摘要
以富平尖柿为材料,利用相关分析、回归分析和主成分分析法,在0.1~3 980 kHz频段范围内的24个频率点上系统地研究了柿果实采后成熟衰老过程中6个电学指标与4个品质指标之间的关系,筛选出了能够用于柿果实无损检测的特征频率和敏感电参数。结果表明,不同频率下复阻抗（Z）、串联等效电阻（Rs）、并联等效电容（Cp）、并联等效电感（Lp）、电导率（σ）和损耗角（Deg）与品质指标的相关性存在明显差异,在398kHz下品质指标与电参数的综合相关性最好,398 kHz可作为尖柿果实采后品质无损检测的特征频率。在特征频率下将各品质指标与特征频率下与其相关性达到显著水平和极显著水平的电参数进行多元逐步回归,在回归方程中,仅用Z就可以反映出尖柿果实采后果肉硬度和可滴定酸含量的变化,Rs和Cp可以反映可溶性固形物和可溶性单宁含量的变化,其标准化残差分析值均在（-2,2）区间内,表明利用电参数Z、Rs和Cp来预测尖柿果实采后不同贮藏时间的品质指标具有很好的可靠性和准确性。Z、Rs和Cp可作为标志尖柿果实成熟衰老过程中品质指标变化的敏感电参数。当尖柿果实采后并联等效电容Cp大于2.66 nF时,尖柿果实已经完全脱涩。
With Fuping persimmon fruit as research material,using analysis of correlation,analysis of regression and principal component analysis,the relation between six electrical parameters and four quality indexes were studied comprehensively at 24 frequencies in the range of 0.1~3980 kHz to find the characteristic frequency and the sensitive electrical parameters that could be used in nondestructive inspection.The results of experimentation indicated that the correlation between complex impedance Z,Paiallel equivalent resistance Rs,parallel equivalent capacitance Cp,conductivity σ and complex impedance angle Deg and quality indexes had obvious discrepancy at different frequency.At 398 kHz,the integrated correlation of quality indexes and electrical parameters was the best.The characteristic frequency of 398 kHz can be used for detecting electrical parameters of persimmon fruit after harvest.Quality indexes and electrical parameters with the significant correlation（P0.05 or 0.01） between them at the characteristic frequency were conducted multiple stepwise regression analysis.Only used Z could reflect the variation of firmness and titratable acid content of persimmon fruit in the regression equations.Rs and Cp could reflect the variation of total soluble solids content and soluble tannin content.The standard residual values were all in the interval（-2,2）.These indicated that using Z,Rs and Cp to forecast the quality indexes of different storage days had good accuracy and reliability.Z,Rs and Cp could be used as the sensitive electrical parameters that indicate mature and senescence of postharvest persimmon fruit.When the quantitative value of parallel equivalent capacitance Cp greater than 2.66 nF,the persimmon fruit was complete de-astringency.
出处
《西北农业学报》
CAS
CSCD
北大核心
2010年第9期80-87,共8页
Acta Agriculturae Boreali-occidentalis Sinica
基金
国家自然科学基金项目(30471001)
关键词
尖柿
电激频率
电学指标
果实品质指标
数学分析
Persimmon
Electric excitation frequency
Electrical parameters
Fruit quality indexes
Mathematical analysis
