为探究冻融循环对食用菌预制菌汤的品质影响,本文以鲜菌汤为参照,对比了冻融过程中微生物数量、菌汤色泽、可溶性蛋白、还原糖、总酚含量等基本指标的变化,并基于超高效液相检测和气相色谱-质谱法分析冻融过程菌汤等鲜度和挥发性风味物...为探究冻融循环对食用菌预制菌汤的品质影响,本文以鲜菌汤为参照,对比了冻融过程中微生物数量、菌汤色泽、可溶性蛋白、还原糖、总酚含量等基本指标的变化,并基于超高效液相检测和气相色谱-质谱法分析冻融过程菌汤等鲜度和挥发性风味物质差异。研究表明,首次冻融大幅减少了菌汤的还原糖、总酚和总氨基酸含量,显著降低了菌汤等鲜度和挥发性成分含量,综合影响了菌汤的成分与风味。进一步通过冻融次数(1~5次)之间的对比,反复冻融3次菌汤可溶性蛋白含量相较于冻融1~2次显著降低(P<0.05),此外,等鲜度由1~2次冻融的0.441~0.450 g MSG/100 g直接下降至0.407 g MSG/100 g,同时微生物开始检出。在此后4~5次冻融过程中,虽然菌汤总酚、总氨基酸含量和等鲜度相对稳定,但核苷酸、可溶性蛋白和挥发性成分不断减少且菌落总数不断升高。因此,预制菌汤若需冻融处理则应控制在2次内为宜。展开更多
The study was to investigate the effects of different thawing temperatures(5,15,40,75,90 ℃) and times(1- 120 s) on properties of post-thaw cow semen by detecting frozen-thawed semen motility,acrosome integrity and ta...The study was to investigate the effects of different thawing temperatures(5,15,40,75,90 ℃) and times(1- 120 s) on properties of post-thaw cow semen by detecting frozen-thawed semen motility,acrosome integrity and tail membrane integrity,further obtaining the optimal thawing method of straw frozen semen from dairy cow. The results showed that(1) Thawing of the straw frozen semen of dairy cow at 75 ℃ for 3 s yielded the highest semen motility,followed by 40 ℃for 20 s,and the least by low temperature 5 ℃ and room temperature 15 ℃ with a semen motility of 0. 3,moreover thawing at high temperature 90 ℃ was not suitable for large scale production due to the difficult control of the temperature;(2) The acrosome intact rate and plasma membrane integrity rate of semens thawed at90 ℃ were remarkably lower than that at 40 ℃ and 75 ℃ significantly(P 【 0. 05),while its semen malformation rate was significantly higher than that at 40 ℃and 75 ℃(P 【 0. 05);(3) The Survival time of semens at 37 ℃ varied largely among different thawing temperature,in detail by 40 ℃ 】 75 ℃ 】 90 ℃. In practice,the thawing method of straw frozen semen of dairy cow should be selected according to the specific circumstance and inseminated immediately,with the recommended condition of thawing at 75 ℃ for 3 s. If the thawed semen could not be inseminated immediately,the thawing should be performed at 20 s for 40 ℃to maintain the motility for a longer term.展开更多
The aim was to discuss the optimal storage environment and proper insemination time after thawing of 0.25 mL straw frozen semen. Straw frozen semen was thawed at 40 ℃ for 20 s, and then stored at 0 -4 ℃, 14 - 16 ℃,...The aim was to discuss the optimal storage environment and proper insemination time after thawing of 0.25 mL straw frozen semen. Straw frozen semen was thawed at 40 ℃ for 20 s, and then stored at 0 -4 ℃, 14 - 16 ℃, 25 -27 ℃ for 2, 4, 6, 8 and 10 h, respectively. The sperm motility was detected. After thawing, semen was stored at 0 - 4 ℃ and 14 - 16 ℃ for 10 h. Their sperm motilities （0.434 ±0. 016 7 and 0.423 ±0.019 6） had no significant differences （P 〉 0.05） with initial thawing motility （0.441 ± 0.030）. Sperm motility reduced as the storage time prolonged at 25 -27 ℃. Sperm motility after 6 h had signifi- cant differences with that of initial thawing motility （P 〈 O. 05 ）, and sperm motilities after 8 and 10 h showed extremely significant differences （P 〈 0.01 ）. Thus, sperm motility after thawing was still very high after stored at 0 -4 ℃ and 14 - 16 ℃ within 10 h, which met the requirements for insemination. Under this temperature and time ranges, sperm could be carried over long distances, which had small effects on sperm quality and reached the expected insemination effects. However, under the temperature of 25 - 27 ℃, semen should be used for insemination within 6 h after thawing.展开更多
以罗非鱼为研究对象,分别在不同真空度条件:15、12、9、6、3和0.8 k Pa进行解冻(样品温度从-20℃升为4℃),测定解冻时间、解冻损失率及解冻后鱼片的TBA值、K值和p H,进而筛选真空解冻罗非鱼片的最佳工艺条件。实验结果表明:与空气解冻相...以罗非鱼为研究对象,分别在不同真空度条件:15、12、9、6、3和0.8 k Pa进行解冻(样品温度从-20℃升为4℃),测定解冻时间、解冻损失率及解冻后鱼片的TBA值、K值和p H,进而筛选真空解冻罗非鱼片的最佳工艺条件。实验结果表明:与空气解冻相比,真空解冻缩短解冻时间,且真空度越大解冻时间越短;其中9 k Pa真空条件下解冻时间仅为30 min,解冻损失率为-0.04%,TBA值为0.097 mg/100 g,K值为7.15%,p H为6.60,均显著优于其他实验组(p<0.05)。即9 k Pa真空条件解冻罗非鱼片时间短,汁液损失少,脂肪氧化程度较小,鲜度较高,整体品质较高,能较好地保持罗非鱼片的品质。展开更多
文摘为探究冻融循环对食用菌预制菌汤的品质影响,本文以鲜菌汤为参照,对比了冻融过程中微生物数量、菌汤色泽、可溶性蛋白、还原糖、总酚含量等基本指标的变化,并基于超高效液相检测和气相色谱-质谱法分析冻融过程菌汤等鲜度和挥发性风味物质差异。研究表明,首次冻融大幅减少了菌汤的还原糖、总酚和总氨基酸含量,显著降低了菌汤等鲜度和挥发性成分含量,综合影响了菌汤的成分与风味。进一步通过冻融次数(1~5次)之间的对比,反复冻融3次菌汤可溶性蛋白含量相较于冻融1~2次显著降低(P<0.05),此外,等鲜度由1~2次冻融的0.441~0.450 g MSG/100 g直接下降至0.407 g MSG/100 g,同时微生物开始检出。在此后4~5次冻融过程中,虽然菌汤总酚、总氨基酸含量和等鲜度相对稳定,但核苷酸、可溶性蛋白和挥发性成分不断减少且菌落总数不断升高。因此,预制菌汤若需冻融处理则应控制在2次内为宜。
基金Supported by the Technical Development and Demonstration Program of Beijing Vocational College of Agriculture(XY-YF-14-20)Agricultural S&T Program from Beijing Municipal Agricultural Commission(20140146)Non-staple Food Project from Beijing Municipal Agricultural Commission(20140204-7)
文摘The study was to investigate the effects of different thawing temperatures(5,15,40,75,90 ℃) and times(1- 120 s) on properties of post-thaw cow semen by detecting frozen-thawed semen motility,acrosome integrity and tail membrane integrity,further obtaining the optimal thawing method of straw frozen semen from dairy cow. The results showed that(1) Thawing of the straw frozen semen of dairy cow at 75 ℃ for 3 s yielded the highest semen motility,followed by 40 ℃for 20 s,and the least by low temperature 5 ℃ and room temperature 15 ℃ with a semen motility of 0. 3,moreover thawing at high temperature 90 ℃ was not suitable for large scale production due to the difficult control of the temperature;(2) The acrosome intact rate and plasma membrane integrity rate of semens thawed at90 ℃ were remarkably lower than that at 40 ℃ and 75 ℃ significantly(P 【 0. 05),while its semen malformation rate was significantly higher than that at 40 ℃and 75 ℃(P 【 0. 05);(3) The Survival time of semens at 37 ℃ varied largely among different thawing temperature,in detail by 40 ℃ 】 75 ℃ 】 90 ℃. In practice,the thawing method of straw frozen semen of dairy cow should be selected according to the specific circumstance and inseminated immediately,with the recommended condition of thawing at 75 ℃ for 3 s. If the thawed semen could not be inseminated immediately,the thawing should be performed at 20 s for 40 ℃to maintain the motility for a longer term.
基金Supported by the Technology Research and Demonstrational Popularization Project of Beijing Vocational College of Agriculture(XY-YF-15-07)(XY-YF-14-21)
文摘The aim was to discuss the optimal storage environment and proper insemination time after thawing of 0.25 mL straw frozen semen. Straw frozen semen was thawed at 40 ℃ for 20 s, and then stored at 0 -4 ℃, 14 - 16 ℃, 25 -27 ℃ for 2, 4, 6, 8 and 10 h, respectively. The sperm motility was detected. After thawing, semen was stored at 0 - 4 ℃ and 14 - 16 ℃ for 10 h. Their sperm motilities （0.434 ±0. 016 7 and 0.423 ±0.019 6） had no significant differences （P 〉 0.05） with initial thawing motility （0.441 ± 0.030）. Sperm motility reduced as the storage time prolonged at 25 -27 ℃. Sperm motility after 6 h had signifi- cant differences with that of initial thawing motility （P 〈 O. 05 ）, and sperm motilities after 8 and 10 h showed extremely significant differences （P 〈 0.01 ）. Thus, sperm motility after thawing was still very high after stored at 0 -4 ℃ and 14 - 16 ℃ within 10 h, which met the requirements for insemination. Under this temperature and time ranges, sperm could be carried over long distances, which had small effects on sperm quality and reached the expected insemination effects. However, under the temperature of 25 - 27 ℃, semen should be used for insemination within 6 h after thawing.
文摘以罗非鱼为研究对象,分别在不同真空度条件:15、12、9、6、3和0.8 k Pa进行解冻(样品温度从-20℃升为4℃),测定解冻时间、解冻损失率及解冻后鱼片的TBA值、K值和p H,进而筛选真空解冻罗非鱼片的最佳工艺条件。实验结果表明:与空气解冻相比,真空解冻缩短解冻时间,且真空度越大解冻时间越短;其中9 k Pa真空条件下解冻时间仅为30 min,解冻损失率为-0.04%,TBA值为0.097 mg/100 g,K值为7.15%,p H为6.60,均显著优于其他实验组(p<0.05)。即9 k Pa真空条件解冻罗非鱼片时间短,汁液损失少,脂肪氧化程度较小,鲜度较高,整体品质较高,能较好地保持罗非鱼片的品质。
