[Detection of Syrup Adulterants in Prepackaged Pure Pineapple Juice by Fourier-Transform Infrared Spectroscopy and Chemometric Analysis].

This study was performed to establish a method that can quickly and accurately identify adulterated syrup in the pure pineapple juice. A attenuated total internal refraction-fourier transform infrared spectroscopy was used to collect the range of 900 -1 500 cm(-1) infrared spectra of 234 samples pure pineapple juice and adulterated syrup by beet syrup, rice syrup and cassava syrup. By using linear discriminant analysis and support vector machine for the identification model, comparing the full spectral and selected wavelengths based on principal component analysis loading plots of the two models to identify adulteration. Studies showed that the correct rate of validation set by linear discriminant analysis and support vector machine model on full spectral were both higher than 88%, variables were significantly reduced from 312 to 8 after selecting the eight characteristic wavelengths, the correct rate of validation set by linear discriminant analysis model was up to 96.15% and support vector machine was increase to 94.87%. The results demonstrated that the model built using a attenuated total internal refraction-fourier transform infrared spectroscopy in combination with chemometric methods after selected characteristic wavelengths could be used for the identification of the adulterated syrup in the pure pineapple juice.

In vitro study of antigrowth capacity and antiacid capacity on Sreptococcus sobrinus 6715 of sorghum procyanidin dimers.

The bacteria grow in oral cavity and product acids, which could induce dental caries. In this study, in order to obtain the relationship between procyanidin dimers from sorghum episperm (sorghum procyanidins, SPC) and its anticaries effect. The extract of SPC purified by macroporous resin was divided into three parts by gel chromatography, marked as GPC-1, GPC-2, and GPC-3 in order. The ESI-MS and MS/MS analysis indicated that the main composition of GPC-2 was procyanidin dimers. In addition, the capacities of antigrowth and antiacid on Sreptococcus sobrinus 6715 were analysised to investigate the effect of SPC dimers in protecting against dental caries. The results indicated that the minimum inhibitory concentration (MIC) of SPC dimers was 16 mg/mL. Furthermore, the SPC dimers had notable preventive effect < against the acid production of Sreptococcus sobrinus 6715 compared with the control group, which suppressed in a dose-dependent manner by pH decline. These findings indicated that SPC dimers had potential to be used as anticaries preventive medicine due to its strong capacity of antigrowth and antiacid.