排序方式: 共有98条查询结果,搜索用时 31 毫秒
81.
为探索快速测定还原糖含量的方法,提出了用傅立叶变换近红外光谱技术结合偏最小二乘法(PLS)建立近红外光谱与蜂蜜还原糖含量的数学模型并进行预测。通过光谱扫描还原糖含量在61.3%~75.22%范围的蜂蜜样本,选择11992.1~7494.6cm-1波数范围、二阶导数、及10个因子数进行光谱预处理,偏最小二乘法(PLS)交叉验证。结果表明,模型的校正决定系数(Rcal)、校正均方差(RMSEE)、交叉验证决定系数(RCV)、交叉验证均方差(RMSECV)分别为99.71%、0.27%、98.44%、0.45%。用该模型对验证集样本进行预测并统计分析,表明预测值与测定值无显著差异。因此,用该方法快速准确定量分析大批蜂蜜中的还原糖含量具有重要意义。 相似文献
82.
83.
蜂花粉总黄酮检测方法的研究 总被引:11,自引:2,他引:9
黄酮类化合物因具有多种生物活性而成为目前天然产物研究的热点。本研究通过三种检测方法的比较,确定了聚酰胺-UV法为蜂花粉总黄酮的测定方法,其检测波长为360nm,以芦丁为标准品,在0.005~0.025mg/ml范围内,其浓度与吸光度呈良好的线性关系,相关系数R2为0.9998,平均回收率分别为95.53%,稳定性、精密度和重现性均理想,其RSD分别为2.124%(n=3)、0.488%(n=3)、0.875%(n=5)。该法检测油菜蜂花粉中总黄酮含量为1.54%。 相似文献
84.
85.
86.
研究了蜂花粉与蜂王浆中葡萄糖、果糖、蔗糖和麦芽糖的离子色谱分析方法。样品用热水溶解,乙腈沉降蛋白,使用2个固相萃取小柱去除色素与脂肪等干扰成分后,以CarboPac PA10分析柱为色谱柱,氢氧化钠和乙酸钠溶液为流动相进行离子色谱分离。葡萄糖、果糖、蔗糖和麦芽糖的检出限分别为0.12,0.14,0.21,0.33mg/L。蜂花粉的回收率93.5%~102.2%,精密度为4.4%~6.3%,蜂王浆的回收率为95.0%~103.5%,精密度为6.7%~10.2%。利用该方法对20个蜂花粉和20个蜂王浆样品进行了分析,花粉中葡萄糖含量为9.9%~20.6%,果糖14.2%~26.9%,蔗糖1.8%~8.3%,麦芽糖0.33%~1.4%;王浆中葡萄糖含量为6.2%~8.3%,果糖7.0%~8.7%,蔗糖0.38%~3.6%,麦芽糖0.27%~0.83%。该方法简单、灵敏度高,可作为标准方法对蜂花粉与蜂王浆中葡萄糖、果糖、蔗糖和麦芽糖进行分析。 相似文献
87.
Sha Yan Liming Wu Xiaofeng Xue 《Comprehensive Reviews in Food Science and Food Safety》2023,22(2):1387-1417
α-Dicarbonyl compounds (α-DCs) are readily produced during the heating and storage of foods, mainly through the Maillard reaction, caramelization, lipid-peroxidation, and enzymatic reaction. They contribute to both the organoleptic properties (i.e., aroma, taste, and color) and deterioration of foods and are potential indicators of food quality. α-DCs are also important precursors to hazardous substances, such as acrylamide, furan, advanced lipoxidation end products, and advanced glycation end products, which are genotoxic, neurotoxic, and linked to several diseases. Recent studies have indicated that dietary α-DCs can elevate plasma α-DC levels and lead to “dicarbonyl stress.” To accurately assess their health risks, quantifying α-DCs in food products is crucial. Considering their low volatility, inability to absorb ultraviolet light, and high reactivity, the analysis of α-DCs in complex food systems is a challenge. In this review, we comprehensively cover the development of scientific approaches, from extraction, enrichment, and derivatization, to sophisticated detection techniques, which are necessary for quantifying α-DCs in different foods. Exposure to α-DCs is inevitable because they exist in most foods. Recently, novel strategies for reducing α-DC levels in foods have become a hot research topic. These strategies include the use of new processing technologies, formula modification, and supplementation with α-DC scavengers (e.g., phenolic compounds). For each strategy, it is important to consider the potential mechanisms underlying the formation and removal of process contaminants. Future studies are needed to develop techniques to control α-DC formation during food processing, and standardized approaches are needed to quantify and compare α-DCs in different foods. 相似文献
88.
蜂王浆具有延缓衰老的功效,对多种条件造成的肾脏损伤也具有一定的保护作用,但蜂王浆是否具有延缓衰老引起的肾脏功能衰退的作用尚不清楚。为研究蜂王浆对衰老小鼠肾脏的作用,以SPF级昆明小鼠为研究对象,50只小鼠(雌雄各一半)分为5组,对照组注射和灌胃生理盐水;另外4组注射D-半乳糖建立小鼠衰老模型的同时,衰老模型组灌胃生理盐水,2个阳性对照组分别灌胃维生素E和六味地黄丸,实验组灌胃蜂王浆,实验期持续90d。研究通过肾脏指数、肾脏病理组织切片、血液尿素氮和肌酐水平评价小鼠的肾脏功能情况,通过总抗氧化能力和超氧化物歧化酶水平评价组织的抗氧化能力;利用非靶标血清代谢组解析蜂王浆调控的主要代谢物和代谢通路。结果表明:衰老小鼠肾脏发生明显变化,肾小囊囊腔明显扩张,肾小球球体萎缩;血液尿素氮、肌酐水平显著上升,总抗氧化能力和超氧化物歧化酶水平显著下降;灌胃维生素E、六味地黄丸和蜂王浆均能不同程度地缓解肾脏生理功能和抗氧化能力的下降,而蜂王浆和六味地黄丸更加明显地减轻了小鼠肾脏病变。衰老小鼠血清代谢结果显示,与六味地黄丸组相比,蜂王浆调控的代谢途径更具有针对性,主要在氨基酸代谢、能量代谢和脂质代谢途径发挥调控作用;与模型组相比,蜂王浆组雌雄小鼠分别有308和343种代谢物发生了显著变化,分别富集在19和15条代谢通路上,这些代谢通路主要涉及抗氧化、提高能量供应和维持肾脏基本功能方面。结果表明,蜂王浆对D-半乳糖致衰老小鼠的肾脏具有较好的保护作用,研究旨在为进一步应用蜂王浆开发功能性食品提供理论依据。 相似文献
89.
以烟曲霉(Aspergillus fumigatus)CEA-1701为生产菌株,通过高效液相色谱(HPLC)法测定发酵液中烟曲霉素的含量,考察碳源、pH值、搅拌速度、发酵温度和接种量对5 L发酵罐中烟曲霉素产量的影响,优化了5 L罐的发酵工艺条件。结果表明,甘油作为唯一的碳源,发酵温度30 ℃,搅拌速度800 r/min,接种量为3%,自然pH条件下,通气量0.5 m3/h,烟曲霉CEA-1701产烟曲霉素效果理想,发酵168 h烟曲霉素产量达到97.76 mg/L。将优化后的工艺进行20 L罐的放大试验,0.5%接种量发酵252 h时烟曲霉素获得最高产量达到130.57 mg/L,中试放大效果良好。 相似文献
90.