Jie Tang,Lincai Peng,Ahmad Ali,Siyu Zhao,Ziyue Zeng,Ke Yuan,Shun Yao
As the famous naturally occurring flavonoid , rutin exists in many foods , beverages, and their processed functional products. To realize highly efficient analysis for it, a novel supramolecular hydrogel was developed as the electrode modification material for sensor. Here 12 amino acid-based ionic liquids ([C n mim][AA]) were synthesized and 6 of them could self-aggregate to form hydrogels. Especially, all the hydrogels possessed dual sensitivities to temperature and pH, as well as relatively excellent electrocatalytic performance. A three-layer electrochemical sensor [C n mim][AA]/MWCNTs/CS/GCE was prepared by decorating glass carbon electrode (GCE) with hydrogels, multiwalled carbon nanotubes (MWCNTs) and chitosan (CS) to detect rutin. After comprehensive characterization, computation and systematic investigation, the results indicated that Ipa was linearly related to the concentration of rutin in the range of 0.5–5 μM and 5–100 μM with a limit of detection (LOD) of 0.05 μM (S/N = 3). The selectivity, repeatability, stability and potential in electrochemical analysis of the developed supramolecular sensor were proved after analysis of black tartary buckwheat tea and related health-care pills.
Herein, a soluble tetramine phthalocyanine indium-decorated reduced graphene oxide (rGO-InTAPc) nanocomposite was prepared via non-covalent functionalization and used to construct a novel electrochemical sensor for sensitive determination of rutin in Tartary buckwheat tea. The rGO-InTAPc as an improved electrode material can significantly increase the electroactive surface area and electron transfer capacity. Moreover, the electrochemical response can be dramatically expanded by the enrichment effect of rutin through the adsorption of π-π stacking. Under optimized conditions, the rGO-InTAPc sensor displayed a linear dependence for rutin concentration ranging from 0.005 to 100 μM with a detection limit of 2.0 nM ( S/N = 3). The proposed sensor with excellent selectivity and reproducibility was quantitatively validated in commercially available Tartary buckwheat tea with rutin level ranging of 9.06–13.87 mg/g, which results were highly consistent with these of HPLC. This strategy of rutin detection will address a long-standing analytical challenge to establishing facile and sensitive methods for quality monitoring in tea drinks.
en Tartary buckwheat tea (TBT) is becoming increasingly popular for its unique flavor and health benefits. However, there is little information regarding the differences in nutritional quality among different kinds of TBT. Two kinds of TBT samples, whole grain tea (WGT) and whole plant tea (WPT), were collected from markets in China. The content of their nutritional compositions, including protein, amino acids, starch, fat, fatty acids, and flavonoids, as well as aroma compounds, were determined. Antioxidant and α-glucosidase inhibitory activities were also evaluated. WPT showed higher levels of protein and fat relative to WGT, but the content of essential amino acids and fatty acids was lower. WPT contained more total flavonoids with quercetin as the predominant flavonoid (81%), while rutin was the principal flavonoid compound (86%) in WGT. GC-MS analysis indicated that there were some differences in the aroma compound profile between WGT and WPT, though 14 aroma compounds were identified in both of them with 3-ethyl-2,5-dimethyl-pyrazine as the predominant compound. In addition, WPT showed superior antioxidant and α-glucosidase inhibitory activities than WGT. However, the total flavonoid content determined in tea soup was decreased by 60% and 98% compared with that in the alcohol extracts of WGT and WPT, respectively. The antioxidant and α-glucosidase inhibitory activities of tea soup were also lowered, especially for WPT. The differences between 2 kinds of TBT might be due to the variety of raw materials and processing methods. Diversified plant materials and scientific processing technologies should be taken into account to develop a nutritional and healthy TBT product. Practical Application pt WPT contained higher protein and total flavonoids, and demonstrated superior antioxidant and α-glucosidase inhibitory activities. However, the dissolution rate of flavonoids in the tea soup of WPT was extremely low, this was due to the water insolubility of its primary flavonoid quercetin, which comes from the conversion of rutin. Processing methods, such as hydrothermal treatment, should be applied to inhibit the conversion of rutin into quercetin and to develop a nutritional and healthy TBT product.
危险品化学品经营许可证（带存储）