The formation and bioactivities of green substances in Chrysanthemum morifolium tea

In silico identification for flavor antioxidant compounds in Chrysanthemi flos uncovers the interactions between saccharides and secondary metabolites

Secondary metabolites and saccharides are responsible for antioxidant activity and flavor of Chrysanthemi flos (CF). However, the flavor antioxidant compounds of CF and their intermolecular interactions remain unclear. Here, we primarily employed in silico methods to identify CF antioxidants. After characterizing by physicochemical properties, FT-NIR and HPLC fingerprint, the "spectrum-effect" fusion correlation was established to select the spectral features of CF antioxidants. Quercetagitrin (QU), chlorogenic acid (CA) and saccharides fragments were clarified based on their characteristic spectrum. The antioxidant efficacy as well as the sweet and bitter taste of these compounds were verified by molecular docking. Quantum chemical calculations demonstrated that non-covalent interactions dominant facilitated the stable existence of CF antioxidants. The most significant binding types between CA, QU and saccharides fragments were hydrogen bonding. These results indicate a novel approach and theoretical support to discovery of new information pertinent to the bioactive compounds related to CF or other tea.

Pickering emulsion gels with curdlan as both the emulsifier and the gelling agent: Emulsifying mechanism, gelling performance and gel properties

For the first time, curdlan (CL) was reported to have emulsifying property. Based on its emulsifying property and gelling property, the CL-based simple-structured emulsion gels were prepared. Among different CLs, CL-4 showed relatively good emulsifying property and its based emulsion showed the best stability, which might be mainly due to its highest hydrophobic property. The initial CL-4 gel formation temperature of the emulsion increased with oil volume fraction, which might be due to the oil droplets' interfering effect. Many non-spherical oil droplets appeared in the emulsion gel, which was mainly due to the squeezing effect of CL-4 gelation. The hardness, chewiness, springiness and cohesiveness of CL-4 based emulsion gels increased with CL-4 content. The texture parameters of emulsion gels with oil ratio ranging from 20 % to 40 % did not change significantly, which might benefit for increasing functional components' transportation efficiency of the emulsion gel without weakening its gel property significantly.

Effects of different ratios of glycerol to erythritol on the structure and properties of starch straws during long term storage

To explore starch straws with low water absorption rate (WAR) and not prone to brittleness during long term storage. Glycerol and erythritol were used as composite plasticizers to explore their effects on the structure of starch straws. The results showed that G:E (60:40) had the lowest bending force (Fb = 12.58 N) and relative crystallinity (RC = 10.05 %). G:E (40:60) had the lowest water absorption rate. With the increase of erythritol contents, the proportion of starch straws short chains (A + B1) increased. Starch straws are easier to be broken during long term storage as the percentages of erythritol increased from 80 to100. However, G:E (40:60) and G:E (60:40) not only had higher flexibility (Eb = 6.12 N/cm and 7.47 N/cm) but greater hardness (Fb = 39.37 N and 45.42 N). Therefore, the addition of glycerol can inhibit the precipitation of erythritol and has an ideal plasticizing effect than single plasticizer.

Substitution of sucrose by erythritol in angel cake: Effect on protein foaming, baking performance and digestion properties

Sugars played an important role in the processing of products such as cakes, however, their high-calorie character often posed a health risk to consumers. Therefore, this paper aimed to better investigate the effect of sugar substitutes on the improvement of egg white foaming properties and angle cake digestibility characteristics. It was demonstrated that the addition of erythritol improved the surface properties of egg whites, thus enhancing their foaming properties. Particularly, when the erythritol substitution was 50 %, the sugar-egg white complex structure unfolded and had the best foaming capacity. On this basis, the baking performance of angel cakes with sucrose replaced by erythritol was analyzed. When the erythritol substitution was lower than 50 %, the specific volume and the baking loss rate of the cakes were basically unchanged, and the texture and sensory taste of the cakes were all excellent. Finally, the gastrointestinal digestive kinetic analysis suggested that erythritol substitution for sucrose was beneficial for reducing blood glucose levels in vivo. Furthermore, for the MgCl2-based samples, both the degree of protein destruction after digestion was weakened and the glucose-lowering effect was better exerted. Overall, this study provided a new theoretical basis for the low-calorie sugar-substituted health food products development in the future.

Optimization of aqueous extraction of antioxidants from Chrysanthemum (C. morifolium Ramat and C. indicum L.) flowers and evaluation of their protection from glycoxidation damage on human αA-crystallin

Chrysanthemum tea is commonly consumed by Chinese consumers mainly due to the Chrysanthemum flower being a potential source of antioxidants. The current study investigates the effects of extraction time and temperature on Chrysanthemum flower aqueous extract (CFAE) antioxidant capacity, including Trolox equivalent antioxidant capacity (TEAC), ferrous iron-chelating activity, and superoxide radical scavenging capacity (SRSC) using a two-factor, three-level factorial design of the response surface method (RSM). The TEAC and SRSC of CFAE are higher at higher temperatures and longer times up to a certain point, and the highest TEAC and SRSC are achieved at a 100 °C extraction temperature for 45 min. The fructose induced-αA-crystallin (Cry) glycation model system was used to evaluate the effects of the CFAE on anti-glycoxidation activities. The antioxidant ingredients obtained from CFAE significantly impede the production of advanced glycation end products from protein glycoxidation products (dityrosine, kynurenine, and N'-methylkynurenine) in the glycation process of αA-Cry and exhibit strong anti-glycating activity. The glycation inhibitory effects of CFAE are concentration-dependent. C. indicum L. exhibits greater potential for preventing cataracts compared to C. morifolium Ramat CFAE's antioxidant and anti-glycation properties suggest its potential application as a natural ingredient in the development of agents to combat glycation.

Analysis of Chemical Constituents of Chrysanthemum morifolium Extract and Its Effect on Postprandial Lipid Metabolism in Healthy Adults

Chrysanthemum extract possesses antioxidant potential and carbohydrate and fat digestive enzyme inhibitory in vitro. However, no evidence supporting chrysanthemum in modulation of postprandial lipemia and antioxidant status in humans presently exists. This study was to analyze the composition of Imperial Chrysanthemum (IC) extract and determine the effect on changes in postprandial glycemic and lipemic response and antioxidant status in adults after consumption of a high-fat (HF) meal. UHPLC-MS method was used to analyze the components of two kinds of IC extracts (IC-P/IC-E) and in vitro antioxidant activities were evaluated using 1,1-diphenyl-2-picrylhydraxyl (DPPH), 2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and Hydroxyl radical (HR) radical scavenging assays. Following a randomized design, 37 healthy adults (age, 25.2 ± 2.6 years, and BMI, 20.9 ± 1.5 kg/m2) were assigned to two groups that consumed the HF meal, or HF meal supplemented by IC extract. Blood samples were collected at fasting state and then at 0.5, 1, 2, 4, 6 and 8 h after the meal consumption. There were 12 compounds with relative content of more than 1% of the extracts, of which amino acid and derivatives, flavonoids, carboxylic acids and derivatives were the main components. Compared with IC-E, the contents of flavonoids in IC-P increased significantly (p < 0.05), and the cynaroside content exceeded 30%. In addition, IC-P showed strong free radical scavenging activity against DPPH, ABTS and HR radicals. Furthermore, according to repeated−measures ANOVA, significant differences were observed in the maximal changes for postprandial glucose, TG, T-AOC and MDA among the two groups. Postprandial glucose has significant difference between the two groups at 1 h after meal and the level in IC group was significantly lower than that in control group. No significant differences were observed in the incremental area under the curve (iAUC) among the two groups. IC significantly improved the serum antioxidant status, as characterized by increased postprandial serum T-AOC, SOD, GSH and decreased MDA. This finding suggests that IC can be used as a natural ingredient for reducing postprandial lipemia and improving the antioxidant status after consuming a HF meal.

Effects of Preharvest Shading on Dynamic Changes in Metabolites, Gene Expression, and Enzyme Activity of Three Tea Types during Processing

Preharvest shading significantly influences tea flavor. However, little attention has been given to the mechanism of shading on metabolites, genes, and enzymes in the processing of different tea types. Our study identified 1028 nonvolatile metabolites covering 10 subclasses using a widely targeted metabolome. The results show that shading had a greater effect on the compositions of amino acids, flavonoids, and theaflavins in tea leaves. The combined transcriptomics and enzyme activity analysis results indicate that the upregulated expression of asparagine, aspartate, and tryptophan synthesis genes and proteolytic enzymes promoted the accumulation of amino acids. The downregulated enzyme genes resulted in the reduction of nongalloylated catechins and flavonoid glycosides. Simultaneously, the accumulation of TFs in shaded tea was due to the enhanced enzymatic activities of polyphenol oxidase and peroxidase during processing. Theaflavin-3-3'-di-O-gallate was also significantly positively correlated with the antioxidant and hypoglycemic activities of shaded tea. The results contribute to a better understanding of how preharvest treatments influence summer tea quality.

Development and Application of a Cultivar-Specific Sequence-Characterized Amplified Region (SCAR) Marker for the Detection of Chrysanthemum morifolium Ramat. 'Daboju'

Chrysanthemummorifolium Ramat. 'Daboju' is a C. morifolium cultivar with important ornamental and medicinal values, and is often used in the treatment of colds, blurred vision, dizziness, and itchy skin. As the morphological characteristics of C. morifolium 'Daboju' are very similar to those of other C. morifolium cultivars, they are often confused in practice. However, the medicinal value and practical use of C. morifolium depends on using the correct rapid and accurate identification of C. morifolium 'Daboju' and its differentiation from other, morphologically similar C. × morifolium cultivars. Twenty-one polymorphic start codon-targeted (SCoT) primers were amplified in 21 distinct C. morifolium cultivars. One cultivar-specific DNA marker was developed with the aim of the rapid and accurate identification of C. morifolium 'Daboju' and its differentiation from other, similar C. morifolium cultivars. Twenty-one polymorphic start codon-targeted (SCoT) primers were amplified in 21 distinct C. morifolium cultivars. One cultivar-specific 385-bp amplicon (named SCoT36-385), amplified only in C. morifolium 'Daboju' (and in all samples of this cultivar), was identified, cloned, and sequenced. Subsequently, a sequence-characterized amplified region (SCAR) marker (named DBJF/DBJR), generating a 360-bp amplicon, was developed from SCoT36-385 and tested for amplification in all 21 C. morifolium cultivars, ten C. morifolium 'Daboju' populations, and different simulated adulterations of 'Daboju' with other cultivars. The primers amplified the specific 360-bp-long DNA fragment in all the tested C. morifolium 'Daboju' samples but failed in the absence of 'Daboju'. The detection limit of the SCAR primer pair (DBJF/DBJR) was 100 pg of DNA extracted from C. morifolium 'Daboju'. Hence, this SCAR marker has a very high detection sensitivity, and can be used for accurate and rapid identification of C. morifolium 'Daboju'. It can play an important role in ensuring the quality of medicinal preparations and protecting C. morifolium 'Daboju' germplasm resources in breeding programs and in identifying lines generated from this cultivar.

Development of microcapsules using chitosan and alginate via W/O emulsion for the protection of hydrophilic compounds by comparing with hydrogel beads

It is a critical challenge to protect hydrophilic compounds in food or pharmaceutical applications due to their strong tendency to leak out of the capsules into the external aqueous phase. In this work, we developed an encapsulation system that can protect hydrophilic ingredients using polyelectrolyte complexes prepared with chitosan and alginate via water-in-oil (W/O) emulsion. Unlike the traditional preparation of hydrogel beads, in which one material was added dropwise to another that had an opposite charge, we prepared microcapsules by electrostatic interaction between the positively charged -NH₃⁺ groups of chitosan and the negatively charged -COO^- groups of alginate by W/O emulsion via ultrasonication, which prevented the formation of large complexes. The preparation conditions were optimized at an ultrasonic power of 375 W and alginate/chitosan ratio of 7:5, in which the alginate/chitosan microcapsules presented a good polydispersity index of 0.26 and zeta potential of -44.6 mV. The SEM and TEM images showed the microcapsule contained multiple, irregular, conglutinated spheres with a core and shell structure. High encapsulation efficiency and retention efficiency showed its potential to protect hydrophilic components from harsh environments. This method provides a simple route that can efficiently encapsulate a wide range of food or pharmaceutical hydrophilic ingredients.

The formation process of green substances in Chrysanthemum morifolium tea

One interesting phenomenon of Chrysanthemum morifolium tea is its formation of a green or dark green color after hours of brewing, and it is important to study the compounds that form this color and whether they might be involved in health benefits. Non-targeted metabolomics could clearly distinguish between green and non-green species by sparse partial least squares discriminant analysis (sPLS-DA) and heat-mapping. We found that the pH was the primary factor in the formation of the green color. Two green precursors (GP1 and GP2) were separated and purified with preparative HPLC. FT-IR analysis and the saccharide content analysis showed that GP1 had the typical characteristics of saccharides. GP2 was identified as chlorogenic acid by ESI-Q-TOF/MS and NMR. We raised the formation process of green substances was caused by the hydrolysates of chlorogenic acid reacting with glycosides or groups attached to the saccharides, which suggests a new mechanism for color-forming reactions.

Extraction Optimization and Evaluation of the Antioxidant and α-Glucosidase Inhibitory Activity of Polysaccharides from Chrysanthemum morifolium cv. Hangju

In order to evaluate the antioxidant and α-glucosidase activities of polysaccharides from Chrysanthemum morifolium cv. Hangju (CMPs), the response surface methodology was applied to optimize the parameters for extraction progress of CMPs by ultrasound, with heat reflex extraction (HRE) performed as the control. The difference in the physicochemical properties of polysaccharides obtained by the two methods were also investigated. The maximum yields (8.29 ± 0.18%) of polysaccharides extracted by ultrasonic assisted extraction (UAE) were obtained under the optimized conditions of ultrasonic power 501 W, extraction time 19 min, and ratio of liquid-to-raw material 41 mL/g. Polysaccharides extracted by UAE possessed lower protein contents (2.56%) and higher uronic acids contents (7.08%) and low molecular weight fractions than that by HRE. No significant differences were found in monosaccharide composition and Fourier transform infrared (FT-IR) spectra of polysaccharides extracted by UAE and HRE, while polysaccharides by UAE possessed stronger antioxidant and α-glucosidase inhibitory activities. Therefore, UAE was an efficient way to obtain CMPs.