Menaquinone-7 (MK-7) provides significant health gains due to its excellent pharmacokinetic properties. However, MK-7 occurs at low concentrations in mainstream foods, heightening the demand for nutritional supplements. MK-7 exists as geometric isomers, and only all-trans MK-7 is bioactive. Exposure to certain environments impacts the isomer profile. Knowledge of these factors and their influence on the isomer composition is important, as the efficacy of fermented MK-7 end products is solely determined by the all-trans isomer. This investigation aimed to evaluate the short- and long-term effect of atmospheric oxygen, common temperatures, and light on the isomer profile. From the short-term study, it was ascertained that MK-7 is moderately heat-stable but extremely light-sensitive. The stability of all-trans MK-7 was then examined during 8 weeks of storage at a low temperature with minimal oxygen exposure in the absence of light. Negligible change in the all-trans MK-7 concentration occurred, suggesting it is reasonably stable during prolonged storage in this environment. These findings will aid the development of optimal storage conditions to preserve bioactive MK-7 in fermented nutritional supplements, the large-scale availability and consumption of which will help compensate for the dietary deficit of this essential vitamin and provide consumers with better health outcomes.

中文翻译：

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Menaquinone-7 的发酵：环境因素和储存条件对异构体特征的影响

Menaquinone-7 (MK-7) 因其优异的药代动力学特性而具有显着的健康益处。然而，主流食品中 MK-7 的浓度较低，这增加了对营养补充剂的需求。MK-7以几何异构体存在，只有全反式MK-7具有生物活性。暴露于某些环境会影响异构体特征。了解这些因素及其对异构体组成的影响非常重要，因为发酵 MK-7 最终产品的功效仅由全反式异构体决定。这项研究旨在评估大气中的氧气、常见温度和光对异构体谱的短期和长期影响。通过短期研究，确定MK-7具有中等热稳定性，但对光极其敏感。然后在低温、无光、氧气暴露最少的情况下储存 8 周，检查全反式 MK-7 的稳定性。全反式 MK-7 浓度的变化可以忽略不计，表明在这种环境下长期储存期间它相当稳定。这些发现将有助于开发最佳储存条件，以保存发酵营养补充剂中的生物活性 MK-7，其大规模供应和消费将有助于弥补这种必需维生素的饮食不足，并为消费者提供更好的健康结果。