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Sweet oranges with distinguished origin label have been becoming a fraud target by confusing or hiding origins. In this study, high-resolution nuclear magnetic resonance (NMR) spectroscopy in combination with chemometrics was used to discriminate the geographical origins of China's sweet oranges from four main producing regions (Hunan, Hubei, Sichuan and Guangxi). Sixty-two components, including various saccharides, amino acids, organic acids, alcohols, ketone, flavanones and other compounds, were identified and quantified via their 1H NMR spectra, and the producing region-specific geographical indication components of China's sweet orange were further screened out. The sweet oranges in Hubei show favorable antioxidant properties due to their rich phenolic compounds, and those in Sichuan show rich and fresh flavors due to their wealthy amino acids. Our results are readily available for nutritional recommendation in human consumption, and helpful to distinguish the geographical origin of sweet oranges based on their nutritional characteristics especially geographical indication markers. • A rapid and inexpensive NMR method was used to analyze sweet orange. • 62 nutritional components in China's sweet oranges were identified and quantified. • The geographical indication markers of each geographical origin were screened out. • The results are available for nutritional recommendation in human consumption. [ABSTRACT FROM AUTHOR]

• Chemical compositions of Chinese honeys were identified via NMR technique. • Different pattern recognition methods were used to honey authentication. • The predictive models of adulterated honey were established with an accurate rate of above 95%. • Eight components were screened out as the potential markers of honey authentication. Honey authentication has been becoming more and more important and necessary to the honey producers, the consumers and the market regulatory authority due to its favorite organoleptic and healthy properties, high value and increasing export but prevalent falsification practice for economic motivation in China and the potential health risk of adulterated honey. In this study, we obtained the spectral profiles of 90 authentic and 75 adulterated Chinese honey samples by means of high resolution nuclear magnetic resonance (NMR) spectroscopy, and 65 kinds of major and minor components in honey were identified and quantified from their NMR spectra. Combining with the multivariate statistical analyses including principal component analysis (PCA), linear discriminant analysis (LDA), and orthogonal partial least squared-discriminant analysis (OPLS-DA), the discrimination models were successfully established to identify the adulterated honeys from the authentic ones with an accurate rate of 97.6%. Furthermore, the corresponding volcano plot was used to screen out 8 components including proline, xylobiose, uridine, β-glucose, melezitose, turanose, lysine and an unknown component, which are responsible for the differentiation between the authentic and adulterated honeys and will help to control Chinese domestic honey market. [ABSTRACT FROM AUTHOR]