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Hovenia acerba Lindl. is a perennial tree of Rhamnaceae family. In the present study, four solvents (80% methanol, ethyl acetate, n-hexane, and water) were used to extract the compounds of Hovenia acerba Lindl. peduncles (HAP). The total contents of phenolics and tannins (TPC and TTC), as well as their antioxidant activities (DPPH, ABTS, and FRAP) of these four different extracts including 80% methanol extract (ME), ethyl acetate extract (EE), n-hexane extract (HE) and water extract (WE) were compared. The antioxidant activities of HAP showed positive correlations with TPC and TTC, indicating that phenolics maybe a major contributor to the antioxidant activities of HAP. The significant difference between antioxidant activities and TPC/TTC implied the respective contribution extent of phenolics for the antioxidant activities of four solvent extracts. Besides, a total of 117 compounds, including 7 oligosaccharides, 11 organic acids, 41 phenolics, 1 steroids, 25 terpenes, 11 fatty acids, 9 amino acids, and 12 other compounds were identified or tentatively characterized in HAP for the first time. Among them, 23 bioactive constituents, including 4 organic acids, 5 phenolic acids, and 14 flavonoids, were quantified. The comparison of characterization and quantitation of 4 extracts demonstrated that 80% methanol showed the widest range of selectivity for both HAP flavonoid aglycones and glycosides, while ethyl acetate preferred to extract the flavonoids aglycone from HAP. Secondly, water and 80% methanol were excellent solvents for the extraction of phenolic acids. And both ethyl acetate and 80% methanol perform well at the extraction of terpenes and steroids.

The hydrophilic extracts of mulberry (HEM) and blueberry (HEB) and lipophilic extracts of mango (LEM) and watermelon (LEW) were mixed in different ratios to assess the antioxidant interactions by chemical-based (DPPH and ABTS assays) and H9c2 cell-based models. There were both synergistic and antagonistic antioxidant interactions among these fruits. Some groups with combinational extracts showed stronger synergistic antioxidant effects than the individual groups, and others (HEM−LEW F1/10, LEW−LEM F5/10, and HEB−LEM F3/10) showed stronger antagonistic effects than the individual groups based on the indicators [the values of DPPH, ABTS, and MTT; the expression of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT), and malondialdehyde (MDA); the release of lactate dehydrogenase (LDH); and the quantification of cellular antioxidant activity]. The principal component analysis (PCA) showed that samples could be defined by two principal components: PC1, the main phenolic acids and anthocyanins, and PC2, carotenoids. From our results, primarily, carotenoids were in the majority in antagonistic groups, and phenolics and anthocyanins were in the majority in synergistic groups. However, the combinational groups containing only hydrophilic compounds did not always show synergistic effects. Therefore, the compatibility of diets indicates balancing the ratios of hydrophilic and lipophlic compounds in our daily food. In addition, the expression of enzymes (SOD, GSH-Px, and CAT) may not be sensitive to the changes of antioxidant activity caused by the combinations with different ratios of hydrophilic and lipophilc compounds. The different structures of lipophilic compounds (β-carotene and lycopene) could influence the antagonistic effects.

oolong tea is famous for its characteristic of durably brewing. to explore suitable brewing cuppages and the scientific methods to brew Oolong tea in multiple steeping process. Dahongpao tea (Zhengyan, Banyan and Zhouyan tea) is well known Oolong tea variety, brewed at 14 times and assessed its chemical composition, infusion colour and sensory quality in different brewing intervals. The results showed that Zhengyan tea (A3) had the best quality of steeping among the chosen tea. It could be brewed up to 10 cuppages with 80% sensory score. The chemical composition and tea infusion colour strength were higher in Zhengyan tea. Though, 70% caffeine leached within first three steeping. The Forest regression model revealed that the suitable brewing time ranges between 4 and 10 in the chosen Dahongpao tea variety. This study provides a scientific method and suitable steeping times for the drinking of different Dahongpao tea through dynamic analysis of quantity of chemical composition, infusion colour strength and sensory quality. Oolong tea is well-known traditional Chinese tea. Dahongpao dated more than 350 years, is a representative of Oolong tea planted in Wuyishan, Fujian Province, China 1. Oolong tea attracts both domestic and foreign consumers due to its quality and characteristic of durably brewing. Generally, Dahongpao tea are classified as Zhengyan (A1, A2, A3) Banyan (B1, B2, B3) and Zhouyan tea (C1, C2, C3) based on different growing environments. Zhengyan tea grows in Wuyishan Scenic Area along the Jiuqu river at high altitude, with lots of gravel in soil, which create good ventilation and moderate acidity of soil for its growing, resulting in excellent quality. Banyan tea is planted around Zhengyan tea region, on red soil with high acidity; moreover, the soil is mostly clay. Therefore, the quality of Banyan tea is not that good as Zhengyan tea. Zhouyan tea is distributed on hilly area with alluvial soil full of calcium, causing its quality not that good as Zhengyan and Banyan tea. Besides, the quality of tea infusion depends on the types and tea/water ration of tea, temperature of water, brewing duration and times 2-4. To realize the best consumption quality experience of tea, scientific brewing methods are the key after cultivation and processing, especially for Chinese famous tea. Consumers are generally told that Oolong tea is suitable for continuous brewing up to more than 7 cuppages. This assertion is highly subjected to consumers' discretion and has not been validated by any scientific research. Sensory evaluation technique helps to determine the brewing cuppages and quality of tea infusion by its flavor strength. The flavor of tea infusion is determined by its chemical composition such as amino acids, caffeine, polyphenols and catechins. Several groups of compounds including phenolic compounds, purine alkaloids, amino acids, carbohydrates, nucleotides, organic acids and ions potentially contribute to the taste of tea. Sweetness of tea is mainly attributed to amino acids, as well as simple sugars such ...

To derive a mutant of L. helveticus SH2‐1 with the capacity of weak postacidification and high texturing, first, taking L. delbrueckii frs4‐1 and S. thermophilus grx02 as the controls, H+‐ATPase activity was demonstrated to be highly related to the postacidification of L. helveticus SH2‐1. Then, by detecting H+‐ATPase activity, the weak postacidify mutant of L. helveticus SH2‐1 (renamed as L. helveticus sh2‐5–66) was selected from 80 UV mutants. The pH and acidity of the milk fermented with L. helveticus sh2‐5–66 were separately 0.57 pH units higher and 57.1 °T lower than that of L. helveticus SH2‐1. The acidification of L. helveticus sh2‐5–66 was further demonstrated to be genetically stable during 100 generations cultivation. Moreover, the milk fermented with L. helveticus sh2‐5–66 showed improvement in textural and rheological properties and flavor during storage which could be further improved by coculture with the commercial starter S. thermophilus st447.