Evaluation of the Eating Quality of Fresh Lotus Seeds at Different Maturation Stages

In order to determine the maturation period of lotus seeds suitable for fresh consumption and to evaluate their quality, the physicochemical and sensory quality of lotus seeds at the milky, waxy, complete and dead ripeness stages were evaluated. The relationship between physicochemical and sensory quality was determined through principal component analysis (PCA), correlation analysis and regression analysis, and the quality characteristics of fresh lotus seeds were quantified. The results showed that the hardness, fullness, starch content, reducing sugar content and soluble protein content of lotus seeds increased gradually with maturity, while the water content decreased; the brittleness, chewability and viscosity increased firstly and then decreased, while the opposite trend was recorded for the contents of soluble solids and soluble sugar. The taste of lotus seeds at the milky ripeness stage was the most popular, whereas the appearance and color of lotus seeds at the waxy ripeness stage were the most satisfactory, and the overall acceptance was the highest. Lotus seeds suitable for fresh consumption were characterized by yellowish-green and shiny peels, high moisture content, low contents of reducing sugar and soluble protein, and low hardness. A model for the prediction of overall acceptance (Y) as a function of hardness (X) was determined as follows: $\hat{Y}$= 9.766 - 0.537X, which simplifies the process of determining the suitability of lotus seeds for fresh eating.