, USA). After omitting several samples that lacked clear information about producing area, 195 samples from 12 producing areas (P1–P12) were eventually included in the two-step clustering analysis. Concentrations of major constituents as well as continuous variables and producing areas as categorical variables, two-step clustering analysis was run with the log-likelihood distance measure. The optimal number of clusters of producing areas was offered through Schwarz’s Bayesian Criterion (BIC). The clustering rationality was assessed by discriminant analysis [22]. Information on seeding date was provided by Institute of Crop Science,

Chinese Academy of Agricultural Sciences (ICS, CAAS). The geographic coordinates (latitude, longitude and elevation) of the production regions were obtained from the Jinnong Web site (http://www.agri.com.cn/host/province/china.htm). The latitude and longitude values were converted see more into a decimal system as followed formula (Eq. 1): Decimal degrees = Degrees + minutes/60. The data was analyzed using Pearson coefficient with t-test of significance and mean were compared by independent-samples t-test. Kolmogorov–Smirnov method was applied for normality test. Chi-square test was used to determine the significance of the categorical variable in clustering analysis. Table 1 shows

the range, mean, and standard deviation of the concentrations of the different components in the sample set and Fig. 1 shows their distribution. Starch, oil and protein content fit a normal distribution (P > 0.05) while total polyphenol did not agreed (P < 0.01). http://www.selleckchem.com/products/PD-0325901.html Except for the relationship between protein and oil, the correlation among Methane monooxygenase the contents of majority of the constituents in faba bean was significant (P < 0.01, Table 2). Protein content was negatively correlated with starch content and total polyphenol content (P < 0.01). Starch content was negatively correlated with oil content (P < 0.01) and total polyphenol (positive, P < 0.01). Oil content had a negative correlation with total polyphenol content (P < 0.01). According to the results of chemical analysis, some faba bean varieties had higher

values of protein, starch, oil as well as lower content of total polyphenol e.g. 91–825 from Yunnan, H0005043 from Qinghai, and H0004355 from Anhui. H0004355 from Anhui contained the minimum content of total polyphenol. As a source of antioxidant material, H0005011 from Qinghai was considered the best choice because it had the highest content value of total polyphenol. NIR spectral patterns of the samples were similar across the whole NIR wavelength region 12,500–4000 cm− 1 (800–2500 nm) (Fig. 2) along the X-axis. While along the Y-axis, the changes of spectral intensities among different samples were clear. PLS regression models of the NIR data were built up on original calibration and validation sets at ratios of 4:1 to 5:1.