Nondairy fermented products, such as fruit and vegetable juices, are gaining popularity among consumers worldwide for health-related and economic reasons. The purpose of this study was to determine the changes in microbiological quality; antimicrobial and antioxidant activity; and phenolic, vitamin C, minerals, and cadmium content occurring during spontaneous fermentation of curly kale juice. The fermentation process contributed to a significant growth of lactic acid bacteria, enterococci, and yeasts, while no pathogens of Escherichia coli and Salmonella spp. were observed. The antimicrobial properties of the obtained juice improved during fermentation for all indicator microorganisms. Total phenolic content and antioxidant activity increased from 48 to 116 mg gallic acid equivalent/100 mL and from 4.5 to 6.8 mM Trolox/100 mL, respectively, while the content of vitamin C decreased. The results indicated that 100 mL of juice provided a significant contribution to the recommended mineral intake. Moreover, the content of heavy metal Cd was within acceptable limit (6 µg/kg). Overall, our findings indicate that fermented curly kale juice may become popular in the functional food sector, especially among vegetarians and consumers with lactose intolerance or allergy to milk proteins. PRACTICAL APPLICATION: As the market for fermented fruit and vegetable products grows, new plant materials rich in biologically active compounds are being sought. Considering the high demand for sauerkraut, the fermentation of other cruciferous vegetables seems interesting. One example is curly kale, which has been classified as "superfood" due to its numerous beneficial health properties, such as strong antioxidant activity, high vitamins, and minerals content. In addition, a market niche exists due to a lack of fermented green curly kale products on the market, making our study particularly relevant.

中文翻译：

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自发发酵羽衣甘蓝汁：微生物质量、营养成分、抗氧化和抗菌特性

由于健康和经济原因，非乳制品发酵产品，如水果和蔬菜汁，在全球消费者中越来越受欢迎。本研究的目的是确定微生物质量的变化；抗菌和抗氧化活性；羽衣甘蓝汁自发发酵过程中产生的酚类、维生素 C、矿物质和镉含量。发酵过程促进了乳酸菌、肠球菌和酵母菌的大量生长，而没有大肠杆菌和沙门氏菌的病原体。被观察到。对于所有指示微生物，在发酵过程中获得的汁液的抗菌特性得到改善。总酚含量和抗氧化活性分别从 48 至 116 mg 没食子酸当量/100 mL 和从 4.5 至 6.8 mM Trolox/100 mL，而维生素C的含量却下降了。结果表明，100 毫升果汁对推荐的矿物质摄入量有显着贡献。此外，重金属 Cd 的含量在可接受的范围内（6 µg/kg）。总的来说，我们的研究结果表明，发酵甘蓝汁可能会在功能性食品领域流行起来，尤其是在素食者和乳糖不耐症或对牛奶蛋白过敏的消费者中。实际应用：随着发酵水果和蔬菜产品市场的增长，人们正在寻找富含生物活性化合物的新植物材料。考虑到对酸菜的高需求，其他十字花科蔬菜的发酵似乎很有趣。一个例子是羽衣甘蓝，由于其众多有益的健康特性，它被归类为“超级食品”，如强抗氧化活性、高维生素和矿物质含量。此外，由于市场上缺乏发酵的绿色羽衣甘蓝产品，因此存在市场利基，这使我们的研究特别相关。