Search

Both linseed oil and coenzyme Q10 (CoQ10) have the disadvantages of low solubility in water, poor stability, and low bioavailability. In this study, linseed oil and CoQ10 were simultaneously dissolved and encapsulated in emulsions, and then dispersed in an aqueous matrix toimprove their stability, solubility, and bioavailability.At the same time, due to the strong antioxidant effect of CoQ10, linseed oil can be further protected from oxidation. Linseed oil and CoQ10 co-loaded emulsions were prepared by high pressure homogenization technology using gum arabic as an emulsifier. The physical and chemical properties of the prepared emulsions were characterized by dynamic light scattering, transmission electron microscopy, in vitro simulated digestion, in vitro release, dilution stability, freeze-thaw stability, ionic strength stability, photostability and accelerated oxidation stability. The results showed that the prepared emulsions were uniformly dispersed spherical droplets with an average particle size of (284 ± 5.6) nm and a polydispersity index (PDI) of 0.112 ± 0.025. The loading and entrapment efficiency of CoQ10 in the prepared emulsions were 0.392% ± 0.008% and 97.08% ± 1.45% respectively, and no linseed oil floating on the emulsion liquid surface was observed. The particle size of the prepared emulsion in the simulated stomach digestion did not change significantly, indicating that the structure of the emulsion did not damage, and it could resist the environment of gastric acid. The particle size of the prepared emulsions increased significantly in the simulated intestinal digestion, indicating that the structure of the emulsion had been destroyed and the emulsions were digested and degraded in the simulated intestine digestive phase. Compared with linseed oil and CoQ10 suspensions, the digestibility rate of linseed oil and the bio-availability of CoQ10 in emulsions were significantly improved. The in vitro release experiment showed that CoQ10 encapsulated in the droplets of the emulsions could slow down the release rate of CoQ10 and achieve a sustained release effect, which would eventually improve the oral bioavailability of CoQ10. The dilution stability displayed that the particle size did not change significantly after the emulsions diluted 100-250 times and the emulsionswere relatively stable. Freezing for 2 hours had little effect on the stability of the emulsions. Over 2 hours, the particle size and PDI of the emulsions increased slightly, but still stable. No stratification and flocculation were observed. Na+ and Ca2+ caused a decrease in the zeta potential of the emulsion, resulting in a decrease in the absolute value of its surface charge, which cannot form a sufficient electrostatic repulsive force and eventually had a greater impact on the stability of the prepared emulsion. The photostability revealed that when CoQ10 was encapsulated in emulsions, CoQ10 was less affected by light degradation and had better light stability. The form of CoQ10 in emulsions can obviously improve the light stability of CoQ10. The accelerated oxidative stability experiment showed that, due to the antioxidant effect of coenzyme Q10, the CoQ10 in linseed oil and CoQ10 co-loaded emulsions had better oxidative stability. This study is helpful to solve the problems related to linseed oil and CoQ10, better apply them to functional foods, and provide consumers with green and healthy functional foods. [ABSTRACT FROM AUTHOR]

A relatively high proportion of vegetable waste is ever increasing in China in recent years, with the rapid development of agriculture. A large amount of spoiled vegetable waste also continues to accumulate. There is a serious threat to environmental health, due to a huge waste of resources. It is a high demand to treat this vegetable waste. Fortunately, anaerobic fermentation has been an important technical way to treat agricultural waste for clean energy. Meanwhile, the biogas slurry and biogas residue produced by fermentation can also be used as organic fertilizer to improve soil fertility. This study aims to clarify the effect of the additives on the thermostatic anaerobic fermentation and aerobic treatment of the mixed raw materials. The process was realized for the rapid conversion of biomass to biogas and biogas fertilizer. Firstly, the ratio of Volatile Solid (VS) was selected as 1:1:1 for the cow dung, tomato stems, and leaves. Three devices were utilized in the 0.56 m3 constant-temperature fermentation, including the no-adding, adding mass concentrations of 1 g/L urea, and 1 g/L plant ash. Among them, the Total Solid (TS) was 8%. The constant temperature batch was set as a fermentation temperature of (26±2)℃ and a period of 54 days during anaerobic fermentation. Secondly, the remaining biogas slurry was treated with the (30±1)℃ and 12 L/min aerobic aeration treatment for 8h. Some parameters were measured in the biogas production, including methane production, pH, Electrical Conductivity (EC), Oxidation-reduction Potential (ORP), Total Dissolved Solid (TDS), volatile fatty acid contents (VFAs), NH+ 4 -N contents change, biogas fertilizer biotoxicity, and nutrient contents. A comparison was then made to explore the effects of the combination of anaerobic fermentation with different additives and aerobic treatment of biogas slurry on the biogas and fertilizer production performance of the device. The results show that each addition after 28d before the reaction presented a significant effect on the systematic biogas production and methane synthesis. Specifically, the best performance was achieved in the urea group during the anaerobic fermentation phase. The cumulative biogas and methane production were 4 917, and 1 746.4 L, respectively, which increased by 91% and 128.7%, compared with the blank group, whereas, 12.6% and 69.4%, compared with the plant ash group. Furthermore, the methane volume fraction of 50% in the urea group and the total system biogas yield of 80% (namely 5 346 L) were all 5d earlier than that of the blank group. However, the total biogas production and total methane production in the whole cycle blank group were higher than in the other two groups. The fastest time was 1, 4, and 1h during the aerobic treatment phase, respectively, particularly for the complete biogas slurry ripening in the blank groups, plant ash, and urea groups. In this case, the germination indexes (GI) were 98%, 124.5%, and 100.4%, respectively, and the Total Dissolved Solids (TDS) were 5 670, 5 350, and 7 010 mg/L, respectively, while the volumes of NH+ 4 -N were 734.4, 538.1 and 862.1 mg/L, respectively. In summary, the best biological effectiveness and production quality of the biogas slurry were achieved in the urea group system. The standard is still needed for the nutrient supplement, or concentrated treatment, compared with the mixed liquid fertilizer. This finding can provide a strong reference to improve the biogas and fertilizer production quality of anaerobic fermentation, in order to reduce the secondary environmental pollution caused by the biogas fertilizer. [ABSTRACT FROM AUTHOR]

Slope cultivated land has been the major grain production base to ensure food security and ecological protection in the mountainous karst areas of southwest China. It is necessary to clarify the spatiotemporal evolution characteristics of the slop cultivated land at present. In this study, a quantitative analysis was performed on the spatiotemporal evolution of slope cultivated land in different terrain gradients using high-precision remote sensing images and Digital Elevation Models (DEM) from 2004 to 2020. Puding County in the typical karst mountainous areas of central Guizhou Province, China was selected as the study area. The driving mechanism was proposed for the slope cultivated land evolution from the terrain niche index, kernel density, and dynamic indicators of cultivated utilization. The results show that: 1) There were the typical characteristics of “more in the southeast and less in the northeast” for the slope cultivated land in the study area from 2004 to 2020. The distribution of slope cultivated land in 2020 mainly belonged to the low-density area of kernel density, followed by the medium-density area, while the high-density area occupied an ever-decreasing small proportion of the area. 2) The contraction of slope cultivated land was classified into three stages: the sharp contraction (2004-2009) with the highest abandonment rate of high terrain slope cultivated land, the slow contraction (2009-2015) with the highest contraction speed of medium terrain slope cultivated land, and the accelerated contraction (2015-2020) with the highest contraction speed of low terrain slope cultivated land. There were spatiotemporal differences in the different terrain gradient ranges in the slope cultivated land. 3) There was the largest area of slope cultivated land in the first and third terrain gradient ranges. 69.67% of the overall transformation area was converted from the low-quality slope cultivated land in the high terrain into forest and grassland. 38.14% of the overall transformation area was shifted from the slope cultivated land with the excellent production conditions in the low terrain to the garden and construction land. 4) The slope cultivated land evolved from the steep to the gentle slope, and from the high to low elevation, indicating the decrease in the aggregation degree. The slope cultivated land in the high terrain was also transformed to improve the regional ecological benefits. The slope cultivated land in the middle and low terrain greatly contributed to the regional ecological-economic benefits. 5) The multiple factors were attributed to the spatiotemporal evolution of slope cultivated land. Specifically, the natural and geographical environment was the basic support, while the social and economic factors were the leading factors, and the policy factors were the external pull. The path of “agricultural restructuring - slope cultivated land transformation” was attributed to the evolution of slope cultivated land in the low terrain gradient, while the “policy-driven - labor migration - slope cultivated land abandonment” was for the middle terrain gradient, and the “resource endowment - slope cultivated land transformation” was for the high terrain. There were different dominant influencing factors of slope cultivated land in the different gradient terrain. The finding can also provide a scientific reference for land use optimization and ecological protection in the mountainous karst areas in southwest China. [ABSTRACT FROM AUTHOR]

Hemerocallis fulva is one of the most popular flowers rich in bioactive substances, such as polyphenols, flavonoids, and alkaloids anthraquinones, particularly on antioxidant, antidepressant and anticancer. The extraction of phenolic compounds and antioxidant properties can also greatly contribute to the popularization of H. flower in the agricultural industry. However, only a few reports were focused on the extraction, forms and antioxidant activities of phenolic compounds in the H. flower. The present study aims to explore the effects of different extraction on the content, composition and antioxidant activity of phenolic compounds in various Hemerocallis flowers. Five kinds of flowers with different colors (yellow, orange, red-orange, jujube red, and bright red) were selected as raw materials. Three processing treatments (ultrasound, enzymolysis-ultrasound, and fermentation-ultrasound) were also utilized to determine the content of total flavonoids, total polyphenols, and scavenging rate of free radicals. Furthermore, high-performance liquid chromatography was adopted to identify the free, conjugated, and bound fractions of phenolic compounds, where the relationship was also established between phenolic compounds and antioxidant activity. Specifically, the types of total flavonoids and polyphenols were as follows: 'Hongyingwu', '63#', 'Jianzhuanglilan', 'Meiguixiniu', and 'Taiyangwu'. The results showed that there was a significant difference (P＜0.05) of antioxidant activity in the different varieties of flowers, where the antioxidant activity was positively correlated with phenolic content. Furthermore, the antioxidant activities of flowers depended mainly on the varieties and extraction. More importantly, the vitamin C equivalents of DPPH (1,1-diphenyl-2-picrylhydrazyl) were 44.32, 40.63, 38.24, 37.64, and 35.60 mg/g, respectively, for the 'Hongyingwu', '63#', 'Jianzhuanglilan', 'Meiguixiniu' and 'Taiyangwu' under the fermentation-ultrasonic processing. The corresponding ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) vitamin C equivalents were 39.74, 36.24, 30.88, 28.38 and 24.88 mg/g, respectively. The vitamin C equivalent of DPPH of 'Hongyingwu' increased from 38.24 mg/g by ultrasonic extraction to 41.49 mg/g by enzymatic ultrasonic extraction and 44.32 mg/g by fermentation-ultrasonic extraction. The vitamin C equivalent of ABTS of 'Hongyingwu' increased from 31.82 mg/g by ultrasonic extraction to 35.12 mg/g by enzymatic ultrasonic extraction and 39.74 mg/g by fermentation-ultrasonic extraction. Among the three fractions, the content of phenolic compounds in the free fraction was the highest, accounting for more than 75% of the total contents. Enzymatic hydrolysis and fermentation significantly (P＜0.05) improved the contents of most phenolic compounds in the free fraction of 'Hongyingwu'. Particularly, the p-Coumaric acid was newly detected, while the free quercetin content after fermentation reached three times that of the original. The Vitamin C equivalent of DPPH and ABTS free radical scavenging rate of free phenols increased from 40.53 and 35.57 mg/g for ultrasonic processing to 48.20 and 47.40 mg/g for fermentation-ultrasonic processing, respectively. Correlation analysis demonstrated that the chlorogenic acid, caffeic acid, quercetin, and rutin in the free fraction were highly correlated with the antioxidant activity, indicating a great contribution to antioxidant activity. The finding can provide a theoretical basis for the development and utilization of H. flower in functional foods and cosmetics. [ABSTRACT FROM AUTHOR]

In rural area of China, due to low income, it has been popularly used for winter-heating with straws and coal. The heating method is so backward that it is promising for heating with solar energy. Since the heat gain from sun is limited to specific area, it is essential to improve the efficiency of solar energy utilization. Some researchers found that on-off modes of circulating pump took obvious effects on heating performance of central heating. In this paper, three different kinds of on-off modes were applied to the solar floor heating system in order to discover the influence of on-off modes. The experiment was conducted during the winter in a single-storey building in Zhangma Village, Minqing county, Gansu province, China. The total area of the building is 117 m2, the residential area of about 103 m2, whose actual heating areas is 64 m2. The heating system consists of 6 sets of vacuum tube solar collectors. Each collector consists of 40 vacuum tubes in Φ58 mm × L 1 800 mm with a 400 L water tank. The heating period was 17:00-23:30 every day in Dec 2015. The system had the same water-flowing duration of 8 min and three different intermittent durations, 5 min intermittent durations on Dec 3th, 11 min on Dec 25th, and 6 min on Dec 30th. Various parameters, such as the solar radiation intensity, the supply and return temperature of the system, the tank temperature, the ambient temperature, the flow rate and the ambient wind speed, were all measured by various sensors in the experiment. All measured parameters were acquisited and recorded automatically by the Agilent 34970A every 10 s. The variation law of difference of supply and return temperature during the heating period was analyzed, the heat supply, heat loss rates, energy consumptions, the solar fractions and average heating efficiency of the system all were calculated, the correlations between various factors with the heat supply were analyzed. The experimental results reveal the following: With the same water-flowing durations, the longer the discontinuous time, the greater the difference of supply and return temperature. Compared with the time interval of 5 min, the solar fraction of the time interval of 6 min was increased by 5.27%, heat loss rate of the system decreased by 2.79%, and the operating energy consumption decreased by 6.67%. The time interval of 6 min had the highest average heating efficiency of the system in 3th to 29th in Dec 2015. Various factors discussed were significantly correlated with the heat supply. The supply temperature and the ambient temperature had greater impact on the heat supply, but the flow rate and the ambient wind speed had less impact on it. According to the operation modes of the solar floor heating system, the water-flowing time was longer than the displacing time of water stored in the pipes under the floor. Not only the water supply displaced the hot water in the pipes completely every time, but also there was some high temperature water flowing through the return pipe. In the further operation, the water-flowing time should be reduced, so that the water-flowing time could be equal to the displacing time of water in the pipes, and the high temperature water was prevented from losing excessive heat through the return pipe. [ABSTRACT FROM AUTHOR]

In order to ensure the annual gas demand of farmers in North China and explore the gas characteristics in the household biogas digester with constant temperature, the 3 m3 solar constant temperature biogas digester was developed. Stability of the biogas, biogas characteristics under different fermentation temperature and different fermenting materials, annual biogas characteristics, and operation strategy were studied with this system. The batch type experimental research showed that the system could be run steadily and continuously throughout the year. And the annual cumulative production of biogas was 398.52 m3 under the weather conditions in Lanzhou area. The system could realize constant temperature anaerobic fermentation at 26, 28 and 37 ℃ when the lowest ambient temperature exceeded -19.9, 0.7 and 6.9 ℃, respectively. In addition, the methane volume fraction was improved prominently or the production gas cycle was shortened when the pig manure was mixed with corn straw, wormwood and lotus leaves by a certain mixing proportion. Compared with pig manure fermentation, the volume fraction of methane of biogas produced by mixed material was promoted by about 8% as the volume ratio of raw material pig manure ∶ wormwood ∶ water ∶ inoculums was 1∶2∶2∶1. It could shorten the fermentation period remarkably when the wormwood, lotus and pig mature were taken as fermentation materials. At the end of the fermentation process with the mixed material at 37 ℃, the daily biogas production was difficult to meet consumers′ demand. And the daily average biogas production could keep 0.8 m3 in a week if we supplied 0.025 m3 new material with the same proportion. This experiment can provide reference for the efficient use of renewable energy. Utilizing the mixed materials can regulate the gas production and gas quality, and advices can be adopted for users to use raw materials which come from local resources according to season conditions. Three pails of new materials with same proportion(0.025 m3) are needed to replenish for anaerobic fermentation equipment every week, when the stability of gas production is unsure and the daily gas production is hard to satisfy users requirement that is to keep the daily gas production of 0.8 m3 one week. When the gas consumption increases, the measures that regulate temperature and feed to add the gas production can be adopted to satisfy the biogas utilization demand. The biogas production system with constant temperature operates steadily all the year round. Meanwhile, biogas can completely satisfy the demand of 3-5 people′s household cooking and gas in a year. And the biogas digester using pig manure as raw materials can still achieve the gas production with(26±1.5) ℃ constant temperature and the daily biogas production of over 1.3 m3, when the average environmental temperature range is between -23.8 and -5 ℃ in winter, even encountering 3 successive overcast or snowy weather. The biogas digester using pig manure and wormwood as raw materials can achieve the 37℃ gas production and the daily biogas production of over 1.7 m3. And when the year-round solar radiation range is 11.7-17.4 MJ/m2, the fermentation tank per cubic meter needs 10 glass vacuum tube solar collectors of φ58 mm×1 800 mm. [ABSTRACT FROM AUTHOR]