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The prevalence of vitamin A deficiency in sub-Saharan Africa necessitates effective approaches to improve provitamin A content of major staple crops. Cassava holds much promise for food security in sub-Saharan Africa, but a negative correlation between β-carotene, a provitamin A carotenoid, and dry matter content has been reported, which poses a challenge to cassava biofortification by conventional breeding. To identify suitable material for genetic transformation in tissue culture with the overall aim to increase β-carotene and maintain starch content as well as better understand carotenoid composition, root and leaf tissues from thirteen field-grown cassava landraces were analyzed for agronomic traits, carotenoid, chlorophyll, and starch content. The expression of five genes related to carotenoid biosynthesis were determined in selected landraces. Analysis revealed a weak negative correlation between starch and β-carotene content, whereas there was a strong positive correlation between root yield and many carotenoids including β-carotene. Carotenoid synthesis genes were expressed in both white and yellow cassava roots, but phytoene synthase 2 (PSY2), lycopene-ε-cyclase (LCYε), and β-carotenoid hydroxylase (CHYβ) expression were generally higher in yellow roots. This study identified lines with reasonably high content of starch and β-carotene that could be candidates for biofortification by further breeding or plant biotechnological means.

A new high performance liquid chromatography (HPLC) method for the measurement of 3-chloropropane-1,2-diol fatty acid esters in oil samples without any derivatization treatment is presented in this paper. The qualification analysis of 3-MCPD esters was performed by UPLC-Q-TOF MS while quantification analysis was carried out by HPLC method using 1,2-dioleoyl-3-chloropropanediol and 1-stearoyl-3-chloropropanediol standards as reference standard substances. The linearity was verified (correlation coefficients > 0.99) within the concentrations ranged from 0.01 to 0.28 mg mL−1. The intraday precision ranged from 2.1 to 4.0%, and the interday precision ranged between 3.2 and 5.6%. The recovery values of 3-MCPD esters standard substances spiked canola oil sample at the concentrations of 800, 1000 and 1200 mg kg−1 were found to be 106.6% ± 11.8, 94.7% ± 13.3 and 105.8% ± 8.8 for 1,2-dioleoyl-3-chloropropanediol, 91.9% ± 12.3, 87.5% ± 5.3 and 108.6% ± 3.7 for 1-stearoyl-3-chloropropanediol, respectively. The limit of detection (LOD) and limit of quantification (LOQ) were 3.43 and 5.71 μg mL−1 for 1,2-dioleoyl-3-chloropropanediol, 2.55 and 5.66 μg mL−1 for 1-stearoyl-3-chloropropanediol, separately. [ABSTRACT FROM AUTHOR]

Nitrated phenols are a group of nitrogen-containing organics ubiquitously present in ambient air, which are also important components of atmospheric light-absorbing organic matter (brown carbon) that have significant impacts on climate change, air quality, and human health. In this study, we collected a total of 265 daily filter samples of fine particles (PM 2.5 ) in northern suburban Nanjing from March 2019 to January 2020. We used ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS) to detect and quantify eight nitrated phenolic species. The results showed that the average annual concentration of total nitrated phenols in the sampling site was 18.77 ng·m -3 , and the average concentrations in spring, summer, autumn, and winter were 16.82, 8.59, 17.28, and 44.79 ng·m -3 , respectively. Such concentrations were obviously higher than those determined in other countries but were similar to those in domestic cities, such as Jinan. 4-Nitrophenol was the most abundant nitrated phenol, followed by 4-nitrocatechol and 2-methoxy-5-nitrophenol. Correlation analysis showed that 3-nitrosalicylic acid was from a specific source different from that of other species. Finally, we used a positive matrix factorization model to quantify the source contributions of nitrated phenols. The major sources were vehicle emissions (32%), mixed coal and biomass burning emissions (44%), and industrial emissions (24%). The mixed coal and biomass burning emissions were dominant in autumn and winter. The mass fraction of 3-nitrosalicylic acid in the factor of industrial emissions was>90%, consistent with the results of the correlation analysis. Overall, this study provides valuable insights into the understanding of concentrations, characteristics, and sources of atmospheric nitrated phenols in ambient air.

The prevalence of vitamin A deficiency in sub-Saharan Africa necessitates effective approaches to improve provitamin A content of major staple crops. Cassava holds much promise for food security in sub-Saharan Africa, but a negative correlation between β-carotene, a provitamin A carotenoid, and dry matter content has been reported, which poses a challenge to cassava biofortification by conventional breeding. To identify suitable material for genetic transformation in tissue culture with the overall aim to increase β-carotene and maintain starch content as well as better understand carotenoid composition, root and leaf tissues from thirteen field-grown cassava landraces were analyzed for agronomic traits, carotenoid, chlorophyll, and starch content. The expression of five genes related to carotenoid biosynthesis were determined in selected landraces. Analysis revealed a weak negative correlation between starch and β-carotene content, whereas there was a strong positive correlation between root yield and many carotenoids including β-carotene. Carotenoid synthesis genes were expressed in both white and yellow cassava roots, but phytoene synthase 2 (PSY2), lycopene-ε-cyclase (LCYε), and β-carotenoid hydroxylase (CHYβ) expression were generally higher in yellow roots. This study identified lines with reasonably high content of starch and β-carotene that could be candidates for biofortification by further breeding or plant biotechnological means. [ABSTRACT FROM AUTHOR]