Fruit quality assessment based on mineral elements and juice properties in nine citrus cultivars

IntroductionCitrus fruit is considered a superfood due to its multiple nutritional functions and health benefits. Quantitative analysis of the numerous quality characteristics of citrus fruit is required to promote its sustainable production and industrial utilization. However, little information is available on the comprehensive quality assessment of various fruit quality indicators in different citrus cultivars.MethodsA total of nine different fresh citrus fruits containing seeds were collected as the experimental materials. The objectives of this study were: (i) to determine the morphological and juice properties of citrus fruits, (ii) to measure the mineral elements in the peel, pulp, and seeds, and (iii) to evaluate the fruit quality index (FQI) using the integrated quality index (IQI) and the Nemoro quality index (NQI) methods.ResultsThere were significant differences in fruit quality characteristics, including morphological, mineral, and juice quality, among the investigated citrus cultivars. The proportion of pulp biomass was the highest, followed by that of peel and seeds. N and Cu had the highest and lowest concentrations, respectively, among the measured elements across all citrus fruits, and the amounts of N, P, Mg, Cu, and Zn in seeds, K and Al in pulp, and Ca, Fe, and Mn in peel were the highest, dramatically affecting the accumulation of minerals in the whole fruit and their distribution in various fruit parts. Additionally, Ningmeng fruits had the highest vitamin C and titratable acidity (TA) but the lowest total soluble solids (TSS) and total phenolic (TP) contents, resulting in the lowest TSS/TA and pH values. In contrast, Jinju fruits had the highest TSS and TP contents. Based on the mineral element and juice quality parameters, principal component analysis showed that the citrus fruits were well separated into four groups, and the dendrogram also showed four clusters with different distances. The FQI range based on the IQI method (FQIIQI) and NQI method (FQINQI) was 0.382-0.590 and 0.106-0.245, respectively, and a positive relationship between FQIIQI and FQINQI was observed.ConclusionOur results highlight the great differences in mineral and juice characteristics among fruit parts, which mediated fruit quality. The strategy of fruit quality assessment using the FQI can be expanded for targeted utilization in the citrus industry

Atomic Ordering Effect of Intermetallic PdCoNi/rGO Catalysts on Formic Acid Electro-oxidation

Pd-based alloys, especially for alloys containing early transition metals, have been extensively designed and applied to electro-oxidize formic acid for direct formic acid fuel cells owing to their capability to directly oxidize formic acid molecules via the dehydrogenation pathway. Adjusting the strain and electronic effects of Pd-based alloys is an effective method to regulate the adsorbing phenomena of intermediates on catalysts during formic acid oxidation and improve the catalytic activity and stability. The ordering degree of alloys plays an important role in modulating the adsorbing ability. In this work, we report a strategy varying the atomic ordering degree of PdCoNi/rGO trimetallic alloys to manipulate the strain and electronic effects and electrocatalytic performance toward formic acid oxidation. A series of PdCoNi/rGO-T trimetallic catalysts are synthesized, in which the atomic order of the trimetallic catalysts is regulated by annealing the wet-chemistry-synthesized PdCoNi/rGO alloy. As the annealing temperature increases, the atomic arrangement among Pd, Co, and Ni is ordered. Eventually, ordered intermetallic PdCoNi/rGO-T catalysts are generated. As the atomic ordering degree increases, the lattice constant decreases, and more charge transfers from Pd to Ni and Co, leading to enhanced strain and electronic effects. Moreover, the ordered intermetallic structure stabilizes Co and Ni atoms to prevent the dissolution of the transition metals in acidic electrolyte, and the strain and electronic effects in ordered PdCoNi/rGO catalysts are maintained. With an annealing temperature of 700 °C, the intermetallic PdCoNi/rGO-700 exhibits the highest specific activity of 8.33 mA/cm2, which is 1.95-fold improved compared to pristine PdCoNi/rGO alloy (3.23 mA/cm2) and 2.48 times compared to Pd/rGO-700 (2.54 mA/cm2). Moreover, PdCoNi/rGO-700 also shows outstanding catalytic durability due to its excellent structural stability. We believe that this research helps in developing Pd-based alloy catalysts with high activity and stability for formic acid electro-oxidation

Bending Resistance Covalent Organic Framework Superlattice: “Nano-Hourglass”-Induced Charge Accumulation for Flexible In-Plane Micro-Supercapacitors

Abstract Covalent organic framework (COF) film with highly exposed active sites is considered as the promising flexible self-supported electrode for in-plane micro-supercapacitor (MSC). Superlattice configuration assembled alternately by different nanofilms based on van der Waals force can integrate the advantages of each isolated layer to exhibit unexpected performances as MSC film electrodes, which may be a novel option to ensure energy output. Herein, a mesoporous free-standing A-COF nanofilm (pore size is 3.9 nm, averaged thickness is 4.1 nm) with imine bond linkage and a microporous B-COF nanofilm (pore size is 1.5 nm, averaged thickness is 9.3 nm) with β-keto-enamine-linkages are prepared, and for the first time, we assembly the two lattice matching films into sandwich-type superlattices via layer-by-layer transfer, in which ABA–COF superlattice stacking into a “nano-hourglass” steric configuration that can accelerate the dynamic charge transportation/accumulation and promote the sufficient redox reactions to energy storage. The fabricated flexible MSC–ABA–COF exhibits the highest intrinsic C V of 927.9 F cm−3 at 10 mV s−1 than reported two-dimensional alloy, graphite-like carbon and undoped COF-based MSC devices so far, and shows a bending-resistant energy density of 63.2 mWh cm−3 even after high-angle and repeat arbitrary bending from 0 to 180°. This work provides a feasible way to meet the demand for future miniaturization and wearable electronics

Spatial epigenome–transcriptome co-profiling of mammalian tissues

Emerging spatial technologies, including spatial transcriptomics and spatial epigenomics, are becoming powerful tools for profiling of cellular states in the tissue context1-5. However, current methods capture only one layer of omics information at a time, precluding the possibility of examining the mechanistic relationship across the central dogma of molecular biology. Here, we present two technologies for spatially resolved, genome-wide, joint profiling of the epigenome and transcriptome by cosequencing chromatin accessibility and gene expression, or histone modifications (H3K27me3, H3K27ac or H3K4me3) and gene expression on the same tissue section at near-single-cell resolution. These were applied to embryonic and juvenile mouse brain, as well as adult human brain, to map how epigenetic mechanisms control transcriptional phenotype and cell dynamics in tissue. Although highly concordant tissue features were identified by either spatial epigenome or spatial transcriptome we also observed distinct patterns, suggesting their differential roles in defining cell states. Linking epigenome to transcriptome pixel by pixel allows the uncovering of new insights in spatial epigenetic priming, differentiation and gene regulation within the tissue architecture. These technologies are of great interest in life science and biomedical research