Determination of the Internal Damage of Purple Sweet Potatoes Non-Destructively Using Ultrasonic Wave Characteristics

Abstract

This study aimed to analyze the ultrasonic wave characterization of Ayamurasaki purple sweet potatoes to predict the internal damage caused by weevil attack non-destructively. Sixty of health and 45 of infected purple sweet potatoes from farmers in Ciampea, Bogor were used for the experiment. Sample divided into 2 groups, the first group of 2/3 part was used in developing the model, and the second group of 1/3 part was used for validation. Ultrasonic wave characterization of purple sweet potatoes that harvested was tested using ultrasonic wave measurement apparatus with 50 KHz frequency. The result shows that the average wave velocity of infected purple sweet potatoes was 247.32 ms-1 and Mo value was 19.45, while the wave velocity of healthy purple sweet potatoes was 235.15 ms-1 and Mo value was 18.72. The average attenuation coefficient of infected purple sweet potatoes was 40.06 Np/m, while in health purple sweet potatoes was 42.69 Np/m. The result of discriminant analysis obtained a linear discriminant model that can distinctly separate between health and infected purple sweet potatoes. Accuracy of this grouping was high enough, around 85.71% so that the discriminant function can be used for grouping the health and infected purple sweet potatoes