Abstract
We developed an innovative non-contact optical viscosity sensing technique, laser-induced capillary wave (LiCW) using pulsed near-infrared heating laser, to measure liquid food viscosity in the measurement time of millisecond. With volume heating using near-infrared wavelength as a heating source, it was confirmed that nano-scale capillary wave can be induced within temperature rise of mK order. Then, we measured viscosities of liquid food sample (mixed milk and lemon juice) for cottage cheese manufacturing process, which is not required fermentation and ripening process. This result showed that we successfully detected viscosity change varied minute to minute due to the liquid separation (cheese and whey).
