- 期刊
- OpenAccess
以手提式近紅外線分光光度計偵測梨的糖度與酸度
Determination of Sugar Content and Acidity of Pears by a Portable Near-Infrared Spectrophotometer
摘要
本研究之目的為探討以手提式近紅外線分光光度計在950-1650nm波長範圍偵測幸水梨及新世紀梨，並測定梨的糖度與酸度，以建立其校正線，達成以近紅外線分光光度計快速偵測梨品質，做為梨分級標價之參考。 試驗結果顯示梨之糖度近紅外線校正線以二次差分之校正線較佳。以PLSR模式建立之二次差分糖度校正線之相關係數(r)高達0.92，預測標準偏差(SEC)與驗證標準偏差(SEP)分別為0.48°Brix與0.49°Brix。以MLR模式選擇五個波長建立之二次差分糖度校正線之相關係數(r)高達0.92，SEC與SEP分別為0.48°Brix與0.50°Brix。此五個波長分別為970、1150、1200、1370及1590nm。經過均勻校正樣本之選取，並配合一次差分或二次差分處理，可有效提昇糖度校正線之預測準確度。 有關梨之酸度之近紅外線校正線，可能因為實驗所用之近紅外線光譜範圍內，對梨所含之酸並無明顯之吸收峰及試驗設備與方法等綜合影響，雖用上述相同的資料處理仍未能達到理想的校正線及預測結果，尚待繼續研究。
並列摘要
The objective of this research was to detect the quality of Sinwater pears and New-century pears by a portable near-infrared spectrophotometer in the wavelength range from 950nm to 1650nm, to analyse the sugar contents and acidity of pears by measurement, and to establish the calibration curves for quick detecting the pear quality for grading and price marking. The experimental results indicated the calibration curves of sugar contents in pears would be better with second difference treatment of spectra. For sugar contents, the calibration curve with PLSR models and second difference treatment had a 0.92 correlation coefficient with a 0.48° Brix SEC and a 0.49° Brix SEP, but with MLR models and second difference treatment had a 0.92 correlation coefficient with a 0.48° Brix SEC and a 0.50° Brix SEP at selected wavelengths of 970, 1150, 1200, 1370 and 1590nm. Uniform sample selection, first and second difference treatment were able to improve the prediction accuracy of calibration curves of sugar contents. For the calibration curves of acidity, some combined factors might affect the calibration curves such as no obvious absorption bands for acid within the experimental scope of near-infrared spectra, unsuitable experimental equipment and methods. Even after the same above mentioned data processing, the result still remained not quite acceptable. Therefore, further study may be required for better calibration and prediction.