyl)methyl cellulose (HPMC), and gelatin (G) were formulated for application as coatings in packages providing antimicrobial activity after photoactivation. First, the antimicrobial properties of two porphyrins (sodium magnesium chlorophyllin, E-140, and sodium copper chlorophyllin, E-141) were analyzed against L. monocytogenes and Escherichia coli. The results indicated that E-140 was more active than E-141 and that chlorophyllins were more effective against Gram-positive bacteria. In addition, both chlorophyllins were more efficient when irradiated with halogen lamps than with LEDs, and they were inactive in dark conditions. Then, coatings on polyethylene terephthalate (PET) film were prepared, and their effect against the test bacteria was similar to that shown previously with pure chlorophyllins, i.e., greater activity in films containing E-140. Among the coating matrices, those based on PE presented the least effect (1 log reduction), whereas PVOH, HPMC, and G were lethal (7 log reduction). The self-sanitizing effect of these coatings was also analyzed by contaminating the surface of the coatings and irradiating them through the PET surface, which showed high efficiency, although the activity of the coatings was limited to L. monocytogenes. Finally, coated films were applied as separators of bologna slices. After irradiation, all the films showed count reductions of L. monocytogenes and the usual microbial load; the gelatin coating was the most effective, with an average of 3 log reduction.