In order to overcome the disadvantages of long drying time and large nutrient loss in the traditional baby cabbage drying process, high-humidity hot air impingement blanching (HHAIB) combined with air impingement drying (AID) technology was explored. The effects of different HHAIB blanching times (0-240 s), blanching temperatures (100-120 ℃) and subsequent AID drying temperatures (50-70 ℃) on drying kinetics, nutrient (ascorbic acid and total phenol) retention effects, antioxidant activities (DPPH radical scavenging rate and ferric reducing antioxidant power), key enzymatic activities (peroxidase and polyphenol oxidase), rehydration behavior and color change were systematically investigated. The results showed that, compared with the unblanched samples, the optimal HHAIB pre-treatment not only shortened the drying time by 40 minutes (17.4%), but also increased the ascorbic acid content and total phenolic content by 161.3% and 10.6%, respectively. Furthermore, the DPPH radical scavenging rate and ferric reducing antioxidant power were increased by 31.3%, and 20.1%, respectively. Meanwhile, by effectively inhibiting the activities of polyphenol oxidase and peroxidase, the good color in the dried product was maintained. A mathematical model was established using Box-Behnken response surface design with the comprehensive quality score calculated by the coefficient of variation method as the response value. The optimal process parameters were determined as blanching temperature of 114 ℃, blanching time of 110 s, and drying temperature of 61 ℃. The predicted comprehensive quality score of the model was 0.839 under this condition, and the experimental validation value was 0.847 ± 0.011, with an error of 0.944%, which verified the reliability of the model. The study aimed to provide a novel technical approach and basis for high-quality drying of leafy vegetables.

Listeria monocytogenes is a foodborne human pathogen responsible for severe listeriosis and poses a great threat to human health. Hence, controlling the growth of L. monocytogenes plays an important role in the prevention of food contamination. Listeria innocua is often studied experimentally as a substitute strain for L. monocytogenes. In order to better maintain the sensory properties and nutrients of foods and extend their shelf life, this study explored the antimicrobial effect and possible mechanism of high pressure processing (HPP) combined with lauroyl arginate ethyl ester hydrochloride (LAE) on L. innocua. The feasibility of applying the combined treatment as a preservative was also investigated in ham. The results showed that 12 mg/L LAE treatment for 60 minutes had a potent antimicrobial effect on L. innocua, achieving a bacterial reduction of 3.12 (lg (CFU/mL)). Under the combined action of HPP and LAE, the surface morphology of bacterial cells became more wrinkled and sunken, and intracellular contents leaked out, suggesting a severe change in cell membrane permeability. The combined treatment of HPP at 350 MPa for 5 min with 12 mg/L LAE reduced L. innocua count by 4.87 (lg (CFU/mL)), which was 3.25 and 3.54 (lg (CFU/mL)) higher than that achieved using HPP and LAE treatments alone, respectively, suggesting a synergistic antimicrobial effect. Such synergistic antimicrobial effect was also observed on ham inoculated with L. innocua. This study could provide a theoretical reference for controlling the contamination of foodborne pathogens in ready-to-eat meat products.