摘要
采用20MHz低场核磁共振弛豫谱分析技术检测苹果不同部位的蔗糖含量,研究含糖量与核磁共振信号之间的关系;利用CPMG序列来测溶液的T2值,得到含糖量和溶液中所含糖信号量的定标线,并用此定标线对苹果不同部位的含糖量进行定量分析。实验结果表明:含糖量的多少不仅影响自由感应衰减信号(free-induction decay signal,FID)的大小,而且影响其横向弛豫时间(T2)和纵向弛豫时间(T1);随着含糖量的升高,样品的自由感应衰减信号呈线性增大(r2>0.94);靠近果核部位的苹果组织含糖量最高,靠近果皮的最低,这与核磁共振波谱分析测试的结果相同,证明了此标线的可行性和准确性。
A 20 MHz nuclear magnetic resonance(NMR) system was used to measure the NMR relaxation spectrum in different parts of the apple and studied the relationship between sugar content and NMR signal.Moreover,the Carr-Purcell-Meiboom-Gill(CPMG) technique was used to measure T2and control the water signal in manganese chloride aqueous solution.Then,the calibration line was used to test the sugar content in apple tissues.Finally,a calibration line of the sugar content and the value of sugar signal were determined.The results show that sugar content influences not only FID but also transverse relaxation time and longitudinal relaxation time;FID signal increases with the increasing of sugar content and the relationship is linear(r2>0.94); tissues close to the core have the highest sugar content and close to the skin are the lowest,this results are the same as the NMR spectrum analysis and prove the feasibility and veracity of the calibration line.
出处
《中国测试》
CAS
北大核心
2014年第4期33-36,共4页
China Measurement & Test
基金
国家质检公益行业科研资助项目(201210079)
