Improved sustained-release properties of ginger essential oil in a Pickering emulsion system incorporated in sodium alginate film and delayed postharvest senescence of mango fruits.

The insufficient water vapor barrier and mechanical capacity of sodium alginate (SA) film limited its application in fruit preservation. Herein, cellulose nanocrystals (CNCs) were used to stabilize Pickering emulsion. Then, we prepared SA composite films. Ginger essential oil (GEO) was loaded as antimicrobials and antioxidants. Finally, the application on mangos were investigated. Compared to coarse emulsion, Pickering emulsion and its film-formation-solution showed more stable system and larger droplet size. The emulsion significantly changed the properties of SA film. Specifically, CNCs improved the thermal, tensile, and barrier properties of the film and GEO enhanced the ultraviolet-visible light barrier capacity. Additionally, the SA/CNC film possessed a homogeneous micromorphology which had a sustained-release effect on GEO, thus maintaining high postharvest quality and long-term bioavailability for mangos. In conclusion, the film prepared via Pickering emulsion showed satisfactory properties which had great potential in fruit preservation.

The combination treatment of chlorogenic acid and sodium alginate coating could accelerate the wound healing of pear fruit by promoting the metabolic pathway of phenylpropane.

Water loss and microbial infection induced by mechanical injury are the main sources of harvested loss of fruits and vegetables. Plenty studies have shown that regulating phenylpropane-related metabolic pathways can effectively accelerate wound healing. The combination treatment of chlorogenic acid and sodium alginate coating on postharvest wound healing of pear fruit were investigated in this work. The result shows combination treatment reduced weight loss and disease index of the pears, enhanced texture of healing tissues, maintained the integrity of cell membrane system. Moreover, chlorogenic acid increased the content of total phenols and flavonoids, and ultimately leads to the accumulation of suberin poly phenolic (SPP) and lignin around wound cell wall. Activities of phenylalanine metabolism-related enzymes (PAL, C4H, 4CL, CAD, POD and PPO) in wound-healing tissue were enhanced. The contents of major substrates such as trans-cinnamic, p-coumaric, caffeic, and ferulic acids also increased. The presented results suggested that the combination treatment of chlorogenic acid and sodium alginate coating stimulated wound healing in pears by elevating the phenylpropanoid metabolism pathway, so that maintain high postharvest fruit quality.

Encapsulation of tannins and tannin-rich plant extracts by complex coacervation to improve their physicochemical properties and biological activities: A review.

As a major class of dietary polyphenols, tannins are demonstrated to have various health-promoting properties. Although tannins have been widely utilized in food, pharmaceutical and many other industries, the applications of tannins are quite limited due to their poor stability, sensory attributes and bioavailability. Encapsulation helps improve all of these properties. Complex coacervation, one of the most effective encapsulation techniques, is known for its simplicity, low cost, scalability and reproducibility in encapsulation of functional components. In recent years, complex coacervation has been successfully used for encapsulation of tannins and tannin-rich plant extracts. In this article, the research progress in encapsulating tannins and tannin-rich plant extracts by complex coacervation to improve their physicochemical properties and biological activities is critically reviewed for the first time. Encapsulation of tannins and tannin-rich plant extracts can effectively improve their sensory characteristics, stabilities, bioavailability, anti-hypercholesterolemia, anti-diabetic, antioxidant, anticancer and antimicrobial activities. In particular, the enhancement of biological activities of tannins and tannin-rich plant extracts is usually correlated to their improved physicochemical properties imparted by the encapsulation technique. Moreover, we introduce the issues that need to be further resolved in future studies on encapsulation of tannins and tannin-rich plant extracts by complex coacervation.

Development and characterization of a novel active and intelligent film based on pectin and betacyanins from peel waste of pitaya (Hylocereus undatus).

In the present study, peel waste of pitaya (Hylocereus spp.) was used to develop a novel active and functional film. The film was developed with a combination of the white-fleshed pitaya peel pectin (WPPP) as a biopolymer and white-fleshed pitaya peel betacyanins (WPPB) as an active constituent, respectively. Furthermore, montmorillonite (MMT), a cheap and environmental-friendly silicate material, was introduced into film matrix as a filler to reduce the moisture sensitivity of the film. The effect of the incorporation of WPPB on the properties of WPPP/MMT films was investigated. The colorimetric response of WPPP/MMT/WPPB to pH and ammonia was examined, respectively. Moreover, WPPP/MMT/WPPB-2 was employed to monitor the freshness of shrimp. The color of the film changed from redness to reddish-brown, and further to brownness, echoing the shrimp turned from fresh to spoiled. Therefore, WPPP/MMT/WPPB-2 composite films showed promise for the applications in monitoring the freshness of shrimp.

Protective effects of dietary icariin on lipopolysaccharide-induced acute oxidative stress and hepatopancreas injury in Chinese mitten crab, Eriocheir sinensis.

To investigate the effects of dietary icariin (ICA) supplementation on acute oxidative stress and hepatopancreatic injury induced by lipopolysaccharide (LPS) injection in Eriocheir sinensis, an 8-week feeding trial of crabs was conducted using 4 diets with different supplementation levels of ICA (0, 50, 100, and 200 mg/kg diet weight, respectively), and then challenged with LPS of 400 µg/kg body weight for 6 h. Results showed that 100 mg/kg ICA supplementation increased the antioxidant capacity, reduced the stress-related indicators in haemolymph, strengthen the mitochondrial membrane potential, and reduce apoptosis compared to the single LPS-treated crabs. The expressions of apoptosis-related genes and proteins were also evaluated to further understand the effects of dietary ICA pretreatment on LPS-induced cell apoptosis. As a result, dietary 100 mg/kg diet weight ICA pre-addition significantly down-regulated the expression of HSP60, HSP70, Caspase 3c, Caspase 8, Caspase 3, Caspase 9, P38, and Bax (P < 0.05), and alleviated the suppressed expression of PI3K, AKT, MEK, and Bcl-2 (P < 0.05) in crabs challenged with LPS. Overall, this research reveals that ICA supplementation of 100 mg/kg diet weight could enhance the resistance to oxidative damage and apoptosis in E. sinensis facing LPS challenge.

Dietary berberine can ameliorate glucose metabolism disorder of Megalobrama amblycephala exposed to a high-carbohydrate diet.

Blunt snout bream (Megalobrama amblycephala) were randomly assigned into three diets: normal-carbohydrate diet (NCD, 30% carbohydrate, w/w), high-carbohydrate diet (HCD, 43% carbohydrate), and HCB (HCD supplemented with 50 mg/kg berberine (BBR)). After 10 weeks' feeding trial, the results showed that higher levels of plasma glucose, triglyceride, and total cholesterol were observed in HCD-fed fish than in NCD-fed fish, while HCB feeding significantly ameliorated this effect. Moreover, HCB feeding remarkably reversed HCD-induced hepatic glycogen and lipid contents. In insulin signaling, BBR inclusion restored HCD-induced suppression of insulin receptor substrate mRNA expression and elevation of forkhead transcription factor 1 mRNA expression. In glucose metabolism, upregulated glucose transporter 2 and glycogen synthase mRNA expressions in the HCD group were observed compared to the NCD group. However, BBR adding reduced the mRNA expressions of glycogen synthase, phosphoenolpyruvate carboxykinase, and glucose-6-phosphatase and increased the transcriptional levels of glucose transporter 2 and pyruvate kinase. In lipid metabolism, BBR supplementation could reverse downregulated hepatic carnitine palmitoyl transferase I mRNA expression and upregulated hepatic acetyl-CoA carboxylase and fatty acid synthetase mRNA expressions in the HCD group. Taken together, it demonstrates that BBR could improve glucose metabolism of this species via enhancing liver's glycolysis and insulin signaling, while inhibiting liver's glycogen synthesis and gluconeogenesis. It also indicates that BBR could reduce the metabolic burden of the liver by inhibiting fat synthesis and promoting lipid decomposition, and then enhance fat uptake in peripheral tissues.

Preparation, characterization and in vitro hypoglycemic activity of banana condensed tannin-inulin conjugate.

To enhance the hypoglycemic effects of inulin, banana condensed tannins (BCT) were grafted onto inulin via a free radical method to synthesize the novel BCT grafted inulin (BCT-g-inulin) complex. Spectroscopic methods, XRD, TGA, 1H NMR, GPC and morphology analyses were utilized to characterize the structural properties of the BCT-g-inulin complex, and our results confirmed the conjugation of BCT and inulin. The conjugation possibly occurred between the hydroxyl group attached at the C6 position of inulin and the C6/C8 position of flavon-3-ol units of BCT. The grafting ratio and grafting efficiency of the BCT-g-inulin complex were 357.54 ± 2.98 g kg-1 complex and 74.57 ± 1.44%, respectively. The data of the antioxidant assays indicated that the BCT-g-inulin complex showed a significantly higher antioxidant activity than native inulin. Also, the grafting reaction remarkably improved the in vitro anti-diabetic activity of inulin. The glucose adsorption capacity and glucose dialysis retardation index of the BCT-g-inulin complex were remarkably higher than those of inulin, while the BCT-g-inulin complex showed much stronger inhibitory effects against α-amylase and α-glucosidase compared with inulin. Notably, the inhibition of both α-amylase and α-glucosidase by the BCT-g-inulin complex occurred through mixed-competitive mode. On the basis of fluorescence spectroscopy, the fluorescence of α-amylase and α-glucosidase could be quenched by the BCT-g-inulin complex through a static quenching mechanism. Hence, the BCT-g-inulin complex might have the potential to be developed as an effective anti-diabetic agent.

Multiple 1-MCP treatment more effectively alleviated postharvest nectarine chilling injury than conventional one-time 1-MCP treatment by regulating ROS and energy metabolism.

The objective of the present study was to investigate the effectiveness of different 1-MCP treatment patterns on alleviating chilling injury (CI) of postharvest nectarine stored at 0 ± 1 °C. Nectarine fruits were subjected to the following treatments: Single-High dose 1-MCP treatment (S-H): 1 µL L-1 application before storage; Multi-low dose 1-MCP treatment: (M-L) Five 0.25 µL L-1 applications after 0, 5, 10, 15, and 20 d of storage; Multi-high dose 1-MCP treatment (M-H): Five 1 µL L-1 applications after 0, 5, 10, 15 and 20 d of storage. The results showed that although all 1-MCP treatments alleviated CI, M-H 1-MCP treatment is the most effective pattern in alleviating CI of nectarine fruit in S-H, M-L, and M-H 1-MCP treatments. Moreover, this study indicated that the reduction of CI in nectarine by 1-MCP application was related to its regulations of ROS and energy metabolism.

Analyses of microstructure and cell wall polysaccharides of flesh tissues provide insights into cultivar difference in mealy patterns developed in apple fruit.

Mealiness is one of the most important textural failure of apple fruit and four patterns of mealiness involving five apple cultivars were identified as the rapid, moderate, slow and none, requiring 3, 7, 14, 49 days at 25 °C, respectively. In comparison with the non-mealy 'Fuji' apple, parenchyma cells of mealy apples became detached and remained intact. Highly methyl-esterified homogalacturonan was strongly immunolabeled in the cell wall of slow and non-mealy apples. The mobility of water was enhanced in the cell wall during mealiness. Principal components analysis of FTIR spectra discriminated the cell wall materials (CWM) based on the mealiness progress. Heavy loss of CWM and its water-insoluble fractions but limited increase of water-soluble fractions, and the increase of crystalline micelles of CWM were closely associated with the mealiness progress. Overall, the occurrence of mealiness might attribute to structural, physical and biochemical modifications of CWM during tissue senescence.

Development of antioxidant chitosan film with banana peels extract and its application as coating in maintaining the storage quality of apple.

In the present study, the antioxidant chitosan (CS)-banana peels extract (BPE) composite film was developed. The different content of BPE (4%, 8% and 12%) was added to the CS film not only as the antioxidant but also as the cross-linking. The CS, CS-4% BPE, CS-8% BPE and CS-12% BPE films were characterized by scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FTIR), X-ray diffraction analysis (XRD) and thermogravimetric analysis (TGA). The physical and mechanical properties possessed by the CS and CS-BPE films were compared as well, and the CS-4 %BPE composite film exhibited the most excellent properties. The decline in moisture contents, water solubility and water vapor permeability of CS-BPE composite film indicated the reduced hydrophilicity. Moreover, the CS-BPE composite film exhibited excellent antioxidant activity in different food simulants. Finally, the optimal concentration of CS-BPE coating treatment was identified and applied to apple fruit, and the results showed that CS-BPE coating was more capable of improving the postharvest quality of apple fruit than CS coating. This study evidences the promising nature of CS-BPE composite film and coating as a desirable alternative for active packaging and it is believed as conducive to valorization of banana peel by-products for allied applications.

Antioxidant and antibacterial chitosan film with tea polyphenols-mediated green synthesis silver nanoparticle via a novel one-pot method.

In the present study, the antioxidant and antibacterial chitosan/tea polyphenols-silver nanoparticles composite film (CS/TP-AgNPs) was developed via a novel one-pot method. The TP was added to the CS film not only as the reducing agent of AgNPs but also as the cross-linking agent and antioxidant. The AgNPs and nanocomposite films developed were characterized by field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). Besides, the physical, mechanical, antioxidant and antibacterial properties of the nanocomposite films were also analyzed. As the content of TP-AgNPs incorporation increased, the color of CS/TP-AgNPs nanocomposite film gradually shifted to brown, accompanied by an increase in opacity and thickness. The decrease in moisture contents and water vapor permeability of CS/TP-AgNPs nanocomposite film indicated that the TP-AgNPs varied the original bond between the CS-CS and CS-water. The denser cross-section of CS/TP-AgNPs nanocomposite film confirmed the enhanced mechanical properties. It is worth noting that CS/TP-AgNPs nanocomposite film exhibited more excellent antioxidant and antibacterial activity than CS film. This study developed the multi-functionality chitosan film by the simultaneous incorporation of AgNPs and TP and revealed the multiple effects of TP acting as reducing agent for AgNPs, cross-linking agent and antioxidant on chitosan film.

Inhibitory Effect of Condensed Tannins from Banana Pulp on Cholesterol Esterase and Mechanisms of Interaction.

In the present study, the inhibitory effect of condensed tannins (CTs) on cholesterol esterase (CEase) was studied. The underlying mechanisms were evaluated by reaction kinetics, turbidity and particle size analyses, multispectroscopy methods, thermodynamics, and computer molecular simulations. CTs showed potent CEase inhibitory activity with an IC50 value of 64.19 µg/mL, and the CEase activity decreased with increasing CT content in a mixed-competitive manner, which was verified by molecular docking simulations. Fluorescence and UV-vis measurements revealed that complexes were formed from CEase and CTs by noncovalent interaction. Isothermal titration calorimetry indicated that the interaction between CEase and CTs occurred through hydrogen bonding and hydrophobic interactions. Circular dichroism analysis suggested that CTs inhibited the activity of CEase by altering the secondary structure of CEase. The inhibition of CTs on CEase in the gastrointestinal tract might be one mechanism for its cholesterol-lowering effect.

Cell wall polysaccharides degradation and ultrastructure modification of apricot during storage at a near freezing temperature.

The effects of near freezing temperature (NFT) storage at -1.9 °C on cell wall degradation of 'Shushanggan' apricot was studied comparing to 0 °C and 5 °C storage. Our results indicated that NFT storage strongly inhibited the solubilization of Na2CO3-soluble pectin and cellulose, by the suppression of cell wall modifying enzymes (polygalacturonase, ß-Galactosidase, pectin methyl esterase and cellulase) and related genes expressions. The loss of side chains was the main modification in CDTA (Cyclohexane-diamine-tetraacetic Acid)-soluble pectin during storage and made the main contribution to the softening of apricot, while the loss of side chain was suppressed by NFT storage. Microscopic observation showed that NFT storage delayed the degradation of pectin fraction and protected cell wall structure from loosing. This study proves that NFT storage is an effective technology to suppress the cell wall polysaccharides degradation and ultrastructure modification of apricot.

Protective roles of flavonoids and flavonoid-rich plant extracts against urolithiasis: A review.

In the urinary system, urolithiasis is the third prevalent disorder which causes severe pain in individuals. Urinary stones are composed of calcium oxalate (CaOx) and calcium phosphate in approximately 80% of patients. Although various drugs and surgery operations are used to treat the disease, side effects of drugs and the high recurrence after therapy in patients cannot be ignored. Flavonoids are a large group of plant polyphenols with presumed beneficial effects on several common diseases. Whereas, a very few have reached clinical use. The results of recent studies have shown that the plant flavonoids could effectively inhibit the formation of CaOx stones in vitro and in vivo, correlating with their diuretic, antioxidant, anti-inflammatory, antibacterial properties and other protective effects. Thus, the flavonoids or flavonoid-rich plant extracts endowed with anti-urolithiasis activities and probable mechanisms of actions were reviewed. In addition, we also put forward some issues needed to be concerned in future investigations as well as offered prospects and challenges for developing the plant flavonoids into drugs for stone prevention.

Compositional modifications of bioactive compounds and changes in the edible quality and antioxidant activity of 'Friar' plum fruit during flesh reddening at intermediate temperatures.

Flesh reddening of 'Friar' plum (Prunus salicina Lindl.) fruit developed rapidly during storage at intermediate temperatures of 5 and 15 °C in comparison to flesh turning yellow at 25 °C and almost no colour change at 0 °C. Thus, modifications of phytochemicals and antioxidant activity during flesh reddening were investigated. Anthocyanins accumulated rapidly in reddening flesh tissue and cyanidin-3-O-glucoside was identified as the absolutely predominant individual anthocyanin. Anthocyanins contributed greatly to the antioxidant activity at 5 °C, and especially at 15 °C by combining with non-anthocyanin phenolics, including protocatechuic, syringic, trans-p-coumaric and caffeic acids. Storage at 15 °C impeded the hydrolysis of sucrose to glucose and fructose, while storage at 5 °C maintained sucrose and accumulated fructose. Intermediate temperatures altered organic acid compositions helping to produce reasonable SSC/TA ratios. These results would provide a postharvest approach for fruit to meet the consumer's demand for diverse tastes and health promoting effects.

Protective effects of banana pectin against aluminum-induced cognitive impairment and aluminum accumulation in mice.

To investigate the effect of pectin on absorption and bio-toxicity of aluminum, pectin extract (100 mg kg-1 d-1) from banana pulp was orally administrated to aluminum exposed mice (35 mg kg-1 d-1) for 6 weeks. Our result showed that body weight gain of the mice treated with aluminum plus banana pectin was 32.5% higher than that of mice exposed to aluminum alone after 6 weeks of the administration. In both the step-down inhibitory avoidance task and Morris water maze test, memory retention of aluminum-exposed mice was significantly improved by the pectin administration. Treatment with banana pectin effectively prevented absorption of aluminum from the gastrointestinal tract, total aluminum excretion of mice treated with banana pectin plus aluminum was 9.3% higher than that of mice exposed to aluminum alone on the 12th day. Aluminum level in serum, cerebrum, or cerebellum of mice treated with aluminum plus banana pectin was 30.8%, 17.5%, or 17.9% lower than that of mice exposed to aluminum alone on the 42nd day, respectively. In conclusion, banana pectin extract can effectively reduce aluminum toxicity in mice.

Identification of the flavonoids in mungbean (Phaseolus radiatus L.) soup and their antioxidant activities.

Mung bean soup (MBS) has been traditionally taken as a kind of health food in China. To learn the mechanisms underlying its health benefits, antioxidant capacities of the soup prepared with three cultivars of mung bean were measured. The highest DPPH radical scavenging or ferric reducing activity was observed in soup of mung bean cv. Huang. The MBS of cv. Huang and Mao exhibited higher ABTS(+) reducing activities than MBS of cv. Ming. The two major flavonoids in the MBS were purified and identified as vitexin and isovitexin, respectively. Modeling samples containing vitexin and isovitexin at the same levels as them in the MBS were prepared to assess their antioxidant contributions in the MBS. Our results showed that antioxidant capacities of the MBS mainly derived from vitexin and isovitexin, these flavonoids accounted for the most of total DPPH radicals scavenging, ferric reducing and ABTS(+) reducing scavenging activities in MBS of all the three cultivars.

Use of UV-C treatment to inhibit the microbial growth and maintain the quality of Yali pear.

UNLABELLED: The effects of UV-C radiation on microbial growth in vitro (Monilinia fruticola) and in inoculated Yali pears (Pyrus bretschneideri Rehd.) were investigated. Moreover, postharvest quality and the activities of defense and antioxidant enzymes were analyzed after the pears were exposed to UV-C irradiation at an energy level of 5 kJ m⁻².The results showed that spore germination of M. fructicola was significantly inhibited by each of the 3 doses (1, 5, and 10 kJ m⁻²) in vitro. In the in vivo assays, lesion diameter on the fruit being inoculated before or after the UV-C treatment was both significantly lower than that on the fruit of control. Meanwhile, the activities of phenylalanine ammonia lyase, ß-1,3-glucanase, superoxide dismutase, catalase, and glutathione reductase were induced to high levels by UV-C treatment. We conclude that UV-C treatment could reduce postharvest disease by the germicidal and induced effects and maintain the quality by enhancing the antioxidant enzyme activities. PRACTICAL APPLICATION: UV-C radiation has recently been proposed as a new technology to avoid chemical fungicides. However, there are few studies regarding the effect of UV-C treatment on Yali pear. In this study, we found that 5 kJ m⁻² UV-C irradiation can control postharvest disease and maintain the quality of Yali pear. This method may be applied to reduce the decay of Yali pears during exporting and storage.

Spirobisnaphthalenes from the endophytic fungus Dzf12 of Dioscorea zingiberensis and their antimicrobial activities.

Five spirobisnaphthalenes, namely palmarumycin CP17 (1), diepoxin kappa (2), diepoxin eta (3), diepoxin xi (4), and diepoxin gamma (5), were isolated from the endophytic fungus Dzf12 associated with the medicinal plant Dioscorea zingiberensis C. H. Wright. Their structures were identified by physicochemical and spectrometric analysis. Among these spirobisnaphthalenes, 2 was found to have antibacterial activity, and the mixture of 3 and 4 was detected to have both antibacterial and antifungal activities.

Chemical composition and in vitro antimicrobial activity of the volatile oils from Gliomastix murorum and Pichia guilliermondii, two endophytic fungi in Paris polyphylla var. yunnanensis.

Volatile oils were obtained by hydro-distillation from Gliomastix murorum and Pichia guilliermondii, two endophytic fungi isolated from the traditional Chinese medicinal herb Paris polyphylla var. yunnanensis. The oils were analyzed for their chemical composition by gas chromatography-mass spectrometry (GC-MS). Palmitic acid (15.5%), (E)-9-octadecenoic acid (11.6%), 6-pentyl-5,6-dihydropyran-2-one (9.7%), and (7Z,10Z)-7,10- hexadecadienoic acid (8.3%) were the major compounds of the 40 identified components in G. murorum volatile oil. 1,1,3a,7-Tetramethyl-1a,2,3,3a,4,5,6,7b-octahydro-1H-cyclopropa[a]- naphthalene (25.9%), palmitic acid (15.5%), 1-methyl-2,4-di- (prop-1-en-2-yl)-1- vinylcyclohexane (7.9%), (E)-9-octadecenoic acid (7.3%), and (9E,12E)-ethyl-9,12-octadecadienoate (5.2%) were the major compounds of the 27 identified components in P. guilliermondii volatile oil. The in vitro antimicrobial activity of the volatile oils was also investigated to evaluate their efficacy against six bacteria and one phytopathogenic fungus. The minimum inhibitory concentration (MIC) values of the volatile oils against the test bacteria ranged from 0.20 mg/mL to 1.50 mg/mL. One of the most sensitive bacteria was Xanthomonas vesicatoria with an MIC of 0.20 mg/mL and 0.40 mg/mL for G. murorum and P. guilliermondii, respectively. The mean inhibitory concentration (IC50) of the volatile oils against spore germination of Magnaporthe oryzae was 0.84 mg/mL for G. murorum and 1.56 mg/mL for P. guilliermondii. These results indicated that the volatile oils from the endophytic fungi have strong antimicrobial activity and could be a potential source of antimicrobial ingredients.