Preparation of carboxymethyl chitosan/double-formaldehyde cellulose based hydrogel loaded with ginger essential oil nanoemulsion for meat preservation.

An antibacterial nano-hydrogel (ginger essential oil nanoemulsion hydrogel, GEONH) based on Schiff base reaction was prepared using double-formaldehyde micro fibrillated cellulose (DAMFC) and carboxymethyl chitosan (CMCS) loaded with ginger essential oil nanoemulsion (GEON). It was found that when the mass ratio of DAMFC/CMCS/GEON was 1/9/270, the gel time, the water absorbency, gel strength, and morphology were the best. The results of X-ray diffraction and FT-IR confirmed that the aldehyde group on the DAMFC molecular chain formed a stable chemical crosslinking with the amino group on the CMCS molecular chain, resulting in a change in the crystal structure. GEONH showed excellent bactericidal activity against Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. Simultaneously, the prepared GEONH decreased the total viable count, Malondialdehyde, and total sulfhydryl content and improved the taste in the storage of boiled salted duck. Therefore, GEONH film is a promising fresh-keeping packaging for storing meat products. Supplementary Information: The online version contains supplementary material available at 10.1007/s10068-023-01437-4.

Novel PVA/carboxylated cellulose antimicrobial hydrogel grafted with curcumin and ε-polylysine for chilled chicken preservation.

PVA/CC/CUR/PL composite films containing curcumin (CUR) and ε-polylysine (PL) were prepared by casting and chemical grafting methods to address the threat to food spoilage. Morphological analysis showed that the grafting of CUR and PL resulted in a rough cross-section of the polymer matrix. Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analysis confirmed the grafting of CUR and PL into the polymer matrix via esterification and amidation reactions, respectively. Thermal weight loss analysis showed that grafting process positively improved the thermal stability. The PVA/CC/CUR/PL films exhibited strong bactericidal activity, reaching 99.0% and 99.8% for Pseudomonas lundensis and Shewanella putrefaciens, respectively. After 8 days of storage, the total number of colonies and the TVB-N content in the PVA/CC/CUR/PL group decreased by 1.51 lg CFU/g and 13.77 mg/100 g, respectively. Therefore, PVA/CC/CUR/PL films are considered as a promising bactericidal material with good mechanical properties, functionality, and other excellent characteristics.

Dual-mode sensor based on the synergy of magnetic separation and functionalized probes for the ultrasensitive detection of Clostridium perfringens.

Clostridium perfringens is an important foodborne pathogen, which has caused serious public health problems worldwide. So, there is an urgent need for rapid and ultrasensitive detection of C. perfringens. In this paper, a dual-mode sensing platform using the synergy between fluorescent and electrochemical signals for Clostridium perfringens detection was proposed. An electrochemical aptasensor was constructed by a dual-amplification technology based on a DNA walker and hybridization chain reaction (HCR). When the C. perfringens genomic DNA was present, it specifically bonded with FAM-labeled aptamer which triggered the DNA walker on hairpin DNA (hDNA) tracks to start the synthesis of double-stranded DNA. HCR occurred subsequently and produced long-chain DNA to absorb more methylene blue (MB). In this cycle, the fluorescent signals of released FAM-labeled aptamer could also be detected. The synergistic effects of MB and FAM significantly improved the sensitivity and accuracy of the dual-mode sensor. As a result, the biosensor displayed an excellent analytical performance for C. perfringens at a concentration of 1 to 108 CFU g-1. A minimum concentration of 1 CFU g-1 and good accuracy were detected in real samples. The proposed ultrasensitive detection method for detecting C. perfringens in food showed great potential in controlling foodborne diseases.

Mathematical Modeling of the Effects of Temperature and Modified Atmosphere Packaging on the Growth Kinetics of Pseudomonas Lundensis and Shewanella Putrefaciens in Chilled Chicken.

The effects of modified atmosphere packaging (MAP) on the growth and spoilage characteristics of Pseudomonas lundensis LD1 and Shewanella putrefaciens SP1 in chilled chicken at 0-10 °C were studied. MAP inhibited microbial growth, TVB-N synthesis, and lipid oxidation. The inhibitory effect of MAP became more significant as the temperature decreased. The kinetic models to describe the growth of P. lundensis LD1 and S. putrefaciens SP1 at 0-10 °C were also established to fit the primary model Gompertz and the secondary model Ratkowsky. The models had a high degree of fit to describe the growth of dominant spoilage bacteria in chilled chicken. The observed numbers of P. lundensis LD1 and S. putrefaciens SP1 at 2 °C were compared with the predicted numbers, and the accuracy factor and bias factor ranged from 0.93 to 1.14. These results indicated that the two models could help predict the growth of P. lundensis and S. putrefaciens in chilled chicken at 0-10 °C. The analyzed models provide fast and cost-effective alternatives to replace traditional culturing methods to assess the influence of temperature and MAP on the shelf life of meat.