In order to put forward countermeasures and suggestions of reform and innovation on the supply system of preschool education in China,the current change process of China’s preschool education supply system is analyze...In order to put forward countermeasures and suggestions of reform and innovation on the supply system of preschool education in China,the current change process of China’s preschool education supply system is analyzed using the historical analysis method.It is believed that there are still some outstanding problems in the supply system of the preschool education in China at present.According to the theory of supply and demand balance of economics and institutional change theory of new institutional economics,the future trend of China’s preschool education supply system is also analyzed.展开更多
为探索不同热加工方式的贻贝在加热过程中的品质变化,本研究以厚壳贻贝为对象,考察沸水加热(boiling water heating,BH)、蒸汽加热(steam heating,SH)、微波加热(microwave heating,MH)、真空隔水加热(vacuum water bath heating,VH)和...为探索不同热加工方式的贻贝在加热过程中的品质变化,本研究以厚壳贻贝为对象,考察沸水加热(boiling water heating,BH)、蒸汽加热(steam heating,SH)、微波加热(microwave heating,MH)、真空隔水加热(vacuum water bath heating,VH)和空气循环加热(air circulation heating,AH)5种热加工方式对其汁液损失率、色泽、质构特性的影响,通过苏木精-伊红(hematoxylin-eosin,HE)染色、扫描电镜(scanning electron microscopy,SEM)观察微观组织结构的变化,并对其蛋白质特性及结构进行测定。结果表明,随着加热时间的延长,5种处理组汁液损失率、a^(*)值、b^(*)值、硬度、弹性、内聚性、咀嚼性不断上升,而L^(*)值先上升后下降。HE染色和SEM结果表明,随着加热时间的延长,5种处理组组织中肌纤维间隙加大,并出现不同程度的断裂,当加热时间为3 min时,VH组贝肉组织中肌纤维完整性较好。凝胶电泳结果表明了贝肉在热加工过程中蛋白组分随加热时间延长均发生了不同程度地热降解及聚集。热加工过程中,5种处理组β-折叠、无规卷曲相对含量随着加热时间延长均先上升后趋向平稳,而肌原纤维蛋白提取率、Ca^(2+)-ATP酶活力、α-螺旋相对含量、β-转角相对含量随着加热时间延长均先下降后趋于平稳。其中在加热前期,MH和AH组肌原纤维蛋白提取率、Ca^(2+)-ATP酶活力、α-螺旋相对含量、β-转角相对含量均高于BH、SH和VH组。综上所述,从食用品质并结合实际情况综合考虑,SH和VH是厚壳贻贝较为适宜的热加工方式,其中在加热2 min时贝肉的品质相对较好。该研究结果可为贝类产品加工的品质控制及发展提供参考。展开更多
文摘In order to put forward countermeasures and suggestions of reform and innovation on the supply system of preschool education in China,the current change process of China’s preschool education supply system is analyzed using the historical analysis method.It is believed that there are still some outstanding problems in the supply system of the preschool education in China at present.According to the theory of supply and demand balance of economics and institutional change theory of new institutional economics,the future trend of China’s preschool education supply system is also analyzed.
文摘为探索不同热加工方式的贻贝在加热过程中的品质变化,本研究以厚壳贻贝为对象,考察沸水加热(boiling water heating,BH)、蒸汽加热(steam heating,SH)、微波加热(microwave heating,MH)、真空隔水加热(vacuum water bath heating,VH)和空气循环加热(air circulation heating,AH)5种热加工方式对其汁液损失率、色泽、质构特性的影响,通过苏木精-伊红(hematoxylin-eosin,HE)染色、扫描电镜(scanning electron microscopy,SEM)观察微观组织结构的变化,并对其蛋白质特性及结构进行测定。结果表明,随着加热时间的延长,5种处理组汁液损失率、a^(*)值、b^(*)值、硬度、弹性、内聚性、咀嚼性不断上升,而L^(*)值先上升后下降。HE染色和SEM结果表明,随着加热时间的延长,5种处理组组织中肌纤维间隙加大,并出现不同程度的断裂,当加热时间为3 min时,VH组贝肉组织中肌纤维完整性较好。凝胶电泳结果表明了贝肉在热加工过程中蛋白组分随加热时间延长均发生了不同程度地热降解及聚集。热加工过程中,5种处理组β-折叠、无规卷曲相对含量随着加热时间延长均先上升后趋向平稳,而肌原纤维蛋白提取率、Ca^(2+)-ATP酶活力、α-螺旋相对含量、β-转角相对含量随着加热时间延长均先下降后趋于平稳。其中在加热前期,MH和AH组肌原纤维蛋白提取率、Ca^(2+)-ATP酶活力、α-螺旋相对含量、β-转角相对含量均高于BH、SH和VH组。综上所述,从食用品质并结合实际情况综合考虑,SH和VH是厚壳贻贝较为适宜的热加工方式,其中在加热2 min时贝肉的品质相对较好。该研究结果可为贝类产品加工的品质控制及发展提供参考。
