Simultaneous Content Determination of Mono-, Di-, and Fructo-oligosaccharides in Citrus Fruit Juices Using an FTIR-PLS Method Based on Selected Absorption Bands

A quantification method was developed to determine the sugar components, either following addition or enzymatic treatment, in citrus fruit juices containing additional fructo-oligosaccharides using midinfrared spectroscopy. For the quantification, we compared the results obtained by applying the simultaneous equation method, which uses very little wavenumber information, and the partial least squares (PLS) regression method, which requires a lot of wavenumber information. In order to prevent overfitting in the PLS method, we concentrated on reducing the amount of spectral data used in the analysis. The corresponding FTIR-PLS method led to an accurate quantification of the sugar contents, even in enzymatically treated orange juices with complicated compositions. The spectral data used for model calibration were significantly reduced by focusing on the absorption and assignment information of the sugar components. The RMSEs of Glc, Fru, Suc, GF2, and GF3 in enzyme-treated orange juice before and after spectral data reduction were 0.50, 0.46, 0.61, 0.74, and 0.61 g/L and 0.51, 0.49, 0.73, 0.86, and 0.61 g/L, respectively. The developed method could be easily implemented for practical applications, using a simple measuring instrument since only absorption information at the limited absorption bands is required.

Study on multiple fingerprint profiles control and quantitative analysis of multi-components by single marker method combined with chemometrics based on Yankening tablets

In this study, we explored the quality consistent evaluation method of Yankening Tablets (YKNT) from different manufacturers by using multiple fingerprint profiles, including dual-wavelength ultra-high performance liquid chromatography (UPLC) serial fingerprint and Fourier Transform Infrared Spectroscopy (FT-IR) fingerprint, combined with quantitative analysis of multi-components by single marker (QAMS) method. In the Average method of systematic quantified fingerprint method (AMSQFM), three fingerprint parameters of macro qualitative similarity (S_m-UPLC-FTIR), macro quantitative similarity (P_m-UPLC-FTIR), and the variation coefficient of fingerprint homogeneity (α_UPLC-FTIR) were calculated based on the ratio method. The S_m-UPLC-FTIR values of all the samples were greater than 0.80, the α_UPLC-FTIR values were less than 0.20, and the P_m-UPLC-FTIR values range from 72.8% to 119.8%. Method validation results showed the established fingerprint method had good precision, solution stability, and method repeatability, all samples could be roughly divided into different levels. The contents of berberine (BBR) and baicalin (BCL) measured by the calibration curve method (CCM) and QAMS method were compared, and t-test results (Pvalue > 0.05) indicated there was no significant difference between the two methods, which showed that QAMS could accurately quantify the markers of the YKNT. The explanatory ability (R²Y) values of BBR and BCL in the PLS model were both greater than 0.94, and the root mean square error of estimation (RMSEE) and root mean square error of prediction (RMSEP) values were both less than 2.5, indicating that the established model was reliable. Hierarchical cluster analysis divided all samples into four categories. This research made a major contribution to the quality consistent evaluation of Traditional Chinese Medicine (TCM) and food.

Emerging approaches to determine maturity of citrus fruit

Owing to their health-boosting properties and other appreciable properties, citrus fruit is widely consumed and commercialized worldwide. Destination markets around the world vary in their fruit quality requirements and are also highly influenced by climatic conditions, agronomical and postharvest practices. Hence, harvesting decisions are arduous. Maturity indices in citrus fruit are highly variable and dependent on the species and varieties, growing regions, and destination markets. For decades, determination of the maturity of citrus fruit and predicting the near time of harvesting was a challenge for producers, researchers, and food safety agencies. Thus, the current review provides a correlation between maturity and internal components and an overview of techniques of maturity determination for citrus fruits. Also, stress has been given to the destructive and nondestructive methods to determine the maturity level of different citrus species. The techniques presented in this review portray continuous productiveness as an excellent quality assessment, particularly as ripening and maturity analysis tools for citrus fruits. Traditional techniques are time-consuming, laborious, costly, destructive, and tedious. Thus, these nondestructive techniques hold great potential to replace conventional procedures.

Integrated quality assessment of Tieshuang Anshen prescription by multiple fingerprint profiles combined with quantitative analysis and chemometric methods

Chinese herbal medicine compound prescription (CHM-CP) contains more complex active compounds than single herbal medicine owing to its compatibility.

Improvement in Analytical Methods for Determination of Sugars in Fermented Alcoholic Beverages

The main objective of this study was to improve the performance of analytical methods for the determination of sugars in fermented alcoholic beverages based on mid-infrared-partial least squares (MIR-PLS), high-performance liquid chromatography with the ultraviolet detector (HPLC-UV), high-performance liquid chromatography with the refractive index detector (HPLC-RI), and sulfuric acid methods. The MIR-PLS method was found to give good prediction of individual sugars: glucose, fructose, sucrose, and maltose in the alcoholic beverages with less than 4% error. The HPLC-UV method can be used for the determination of glucose in alcoholic beverages after derivatization with p-aminobenzoic acid ethyl ester. The HPLC-RI method was found to be applicable for the determination of individual sugars: glucose, fructose, sucrose, and maltose in the alcoholic beverages. The limit of detection (%, w/w) and recovery (%) of the individual sugars by the HPLC-RI method were fructose 0.001, 89.4-106; glucose 0.002, 92.4-109; and sucrose 0.002, 94.2-95.1. The sulfuric acid method was found to be useful for the determination of total sugar in the alcoholic beverages. The limit of detection (%, w/w) and recovery (%) of the total sugar by the sulfuric acid method were found to be 0.009, 98.2-109. The HPLC-RI method was applied to determine the level of individual sugars, while the sulfuric acid method was used to determine total sugar in Ethiopian traditional fermented alcoholic beverages: Tella, Netch Tella, Filter Tella, Borde, Tej, Korefe, Keribo, and Birz. The sugar contents in the real samples were found in the ranges (%): glucose 0.07-5.60, fructose 0.09-8.50, sucrose and maltose 0.08-3.00, and total sugar 12.0-64.5. The levels of sugars in Ethiopian traditional fermented alcoholic beverages were found to be comparable with literature data.

Quantitative Determination of Tetraacetylethylenediamine in Laundry Powder by FTIR Spectrometry Using Partial Least Squares Algorithm

Attenuated total reflectance Fourier transform infrared spectrometry was applied for determination of tetraacetylethylenediamine (TAED) in commercial laundry powder samples. Investigating different spectral regions, 1724–1670 cm−1 was selected as the best region. Spectroscopic data were compared with gas chromatography results, demonstrating reliability of the proposed method, higher accuracy and precision. Standard error of estimation (SEE), standard error of prediction (SEP), correlation coefficient (R2) and root mean square error of prediction (RMSEP) was 0.022, 0.031, 0.998 and 0.138 in the selected spectral region, respectively.

Measuring the metabolome: current analytical technologies

The post-genomics era has brought with it ever increasing demands to observe and characterise variation within biological systems. This variation has been studied at the genomic (gene function), proteomic (protein regulation) and the metabolomic (small molecular weight metabolite) levels. Whilst genomics and proteomics are generally studied using microarrays (genomics) and 2D-gels or mass spectrometry (proteomics), the technique of choice is less obvious in the area of metabolomics. Much work has been published employing mass spectrometry, NMR spectroscopy and vibrational spectroscopic techniques, amongst others, for the study of variations within the metabolome in many animal, plant and microbial systems. This review discusses the advantages and disadvantages of each technique, putting the current status of the field of metabolomics in context, and providing examples of applications for each technique employed.

Application of FTIR spectroscopy for the quantification of sugars in mango juice as a function of ripening

FTIR-ATR spectroscopy and multivariate analysis were used for quantification of sugars in mango juices as a function of ripening. Calibration was based on sucrose/glucose/fructose mixtures, with six concentration levels and following a triangular experimental design. PLS1 regression of the spectra first derivatives gave the best results, enabling quantification of fructose, sucrose, and glucose with 1.4, 1.4, and 4.9% prediction errors, respectively. Throughout ripening, sucrose and fructose were accurately quantified by PLS-FTIR, whereas the accuracy of glucose determination decreased at later stages, when concentrations fell to 0.6-1.5 g/L. These results enabled a correlation with fruit ripening stage to be established. This may be particularly useful to detect over-ripening in fresh fruits, a period when other indicators (pH and % soluble solids (SS)) do not change significantly; this knowledge may help in predicting fruit stability to transport and storage. Similar information obtained for nonfresh juices (in which pH and %SS may be masked by additives), may help determine whether the source fruits had suitable ripening stages.

Rapid analysis of sugars in fruit juices by FT-NIR spectroscopy

A simple analytical procedure using FT-NIR and multivariate techniques for the rapid determination of individual sugars in fruit juices was evaluated. Different NIR detection devices and sample preparation methods were tested by using model solutions to determine their analytical performance. Aqueous solutions of sugar mixtures (glucose, fructose, and sucrose; 0-8% w/v) were used to develop a calibration model. Direct measurements were made by transflection using a reflectance accessory, by transmittance using a 0.5-mm cell, and by reflectance using a fiberglass paper filter. FT-NIR spectral data were transformed to the second derivative. Partial least-squares regression (PLSR) was used to create calibration models that were cross-validated (leave-one-out approach). The prediction ability of the models was evaluated on fruit juices and compared with HPLC and standard enzymatic techniques. The PLSR loading spectra showed characteristic absorption bands for the different sugars. Models generated from transmittance spectra gave the best performance with standard error of prediction (SEP) <0.10% and R(2) of 99.9% that accurately and precisely predicted the sugar levels in juices, whereas lower precision was obtained with models generated from reflectance spectra. FT-NIR spectroscopy allowed for the rapid ( approximately 3 min analysis time), accurate and non-destructive analysis of sugars in juices and could be applied in quality control of beverages or to monitor for adulteration or contamination.