Poor postharvest handling, microbial infestation, and high respiration rate are some the factors are responsible for poor storage life of perishable commodities. Therefore, effective preservation of ...these commodities is needed to lower the damages and extend shelf life. Preservation is regarded as the action taken to maintain desired properties of a perishable commodity as long as possible. Persimmon (Diospyros kaki) is perishable fruit with high nutritive value; however, has very short shelf-life. Therefore, effective preservation and drying is needed to extend its storage life. Drying temperature and preservatives significantly influence the quality of perishable vegetables and fruits during drying. The current study investigated the effect of different temperatures and preservatives on drying kinetics and organoleptic quality attributes of persimmon. Persimmon fruits were treated with preservatives (25% honey, 25% aloe vera, 2% sodium benzoate, 1% potassium metabisulfite, and 2% citric acid solutions) under different drying temperatures (40, 45, and 50°C). All observed parameters were significantly affected by individual effects of temperatures and preservatives, except ash contents. Similarly, interactive effects were significant for all parameters except total soluble sugars, ash contents, and vitamin C. Generally, fruits treated with citric acid and dried under 50°C had 8.2% moisture loss hour.sup.-1, 14.9 drying hours, 0.030 g H.sub.2 O g.sup.-1 hr.sup.-1, 1.23° Brix of total soluble solids, 6.71 pH, 1.35% acidity, and 6.3 mg vitamin C. These values were better than the rest of the preservatives and drying temperatures used in the study. Therefore, treating fruits with citric acid and drying at 50°C was found a promising technique to extend storage life of persimmon fruits. It is recommended that persimmon fruits dried at 50°C and preserved in citric acid can be used for longer storage period.
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The effective extraction of gallium(Ⅲ) from alkaline solutions is a crucial strategy for the sustainable development of gallium resources. However, the conventional adsorption method ...is limited in terms of both the adsorption capacity and adsorption rate of gallium(Ⅲ). In this study, the optimal nitrogen-doped persimmon-powder activated carbon aerogel (NPAC) was prepared via optimizing synthesis conditions such as hydrothermal time, hydrothermal temperature, mass ratio of zinc chloride, and pyrolysis temperature to investigate the electrosorption effect of NPAC on gallium(Ⅲ). The results demonstrated that the electrode prepared from NPAC（NPAC@CF） exhibited exceptional electrochemical performance, attributed to the synergistic effect of reduced impedance, enhanced reversibility, and controlled capacitance (the capacitive contribution can be accurately quantified). At a bias voltage of 1.2 V, a pH of 11 and an initial concentration of NaGaO2 of 160 mg/L, the NPAC@CF electrode reached an outstanding electrosorption capacity of 250.69 mg g−1 for gallium(Ⅲ), which surpassed that of the conventional adsorption by over twofold. Electrosorption not only notably enhanced the adsorption capacity of NPAC for gallium(Ⅲ) but also elevated the adsorption rate, reducing the adsorption equilibrium time to just 40 min. The electrosorption mechanism of GaO2- on the surface of NPAC@CF was further understood by FTIR and XPS analyses, which mainly involved capacitive adsorption and the interaction of N/O-containing functional groups with GaO2-. Consequently, the electrosorption technology emerges as a promising, novel, and efficient approach for gallium extraction from alkaline solutions.
Persimmon fruit quickly softens after harvest, which limits its industrial value. The hormone melatonin has been reported to delay fruit ripening and softening. However, the effect of melatonin on ...postharvest persimmon fruit remains inconclusive. In this study, we found 10 μM melatonin treatment delayed the softening of persimmon fruit, accompanying with lower levels of endogenous ethylene and abscisic acid (ABA). Further, transcriptomic and metabolomic analysis were applied to investigate the regulatory mechanism. In total, 6831 differentially expressed genes (DEGs) and 1224 differentially accumulated metabolites (DAMs) were identified. We also investigated the metabolism pathways and regulatory networks incorporating crucial structural genes and TF during persimmon fruit softening. They were involving functions of saccharides, organic acids, ethylene biosynthesis, and ABA biosynthesis. In conclusion, our results indicate that melatonin can delay the biosynthesis of ethylene and ABA during persimmon softening and provide new insights into the regulatory pathways of melatonin-maintained persimmon fruit quality.
•Melatonin delayed persimmon fruit softening and suppressed the biosynthesis of endogenous ethylene and abscisic acid.•A total of 6831 DEGs and 1224 DAMs were obtained.•Complex regulatory networks involved in pathways of saccharides and organic acids, ethylene biosynthesis and ABA biosynthesis were constructed.
Drying persimmon pulp causes an increase in astringency, which is a great concern for persimmon manufacturers. This research investigates the increment in astringency observed during three drying ...technologies, freeze, vacuum and hot air drying, respectively, and proposes two mitigation pretreatments. The phenols in persimmon samples were correlated with their astringent level measured by tannin content, mean degree of polymerization (mDP) and degree of galloylation (DG). The astringency of fresh persimmon pulp increased four times after freeze drying, which is the least compared to hot air and vacuum drying. However, pH adjustment and pectinase hydrolysis can effectively mitigate the astringent taste. The best pre-treatment was pectinase hydrolysis since it decreased the mDP to 4.7 and DG to 13 %, similar to the level of fresh pulp. The acidic pH treatment (pH=2) can also significantly decrease the astringent level, however, the taste perception also changed dramatically. An HPLC-MS-DAD analysis has identified and quantified the phenol profile of dried persimmon, and the concentration of small molecular weight phenols was negatively correlated to the tannin content, thus astringent level. A further multivariate analysis including tannin concentration, phenols quantification and taste simulation by e-tongue confirmed that pectinase pretreatment has the least increment in astringency and similar taste perception.
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•The re-astringency of persimmon pulp during drying was observed and characterized.•The efficiency of pH and enzyme treatments to mitigate re-astringency was evaluated.•Gallic acid and its derivatives were the most important compounds in persimmon.•A high correlation was observed between tannin content and oral perception.•Pretreatment with pectinase is able to mitigate re-astringency significantly.
In the present study, multi-scale methods, including emulsifying capability evaluation and emulsion stability determination, were used to explore the effect of persimmon tannin (PT) on the ...emulsification performance of persimmon pectin (PP). A series of PP-PT solutions containing 10 mg/mL of PP and 0.05–2 mg/mL of PT were prepared and used to fabricate oil-in-water emulsions. Further, the potential influencing mechanism of PT on the emulsifying characteristics of PP was exploited by the Cryo-SEM morphology, interfacial tension, and interfacial dilatational rheology measurements. The results indicated that the emulsifying and emulsion-stability potential of PP was enhanced with the addition of high-level PT (1 and 2 mg/mL), reflected by the improvement in emulsifying capacity, droplet sizes (D32, D43, and particle size), TSI value, creaming thickness, and the strengthened tolerance to salt ions (100–1000 mmol/L NaCl and 100–500 mmol/L CaCl2), heating treatment (50–90 °C for 60 min), and accelerated destruction process (thermal cycling and accelerated centrifugation). However, PT in low concentrations (0.05, 0.1, and 0.2 mg/mL) displayed emulsion-damaging effects. In addition, high concentrations of PT (1 and 2 mg/mL) promoted the 3D-network structure, formed the honeycomb structure of emulsions and enhanced the viscoelasticity of the interfacial film to resist unfavorable factors. In contrast, the network structure and interfacial viscoelasticity deteriorated when low levels of PT (0.05, 0.1, and 0.2 mg/mL) were added. Overall, high levels of PT can be a cooperative agent for enhancing the emulsification properties of PP. Our data might provide a scientific basis for broadening the application of PP and PT as functional ingredients in the food industry.
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•PT significantly affected the emulsification properties of PP.•High concentrations of PT enhanced PP's emulsifying performance; by contrast, the low levels damaged it.•High concentrations of PT promoted the 3D-network structure and formed the honeycomb structure to resist unfavorable factors.
Herein, using dialdehyde waste paper (DAWP) as a cross-linking agent to immobilize persimmon tannin (PT) was first used to remove the U(VI) and Cr(VI) via the “waste control by waste” concept. The ...microscopic and macroscopic surface properties of the as-prepared adsorbent was characterized by the advanced characterization techniques. Factors that affected the elimination process such as variable pH, coexistence ions and equilibrium time were investigated by batch techniques. The results showed that the maximal removal capacities of U(VI) and Cr(VI) on DAWP-PT were 242.3 mg/g (pH = 6.0) and 178.7 mg/g (pH = 2.0) at 298 K, which exhibited competitiveness with most of the reported solid materials. Meanwhile, adsorption data were fitted perfectly to the Langmuir and Pseudo-second-order equations, which indicated that the monolayer and homogenous chemisorption dominated the removal process. The SEM-EDX, DFT and XPS analysis conformed that adsorption of U(VI) was mainly via surface complexation, while the elimination of Cr(VI) was a redox reaction process, and about 65.33% of Cr(III) and 34.67% of Cr(VI) co-existed onto the surface of DAWP-PT. Thus, this study would provide a high-efficiency and low-cost adsorbent for radionuclide and heavy metal treatment.
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•An efficient bio-adsorbent (DAWP-PT) was successfully prepared.•DAWP-PT exhibited an excellent elimination ability for Cr(VI) and U(VI).•Water environmental conditions played a vital role in Cr(VI) and U(VI) removal.•Removal of Cr(VI) was a redox reaction, while adsorption of U(VI) was surface complexation.
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