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

Abstract

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.

Latest Advances in Preservation Technology for Fresh Fruit and Vegetables

“…This Special Issue aimed to collect the latest trends in diverse mechanisms of fresh product preservation and covered six chemical treatments: 1-Methylcyclopropene (1-MCP) [ 1 ], calcium chloride (CaCl 2 ) [ 2 ], melatonin [ 3 ], hydrogen sulfide (H 2 S) [ 4 ], essential oils [ 5 ], lactic acid and acetic acid [ 6 ], in a broader postharvest quality attribute. Other treatments, such as cold shock, modified atmospheric packaging [ 7 ], and chlorophyllin-based photodynamic inactivation [ 8 ], were utilized in postharvest conditions.…”

“…Concerning another physical treatment, chlorophyllin-based photodynamic inactivation (ChI-PDI) affects the storage quality of pakchoi ( Brassica rapa subsp. chinensis ) [ 8 ]. The report demonstrated that chlorophyllin (1 × 10 –5 mol L −1 and 405 nm light (22.27 J cm −2 per day)) treatment improved quality indicators, including vitamin C, total soluble solids and color preservation.…”

“…The chlorophyllin treatment possibly attacked bacterial extracellular polysaccharides and extracellular proteins in vegetables. Hence, ChI-PDI is effectively used for fresh-cut preservation and displays good antimicrobial properties [ 8 ].…”

Antimicrobial Resistance: Is There a ‘Light’ at the End of the Tunnel?

“…Blue light at 400–415 nm in itself has been shown to elicit significant antimicrobial effects without requiring exogenous photosensitizer ([ 43 ], see below; Section 2.2 ) and it has been explored in aPDT research. Studies have used blue light within this narrow spectral region in combination with chlorophyllin [ 71 ], chlorin e6 [ 72 ], protoporphyrin IX [ 73 ], or delta-aminolevulinic acid (5-ALA) [ 74 ] to eliminate microbes from food products, in in vitro cultures, and in vivo in pre-clinical infections and is even applied clinically to manage acne vulgaris [ 75 ]. Longer wavelength blue light (450 nm) in combination with curcumin has been used to treat dental infections [ 76 ].…”