NIR Spectroscopy and Chemometrics Study on Non-Destructive Evaluation in New Cooking System

Introduction
In new cooking systems, such as vacuum packed pouch cooking, standardizations of taste and nutrition are important. In this study, the NIR spectroscopy was applied to evaluate the completion state of the Taro by vacuum cooking.
Experimental
The frozen taros (globular form, medium size, from China) were purchased. The 50% (w/w) of two types (rich and light tastes) of commercial liquid seasonings were used to the cooking with purchased frozen taro in vacuum packed pouch. A portable “Fruits Selector” Kubota K-BA100R was used for the NIR measurements. The destructive measurements of sugar and salt concentrations were performed for portions of central surface parts of the vacuum cooked taros. The chemometorics analyses were carried out by the Unscrambler-X (Camo) for classification and presumption of sugar and salt contents by PCA and PLS methods.
Results and discussion
The obtained NIR spectra show the spectral change in progressing of osmosis accompanying preservation, suggesting a potential of nondestructive evaluation of osmosis condition for vacuum cooked taros by NIR. The PLS calibration plot of the NIR sugar content versus conventional method for two types of commercial liquid seasonings is calculated. Although R2 coefficients of determination were slightly low in this PLS plot, this result indicates that the sugar concentration of center in taros is determined by NIR method without unpacking.