A Comparative Study on Polyphenolic Composition of Berries from the Tibetan Plateau by UPLC‐Q‐Orbitrap MS System

2020 ◽  
Vol 17 (4) ◽  
Author(s):  
Qiangqiang Jia ◽  
Shoude Zhang ◽  
Hongyang Zhang ◽  
Xijuan Yang ◽  
Xinli Cui ◽  
...  
Author(s):  
Yao Feng ◽  
Hong Wang ◽  
Wenbin Liu ◽  
Fubao Sun ◽  
Huijuan Cui

Multiple indices have been created to measure hot conditions that may cause discomfort, stress even death to humans. However, distinctions among these indices and their performance in measuring heat remain undisclosed. We conduct a comparative study of multiple heat indices and revisit the spatiotemporal changes in summer heat across China. The maximum temperature-based index, more sensitive to average and maximum temperatures, suggests a larger increasing trend (0.42°C/10a) in heat intensity than those average temperature-based ones which are more sensitive to minimum temperature. The absolute threshold-based heat-day indices are not so applicable as the relative ones in measuring the increasing heat days over the Tibetan Plateau. During 1960–2018, significant ( p < 0.05) increasing trends in heat intensity (0.11–0.42°C/10a) and heat day (0.63–2.67 days/10a) are revealed with a jump-like increase after the mid-1990s at the country level. Stronger heat intensity occurs over the southeast and north China with larger increasing trends over the Tibetan Plateau and northwest China. Northern China with larger increasing heat intensity and days should take effective measures of adaptation to reduce suffering from the summer heat. Given differences among multiple indices and the performance over different regions, a rational selection of heat index considering the research subject of interest and regional climatology is highly recommended.


2020 ◽  
Vol 26 (4) ◽  
pp. 301-308
Author(s):  
Qiangqiang Jia ◽  
Qiuxia Dong ◽  
Qingni Sang ◽  
Mingfang Wang ◽  
Hongyang Zhang ◽  
...  

Nitraria tangutorum B. (NT), Hippophae rhamnoides L. (HR), Lycium ruthenicum M. (LR), Lycii fructus (LF), Rosa xanthina L. (RX), and Rubuscor chorifolius L. f. (RC) are six berries from Tibetan Plateau. They have been used in traditional folk medicine with a long history, which are rich in anthocyanins. However, detailed study of their anthocyanins remains scarce. Therefore, a method for rapid simultaneous identification and quantification of 12 anthocyanins from berries using UPLC-Quadruple-Orbitrap MS system (UPLC-Q-Orbitrap MS) was established in this work. It was verified with limit of detection (3.86–11.61 µg/L), limit of quantification (3.86–11.61 µg/L), precision (0.95–2.38%), repeatability (0.96–2.08%), stability (0.86–2.31%), mean recovery (95.8–103.1%), recovery range (93.1–107.2%) and RSD less than 5.21%. It was then used in the analysis of anthocyanins in six berries species; 8, 7, 7, 7, 6 and 9 species of anthocyanins have been identified in NT, LF, LR, HR, RC and RX, respectively based on their own retention time and exact mass in positive mode, and for the first time quantified successfully in each berry (31.11 ± 0.42–2978 ± 25.67 μg.g−1). Finally, 2, 2-azinobis (3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radical scavenging activity (0.92 ± 0.12–5.61 ± 0.23 mM TE/100 g), ferric reducing antioxidant power (FRAP) (1.23 ± 0.15–7.42 ± 0.28 mM TE/100 g) and total antioxidant activity (T-AOC) assays were used to evaluate the antioxidant activities of the six berries.


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