This study proposed a method using hyper-spectral imaging technology in determining eggs' quality in term of freshness from a biochemical perspective by estimating the S-ovalbumin content. This method has the potential in assessing eggs' quality rapidly and non-destructively. Hyper-spectral image of egg was captured using a hyper-spectral imaging system and regression model was built to estimate the S-ovalbumin content. The successive projections algorithm (SPA) was used to select significant wavebands followed by building a partial least squares regression (PLSR) model and a multiple linear regression (MLR) model. The MLR model could predict S-ovalbumin content better than PLSR model with a higher correlation coefficient (0.922) and lower root mean square error (0.086) of the calibration set, a higher correlation coefficient (0.911) and lower root mean square error (0.119) of the validation set, and a higher residual predictive deviation (2.348). The regression equation from the MLR model was used to compute each pixel of the image in the validation set and visualisation of S-ovalbumin content distribution in the egg was obtained using pseudocolor image. The findings implied that the proposed hyper-spectral imaging system with the regression model developed has the potential in determining and visualising the eggs' quality.

Temperature is an important factor affecting the changes in the amount of gas exchanged between eggs and the surrounding during storage. The effect of temperature changes on the release of carbon dioxide (CO2) from eggs was studied using eggs from the same breed. The experimental samples were divided into three groups, and placed in a storage box at 4, 25, or 35°C with 65% relative humidity for 20 days, and a breathalyser was used to measure the amount of CO2 released by the eggs. The FLUENT software was used to simulate the diffusion at different temperatures. The conclusion from the present work was that as the temperature decreased, the amount and speed of CO2 released by the eggs also decreased. The simulation results show that the diffusion of CO2 released by egg respiration can be divided into the following sequential stages: initial, descending, mixing, and turbulence. When the storage temperature was 4°C, the CO2 cloud of eggs was the lowest, followed by 35°C, and finally 25°C. The results show that the direction of gas diffusion was mainly affected by temperature, diffusion volume, and diffusion velocity, and that temperature mainly affected vertical gas diffusion. The present work thus provides a theoretical basis for egg respiration related research.