Suitability evaluation of potato varieties used for chips processing

Abstract: Influenced by Western diet culture and growth in the standard of living, potato chips are currently fashionable as one kind of essential snack food during people's leisure time. The modern potato chip processing industry requires a forward upgrade and higher demands concerning the quality of utilize materials. The Chinese potato industry possesses a wide variety and adequate supply of potatoes currently. Quality indexes were different among cultivars, and these differences determine the quality of fried potato chips to a large extent. In order to determine the suitability of different cultivars for potato chips processing, 74 widely cultivated potato cultivars were investigated. All samples were grown in the same place with the same fertilization. Potato harvesting, storage, processing and index analysis were conducted in the shortest time. Eight main quality indicators of potatoes (water, starch, reducing sugar, total sugar, ash, total soluble solid, Vitamin C and protein) and four quality indicators of potato chips (protein, sensory evaluation, crispness and whiteness) were measured in the laboratory. 56 samples were removed randomly for the validation set, and the other 18 samples for the calibration set. Comprehensive evaluation indicators of potato chips were calculated by the normalization method and Euclidean distance of four individual indicators. Correlation analysis showed that the comprehensive evaluation indicator was significant in represent four individual indicators of potato chips. A principal component analysis was applied to select four irrelevant principal components (F1-F4) which could cover most information of the potato samples. An stepwise regression method was used to establish the model of comprehensive evaluation indicators and four principal components (F1-F4). Substituted with the original eight main quality indicators of potatoes(X1-X8), the final model was determined. The determination coefficient R2 is 0.607, adjusted R2 is 0.585, F-value is 26.815 greater than F (0.001, 3, 52), and sig. value is less than 0.001. The model effect was relatively good with a high degree of fitting and significant correlation. 18 samples from the validation set were used to validate the effect of the model. The results showed that the correlation coefficient for the true value and prediction value of the comprehensive evaluation indicator is 0.502, sig. value is 0.034 that is less than 0.05, and the model is applicable to the actual suitability evaluation of potato chips processing. The suitability of 74 cultivars for potato chips processing was preliminarily classified into three types based on the K-means clustering method. 15 samples were selected as optimal cultivars for potato chips processing, which was in accord with practical applications. However, the precision of the model needs to be improved in future research. The results of this research can be applied in practice. Comprehensive evaluation indicators of potato chips can be determined without a tedious laboratory analysis, proper potato material can be founded for chips' processing, and the result has guiding significance for the chip processing industry.