foods Article Real-Time Gauging of the Gelling Maturity of Duck Eggs Pickled in Strong Alkaline Solutions Ching-Wei Cheng 1, Kun-Ming Lai 2,3, Wan-Yu Liu 4 , Cheng-Han Li 5 , Yu-Hsun Chen 6 and Chien-Chung Jeng 6,* 1 College of Intelligence, National Taichung University of Science and Technology, Taichung 404, Taiwan;
[email protected] 2 Department of Health Industry Technology Management, Chung Shan Medical University, Taichung 402, Taiwan;
[email protected] 3 Department of Nutrition, Chung Shan Medical University Hospital, Taichung 402, Taiwan 4 Department of Forestry, National Chung Hsing University, Taichung 402, Taiwan;
[email protected] 5 Department of Bio-Industrial Mechatronics Engineering, National Chung Hsing University, Taichung 402, Taiwan;
[email protected] 6 Department of Physics, National Chung Hsing University, Taichung 402, Taiwan;
[email protected] * Correspondence:
[email protected]; Tel.: +886-4-2284-0427 (ext. 718) Abstract: Although many ultraviolet-visible-near-infrared transmission spectroscopy techniques have been applied to chicken egg studies, such techniques are not suitable for duck eggs because duck eggshells are much thicker than chicken eggshells. In this study, a high-transmission spectrometer using an equilateral prism as a dispersive element and a flash lamp as a light source was constructed to nondestructively detect the transmission spectrum of duck eggs and monitor the pickling of eggs. The evolution of egg transmittance was highly correlated with the albumen during pickling. The Citation: Cheng, C.-W.; Lai, K.-M.; transmittance exponentially decays with time during this period, and the decay rate is related to Liu, W.-Y.; Li, C.-H.; Chen, Y.-H.; Jeng, C.-C.