Development of the pungency measuring system for red-pepper powder

摘要

Many researchers have been tried to find a rapid pungency measuring method for the capsaicinoids, the main component of spicy to overcome the disadvantages of the conventional HPLC measurement which is labor-intensive, time-consuming, and expensive. In this research, an on-line based pungency measuring system for red-pepper powder was developed using a UV/Visible/Near-Infrared spectrometer with the wavelength range of 400 ~ 1050 nm. The system was constructed with a charge-couple device(CCD) spectrometer, a reference measuring unit, and a sample transfer unit. Predetermined non-spicy red-pepper powder were mixed with spicy one (var. Chungyang) to produce samples with a wide range of spicy levels. Total 33 different samples with 11 spicy levels and three particle size(below 0.425 mm, 0.425 ~ 0.71 mm, 0.71 ~ 1.4 mm) were prepared for measurements. The Partial Least Square Regression Model (PLSR model) was developed to predict the capsaicinoids content with the obtained spectra using the developed pungency measuring system and compared with the results measured by HPLC. The best result of PLSR model (R2 = 0.979, SEP = ± 6.56 mg%) was achieved for the spectra of red-pepper powders of the particle size below 1.4 mm with a pretreatment of smoothing with a 6.5 nm wavelength gap. The results show the potential of NIRS technique for non-destructive and on-line measurement of capsaicinoids content in red-pepper powder.