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111.
112.
Shih CH Siu SO Ng R Wong E Chiu LC Chu IK Lo C 《Journal of agricultural and food chemistry》2007,55(2):254-259
3-Deoxyanthocyanidins are structurally related to the anthocyanin pigments, which are popular as health-promoting phytochemicals. Here, it is demonstrated that the 3-deoxyanthocyanidins are more cytotoxic on human cancer cells than the 3-hydroxylated anthocyanidin analogues. At 200 microM concentration, luteolinidin reduced the viability of HL-60 and HepG2 cells by 90 and 50%, respectively. Sorghum is a major source of 3-deoxyanthocyanidins, which are present as seed pigments and as phytoalexins responding to pathogen attack. On the basis of the collision-induced dissociation spectra of luteolinidin and apigeninidin, an LC-MS/MS method, operating in multiple-reaction monitoring mode, was developed for the specific detection and accurate quantification of these compounds in complex mixtures, which may be difficult to analyze using absorbance measurements. The results demonstrated that inoculated sorghum seedlings could be utilized for convenient and large-scale production of 3-deoxyanthocyanidins. A quantity of almost 270 microg/g (fresh weight) of luteolinidin was produced 72 h after fungal inoculation of 1-week-old seedlings. 相似文献
113.
Chiu YT Chiu CP Chien JT Ho GH Yang J Chen BH 《Journal of agricultural and food chemistry》2007,55(13):5123-5130
Tomato pulp waste, a byproduct obtained during the processing of tomato juice, has been shown to be a rich source of lycopene. The objectives of this study were to use gelatin and poly(gamma-glutamic acid) (gamma-PGA) as coating materials for the encapsulation of lycopene extract from tomato pulp waste. Initially, lycopene was extracted with supercritical carbon dioxide, followed by microencapsulation using an emulsion system consisting of 4.5% gelatin, 10% gamma-PGA, and 4.8% lycopene extract. Analysis of differential scanning calorimetry revealed that the thermal stability of the coating material could be up to 120 degrees C, with a mean particle size of 38.7 microm based on Coulter counter analysis. The total weight of microencapsulated powder was 617 microg with the yield of lycopene being 76.5%, indicating a 23.5% loss during freeze drying. During storage of microencapsulated powder, the concentrations of cis-, trans-, and total lycopene decreased along with increasing time and temperature. A fast release of lycopene in the powder occurred at pH 5.5 and 7.0, while no lycopene was released at pH 2.0 and 3.5. 相似文献
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Stability of black tea polyphenol, theaflavin, and identification of theanaphthoquinone as its major radical reaction product 总被引:1,自引:0,他引:1
Jhoo JW Lo CY Li S Sang S Ang CY Heinze TM Ho CT 《Journal of agricultural and food chemistry》2005,53(15):6146-6150
In the current study, we have focused on isolation and detection of major radical oxidation products from theaflavin in order to better understand antioxidation mechanisms of this compound. Theanaphthoquinone was identified as a major oxidation product of theaflavin from two different oxidant model systems: DPPH and peroxidase/hydrogen peroxide. This result indicated that the benzotropolone moiety in theaflavin may play an important role in its antioxidant properties. The stability of theaflavin was studied in varying pH solutions: simulated gastric juice and buffer solutions of pH 5.5, pH 7.4, and pH 8.5. The results indicated that theaflavin is unstable in alkaline conditions, while it was stable in acidic conditions. Theanaphthoquinone was identified as an autoxidation product of theaflavin during its stability study in alkaline conditions. 相似文献
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118.
(-)-Epigallocatechin-3-gallate (EGCG), a major polyphenol of green tea, undergoes substantial biotransformation to species that includes the methylated compounds. Recent studies have demonstrated that the methylated EGCG has many biological activities. In this study, we have investigated the composition of the three O-methylated EGCG derivatives, (-)-epigallocatechin-3-O-(3-O-methyl)gallate (3' '-Me-EGCG), (-)-epigallocatechin-3-O-(4-O-methyl)gallate (4' '-Me-EGCG) and (-)-4'-methyl epigallocatechin-3-O-(4-O-methyl)gallate (4',4' '-di-Me-EGCG) in tea leaves which were picked from various species and at various seasons, ages of leaves, locations, and fermentation levels. Higher levels of 3' '-Me-EGCG and 4' '-Me-EGCG were detected in Chinshin-Kanzai (a species of Camellia sinensis) cultivated in the mountain area of Sansia, Taipei County, Taiwan. Also, these O-methylated EGCG levels were found to be higher in autumn and winter than in spring and summer. The young leaves were found to be richer in the O-methylated compounds than old leaves and the amount of O-methylated EGCG was higher in unfermented longjin green tea than in semifermented oolong tea. However, the fermented black tea and puerh tea did not contain these compounds. 4',4' '-diMe-EGCG could not be detected in either fresh tea leaves or commercial tea leaves. We also found that 3' '-Me-EGCG has a higher inhibitory effect on the nitric oxide generation and inducible nitric oxide synthase (iNOS) expression as compared with EGCG, while 4' '-Me-EGCG and 4',4' '-di-Me-EGCG were less effective. 相似文献
119.
We used chemical extraction methods and 31P-nuclear magnetic resonance (NMR) to investigate the effects of vegetation on the amount and structural composition of phosphorous (P) in the sub-alpine soils of central Taiwan. Chemical extraction methods were used to measure inorganic P (Pi) and organic P (Po) in main soil horizons. The soil P composition was assessed by 31P-NMR spectroscopy on alkaline EDTA–NaOH extracts. According to the results of chemical extractions, the forest soil had a higher amount of Pi than the grassland soil, which might be a result of the mineralization of Po. 31P-NMR spectra showed inorganic orthophosphate (up to 67%) and orthophosphate monoesters (up to 75%) as the major forms of P extracted in forest and grassland soils, respectively. Smaller proportions of orthophosphate diesters and trace amounts of phosphonates and pyrophosphate were found. With possible hydrolysis of P compounds during chemical extraction and slight systemic error in the processes of extraction with NMR, the results from NMR analysis are, in general, consistent with those of chemical extraction. 相似文献
120.
The fruit of the tomato plant is composed of elongated tomato cells filled with organelles called chromoplasts (plastids). These plastids scattered throughout the cell are rich in nutrients, particularly protein (33%) and lipids (20%). They can be released from the cells by rupture of their cell membranes and then isolated. Plastids and their cell contents can be utilized by the food-processing industry for the preparation of special food products. This study was designed to examine the macronutrient content of isolated tomato plastids and, therefore, determine its potential nutritional value. Use of tomato plastids in pasta sauces and rice dishes, salsa, and extrusion products would increase the nutritional value of the product. Because glucose has been removed in the process of plastid isolation, tomato plastids are useful in the diets of diabetics and cardiovascular patients, as well as for patients in need of weight reduction. Composition comparison of tomato plastid is made with tomato paste, from which glucose has not been removed. Many people require low-sugar products for medical reasons (diabetics and those with cardiovascular disease) and others for weight loss. Therefore, tomato chromoplasts having high protein and lipid contents and low sugar content may be useful in meeting these particular human needs. 相似文献