Abstract

Raw edible bird's nest (EBN) either from human farming or naturally-harvested can be tainted by fell feathers, dusts of various sizes, fungi and bird feces. For local EBN farmers in Thailand, EBNs are manually cleaned by hand-picking. Due to elaborate cleaning process, experienced labour used approximately eight hours to properly clean three nests, excluding five hours of water immersion. In this work, ultrasonic waves of two frequencies, 37 and 80 kHz, are used together spiral fin, for turbulently stirring the water. An ultrasonic bath has the volume of 6 litres and temperature control is required to prevent EBN from being cooked in the bath. Soaked EBNs are then irradiated with ultrasonic waves for the designated frequencies and duration of ultrasonic exposure with the fin spinning or standing. The cleanliness of the nest is then measured using image processing technique. The taken images are then analysed to acquire the summation of pixel brightness (SPB) as it is used for the visual cleanliness representation. We find that our system improves the visual cleanliness of EBNs up to 30% as compared to those before ultrasonic exposure.