Effect of Hydrolysis on Tannin and Carotenoid Contents, and Antioxidant Activity of Pouteria campechiana

The medicinal properties of Pouteria campechiana fruit in Vietnam currently have not been studied much. This study was conducted to evaluate hydrolysis's effect on the carotenoid, tannin, and antioxidant activity through the correlation between IC50 and TPC values of Pouteria campechiana extract. This study examined hydrolysis conditions, such as enzyme type, enzyme concentration, temperature, and hydrolysis time. Experimental results showed that at pectinase enzyme concentration of 0.6 wt%, cellulase enzyme concentration of 0.6 wt%, at hydrolysis temperature of 600C, and 65 minutes for hydrolysis, the study found carotenoid of 115.14±4.14 (µg/g) and tannin of 45.88±2.37 (mgTAE/g)in the extract. IC50 value (7.82±0.21 mg/mL) and TPC content were highly correlated (R2=0.98). This study's results contributed to the provision of valuable scientific data on Pouteria campechiana fruit, especially for the food industr

Challenges to Accurate Estimation of Methane Emission from Septic Tanks with Long Emptying Intervals

Septic tanks in low- and middle-income countries are often not emptied for a long time, potentially resulting in poor pollutant removal efficiency and increased greenhouse gas emissions, including methane (CH₄). We examined the impact of long emptying intervals (4.0–23 years) on the biochemical oxygen demand (BOD) removal efficiency of 15 blackwater septic tanks and the CH₄ emission rates of 23 blackwater septic tanks in Hanoi. The average BOD removal efficiency was 37% (−2–65%), and the average CH₄ emission rate was 10.9 (2.2–26.8) g/(cap·d). The emptying intervals were strongly negatively correlated with BOD removal efficiency (R = −0.676, p = 0.006) and positively correlated with CH₄ emission rates (R = 0.614, p = 0.001). CH₄ emission rates were positively correlated with sludge depth (R = 0.596, p = 0.002), but against expectation, negatively correlated with BOD removal efficiency (R = −0.219, p = 0.451). These results suggest that shortening the emptying interval improves the BOD removal efficiency and reduces the CH₄ emission rate. Moreover, the CH₄ emission estimation of the Intergovernmental Panel on Climate Change, which is a positive conversion of BOD removal, might be inaccurate for septic tanks with long emptying intervals. Our findings suggest that emptying intervals, sludge depth, and per-capita emission factors reflecting long emptying intervals are potential parameters for accurately estimating CH₄ emissions from septic tanks

Oil Production from Yarrowia lipolytica Po1g Using Rice Bran Hydrolysate

The purpose of this study was to produce microbial oil from Yarrowia lipolytica Po1g grown in defatted rice bran hydrolysate. After removing oil from rice bran by Soxhlet extraction, the bran is subjected to acid hydrolysis with various sulfuric acid concentrations (1–4% v/v), reaction times (1–8 h), and reaction temperatures (60–120°C). The optimal conditions for maximum total sugar production from the hydrolysate were found to be 3% sulfuric acid at 90°C for 6 h. Glucose was the predominant sugar (43.20 ± 0.28 g/L) followed by xylose (4.93 ± 0.03 g/L) and arabinose (2.09 ± 0.01 g/L). The hydrolysate was subsequently detoxified by neutralization to reduce the amount of inhibitors such as 5-hydroxymethylfurfural (HMF) and furfural to increase its potential as a medium for culturing Y. lipolytica Po1g. Dry cell mass and lipid content of Y. lipolytica Po1g grown in detoxified defatted rice bran hydrolysate (DRBH) under optimum conditions were 10.75 g/L and 48.02%, respectively

Subcritical water and dilute acid pretreatments for bioethanol production from Melaleuca leucadendron shedding bark

Subcritical water and dilute acid pretreatments for bioethanol production from Melaleuca leucadendron shedding bar

Precipitation of rice bran protein using carrageenan and alginate

Precipitation of rice bran protein, a high-quality nutritional protein, using polysaccharides (alginate and carrageenan) was investigated at various pH, temperature and amount of polysaccharide with the objective of obtaining higher protein recovery and possible wider industrial application. Both alginate and carrageenan were found to be effective in precipitating rice bran protein. At pH 3.5, the maximum amount of protein precipitated were 95% for a carrageenan-to-protein ratio of 2:1, and 93% for an alginate-to-protein ratio of 1:1. However, change of temperature (20–55°C) did not have a significant effect (p\u3e0.05) on the amount of protein precipitated. The precipitate formed using alginate and carrageenan had protein content of 42.15 and 26.48g/100g of precipitate, respectively. The freeze dried product obtained from the rice bran extract precipitated with polysaccharides was capable of forming foam and emulsion, indicating its possible utilization as a food ingredient

Bioethanol production from yarrowia lipolytica Po1g biomass

Bioethanol production from the yeast Yarrowia lipolytica biomass was studied. The effects of temperature (90–150°C) and H2SO4 concentration (2–15% w/w) on the saccharification of biomass at a hydrolysis time of 1 h were investigated. A maximum glucose concentration of 35.89 g/L can be produced from defatted biomass using 6% H2SO4 at 120°C. Subcritical water (SCW) pretreatment has negligible effect on maximizing glucose yield. Only 14.53 g/L glucose can be produced using 6% H2SO4 at 120°C if undefatted biomass was used. The highest ethanol concentration achieved was 13.39 g/L with a corresponding ethanol yield of 0.084 g/g dry biomass (0.38 g ethanol/g glucose)

In situ biodiesel production from wet Chlorella vulgaris under subcritical condition

The conventional base catalyzed biodiesel production process uses refined vegetable oil as feedstock oil and is not environmentally friendly. The supercritical methanol technology does not require the use of catalyst but it is energy intensive due to the high temperature and pressure required in the process. In this work, a process was developed for producing biodiesel directly from wet Chlorella vulgaris biomass (80% moisture content) using subcritical water as catalyst. Under the following conditions: The ratio of wet biomass to methanol is 1/4 (g/mL), the reaction temperature is 175° C and after 4 h, the reaction product contained 89.71% fatty acid methyl esters (FAMEs). The yield is 0.29 g FAME per g dry biomass. This is considerably higher than the yield of 0.20 g FAME per g dry biomass obtained when the neutral lipid of C. vulgaris biomass was extracted and converted into FAME

Bioethanol production from pretreated Melaleuca leucadendron shedding bark – Simultaneous saccharification and fermentation at high solid loading

Bioethanol production from the shedding bark of Melaleuca leucadendron (Paper-bark Tree, PBT) was studied using subcritical water (SCW) pretreatment at various severities (So). High ethanol production was attained by implementing a factorial design on three parameters (So, solid loading and enzyme loading) in simultaneous saccharification and fermentation (SSF) mode. Ethanol concentration of 63.2 g L(-1) corresponding to ethanol yield of 80.9% were achieved from pretreated biomass (So=2.37) at 0.25 g mL(-1) solid and 16 FPU g(-1) glucan enzyme loadings. Similarly at 0.15 g mL(-1) solid loadings both high ethanol concentration (43.7 g L(-1)) and high ethanol yield (91.25%) were achieved. Regression analysis of experimental results shows that all process parameters had significant role on maximum ethanol production, glucose solubility, ethanol yield and ethanol volumetric productivity. SSF of SCW treated PBT biomass is economically feasible for production of bioethanol

Automation with renewable energy to optimize the exploitation of water supply networks in Ninh Thuan province

The research that was conducted on the water supply network of Phan Rang city, Ninh Thuan province, is aimed at using renewable energy to optimize the management and reduce the water loss. The research has conducted DMA (District Metering Area) setup, construction and installation of flow meter and pressure reducing valve chamber for flow and pressure control with active pressure regulation, and the use of hydraulic power generator to generate power at the site. Research results provide management agencies, in particular, water supply companies, with optimal solutions in network management and energy saving, reducing the amount of water loss effectively, thereby increasing revenue and saving clean water - precious resources are gradually depleted