Weiguo Wu

Chemometric tools and GC-MS were employed to detect the adulteration of camellia seed oil. In the training set, 65 samples were formulated by blending pure camellia seed oil with varying concentrations of soybean, peanut and rapeseed oil and their fatty acid contents were used in chemometric analysis. Principal Component analysis revealed the distribution patterns of samples that showed a clear stratiform agglomeration according to varying amount of camellia seed oil. Fisher Discriminant Analysis (FDA) was combined to establish the classification models and the correct classification rate of cross-validation model and original model reached 92.5% and 82.5%, respectively. To test the quality of the model, a new test set was prepared and the results showed a high accuracy of 88%. This was indicated that the developed discrimination model established by PCA plus FDA was efficient in predicting the presence of other low-price edible oils in camellia seed oils.

The gel properties and structural changes of sweet potato starch induced by heat-moisture treatment (HMT) were investigated, and its vermicelli textural properties were revealed. HMT increased the relative crystallinity, and the crystallinity reduced with increasing moisture content, which was consistent with the results of DSC. RVA results revealed that the HMT starches showed an increased setback viscosity and a reduced breakdown viscosity, indicating that the HMT starches gel lead a stronger retrogradation tendency. Rheometer results indicated that the HMT starches had a stronger elasticity behavior. The content of amylose of starch and the possible amylose fine molecular change during HMT at different water content were hypothesized, and this caused the gel properties of starch. Consequently, the HMT starch vermicelli exhibited higher hardness, springiness, and chewiness. These mechanistic relations among starch structure, gel properties, and vermicelli quality during HMT will provide useful information for the starch vermicelli industry.