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

激光多普勒法水果成熟度及品质测定系统的研制

基本信息

批准号：
12556006
负责人：
SAKURAI Naoki
金额：
$ 8.77万
依托单位：
HIROSHIMA UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2002
项目状态：
已结题

项目摘要

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.

振动模态的确认表明，水果的弹性和粘度是根据二次共振时的振动峰计算的。用软件进行了计算，使我们能够通过弹性和粘度自动评价水果的软化程度。这也促使我们以每0.1秒的速度进行高速选择水果的程序。细胞壁多糖的分析表明，果胶多糖的降解导致果实软化过程中粘度降低，木聚糖的降解导致弹性降低。在6个苹果品种中，有4个品种的果实硬度与磁力-泰勒仪测定结果呈极显著相关。甲基溴处理导致苹果果肉内褐变。LDV可以检测到其内部缺陷。像“La France”这样的梨在收获后成熟时表现出弹性的双阶段下降，就像猕猴桃一样。低温贮藏时，梨的弹性变化规律为单相下降。通常在低温条件下储存两周后，果肉会变成一种具有特色的融化质地，这是消费者最喜欢的。LDV检测不出梨成熟过程中的溶化结构。为了检测梨的融化纹理，我们开发了一种新的多功能测量系统，称为AMC（声学测量脆度）。将探针插入水果果肉中检测到的振动进行监测，并通过快速傅立叶变换将其转换为频谱。AMC方法可以评价水果的脆度，也可以检测梨和甜瓜的融化质地。利用主成分分析法，对LDV法获得的数据进行了脆度计算。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，如融化纹理。