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Pectinex XXL, a commercially prepared pectinase, was investigated for its potential application in the fruit juice industry. Polygalacturonic acid was used as the substrate for determining the enzymatic properties of Pectinex XXL using the DNS method. According to the results, the optimal pH for Pectinex XXL activity was 4.5, and the enzyme was stable in the pH range of 3.0~4.5. The optimal pH and pH stability range are consistent with those of some tropical and subtropical fruits. The optimal temperature for Pectinex XXL activity was 60 °C, and the enzyme remained stable after one hour in a water bath set at 40 C . Additionally, the enzymatic activity was not inhibited in the presence of 1 mmol/L of Na+, Mg2+, Ba2+, Co2+, Zn2+, and Fe2+, whereas it was slightly inhibited in the presence of 2 mmol/L of K+ and Fe2+ and partially inhibited in the presence of 1 and 2 mmol/L of Ca2+ and Mn2+, demonstrating its good stability in acids and excellent thermal catalytic performance. Based on the above experimental results, depectinization experiments were performed on plantain and cherry tomato juices using different amounts of Pectinex XXL. After one hour reaction with 16 U/mL of the enzyme, the yields of the plantain and cherry tomato juices were substantially increased by 119.03% and 15.97%, respectively, while their light transmittance was remarkably enhanced by 37.65% and 12.35%, respectively. Furthermore, the enzyme reduced the viscosity of the plantain and cherry tomato juices by 88.29% and 29.50%, respectively. The juice production experiments confirmed that this enzyme can significantly improve the yield and light transmittance of plantain juice, while effectively reducing its viscosity. These findings indicate the potential of Pectinex XXL in the industrial production of plantain juice. [ABSTRACT FROM AUTHOR]

[Objective] Since the Paleogene, with the uplift of the Qinghai-Tibetan Plateau and the large-scale thrust and strike-slip of the strata, many inland basins were formed in the northern part of the Qinghai-Tibetan Plateau. Be-cause of their particular location, the evolution of paleoclimate and paleo-vegetation in the basins is very significant for clarifying the climatic evolution in the Paleogene in Eurasia. [Methods] In this study, the evolution history of paleoclimate and paleo-vegetation in the Nangqian Basin in central and eastern Qinghai-Tibetan Plateau (51.8-37.5 Ma) was reconstructed from biomarkers and total organic carbon (TOC). [Results and Conclusions] The evolution history of Paleogene climate index in Nangqian Basin is in three stages, each with different changes of sedimentary facies. Stage I (51.8-46.4 Ma) : The sedimentary facies are mainly fluvial and short-term lacustrine, with lower CPI and TOC values and higher Paq values. ACL and nC27/nC3, show an obvious change trend in this period, which may have been affected by the mixing of terrestrial sediments brought by rivers. Most of the main peak carbon was nC22 and nC23; the vegetation type was predominantly woody plants, and the climate was relatively humid. Stage II (46.4-42.7 Ma): The Paq value and nC27/nC3, ratio gradually decreased, ACL gradually increased, the carbon number of the main peak gradually changed from low to medium or high, the vegetation gradually changed from woody to herbaceous plants, and the climate gradually became drought alternating with wet conditions. Stage III (42.7-37.5 Ma) : Paq, nC27/nC3, and ACL changed little, the carbon number of the main peak increased significantly, n-alkanes with high carbon numbers increased significantly, and drought conditions increased. TOC also significantly increased, reflecting increasing total vegetation productivity, which may have been a response to the warm Middle Eocene Climatic Optimum (MECO). In addition, from comparisons with previous reports of climate change in the study area and adjacent basins, it is considered that the climate change in the Nangqian Basin during 51.8-37.5 Ma was mainly affected by global climate change and the retreat of the Tethys Sea. The uplift of the Qinghai-Tibetan Plateau and its higher elevation greatly influenced water vapor in the Nangqian Basin, whereas monsoons have little influence on water vapor. [ABSTRACT FROM AUTHOR]

The climate reconstruction of the Tibetan Plateau, which was called the Third Pole Environment, has been a research hotspot in recent years. However, there are few studies on C3 and C4 plants evolution and it is an area of active debate on whether there are C4 plants existing on the Tibetan Plateau. In this study, the paleoclimate of the Hurleg Lake on the northeastern Tibetan Plateau is reconstructed based on n‐alkane‐induced indicators, while the C4 plant evolution history is established by compound‐specific isotope of long‐chain n‐alkanes since 14.1 cal kyr BP. The response of C4 plant evolution history to climate change on the northeastern margin of the Tibetan Plateau demonstrated that C3 and C4 plants were sensitive to local and global climate change. Solar radiation in summer, insolation‐affected East Asian monsoon, and seasonal climate (including seasonal variation of the solar radiation, temperature, and precipitation) had significant effects on the long‐term growth of C4. On the other hand, factors such as temperature, precipitation, and other potential factors affected the detailed variation of C4 plants in a relatively short‐term. Our finding maintained the existence of C4 plants in the high‐altitude region and indicated that the abundance of C4 plants might increase significantly and the ecological pattern of vegetation on the Tibetan Plateau will change distinctly in the coming warmer climate conditions. Key Points: Paleoclimate and C4 plant evolution on the northeastern Tibetan Plateau since the Last Deglacial were revealedC4 plants on the northeastern Tibetan Plateau were relatively abundant during the Younger Dryas periodInsolation, temperature, East Asian monsoon, and seasonal differences play significant roles in the evolution of C4 plants [ABSTRACT FROM AUTHOR]