Development of measuring system of maturity and quality of fruits by laser Doppler method

振动模式的确认表明，水果的弹性和粘度是由二次共振时的振动峰计算的。编制了计算软件，可根据弹性和粘度自动评价水果的软化程度。这也促使我们进行每0.1秒高速选择水果的程序。细胞壁多糖的分析表明，在果实软化过程中，果胶多糖的降解导致粘度下降，木葡聚糖的降解导致弹性下降。在6个苹果品种中，有4个品种的硬度值与激光多普勒振动仪（LDV）测定的硬度值呈极显著正相关。溴甲烷处理引起苹果内部果肉布朗宁。LDV可以检测到其内部缺陷。像'法国'梨表现出双相性下降的弹性在成熟后收获，就像猕猴桃。在冷藏条件下，梨的弹性变化为单相下降。通常，当它们在寒冷条件下储存2周时，果肉变成最受消费者喜爱的特征融化质地。LDV检测不到梨成熟过程中的融化质地。为了检测梨的融化质地，我们开发了一种新的多功能测量系统，称为AMC（声学脆度测量）。将探头插入水果果肉中，对水果的振动进行监测，并利用快速傅立叶变换将其转换成频谱。AMC法可用于评价水果的脆度，也可用于检测梨和甜瓜的融化质地。利用主成分分析法，我们试图从LDV法获得的数据计算脆度。以梨为材料，多元回归分析表明LDV数据可以检测梨的果肉品质，如融化质地。

Confirmation of vibration mode has revealed that the elasticity and viscosity of fruits was calculated from the vibration peak at second resonance. Software was made for the calculation and it enables us to evaluate automatically the softening of fruits by elasticity and viscosity. It also prompted us to proceed the program for high-speed selection of fruits at every 0.1 second. Analysis of cell wall polysaccharides suggests that degradation of pectic polysaccharides results in the viscosity decrease and that of xyloglucan in elasticity decrease during fruit softening. Among 6 apple cultivars, we got a high significant correlation between fruit firmness evaluated by Mageness-Taylor type device and that by laser Doppler vibrometry (LDV) in 4 cultivars. Methyl bromide treatment causes browning of interior flesh of apple. LDV could detect its interior defects. Pears like 'La France' showed biphasic decrease in elasticity during maturity after harvest, just like a kiwifruit. When the pears are stored under cold condition, the pattern of changes in elasticity reaches mono-phasic decrease. Usually when they are stored for 2 weeks under cold condition, the flesh becomes a characteristic melting texture that is most acceptable for consumers' favorite. LDV could not detect the melting texture during pear maturity. In order to detect the melting texture in pears, we developed a new versatile measuring system, called AMC (acoustic measurement of crispness). Vibration detected by the probe that is introduced into the flesh of fruits is monitored and transferred into frequency spectrum by fast Fourier transfer. AMC method could evaluate degree of crispness of fruits and it also detect the melting texture in pears and melon. Using principal component analysis, we tried to calculate the crispness from the data obtained by LDV method. Using pears as material, multiple regression analysis revealed that LDV data could detect the flesh quality such as melting texture.