Enzymatic hydrolysis and auto-isomerization during ß-glucosidase treatment improve the aroma of instant white tea infusion.

The aroma changes in instant white tea resulting from ß-glucosidase treatment was investigated by quantitative descriptive analysis (QDA), gas chromatography-mass spectrometry (GC-MS), odour activity value analysis (OAV), aroma reconstruction and omission tests. The grassy, floral and sweet notes increased significantly (P < 0.05), and the roasted note decreased significantly (P < 0.05) upon ß-glucosidase treatment. Quantitative analysis showed that the concentrations of benzaldehyde, benzeneacetaldehyde, (Z)-3-hexen-1-ol, linalool, phenylethyl alcohol, cis-linalool oxide, trans-linalool oxide, hexanol, hotrienol and (E)-2-hexen-1-ol increased significantly (P < 0.05) after treatment; however, (Z)-3-hexen-1-ol isomerized to (E)-2-hexen-1-ol. OAV analysis, aroma reconstruction and the omission test showed that the grassy, floral and sweet notes increased as the (Z)-3-hexen-1-ol, cis/trans-linalool oxide and benzeneacetaldehyde increased, whereas the roasted note declined under the same conditions. The enzymatic hydrolysis of glycosidic precursors and the auto-isomerization of volatile compounds provide new information for understanding how ß-glucosidase treatment improves the aroma of tea products.

Seasonal and Antioxidant Evaluation of Essential Oil from Eugenia uniflora L., Curzerene-Rich, Thermally Produced in Situ.

The essential oil of Eugenia uniflora has been attributed anti-depressive, antinociceptive, antileishmanial, larvicidal, antioxidant, antibacterial, and antifungal activities. It is known that the cultivation of this plant can be affected by seasonality, promoting alteration in the oil composition and its biological activities. This study aims to perform the annual evaluation of the curzerene-type oil of E. uniflora and determine its antioxidant activity. The oil yield from the dry season (1.4 ± 0.6%) did not differ statistically from that of the rainy season (1.8 ± 0.8%). Curzerene, an oxygenated sesquiterpene, was the principal constituent, and its percentage showed no significant difference between the two periods: dry (42.7% ± 6.1) and rainy (40.8 ± 5.9%). Principal component and hierarchical cluster analyses presented a high level of similarity between the monthly samples of the oils. Also, in the annual study, the yield and composition of the oils did not present a significant correlation with the climatic variables. The antioxidant activity of the oils showed inhibition of DPPH radicals with an average value of 55.0 ± 6.6%. The high curzerene content in the monthly oils of E. uniflora suggests their potential for use as a future phytotherapeutic alternative.

Highly Sensitive Room-Temperature Sensor Based on Nanostructured K2W7O22 for Application in the Non-Invasive Diagnosis of Diabetes.

Diabetes is one of the most rapidly-growing chronic diseases in the world. Acetone, a volatile organic compound in exhaled breath, shows a positive correlation with blood glucose and has proven to be a biomarker for type-1 diabetes. Measuring the level of acetone in exhaled breath can provide a non-invasive, low risk of infection, low cost, and convenient way to monitor the health condition of diabetics. There has been continuous demand for the improvement of this non-invasive, sensitive sensor system to provide a fast and real-time electronic readout of blood glucose levels. A novel nanostructured K2W7O22 has been recently used to test acetone with concentration from 0 parts-per-million (ppm) to 50 ppm at room temperature. The results revealed that a K2W7O22 sensor shows a sensitive response to acetone, but the detection limit is not ideal due to the limitations of the detection system of the device. In this paper, we report a K2W7O22 sensor with an improved sensitivity and detection limit by using an optimized circuit to minimize the electronic noise and increase the signal to noise ratio for the purpose of weak signal detection while the concentration of acetone is very low.

Effects of volatile components in Oroxyli Semen on H22 bearing mice and its possible mechanisms / 中国药理学通报

Aim To study the inhibitory effect of volatile components in Oroxyli Semen on liver cancer and its possible mechanisms.Methods H22 bearing mouse model was used,the mice were divided into six groups:blank,model,positive (cytoxan,100 mg · kg-1),low-,mid-,and high-dose (17.5,35,and 70 mg · kg-1) volatile components groups,and then the mice were ig given once daily for consecutive 12 d.Then the tumor growth inhibitory rate,spleen and thymus indexes were calculated;the serum levels of IL-2,IL-6 were determined.HE staining was used to study of the apoptosis of the solid tumor.After treatment of SMMC-7721 cells with 0 ～ 1 g · L-1 of volatile components for 24,48 and 72 h,MTT assay was used to examine the proliferation.TUNEL method was applied to detect cell apoptosis,and RT-PCR method to detect Bax,Bcl-2,caspase-3 mRNA experssion.Results The inhibitory rate of volatile components high-dose on H22 bearing mice was 42.08％.The thymus index and the contents of serum IL-2 and IL-6 of H22 bearing mice were significantly higher than those in model group.Volatile components could significantly inhibit proliferation and induce apoptosis of SMMC-7721 cells,downregulate the expression of Bcl-2 mRNA,and up-regulate the expression of Bax,caspase-3 mRNA.Conclusions The volatile components in Oroxyli Semen have obvious anti-tumor activity in vitro and in vivo,and its mechanism may be related to enhancing immune system and promoting tumor cell apoptosis.

Comparison of the impact of the Tobacco Heating System 2.2 and a cigarette on indoor air quality.

The impact of the Tobacco Heating System 2.2 (THS 2.2) on indoor air quality was evaluated in an environmentally controlled room using ventilation conditions recommended for simulating "Office", "Residential" and "Hospitality" environments and was compared with smoking a lit-end cigarette (Marlboro Gold) under identical experimental conditions. The concentrations of eighteen indoor air constituents (respirable suspended particles (RSP) < 2.5 µm in diameter), ultraviolet particulate matter (UVPM), fluorescent particulate matter (FPM), solanesol, 3-ethenylpyridine, nicotine, 1,3-butadiene, acrylonitrile, benzene, isoprene, toluene, acetaldehyde, acrolein, crotonaldehyde, formaldehyde, carbon monoxide, nitrogen oxide, and combined oxides of nitrogen) were measured. In simulations evaluating THS 2.2, the concentrations of most studied analytes did not exceed the background concentrations determined when non-smoking panelists were present in the environmentally controlled room under equivalent conditions. Only acetaldehyde and nicotine concentrations were increased above background concentrations in the "Office" (3.65 and 1.10 µg/m(3)), "Residential" (5.09 and 1.81 µg/m(3)) and "Hospitality" (1.40 and 0.66 µg/m(3)) simulations, respectively. Smoking Marlboro Gold resulted in greater increases in the concentrations of acetaldehyde (58.8, 83.8 and 33.1 µg/m(3)) and nicotine (34.7, 29.1 and 34.6 µg/m(3)) as well as all other measured indoor air constituents in the "Office", "Residential" and "Hospitality" simulations, respectively.

Antitumor effect of volatile oil from Sinapis Albae Semen on H22-bearing mice and its mechanism / 中草药

Objective: To investigate the antitumor effect of volatile oil from Sinapis Albae Semen (VOSAS) on H22-bearing mice and to determine the mechanism. Methods: To establish the H22 implanted hepatocellular carcinoma animal model which was used to analyze the effect of VOSAS on the growth of transplanted tumor. Mice were divided into five groups 24 h after modeling: model, cytoxan (CTX, 25 mg/kg) positive control, low-, mid-, and high-dose (20, 40, and 80 mg/kg) VOSAS groups. The mice were ip administered once daily for 10 d. Morphological changes in H22 solid tumor cells were observed by both Hematoxylin-eosin (HE) and acridine orange (AO) staining. The expression of Bax and Bcl-2 in the tumor tissue was determined using immunohistochemistry. Results: VOSAS could inhibit the tumor growth and extend the life span of H22-bearing mice (P < 0.01); and it could also raise the expression of Bax while suppress the expression of Bcl-2; the antitumor effect of VOSAS on H22-bearing mice demonstrated a good dose-effect relationship, but the high-dose group of the volatile oil has obvious toxicity and side effects on the mice. Conclusion: VOSAS could inhibit the growth of H22 tumor cells and the mechanism may be related to up-regulating the expression of Bax and down-regulating the expression of Bcl-2, and the induction of apoptosis.