Curcumin-mediated photodynamic treatment extends the shelf life of salmon (Salmo salar) sashimi during chilled storage: Comparisons of preservation effects with five natural preservatives

Reduction of biofilm and pathogenic microorganisms using curcumin-mediated photodynamic inactivation to prolong food shelf-life

Pathogenic microbial contamination (bacteria and fungi) in food products during production poses a significant global health risk, leading to food waste, greenhouse gas emissions, and aesthetic and financial losses. Bacteria and fungi, by forming solid biofilms, enhance their resistance to antimicrobial agents, thereby increasing the potential for cross-contamination of food products. Curcumin molecule-mediated photodynamic inactivation (Cur-m-PDI) technology has shown promising results in sterilizing microbial contaminants and their biofilms, significantly contributing to food preservation without compromising quality. Photosensitizers (curcumin) absorb light, leading to a chemical reaction with oxygen and producing reactive oxygen species (ROS) that effectively reduce bacteria, fungi, and biofilms. The mechanism of microorganism inhibition is caused by exposure to ROS generated via the type 1 pathway involving electron transfer (such as O2•-, H2O2, -OH•, and other radicals), the type 2 pathway involving energy transfer (such as 1O2), secondary ROS, and weakening of antioxidant enzymes. The effectiveness of the inactivation of microorganisms is influenced by the concentration of curcumin, light (source type and energy density), oxygen availability, and duration of exposure. This article reviews the mechanism of reducing microbial food contamination and inhibiting their biofilms through Cur-m-PDI. It also highlights future directions, challenges, and considerations related to the effects of ROS in oxidizing food, the toxicity of PDI to living cells and tissues, conditions/types of food products, and the stability and degradation of curcumin.

Effects of quaternization sites and crossing methods on the slow-release and antibacterial effects of hydroxypropyltrimethyl ammonium chloride chitosan/dialdehyde chitosan-based film

In this study, the active food packaging film were prepared using hydroxypropyltrimethyl ammonium chloride chitosan with different substitution sites (O-HACC & N-HACC) and dialdehyde chitosan (DCS) grafted with protocatechuic acid (PA). To explore the effect of chitosan quaternization positions and crosslinking approaches on the slow-release and antibacterial properties, the double-crosslinked film were fabricated through the self-coupling reaction of PA and Schiff base reaction between amino groups on HACC and aldehyde groups on DCS. The HACC/DCS-based film exhibited stable porous three-dimensional networks with high nisin loading ratios (>90 %). With the participation of the catechol-catechol structure, the dense double-crosslinked film effectively restricted the diffusion of the water molecules, resulting in excellent slow-release properties fitting with the Korsmeyer-Peppas kinetic model. Especially, O-HACC/PA-g-DCS film, which had more reaction sites for Schiff base crosslinking than N-HACC, exhibited the equilibrium swelling ratio of 800 % at 60 h and could sustainably release nisin via non-Fickian diffusion behavior until 48 h. Moreover, the HACC/DCS-based double-crosslinked film performed good long-time antibacterial activity and preservation effects on salmon. On the 10th day of storage, the TVBN of N-HACC/PA-g-DCS and O-HACC/PA-g-DCS groups were only 28.26 ± 1.93 and 29.06 ± 1.68 mg/100 g and still lower than the thresholds.

Photodynamic inactivation of edible photosensitizers for fresh food preservation: Comprehensive mechanism of action and enhancement strategies

Foodborne harmful bacteria not only cause waste of fresh food, but also pose a major threat to human health. Among many new sterilization and preservation technologies, photodynamic inactivation (PDI) has the advantages of low-cost, broad-spectrum, energy-saving, nontoxic, and high efficiency. In particular, PDI based on edible photosensitizers (PSs) has a broader application prospect due to edible, accessible, and renewable features, it also can maximize the retention of the nutritional characteristics and sensory quality of the food. Therefore, it is meaningful and necessary to review edible PSs and edible PSs-mediated PDI, which can help to arouse interest and concern and promote the further development of edible PSs-mediated PDI in the future field of nonthermally sterilized food preservation. Herein, the classification and modification of edible PSs, PS-mediated in vivo and PS-mediated in vitro mechanism of PDI, strengthening strategy to improve PDI efficiency by the structure change synergistic and multitechnical means, as well as the application in fresh food preservation were reviewed systematically. Finally, the deficiency and possible future perspectives of edible PSs-mediated PDI were articulated. This review aimed to provide new perspective for the future food preservation and microbial control.

Novel Halogenated Curcumin-Mediated Photodynamic Inactivation for the Preservation of Small Yellow Croaker (Larimichthys polyactis)

A novel class of halogenated curcumin, X-Cur (X = F, Cl, or Br), was synthesized, and its photosensitivity was evaluated. The results showed that Br-Cur with the highest singlet oxygen (1O2) generation capacity exhibited a better photodynamic inactivation (PDI) effect on the small yellow croaker (Larimichthys polyactis) than curcumin. This was attributed to the heavy atom effect of Br, which resulted in Br-Cur having the smallest singlet-triplet energy difference ΔEst(S1-T3) (0.140 eV) and the largest spin-orbit coupling value (0.642262 cm-1). When L. polyactis was treated with 0.025 wt % Br-Cur and exposed to blue LED irradiation (450 nm, 20 mW/cm2) for 20 min, the increase in the total volatile basic nitrogen content (28.23 ± 2.38 mg/100 g on day 6), pH, and total viable count (6.13 ± 0.06 log CFU/g on day 6) could be effectively controlled. Accordingly, Br-Cur is a promising photosensitizer for PDI preservation.

Chitosan-based packaging films with antibacterial-sterilization integrated continuous activity for extending the shelf life of perishable foods

The current food packaging films can be preservative but lack the function of combining antibacterial and sterilization which lead to films can not maximize prolong shelf life of perishable foods. This study provided a new strategy to realize prolonging shelf life of perishable foods by integrating antibacterial and sterilization which focused on applying photodynamic inactivation to films with continuous activity, where curcumin (CUR) and sodium copper chlorophyll (SCC) were loaded into chitosan (CS) films. Compared to pure CS films, the barrier capacity (oxygen permeability and water vapor permeability) and mechanical properties of composite films were improved by introducing CUR and SCC. In addition, the composite film can effectively against food-borne pathogenic bacteria and significantly prolong the shelf life of cherries and pork. The provided strategy has potential application prospects in food preservation packaging.

Research on Food Preservation Based on Antibacterial Technology: Progress and Future Prospects

The nutrients present in food are not only prone to a series of physicochemical reactions but also provide conditions for the growth and reproduction of foodborne microorganisms. In recent years, many innovative methods from different fields have been introduced into food preservation, which extends the shelf life while maximizing the preservation of the original ingredients and properties of food. In this field, there is a lack of a systematic summary of new technologies emerging. In view of this, we overview the innovative methods applied to the field of food preservation in recent 3 years, focusing on a variety of technological approaches such as antimicrobial photodynamic therapy based on nanotechnology, electromagnetic radiation sterilization based on radiation technology, and antimicrobial peptides based on biomolecules. We also discuss the preservation mechanism and the application of the different methods to specific categories of products. We evaluated their advantages and limitations in the food industry, describing their development prospects. In addition, as microorganisms are the main causes of food spoilage, our review also has reference significance for clinical antibacterial treatment.

Curcumin-loaded food-grade nano-silica hybrid material exhibiting improved photodynamic effect and its application for the preservation of small yellow croaker (Larimichthys polyactis)

Two types of curcumin-loaded food-grade nano-silica (F-SiO2) hybrid materials were successfully synthesized using the rotary evaporation method (F-SiO2@Cur) and the adsorption method (Cur@F-SiO2). The microstructure and spectral analyses confirmed that the curcumin in F-SiO2@Cur was loaded within the nanopores in a non-aggregate form rather than being adsorbed onto the surface (Cur@F-SiO2). Additionally, F-SiO2@Cur exhibited remarkable water solubility (1510 ± 50.33 µg/mL) and photostability (a photodegradation ratio of only 59.22 %). Importantly, F-SiO2@Cur obtained a higher capacity for the generation of singlet oxygen (1O2) compared to control groups. Consequently, F-SiO2@Cur-mediated photodynamic inactivation (PDI) group attained the highest score in sensory evaluation and the best color protection effect in PDI experiment of small yellow croaker (Larimichthys polyactis) at 4 °C. Moreover, F-SiO2@Cur could effectively controlled total volatile basic nitrogen (TVB-N) content, pH, and total viable count (TVC), thereby prolonging the shelf life. Therefore, F-SiO2@Cur-mediated PDI is an effective fresh-keeping technology for aquatic products.

Antibacterial efficiency of the curcumin-mediated photodynamic inactivation coupled with L-arginine against Vibrio parahaemolyticus and its application on shrimp

The aim of this study was to investigate the antibacterial potency of a novel photodynamic inactivation (PDI) system with an enhanced bactericidal ability against Vibrio parahaemolyticus in vitro and in vivo. The synergistically bactericidal action of curcumin (Cur) and L-arginine (L-Arg) was firstly investigated, and then a novel curcumin-mediated PDI coupled with L-Arg was developed. Meanwhile, its potent inactivation mechanism against V. parahaemolyticus and preservation effects on shrimp were explored. Results showed that L-Arg disrupted the cell membrane by binding to membrane phospholipids and disrupting iron homeostasis, which helped curcumin to damage DNA and interrupt protein synthesis. Once irradiated by blue LED, the curcumin-mediated PDI produced the reactive oxygen species (ROS) which reacted with L-Arg to generate NO, and the NO was converted to reactive nitrogen species (RNS) with a strong bactericidal ability by consuming ROS. On this basis, the curcumin-mediated PDI coupled with L-Arg potently killed >8.0 Log CFU/mL with 8 μM curcumin, 0.5 mg/mL L-Arg and 1.2 J/cm2 irradiation. Meanwhile, this PDI also effectively inhibited the colour and pH changes, lipids oxidation and protein degradation of shrimp. Therefore, this study proposes a new potent PDI system to control microbial contamination in the food industry.