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This study evaluates the effect of multimodal ultrasound on the extraction efficiency and immunoregulatory activity of polysaccharides from Lepidium meyenii Walp. (LMP). The separation and purification of maca polysaccharides were investigated by the DEAE-52 cellulose column, and the monosaccharide compositions were identified by HPGPC. Their immune activity was analyzed by the secretion of cytokines (TNF-α and IL-6) from RAW 264.7 macrophage. The results showed that the optimal extraction conditions were energy aggregation alternation dual-frequency ultrasound (EADU) with frequency combinations of 20/35, extraction time of 15 min, material/water ratio of 1:10 g/mL, ultrasonic power intensity of 150 W/L, intermittent time ratio of 4 s/3 s, and extraction temperature of 50 ℃. The extraction rates of purified polysaccharides (US3) increased by 44.90%. The LMP extracted by EADU contained arabinose, galactose, and glucose in the molar ratios of 2.9:2.72:5.05. In addition, US3 promoted the release of TNF-α and IL-6 from RAW 264.7 better than RS3 (purified polysaccharides extracted by hot water), which indicated that US3 exerted remarkable immune activity. It could be an excellent functional additive in food or medicine. 相似文献
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以玛卡为碳源,采用水热法制备荧光碳点。碳点水溶液在激发波长为315 nm时,最大荧光发射波长为425 nm。在玛卡荧光碳点的磷酸盐缓冲液(0.2 mol/L,pH 5.8)中,加入苦味酸,其荧光被猝灭,基于此建立了以玛卡荧光碳点为荧光探针测定苦味酸的方法。本方法检测苦味酸的线性范围为0.4~80 mmol/L,相关系数为0.9978,检出限为110 nmol/L(S/N=3),本方法线性范围宽、灵敏度高、响应快(2 min内),选择性和抗干扰能力良好。用于实际水样中苦味酸的检测,加标回收率为92.0%~110.0%,结果令人满意。 相似文献
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