Yutaka Chuma

Simultaneous Measurement of Size, Surface Area, and Volume of Grains and Soybeans

ABSTRACT PHOTOGRAPHIC pictures of grains and soybeans screened on a shadowgraph were taken after being magnified ten times. Cartesian coordinates of the image profiles were read by a digitizer and logged into a micro-computer. The size, surface area and volume were calculated from the coordinates using Langranges inter-polation formula and Simpsons rule. Accuracy of the method was tested on specific shaped objects, cyclinder, sphere, ellipse and a sector. The error in the area estima-tion was found to be 0.5 percent for the sphere and was largest in the sector, at 1.6 percent. The shape of the ob-ject was found not to affect the accuracy of the estimated volume.

Maturity Evaluation of Bananas by Delayed Light Emission

ABSTRACT THE fundamental characteristics of the delayed light emission (DLE) of bananas, such as decay period, dark period, exciting time and illuminance, and fruit temperature were determined, and the changes of DLE due to ripening were investigated. Intensity of DLE had a high correlation with the ripening indices of bananas such as the hue of peel color, sugar content, and firm-ness. Hence, the intensity of DLE proved to be useful as a means of maturity evaluation of bananas.

Delayed Light Emission As a Means of Automatic Selection of Satsuma Oranges

ABSTRACT CONDITIONS effecting the delayed light emission (DLE) intensity were investigated for the Satsuma orange. DLE intensity indices were established for the fruit conditions such as peel temperature, chlorophyll con-tent, peel treatment in the packing house line (such as brushing or waxing), and correlated to the storage period for the purpose of providing an automatic mechanization of selecting process.

Cryogenic Properties of Fruits and Vegetables

ABSTRACT A computerized liquefied nitrogen gas spray freezer was constructed and was used for freezing seven kinds of fruits and vegetables. The materials were frozen between -20 °C and -150 °C. The frozen samples were tested for stiffness and breaking characteristics by a Universal Testing Machine. It was observed that the stiffness of the materials increased with decrease in the freezing temperature. The materials attained plastic equilibrium from -60 °C and below. From -60 °C and below, the materials started to break into smaller pieces whose number decreased with decrease in the freezing temperature.