ABSTRACT
Five compounds, huyouyisu (1), vomifoliol (2), isoferulic acid (3), 1,2,3-trihydroxyphenol (4) and p-hydroxy-phenol (5), were isolated from the peels of Citrus changshan-huyou Y. B. Chang for the first time by utilizing repeated column chromatography on silica gel. Among them, huyouyisu (1) is a new compound. The structure was elucidated by using 1D and 2D spectra.
Subject(s)
Butanols , Chemistry , Cinnamates , Chemistry , Citrus , Chemistry , Cyclohexanones , Chemistry , Molecular Structure , Phenols , Chemistry , Plants, Medicinal , ChemistryABSTRACT
Volatile components of Fuzhou Yulu, a Chinese fish sauce, were analyzed by gas chromatography-mass spectrometry (GC-MS), and two pretreatment methods, i.e., purge and trap (P&T) GC-MS and ethyl acetate extraction followed by GC-MS, were compared. P&T-GC-MS method determined 12 components, including sulfur-containing constituents (such as dimethyl disulfide), nitrogen-containing constituents (such as pyrazine derivatives), aldehydes and ketones. Ethyl acetate extraction followed by GC-MS method detected 10 components, which were mainly volatile organic acids (such as benzenepropanoic acid) and esters. Neither of the two methods detected alcohols or trimethylamine. This study offers an important reference to determine volatile flavor components of traditional fish sauce through modern analysis methods.
Subject(s)
Fermentation , Fish Products , Gas Chromatography-Mass Spectrometry , Methods , VolatilizationABSTRACT
Near-infrared (NIR) spectroscopy combined with chemometrics techniques was used to classify the pure bayberry juice and the one adulterated with 10% (w/w) and 20% (w/w) water. Principal component analysis (PCA) was applied to reduce the dimensions of spectral data, give information regarding a potential capability of separation of objects, and provide principal component (PC) scores for radial basis function neural networks (RBFNN). RBFNN was used to detect bayberry juice adulterant. Multiplicative scatter correction (MSC) and standard normal variate (SNV) transformation were used to preprocess spectra. The results demonstrate that PC-RBFNN with optimum parameters can separate pure bayberry juice samples from water-adulterated bayberry at a recognition rate of 97.62%, but cannot clearly detect water levels in the adulterated bayberry juice. We conclude that NIR technology can be successfully applied to detect water-adulterated bayberry juice.
Subject(s)
Beverages , Food Contamination , Myrica , Neural Networks, Computer , Principal Component Analysis , Methods , Spectroscopy, Near-Infrared , MethodsABSTRACT
A FAST (fluorescence of advanced Maillard products and Soluble Tryptophan) method for identification of reconstituted milk made from skim milk powder in the fresh milk was developed. Considering milk and skim milk powders variations from different seasons and countries, milk was collected from different dairy farms in different seasons and skim milk powders were collected from different countries to measure the Tryptophan (Trp), advanced Maillard products (AMP) fluorescence values. The results showed that there were differences (P<0.01) between raw and reconstituted milk. The plot of values in each mixed level of raw and reconstituted milk had a correlation coefficient >0.97. The FAST method is a simple, rapid, low-cost and sensitive method enabling the detection of 5% reconstituted milk in fresh milk. The measurement of the Trp, AMP fluorescence values and calculation of the FAST index is a suitable method for large-scale monitoring of fresh milk samples.
Subject(s)
Animals , Cattle , Food Analysis , Methods , Food Contamination , Glycation End Products, Advanced , Maillard Reaction , Milk , Chemistry , Classification , Powders , Spectrometry, Fluorescence , Methods , TryptophanABSTRACT
<p><b>OBJECTIVE</b>To reveal the pharmacological activities of the components for their further utilization and development by studying the chemical constituents of Citrus changshan-huyou.</p><p><b>METHOD</b>The structures were determined by repeated silica gel chromatographic separation and spectral analysis.</p><p><b>RESULT</b>Five compounds were obtained, and identified as 3-oxo friedelin (I), limonin (II), beta-sitosterol (III), 8-(2',3'-dihydroxy-4'-methylbutane)-7-methoxycoumarin (IV), sucrose (V).</p><p><b>CONCLUSION</b>The five compounds were obtained from this plant for the first time.</p>