Hydroxyl Radical Scavenging Rate Research Articles

Multi-index evaluation of different parts of Amomum villosum

To investigate the quality differences between the seeds and husks of Amomum villosum and explore the rationality of using the seeds without husks, this study determined the content of protocatechuic acid, vanillic acid, epicatechin, quercitrin, volatile oil, water extract, and ethanol extract. The 2,2-diphenyl-1-picrylhydrazyl(DPPH), 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)(ABTS), and hydroxyl radical scavenging activities were determined to evaluate the antioxidant activities of seeds and husks. The quality differences between the seeds and husks were assessed through orthogonal partial least squares-discriminant analysis(OPLS-DA) and analytic hierarchy process(AHP) combined with the entropy weight method(EWM). Significant differences(P<0.05) were observed in all 10 indicators between the seeds and husks. The levels of epicatechin, quercetin, and volatile oil were higher in the seeds, whereas those of protocatechuic acid, vanillic acid, water extract, and ethanol extract were higher in the husks. The seeds showed stronger scavenging ability against DPPH and ABTS radicals, while the husks showed a stronger scavenging effect on hydroxyl radicals. OPLS-DA significantly discriminated between the seeds and husks. Furthermore, volatile oil, water extract, DPPH radical scavenging rate, quercitrin, ABTS radical scavenging rate, hydroxyl radical scavenging rate, and vanillic acid were selected as the main differential indicators by variable importance in projection(VIP). Comprehensive scores calculated by AHP combined with EWM indicated that the seeds were superior to husks in terms of overall quality. However, there are still some dominant components and a certain antioxidant effect in the husks. Therefore, it is suggested to using Amomi Fructus with a certain amount of husks or utilizing the husks for other purposes.

In vitro antioxidant activity evaluation of pine nut peptides (Pinus koraiensis) fermented by Bacillus subtilis LS-45

In this study, we utilized the remarkable capabilities of Bacillus subtilis ls-45 during the fermentation process to generate pine nut peptide. Through gene sequencing, we confirmed the proficiency of Bacillus subtilis ls-45 in producing protease, thereby serving as a valuable enzymatic source for protein hydrolysis. Our investigation focused on examining the variations in amino acid types and quantities between enzymatic pine nut protein peptide (EPP) and fermented pine nut protein polypeptide (FPP). Furthermore, we conducted a comprehensive assessment of the in vitro antioxidant activities of EPP and FPP, encompassing measurements of their Hydroxyl radical scavenging rate, Total reducing capacity, Superoxide anion scavenging rate, and ABTS+ radical scavenging rate. Notably, FPP exhibited superior antioxidant capacity compared to EPP. By employing semi-inhibitory mass concentration (IC50) analysis, we determined that FPP displayed enhanced efficacy in neutralizing hazardous free radicals when compared to EPP.

Optimization of extraction procedure and antioxidant activity of C50 carotenoids from Halorubrum sp. HRM-150

C50 carotenoids are promising bioactive compounds produced by halophilic archaea. Relevant studies have focused on their outstanding antioxidant activity, whereas the extraction process has received less attention. In this study, the effect of factors on carotenoid extraction efficiency was explored through single-factor and orthogonal experiments. The results showed that the C50 carotenoids were effectively extracted by suspending and homogenizing cell pellets in methanol (1:30, w-v) for 10 min, subsequently incubating at 30 °C for 30 min in the dark, finally centrifuging and drying over vacuum rotary evaporation at 30 °C in the dark. The carotenoid content increased 1.84 times by the above procedure than that before optimization. Moreover, the UVVis spectra, TLC and HPLCMS analysis revealed that the main component of carotenoids extracted from Halorubrum sp. HRM-150 was bacterioruberin (84.12 %), followed by monoanhydrobacterioruberin (15.13 %). Both carotenoid extract and bacterioruberin exhibited antioxidant capacity, which were significantly higher than that of astaxanthin (p < 0.05) by scavenging assays of 2,2-azinobis-3-ethyl-benzothiazole-6-sulfonic acid, 2,2-diphenyl-1-picrylhydrazyl and hydroxyl radicals. In addition, the hydroxyl radical scavenging rate of bacterioruberin was significantly higher than that of carotenoid extract (p < 0.01), indicating its potential activity against or delaying diseases caused by reactive oxygen species. C50 carotenoids (especially BR) have great application prospects in human health due to their excellent antioxidant capacity.

Development and properties evaluation of multi-strain probiotic with cholesterol-lowering potential in vitro.

Probiotics have a cholesterol-lowering effect. Multi-strain probiotics (MSPs) outperformed single-strain probiotics due to the interaction of strains. Hence, we expect to develop a high-efficiency MSP for lowering cholesterol. Three strains, including Lactobacillus caseiS1, Enterococcus faeciumS4, and L. harbinensisS6, were used to develop the MSPs. To evaluate their effect, gastrointestinal tolerance, bile salt hydrolase (BSH) activity, cholesterol-lowering rate, antioxidant ability, gamma-aminobutyric acid (GABA) production, and antibiotic sensitivity were determined. The triple lactic acid bacteria probiotic (TLP) was the most efficient one. After 24h treatment with artificial gastric fluid, 47.88% of TLP survived. TLP exhibited the highest BSH activity (149.40 U·ml-1) and cholesterol-lowering rate (75.05%) in vitro, with co-precipitation reducing the majority of cholesterol. The reducing power and superoxide radical scavenging rate of the cell-free supernatant and the hydroxyl radical scavenging rate in viable cells were 1.52, 85.03%, and 89.66%, respectively, and the GABA production was 0.67mg·ml-1, which enhanced the health benefit effects. By fuzzy mathematical analysis, TLP was the optimal probiotic and was competitive with commercial probiotics. The three strains were susceptible to 13 antibiotics. Therefore, TLP has the potential to develop into a cholesterol-lowering probiotic preparation.

Degradation of soybean meal proteins by wheat malt endopeptidase and the antioxidant capacity of the enzymolytic products.

This study investigated the hydrolysis effect of the endopeptidase from wheat malt on the soybean meal proteins. The results indicated that the endopeptidase broke the peptide bonds of soybean meal proteins and converted the alcohol- and alkali-soluble proteins into water-soluble and salt-soluble proteins. In addition, wheat malt endopeptidase did not break the disulfide bonds between proteins but affected the conformation of disulfide bonds between substrate protein molecules, which were changed from the gauche-gauche-trans (g-g-t) vibrational mode to the trans-gauche-trans (t-g-t) vibrational mode. Wheat malt endopeptidase exhibited the highest enzymatic activity at 2 h of enzymatic digestion, demonstrating the fastest hydrolytic rate of soybean meal proteins. Compared with the samples before enzymatic hydrolysis, the total alcohol- and alkali-soluble proteins were decreased by 11.89% but the water- and salt-soluble proteins were increased by 11.99%, indicating the hydrolytic effect of endopeptidase. The corresponding water-soluble proteins had molecular weights of 66.4-97.2, 29-44.3, and 20.1 kDa, while the salt-soluble proteins had molecular weights of 44.3-66.4, 29-44.3, and 20.1 kDa, respectively. The degree of enzymatic hydrolysis of soybean meal reached the maximum at 8 h. The newly created proteins exhibited significantly antioxidant properties, which were inversely related to the molecular weight. Proteins with molecular weight <3 kDa had the highest antioxidant performance with an antioxidant capacity of 1.72 ± 0.03 mM, hydroxyl radical scavenging rate of 98.04%, and ABTS [2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)] radical scavenging capacity of 0.44 ± 0.04 mM.

Proteolysis of burley tobacco-leaf extracts and antioxidant activity of the hydrolysates

Burley tobacco-leaf protein extracted by alkali and precipitated by acid was hydrolyzed enzymatically, and optimum protease and hydrolysis parameters were determined. Pepsin was best and gave the highest hydrolysis rate (15.55%). As per results of the single-factor test, optimum hydrolysis conditions were: temperature 37 °C, pH 2, and an [E]/[S] ratio of 5%. These hydrolysis conditions were optimized by an orthogonal experiment that rendered the same results as the single factor experiment. The ratio of essential to total amino acids and that of essential to non-essential amino acids contained in the burley tobacco-leaf protease hydrolysate were higher than the FAO/WHO standard values of 0.4 and 0.6, among which hydrophobic amino acid content was the highest, followed by negatively and positively charged amino acid contents. In vitro antioxidant experiments showed that the scavenging rates of DPPH, superoxide anion, and hydroxyl radicals of tobacco-leaf protein hydrolysates were higher than those before hydrolysis. Further, the hydroxyl radical-scavenging rate was the most significant, and total antioxidant capacity was improved. The nutritive value of the burley tobacco-leaf protein hydrolysate improved upon pepsin-mediated hydrolysis, and the antioxidant activity was better. These results provide a theoretical basis for further development and utilization of tobacco protein resources.

ROS scavenging carbon dots chelated hydroxyapatite filler: Target synthesis and enhancing adhesion of hydrogel

Carbon dots/hydroxyapatite filler could have the reactive oxygen species (ROS) scavenging ability of CDs and the mechanical property improvement ability of hydroxyapatite. Carbon dots (CDs) not only have optical fluorescence by its physical property, but also regulates ROS by its biological property and had the binding ability of calcium ions by its chemical property. Based on the chelation ability and ROS regulation ability of CDs, ROS scavenging carbon dots chelated hydroxyapatite filler (ROS-HA) was target synthesized via chelating ability and the synthetic yield was 70.9%. The chelation sites of CDs were 2.89 ± 0.02 and after chelated hydroxyapatite, the chelation sites of ROS-HA were 0.69 ± 0.02. The maximum hydroxyl radical scavenging rate and superoxide radical scavenging rate of ROS-HA were 72% and 60%, respectively. ROS-HA improved 86% the adhesion performance of hydrogel-based composites compared to the hydrogel. ROS-HA provided new filler for construction the ROS regulation, tissue adhesive and fluorescent hydrogel application in wound dressing.

Optimization of enzymatic extraction, characterization and bioactivities of Se-polysaccharides from Se-enriched Lentinus edodes

Selenium (Se) is a necessary micronutrient, while Se-deficiency is common in most areas worldwide. Developing dietary Se-supplements can address this issue. Se-enriched Lentinus edodes are good sources of natural Se-polysaccharides that are promising dietary Se-supplements. However, Se-polysaccharides from Se-enriched Lentinus edodes (Se–P-LE) fruit body via enzymatic-extraction (EE) have only been sparsely studied. Thus, the EE of Se–P-LE was optimized via Box-Behnken and uniform test, and the physicochemical and bio-functional properties of Se–P-LE were investigated herein. The results showed that the optimized EE conditions were: extracting temperature of 45 °C, pH of 4.5, time of 85 min and a liquid-solid ratio of 20:1 mL/g. The addition amount of cellulase, papain and pectinase were 0.80, 0.65 and 0.8 g/100 g samples, respectively. Under this condition, Se–P-LE yield was 18.16 ± 0.10%, and the Se content of Se–P-LE was 29.51 ± 0.23 μg/100 g. Characterization of Se–P-LE showed that Se–P-LE were Se-conjugated polysaccharides with pyranoglycan and β-glycosidic linkages. Se–P-LE were composed of 8 monosaccharides with shear-thinning properties and microcrystalline/amorphous structures. The bioactivities assays showed that Se–P-LE displayed a higher DPPH and hydroxyl radical scavenging rate than ordinary polysaccharides. Besides, Se–P-LE significantly reduced mRNA expression and levels of pro-inflammation factors (NO, IL-6/1β and TNF-α) caused by LPS in RAW264.7 cell line.

Characterization and Anti-Aging Activity of Polysaccharides from Akebia trifoliata Fruit Separated by an Aqueous Two-Phase System.

Bioactive polysaccharides have numerous pharmacological effects that are beneficial to human health. Akebia trifoliata (Thunb.) Koidz. has great development prospects as a food resource with medicinal value. The polysaccharides (ATFP) were extracted from A. trifoliata fruit by an aqueous two-phase system. ATFP-3, purified with DEAE-52 and Sephadex G-200 from ATFP, was mainly composed of glucose (47.55%) and galactose (20.39%). Its hydroxyl radical scavenging rate was 89.30% at 1.60mg/mL and its IC50 was 0.29mg/mL. ATFP-3 significantly enhanced the survival rate of Caenorhabditis elegans under thermal or oxidative stress. Furthermore, ATFP-3 could prolong the lifespan of C. elegans and improve the activities of the antioxidant enzyme, while also decrease the accumulation of lipofuscin and the level of malondialdehyde (MDA) in aging worms. Thus, ATFP-3 has application potential in health benefits for humans.

Variations of Antioxidant Properties and Enzymes Activities during the Whole Fruit Fermentation of Two Kiwifruit (Actinidia chinenesis Planch.)

ABSTRACT In this study, antioxidant properties and enzymatic activities during fermentation of Kiwifruit from two Actinidia genotypes were evaluated. The samples were evaluated for solid content (SSC), total phenols, superoxide dismutase (SOD) and protease. Antioxidant capacity was determined using four assays: 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2’-azimo-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), hydroxyl radical (HR) scavenging rate and superoxide anion radical (SAR) scavenging rate. In the process of fermentation, the antioxidant and enzyme activities of artificial fermentation kiwifruit products were significantly higher than those of natural fermentation (p < .05). At the end of fermentation, the contents of total phenols and SSC in the fermented products of Hongyang kiwi fermentation (HKF) group and Cuiyu kiwi fermentation (CKF) group were significantly decreased, while the antioxidant properties of DPPH, ABTS, HR and SAR were significantly increased compared with the fresh kiwi (p < .05). In addition, the content of protease and superoxide dismutase was also increased. It was also found that the antioxidant properties and the enzyme activities in the HKF group were higher than those in the CKF group. ABTS and SOD activities were more obvious, which were 1.42 times and 2.22 times of the CKF, respectively. HKF group showed better nutritional properties and biological activities.

Optimization of the Theabrownins Process by Liquid Fermentation of Aspergillus niger and Their Antioxidant Activity

Theabrownins are macromolecular compounds with many hydroxyl, carboxyl, and phenolic functional groups. They are usually extracted from dark tea, in which they are present at low concentrations. In this paper, a low-cost microbial liquid fermentation method was established by inoculating Aspergillus niger with minced tea extract as the raw material. After applying the Box–Behnken and response surface approach design, the optimum fermentation conditions in the fermentor were determined to be an 8% (80 g/L) sucrose concentration, 1:31 (0.03226 g/mL) solid–liquid ratio, 4.141 × 106 CFU/mL bacterial liquid concentration, 5 d fermentation time, 28 °C fermentation temperature, 187 r/min (rpm) rotation speed, and an oxygenation of 0.5 V/V·min (V). After fermenting about 168 h, the theabrownins content reached the maximum of 28.34%. The total phenolic content of the liquid-fermented theabrownins was 25.74% higher than that of solid fermentation. Acidic functional groups were determined, indicating that the phenolic hydroxyl groups were the main acidic groups of the theabrownins. The antioxidant activity of theabrownins was verified by measuring the potassium ferricyanide reducing power, hydroxyl radical scavenging rate, superoxide anion radical scavenging rate, and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging rate of solid- and liquid-fermented chabein. The results of this study show that the production of theabrownins by the liquid fermentation of Aspergillus niger is fast, high in yield, and has antioxidant activity, which provides a basis for industrial production of theabrownins.

Optimization of Extraction of Compound Flavonoids from Chinese Herbal Medicines Based on Quantification Theory and Evaluation of Their Antioxidant Activity

Plant-derived flavonoids have been attracting increasing research interest because of their multiple health promoting effects, where numerous investigations were carried out on the optimization of extraction and bioactivities. This study aims to optimize the extraction process of compound flavonoids (CFs) from Chinese herbal medicines and detect their antioxidant activity in vitro. CFs were extracted from the raw materials named “medicine food homology,” composed of hawthorn, lotus leaf, tartary buckwheat, cassia seed, Lycium barbarum, and Poria cocos in a mass ratio of 4 : 2 : 2 : 1.5 : 1 : 1. L9 (34) orthogonal design, level effect and engineering average estimation, and quantification theory were utilized to improve the extraction method of CFs, and the predictive model for CFs yield was constructed. The 2,2ʹ-diphenyl-1-picrylhydrazyl (DPPH), 2,2ʹ-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), hydroxyl radical scavenging rate, and reducing power of CFs were measured. The highest CFs yield was obtained under the following extraction condition: liquid-solid ratio of 35 : 1 mL/g, extraction temperature of 75°C, extraction duration of 75 min, and extraction mode enzyme-assisted extraction. The forecasted yield was 37.62%. The result was accurate and the established prediction equation was reliable (R = 0.95). The antioxidant activity of CFs was significantly positively correlated with the concentration from 0.05 to 0.4 mg/mL. The DPPH, ABTS, hydroxyl radical scavenging abilities, and the reducing power of CFs were 81.82 ± 1.75%, 49.35 ± 0.09%, 89.78 ± 0.66%, and 0.232 ± 0.001 at the concentration of 0.4 mg/mL, respectively. CFs could be exploited as natural antioxidants in pharmaceuticals and functional foods.

Effect of high hydrostatic pressure pretreatment on flavour and physicochemical properties of freeze‐dried carambola slices

SummaryRipe carambolas are hard to store and transport, while freeze‐dried ones are easy to store. However, its long production time leads to higher costs. This study shows that high hydrostatic pressure (HHP) treatment could shorten the freeze‐drying time of carambola slices. After HHP treatment (25–250 MPa), the drying time of the fresh sample can be shortened by 33.3–44.4% and the distribution of water and pigment in tissues is much uniform. With the increment of the pressure, 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) and hydroxyl radical scavenging rate are increased. At 250 MPa, the total phenolic content (TPC) increased from 11.34 to 13.36 mg GAE g−1, and the total flavonoid content (TFC) of the control sample was increased from 10.77 to 12.73 mg RE g−1. Compared with the untreated sample, HHP treatment can enhance the flavour and shorten the freeze‐drying time. This work guides the application of HHP technology for drying food processing.

Feed-additive Limosilactobacillus fermentum GR-3 reduces arsenic accumulation in Procambarus clarkii

Procambarus clarkii (crayfish) accumulates a high concentration of Arsenic (As) from the aquatic environment and causes considerable human health risks. In this study, Limosilactobacillus fermentum GR-3 strain was isolated from “Jiangshui” and applied for As(III) adsorption and antioxidant abilities. Strain GR-3 removed 50.67% of 50 mg/L As(III) and exhibited the high antioxidant potential of DPPH (1,1-Diphenyl-2-picrylhydrazyl) (87.63%) and hydroxyl radical (74.51%) scavenging rate in vitro. P. clarkii was feed with strain GR-3, the results showed that As(III) concentration reduced, and residual level in hepatopancreas was decreased by 36%, compared to As(III)-exposed group (control). Gut microbial sequencing showed that strain GR-3 restores gut microbiota dysbiosis caused by As(III) exposure. Further application in the field scale was performed and revealed a decrease in As(III) accumulation and increasing 50% aquaculture production of the total output. In summary, feed-additive probiotic is recommended as a novel strategy to minimize aquaculture foods toxicity and safe human health.

Evaluation of a sugarcane juice beverage fermented by Ganoderma lucidum: nutritional and antioxidant activity

A novel sugarcane juice beverage was successfully produced by liquid fermentation of G. lucidum and homogenate process with selecting the day 10 fermentation broth as the raw materials. The beverage was evaluated for its sensory, nutritional and antioxidant activities. The results showed that the beverage by the G.lucidum fermentation was rich in polysaccharides, triterpenes, proteins, and flavonoids, which were all significantly higher than sugarcane juice, especially polysaccharides and triterpenoids. And the beverage could retain the sensory quality of sugarcane juice and could therefore be favored by the consumers. The in vitro antioxidant activity showed that the beverage had high scavenging and reducing abilities. DPPH and ABTS•+ radical scavenging rate of 1 mL fermented beverage were similar to 0.04 mg/mL VC, while the hydroxyl radical scavenging rate and reducing power of 1 mL of fermented beverage were similar to 1.68 mg/mL and 0.19 mg/mL VC, respectively. Taken together, the sugarcane juice fermented beverage was a natural flavor substances with high antioxidant activity and non-toxicity.

Preparation of Black Chokeberry Juice Beverage and Evaluation of Its Quality and Antioxidant Activity

In order to develop black chokeberry juice beverage with healthy function and investigate its antioxidant activity, with the black chokeberry fruit as the main raw material, sucrose, citric acid and β- cyclodextrin were added, and sensory scores as the index. By single factor experiments and orthogonal experiment, the optimum formula of black chokeberry fruit juice beverage was determined as follows: The dosage of chokeberry extract juice was 60%, the dosage of 60% sucrose syrup was 10%, the dosage of 2% citric acid solution was 2.0%, and the dosage of 1% β-cyclodextrin was 3.0%. The sensory scores of the beverage prepared by this formula could reach 94.5 scores. The beverage prepared by the formula was rich in 16 kinds of amino acids, with a total amount of 374.79 μg/mL, it had the characteristic aroma of black chokeberry fruit, with bright and uniform color, harmonious and refreshing taste, and uniform texture. The results of antioxidant activity in vitro showed that the prepared black chokeberry beverage had good antioxidant capacity on DPPH radical scavenging rate, hydroxyl radical scavenging rate, ABTS+ radical scavenging capacity and total reducing capacity, which reached 36.42%, 32.58%, 0.54 mmol/L and 0.289, respectively. The results of this experiment would provide a theoretical basis for the development of black chokeberry functional beverage.

Study on Alkaline Extraction Process Optimization of Polysaccharides from Coelomic Fluid of Phasolosma esculenta and Its Antioxidant Activity in vitro

In order to improve the utilization rate of the coelomic fluid of Phascoloma esculenta, the optimal extraction technology and its antioxidant properties in vitro were explored. The polysaccharide of Phascoloma esculenta was extracted by alkali extraction method and optimized by orthogonal experiment. The total reducing power, DPPH scavenging rate and hydroxyl radical scavenging rate were used to determine its antioxidant properties. The composition of monosaccharides was determined by high performance liquid chromatography, and the polysaccharide composition was analyzed by infrared spectroscopy. The results showed that the optimal extraction process conditions for polysaccharides from the coelomic fluid of Phascoloma esculenta were extraction temperature of 50 ℃, alkaline extraction time of 3 h, and NaOH concentration of 1.5%. The yield of polysaccharides under this process was 0.92%. The half scavenging concentration (IC50) of the total reducing power, DPPH scavenging rate and hydroxyl radical scavenging rate concentration were 2.976, 0.567 and 0.605 mg/mL, respectively. The results of HPLC showed that the polysaccharide was mainly composed of glucose and infrared spectroscopy showed that the polysaccharide contained acetylamino and pyran rings and connected by α-glycosidic bonds. It could be seen that the polysaccharides from the coelomic fluid of Phascoloma esculenta have good antioxidant properties and application prospect.

Effect of heating under pressure treatment on the antioxidant of quinoa

Abstract Heating under pressure treatment (HUP) is a method which can keep the complete form of quinoa grain after processing, which is beneficial to the development of subsequent products. The conditions for quinoa heating under pressure was optimized by response surface methodology to be: quinoa grains were regulated with adding 6.3% of pH 7.0 water and heated under 0.36 MPa pressure for 3–5 min, resulting in the predicted maxima of total phenolic content (TPC), Flavonoid and Saponin content were 313.21 mg GAE/100 g, 1.621 mg/g, and 16.78 mg/g and the values of OH Scavenging Rate, DPPH Scavenging Rate, ABST+ Scavenging Rate were 69.45, 91.73, and 52.38% separately. The content of flavonoid and saponin in the HUP samples were more than that in the boiled, baked, and extruded samples, which were close to that in raw quinoa sample, and meaning high retention of active phytochemicals and antioxidation activity in HUP quinoa. The hydroxyl radical scavenging rate is related to the content of polyphenol, flavonoid and saponin.

1-Methylcyclopropene maintains the postharvest quality of hardy kiwifruit (Actinidia aruguta)

The storage life of optimum quality in postharvest hardy kiwifruit (Actinidia aruguta) is short. The effect of 0.8 μL L−1 1-Methylcyclopropene (1-MCP) on the storage quality of harvested hardy kiwifruit was investigated at temperature of 1 °C for 70 days. The results indicated that 1-MCP treatment maintained the firmness and total soluble solids content of hardy kiwifruit as well as inhibited the respiratory rate and the decrease of vitamin C and glutathione contents. The antioxidant enzymes activity of superoxide dismutase, peroxidase, catalase, and glutathione reductase were enhanced in 1-MCP treatment hardy kiwifruit, meanwhile, 1-MCP treatment induced the radical scavenging capacity (DPPH radical scavenging rate, hydroxyl radical scavenging rate, and superoxide anion scavenging capacity) in fruit during storage. These results demonstrated that hardy kiwifruit with 1-MCP treatment stimulated a series of physiological responses to delay ripening and senescence and improve storage quality. Therefore, 1-MCP treatment could be used to extend the shelf-life of commercially produced hardy kiwifruit.

The pH and Ammonia Sensitivity and Antioxidant Activity of Anthocyanins from Lycium ruthenicum

In this paper,the anthocyanin extracted from dried Chinese wolfberry was extracted with ethanol as the extraction liquid,and its pH sensitivity,response to volatile ammonia and meat putrid gas,and antioxidant activity were studied. The results showed that the anthocyanin content in the anthocyanin concentrate was 291.93 mg/L. The anthocyanins of Lycium ruthenicum had good pH sensitivity,and the color of anthocyanin solution changed significantly between pH1 and pH13. As the pH value increased,the solution changed from purple pink to light green,yellow-green,brown-yellow and bright yellow,and the corresponding wavelength of the maximum absorption peak shifted from 522 nm to 619 nm. Black fruit of Chinese wolfberry anthocyanins on volatile ammonia and corruption for meat gas response effect was good,when the ammonia concentration increased,anthocyanins solution maximum absorption peak decreased,and its corresponding wavelength was obviously red shifted,and the higher the concentration of ammonia,the faster the reaction rate,the lower the freshness of meat food and the faster the volatilization of volatile base nitrogen gas. The full band scanning pattern of the meat products was similar to that in ammonia water.Anthocyanin solution and vitamin C(VC)solution were both with strong hydroxyl radical scavenging rate and anthocyanin solution had stronger scavenging capacity than VC,and the IC50 of the two was 5.54 and 10.19 mg/L,respectively. The results can provide a reference for the development and utilization of Lycium barbarum anthocyanins.