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Chard, collard greens, and kale juices as representative dark leafy green vegetable juices (DLGVJs) have gained increasing attention due to their rich nutritional profiles and health-promoting properties. Conventional dark leafy green vegetables (DLGVs) represent the majority of the DLGV market; however, the microbial changes in conventional DLGVJs during refrigerated storage remain poorly understood. This study aimed to characterize the microbial profiles of fresh and spoiled conventional DLGVJs using both culture-dependent and culture-independent methods, alongside monitoring physicochemical changes (pH and color) over 21 days of refrigerated storage. Results showed a general decrease in pH and a shift toward more saturated color in all DLGVJs. Initial aerobic plate counts (APC) in chard, collard greens, and kale juices were 7.71 ± 0.03, 7.57 ± 0.14, and 7.61 ± 0.09 Log CFU/mL, respectively, while fungal populations were 5.85 ± 0.03, 6.01 ± 0.15, and 6.15 ± 0.03 Log CFU/mL. APC showed an overall decrease while fungal populations exhibited an initial increase followed by a decline during refrigerated storage. High-throughput sequencing revealed Pseudomonas , Leuconostoc , and Periweissella as core spoilage-associated bacterial genera, while Sporobolomyces , Alternaria , and Symmetrospora were predominant fungal genera in spoiled conventional DLGVJs. Although microbial compositions showed similarities between conventional and organic DLGVJs, distinct microbial communities were observed, with some taxa uniquely associated with a specific cropping system. The dominant lactic acid bacteria isolated from DLGVJs were identified as Enterococcus faecium and Leuconostoc mesenteroides . These findings advance our understanding of microbial ecology in DLGVJs and provide a scientific basis for developing targeted interventions to ensure microbial quality and safety, supporting the growth of the DLGVJ market.
Guo et al. (Wed,) studied this question.