3种紫外辐照处理食用菌粉中维生素D2及麦角甾醇热稳定性分析

Thermal Stability of Vitamin D and Ergosterol in Three Edible Mushrooms Powder Treated by UV Irradiation

食用菌通过紫外辐照处理,维生素D2(vitamin D2,VD2)含量大幅度提高,可作为补充维生素D的功能食品和普通食品的重要天然原料。为进一步考察以食用菌粉为载体的VD2热稳定性,比较紫外辐照处理的金针菇、平菇和香菇在40、60、80、100、120℃不同温度下处理20、40、60、90、120 min,以及115℃高压湿热灭菌处理15 min后VD2和其前体麦角甾醇的含量变化,同时对热处理样品进行色差分析。结果表明以食用菌粉为载体的VD2热稳定性较差,且对3种食用菌的影响程度和变化规律不尽相同。其中对香菇的影响最大,在100℃处理40、60、90、120 min时,VD2的存留率分别为82.30%、65.68%、46.27%和32.54%;在120℃处理20 minVD2的存留率仅为36.08%,处理40 min VD2的损失率为100%。在120℃处理40、60、90、120 min时,麦角甾醇的存留率分别为74.60%、54.66%、33.83%和21.82%;对于金针菇,在100、120℃处理2 h,VD2的存留率为84.16%和46.94%,麦角甾醇的存留率为67.47%和49.14%;对于平菇,在100、120℃处理2 h,VD2的存留率为74.82%和56.91%,麦角甾醇的存留率为57.80%和51.70%。在115℃湿热灭菌15 min下,香菇中的VD2全部损失,平菇和金针菇中VD2的存留率为18.28%和47.34%。香菇和金针菇分别在60℃和80℃及更高温度处理下,其干粉△L值与对照处理相比均极显著降低。研究结果为富含VD2的食用菌产品开发及膳食应用提供了重要的理论基础和数据支撑。

The content of vitamin D2(VD2)in edible mushroom could be enhanced by application of UV irradiation,and thus could be used as an important natural material of functional food and common food to supplement vitamin D. In order to further investigate the thermal stability of VD2 in mushroom powder,content of and its precursor ergosterol in Flammulina velutipes,Pleurotus ostreatus and Lentinus edodes powders treated by UV irradiation under different temperatures(40,60 80,100,120 ℃)and different times(20,40,60,90,120 min),as well as sterilized at 115 ℃ for 15 min,the chromatic difference analysis was also carried out. The results showed that the VD2 thermal stability in mushroom powders was not well and differed from mushrooms. For shiitake mushroom,the effect was the largest. The retention rate of VD2 were 82.30 %,65.68 %,46.27 % and32.54 % when treated at 100 ℃ for 40,60,90,120 min,respectively. The retention rate of VD2 was 36.08 %and 100 % when treated at 120 ℃ for 20 min and 40 min. The retention rate of ergosterol were 74.60 %,54.66 %,33.83 %,and 21.82 % when treated at 120 ℃ for 40,60,90,120 min,respectively. For enoki mushroom when treated at 100 ℃ and 120 ℃ for 2 h,the retention rate of VD2 were 84.16 % and 46.94 %,the retention rate of ergosterol were 67.47 % and 49.14 %,respectively. For oyster mushroom when treated at 100 ℃ and 120 ℃ for2 h,the retention rate of VD2 were 74.82 % and 56.91 %,the retention rate of ergosterol were 57.80 % and51.70 %,respectively. After sterilizing at 115 ℃ for 15 min,VD2 in shiitake mushroom was all lost,and the retention rate of VD2 in oyster mushroom and enoki mushroom were 18.28 % and 47.34 %,respectively. When treated at 60 ℃,80 ℃ and higher temperatures,the △L value of dry shiitake mushroom and enoki mushroom were significantly reduced compared with the control. The results provided important theoretical basis and data support for the development and dietary application of enriched VD2 edible mushrooms.