RENEWABLE ENERGY
·
2023
·
IF 8.7
Yujiao Zhang,Shengli Niu,Yanan Hao,Sitong Liu,Jisen Liu,Kuihua Han,Yongzheng Wang,Chunmei Lu
The strontium oxide (SrO) is considered as an efficient heterogeneous catalyst for biodiesel production . However, the resistance of SrO to high free fatty acids (FFAs) in low-quality raw materials is a great challenge. In this study, the SrZrAl multiple oxide catalysts are prepared and applied in transesterification of the acidified palm oi. The preparation of the SrZrAl catalysts is optimized from the aspects of the preparation method and zirconium content, where the co-precipitation method with Sr, Zr and Al molar ratio of 6:6:1.5 is preferentially determined. The microstructure and surface chemical properties of SrZrAl catalyst are thoroughly characterized by XRD , CO 2 /NH 3 -TPD, XPS and SEM-EDS. The GA-PSO-BP algorithm is used to optimize the transesterification parameters, where the FAME yield of 94.4% could be achieved with the addition of oleic acid of 5 wt% under the condition of the methanol to oil molar ratio of 16:1 and catalyst amount of 3.8 wt% at 171 °C in 2.6 h. Excellent reusability of the SrZrAl catalyst is demonstrated by the fact that the FAME yield of 80.3% is still obtained at the fifth reuse cycle. In addition, the FAME yield reaches 83.4% even at a high oleic acid addition of 15 wt%.
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DYES AND PIGMENTS
·
2023
·
IF 4.5
Lei Qian,Shuaijun Fang,Xiyu Song,Hongfei Qian
Due to the limitations of dye solubility in reaction solvents, the crosslinking reaction between two monoazo disperse dyes will tend to result in low yield and multiple by-products. In this work, an alternative synthetic strategy was used to prepare three disazo disperse dyes , which involved first synthesizing crosslinked coupling components with diisocyanate compounds followed by diazotization with a double diazonium salt. The structures of these new dyes were characterized by nuclear magnetic resonance (NMR), mass spectrometry (MS), and fourier transform infrared spectroscopy (FT-IR) analysis, and the spectral characteristics of the dyes in dimethylformamide (DMF) solutions were evaluated. Three synthesized disazo dyes were applied to the polyester fabrics by high-temperature and hot-melt dyeing processes. The results showed that a higher yield was obtained for all three dyes, and each of the dyes had relatively high molar extinction coefficient and slow dyeing rate on the polyester fabric due to the existence of the double-chromophore. Therefore, a certain amount of carrier or solubilizer had to be added to the dyebath to improve the dyeing rate. At 220 °C for 2.5 min, a satisfactory dyeing effect was achieved, which demonstrated that the disazo disperse dyes exhibited excellent colorfastness properties. Compared with high-temperature dyeing, thermosol dyeing produced higher dye uptake, build-up, and fastness properties , and this process was suitable for the dyeing of polyester fabrics with the disazo disperse dyes.
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Foods
·
2023
·Vol. 12
·期 11
·2151
·
IF 5.2
Baorong Chen,Xiaodan Wang,Yumeng Zhang,Wenyuan Zhang,Xiaoyang Pang,Shuwen Zhang,Jing Lu,Jiaping Lv
This study aimed to determine chemical composition and assess exposure in flavored milk among Chinese residents, based on risk assessment methodologies of acceptable daily intake (ADI) and toxicological concern threshold (TTC). Esters (32.17%), alcohols (11.19%), olefins (9.09%), aldehydes (8.39%), and ketones (7.34%) comprised the majority of the flavoring samples. Methyl palmitate (90.91%), ethyl butyrate (81.82%), and dipentene (81.82%) had the highest detection rates in flavor samples. This study screened fifteen flavor components of concern and discovered that 2,3,5-trimethylpyrazine, furfural, benzaldehyde, and benzenemethanol were detected in 100% of flavored milk samples. Benzenemethanol was found in the highest concentration (14,995.44 μg kg−1). The risk assessment results revealed that there was no risk for Chinese residents in consuming flavored milk, and the maximum per capita daily consumption of 2,3,5-trimethylpyrazine, furfural, and benzenemethanol were 226.208 g, 140.610 g, and 120.036 g, respectively. This study could provide guidelines for amounts of flavor additive ingredients in milk.Keywords:flavored milk;SPME-GC/MS;flavor components;acceptable daily intake;toxicological concern threshold
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Food Chemistry-X
·
2022
·
IF 6.443
Chao Wang,Wazhen Xu,Yuqi Yuan,Yuke Zhai,Tengfei Hu,Jianan Huang,Zhonghua Liu,Qin Li
The odor-active compounds in Fu-brick tea and their release behaviors during boiling-water were studied. Fifty-one odor-active compounds were identified, and their release behaviors were identified by continuously recovering 16 sections of condensed water combined with sensory, instrumental, and nonlinear curve fitting analysis. The odor intensities of condensed water and the concentrations of odor-active compounds could be significantly fitted ( p < 0.01) to power-function type curves. Hydrocarbons showed the fastest release rate, while organic acids showed the slowest. The release rates had very little correlation with their concentrations, molecular weights, and boiling points. Most odor-active compounds (≥70 %) released need to evaporate more than 24 % of the added water during boiling-water extraction. Meanwhile, on the basis of odor activity value (OAV) calculation, the aroma recombination experiments were performed to explore the odor-active compounds that made major contributions to the formation of the aroma profile of each condensed water.
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Horticulturae
·
2022
·Vol. 8
·期 12
·1208
·
IF 2.923
Di Gong,Yang Bi,Yongcai Li,Yi Wang,Dov Prusky,Noam Alkan
Antioxidant activity is an important feature for evaluating fruit quality and tolerance to biotic or abiotic stresses. Moreover, antioxidant activity is involved in chilling injury (CI) response and postharvest quality in fruit. Chemical elicitors can induce systemic acquired resistance in fruit against pathogens, which could partially replace synthetic fungicides. Recently, researchers have found that preharvest sprays with chemical elicitors can improve antioxidant activity, reduce CI, and maintain quality in harvested fruit. In this review, we summarize that preharvest elicitors spray improve antioxidant activity in harvested fruit by promoting antioxidant components biosynthesis as well as antioxidant ability in vitro. Moreover, preharvest elicitors spray alleviates CI in fruit by regulation of membrane lipid metabolism and reactive oxygen species metabolism. In addition, preharvest elicitors spray maintains fruit quality by modulation of respiration and ethylene release. Finally, this review points out the issues existing and proposes an outlook on preharvest elicitors spray to maintain postharvest fruit quality.Keywords:fruit;preharvest elicitor spray;antioxidant activity;chilling injury;postharvest quality
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FOOD CHEMISTRY
·
2023
·
IF 8.8
Tingting An,Shanshan Shen,Zhongqi Zu,Mengxue Chen,Yu Wen,Xu Chen,Qi Chen,Yu Wang,Shaoyun Wang,Xueling Gao
Instant dark tea (IDT) was prepared by liquid-state fermentation inoculating Eurotium cristatum . The changes in the volatile compounds and characteristic aroma of IDT during fermentation were analyzed using gas chromatography-mass spectrometry by collecting fermented samples after 0, 1, 3, 5, 7, and 9 days of fermentation. Components with high odor activity (log 2 FD ≥ 5) were verified by gas chromatography–olfactometry. A total of 107 compounds showed dynamic changes during fermentation over 9 days, including 17 alcohols, 7 acids, 10 ketones, 11 esters, 8 aldehydes, 37 hydrocarbons, 4 phenols, and 13 other compounds. The variety of flavor compounds increased gradually with time within the early stage and achieved a maximum of 79 compounds on day 7 of fermentation. β -Damascenone showed the highest odor activity (log 2 FD = 9) in the day 7 sample, followed by linalool and geraniol. These results indicate that fungal fermentation is critical to the formation of these aromas of IDT.
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Agronomy-Basel
·
2023
·Vol. 13
·期 2
·339
·
IF 3.7
Jinjia Liu,Min Chen,Weihua Ma,Lifang Zheng,Bing Zhang,Huiting Zhao,Yusuo Jiang
Strawberries are popular fruits around the world, and their yield and fruit quality rely on pollination by honey bees and bumblebee colonies. Both bee species have their own advantages in strawberry pollination. This study investigates the characteristic of strawberry (Fragaria×ananassa‘Red Face’) flower volatiles and their effects on bee pollinators by (1) detecting the volatile compounds of strawberry flowers by polydimethylsiloxane (PDMS) combined gas chromatography-mass spectrometry (GC-MS), (2) determining whetherBombus terrestrisorApis melliferashowed antennae responses to certain compounds of strawberry flower volatiles by an electroantennography test (EAG), and (3) testing whether these compounds could elicit a corresponding behavioral response in bees. The results showed that (1) there were 38 chemical compounds in ‘Red Face’ volatiles with 7 types, most of which were known to be generally emitted by flowers but also have some compounds that have not been reported in strawberry flowers; (2)B. terrestrisandA. melliferahad strong EAG responses to several compounds, respectively, especially to ethyl benzoate, (Z)-3-hexenyl propionate, (Z)-3-hexenyl acetate, benzeneacetaldehyde and melonal; and (3) both bee species showed significant avoidance behaviors to four tested compounds, especially theB. terrestris. Flower volatiles of strawberry ‘Red face’ were different from other strawberry varieties that have been reported; some of these electrophysiologically active compounds could cause antennal potential responses in bees, as well as behavioral responses. Our study supports the idea that strawberry flower volatiles are one of the factors influencing bee foraging decisions and provides a reference for formulating more reasonable bee pollination to improve strawberry fruit quality.Keywords:strawberry flower volatiles;Bombus terrestris;Apis mellifera;EAG response;behavior response
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Insects
·
2023
·Vol. 14
·期 12
·930
·
IF 3
Jianjun Cheng,Jiawei Gui,Xiaoming Yao,Hong Zhao,Yujie Zhou,Yongjun Du
Simple SummaryThe rice leaf roller,Cnaphalocrocis medinalis,is a migratory insect pest threatening rice production. Monitoring its population dynamics is a critical component of the integrated management system for this pest. Plant odor-trapping has been used as a tool for population monitoring. However, there is a lack of knowledge on the molecular mechanism by which theC. medinalismoth recognizes the plant odor. In the present study, we amplified 12 odor receptor genes and tested differential expression of these genes in male and female moths ofC. medinalis. We identified the function of three olfactory receptor genes inC. medinalis.CmedOR31 was a specific receptor for geraniol, and CmedOR32 was a broad-spectrum OR receptor that responds to both foliar odor and floral scent. The ligands of CmedOR1 were linalool, phenethyl alcohol, 2-phenylethanol, and phenylacetaldehyde. CmedOR1 belonged to a unique conserved OR lineage that strongly responded to phenylacetaldehyde in the evolution ofGlossataspecies, and the OR1 expression inC. medinalisantennae was significantly higher in females than in males. CmedOR1 was the odor receptor forC. medinalisadults to locate food sources.AbstractCnaphalocrocis medinalis(Lepidoptera: Crambidae) is a migratory insect pest on rice crops. The migratoryC. medinalispopulation in a particular location may be immigrants, local populations, emigrants, or a mix of these. Immigrants are strongly attracted to plant odor. We conducted research to identify the olfactory receptors in a floral scent mixture that is strongly attractive toC. medinalis. Through gene cloning, 12 olfactory receptor (OR) genes were amplified and expressed in Xenopus oocytes in vitro, and three of them were found to be responsive to plant foliar and floral volatiles. These were CmedOR31, a specific receptor for geraniol; CmedOR32, a broad-spectrum OR gene that responded to both foliar and floral odors; and CmedOR1, which strongly responded to 10−4M phenylacetaldehyde. The electrophysiological response to phenylacetaldehyde was extremely high, with a current of 3200 ± 86 nA and an extremely high sensitivity. We compared the phylogenetic tree and sequence similarity of CmedOR genes and found that CmedOR1 belonged to a uniquely conserved OR pedigree in the evolution ofGlossataspecies, and the ORs of this pedigree strongly responded to phenylacetaldehyde. The expression of OR1 was significantly higher in the females than in the males. Localization of CmedOR1 in the antennae ofC. medinalisby fluorescence in situ hybridization showed that CmedOR1 was expressed in both males and females. CmedOR1 may be an odor receptor used by females to locate food sources. The function of these ORs and their role in pest monitoring were discussed.Keywords:functional identification;Cnaphalocrocis medinalis;floral odorant;olfactory receptor
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JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2023
·
IF 6.1
Danxia Wu,Li Wang,Wei Li,Xiangyang Li
Insects rely on odorant-binding proteins (OBPs) for chemical perception, making OBPs a promising target for studying attractants and repellents of pests, such as Bemisia tabaci. However, no reports have reported using B. tabaci OBPs (BtOBPs) as pesticide screening targets. To fill this gap, we obtained BtOBP8 through prokaryotic expression and purification. Then, we confirmed its identity using western blotting and mass spectrometry. Next, we used the sitting drop and hanging drop methods to screen its crystal conditions. Using microscale thermophoresis and isothermal titration calorimetry, we identified the highest affinity ligand, 3l, from 30 compounds. Furthermore, point mutation techniques identified Val119 as a key amino acid residue in binding 31 to BtOBP8. Finally, we tested the bioactivity of B. tabaci Mediterranean and found that 3l more effectively inhibits the bioactivity of B. tabaci MED than imidacloprid. This study presents a new approach for developing green insecticides specific to B. tabaci MED by targeting OBPs. Conclusively, identifying and targeting specific OBPs can create more targeted and effective pest control strategies without relying on toxic chemicals.
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Small
·
2023
·Vol. 19
·期 49
·2304644
·
IF 13.3
Ping Lu,Zhaoyang Qi,Jie Chen,Changshen Ye,Ting Qiu
High-efficiency adsorption of aromatic sulfur-containing compounds from liquid hydrocarbon fuels over metal-organic frameworks (MOFs) is challenging because of inert metal sites. A new method, the Ce-enhanced modulation of MOFs’ microenvironment, is proposed to modulate the –COO···Cu(II)– coordination microenvironment of Hong Kong University of Science and Technology (HKUST-1) using Ce(III) as a molecular scalpel for fabricating abundant high-efficiency Cu(I) and Cu-coordination-unsaturated sites and improving the pore structures around adsorptive sites. The optimal CH-250 thus exhibits adsorptive capacities for 20.2, 28.0, and 58.3 mg S g –1 of thiophene, benzo-thiophene, and dibenzothiophene, respectively, which are superior to most reported MOFs, zeolites, and nanoporous carbons. The constructed Cu(I) sites show stronger affinity for dibenzothiophene (−0.86 eV) than the initial Cu(II) (−0.74 eV) for out-of-plane adsorption. Further, they are far stronger in-plane adsorption interactions in DBT/CH-250 (−0.90 eV) than those in DBT/HKUST-1 (−0.37 eV). Thus, molecular engineering for modulating the coordination microenvironment of MOFs shows great potential for adsorption desulfurization.
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RENEWABLE ENERGY
·
2023
·
IF 8.7
Hewei Yu,Jichao Sun,Xiuxiu Chen,Bing Wang,Xiaohui Liang,Mingjie Gao,Hongyu Si
A novel acid-base bifunctional Zn/Ca–Zr catalyst has been synthesized successfully for biodiesel production from palm oil and acidified oil. The influence of synthetic factors on the catalytic activity of resulting Zn/Ca–Zr were discussed. Furthermore, the FAMEs yield was optimized to achieve the maximum value using the Taguchi approach. Results showed that the catalyst synthesized using a metal stoichiometric ratio of 4 : 4: 4, hydrothermal conditions, and activation temperature of 850 °C exhibited the best activity. The highest FAMEs yield was found to be 94.9% under the conditions of 5 wt% catalyst dosage, methanol/palm oil molar ratio of 20, and temperature of 170 °C at 3 h. The contribution percentage indicated that the methanol/oil molar ratio had the most significant effect on the FAMEs yield. Moreover, the Zn/Ca–Zr catalyst can catalyze the simultaneous esterification and transesterification of acidified palm oil with a 95.1% FAMEs yield and 93.3% acid reduction rate. And a 78.2% FAMEs yield can be maintained after four repeated cycles. Molecular simulations indicated the active site of Zn was more easily attacked by FFAs for esterification, while the active site of Ca was retained to adsorb methanol for transesterification, which explained the catalyst's acid-base bifunctional characteristics.
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RENEWABLE ENERGY
·
2023
·
IF 8.7
Yujiao Zhang,Shengli Niu,Sunwen Xia,Sitong Liu,Jisen Liu
The novel heterogeneous catalysts of SrZr 1- x Fe x O 3 ( x = 0, 0.05, 0.10, 0.15, 0.20, 0.25, 0.30 or 0.40) with acid-base bifunctional property are prepared through the sol-gel method and applied in catalyzing transesterification and esterification from acidified oil to produce biodiesel . The substitution of Zr by Fe in the SrZrO 3 perovskite results in the lattice distortion to generate abundant surface oxygen vacancies . Also, the enhancement of electron density on active sites improves the acidity and basicity of catalyst to construct the acid-base pair sites for high efficiency of biodiesel production . The SrZr 0.75 Fe 0.25 O 3 catalyst shows the strongest catalytic activity and the maximum FAME yield of 99.5% is achieved at the reaction temperature of 178 °C, catalyst amount of 4.5 wt%, methanol to oil molar ratio of 19:1 and reaction duration of 3.4 h through optimizing reaction parameters by convolutional neural network . The catalyst exhibits strong acid resistance and the FAME yield of 93.9% is achieved with 30 wt% oleic acid addition, where methanol is readily adsorbed to Sr site for transesterification and free fatty acids are readily adsorbed to Fe site for esterification. In addition, the SrZr 0.75 Fe 0.25 O 3 catalyst shows satisfactory reusability and the FAME yield of 96.2% is maintained for the fifth reused cycle.
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