Effect of Process Parameters of Microwave Assisted Extraction (MAE) on Polysaccharides Yield from Pumpkin

Process parameters of microwave assisted extraction （MAE） of the polysaccharides from pumpkin viz. extraction temperature, time and liquid-solid ratio were studied by using single factor and response surface methodology method. The results showed that the liquid-solid ratio was the most important factor in polysaccharides yield, followed the extraction temperature was the least important factor. The optimum microwave assisted extraction co by ndi extraction time, and tions for the highest polysaccharides yield from pumpkin （16.76%-4-0.38%） were obtained by using the response surface methodology with extraction time of 29 min, an extraction temperature of 79 ℃ and a liquid-solid ratio of 22 mL·g^-1. Validation experiment result well agreed with predicted value.

Mathematical Modeling and Optimization of the Microwave Assisted Extraction of the Natural Polyphenols and Flavonoids from the Raw Solid Waste of the Orange Juice Industry

Orange pomace is the solid waste of the orange juice industry which accounts for approximately 50%of the quantity of the fruits processed into juice and is a good raw material for production of high added value products with diverse uses.Orange pomace is rich in polyphenols and flavonoids which can substitute the potentially hazardous or less desirable chemical antioxidants/antimicrobials used in agro-food and cosmetics industry.In this work,an eco-friendly aqueous microwave assisted extraction of orange pomace was investigated and optimized in order to produce aqueous bioactive antioxidant/antimicrobial extracts.A three factorial Response Surface Optimization methodology with centered Box&Behnken experimental design was used to obtain optimum values of total polyphenols and total flavonoids and build predictive models for their optimal extraction conditions.The three optimization factors in terms of applied process parameters were(a)water/solid ratio,(b)extraction temperature and(c)extraction time.The effectiveness and statistical soundness of the two corresponding models regarding optimal total polyphenols and flavonoids were verified by Analysis of Variance(ANOVA).

Mathematical Modeling and Optimization of the Microwave Assisted Extraction of the Solid Waste of the Pomegranate Juice Industry

Pomegranate pomace is the solid waste of the pomegranate juice industry which accounts for approximately 50%of the quantity of the fruits,which is processed into juice and is a good raw material for production of high added value products with diverse uses.Pomegranate pomace is rich in polyphenols and flavonoids which could substitute the potentially hazardous synthetic antioxidants/antimicrobials used in agro-food and cosmetics sectors.In this work,eco-friendly aqueous microwave assisted extraction of pomegranate pomace was investigated and optimized in order to produce effectively novel natural antioxidant/antimicrobial extracts.A three-factorial response surface optimization methodology with centered Box&Behnken experimental design was used to obtain the predictive models and the maximum values of total polyphenols,total flavonoids and total antioxidant capacity(TAC).The three optimization factors involved were:(a)water/solid ratio;(b)extraction temperature;(c)extraction time and the effectiveness and robustness of the three models were statistically verified by ANOVA.

Microwave Assisted Extraction,Antioxidant Potential and Chromatographic Studies of Some Rasayana Drugs

Objective： To study and compare the conventional extraction procedure with microwave assisted extraction （MAE） for some Ayurvedic Rasayana drugs and to evaluate their antioxidant potential and carry out the characterization of extracts by thin layer chromatography. Methods： Three Ayurvedic rasayana plants Allium sativum Linn., Bombax ceiba Linn. and Inula racemosa Hook. were evaluated for an improved MAE methodology by determining the effects of grinding degree, extraction solvent, effect of dielectric constant and duration of time on the extractive value. Antioxidant potential of all three drugs was evaluated with 2,2-diphenyl-l-picrylhydrazyl （DPPH） radical scavenging activity and reducing power was determined by using Gallic acid as standard. Further thin layer chromatographic （TLC） analysis was performed on pre-activated Silica Gel G plates and Rf value were compared with those reported for the important biomarkers. Results： The total extractive value for Allium sativum Linn. was 36.95% （w/w） and 49.95% （w/w） for ethanol extraction respectively. In case of Bombax ceiba Linn. the yield of aqueous extract by MAE was 50% （w/w） compared to 42% （w/w） in ethanol （50% v/v）. Percent yield of Inula racernosa Hook. in aqueous extract was found to be 27.55% （w/w） which was better than ethanol extract （50%） where the yield was 25.95% （w/w）. Upon antioxidant activity evaluation A. safivum extract showed an absorbance of 0.980 ± 0.92 at concentration of 500 μg with maximum reducing capacity. This was followed by B. ceiba Linn. 0.825 ± 0.98 and I. racemosa Hook. with 0.799 ± 2.01 at a concentration of 500 μ g. TLC based standardization of A. sativum Linn. extract shows single spot with Rf value of 0.38, B. ceiba Linn. extract shows Rf values were 0.23, 0.58, 0.77, 0.92 and I. racemosa Hook. extract spot had a Rf value of 0.72. Conclusions： A significant improvement in extractive values was observed as a factor of time and other advantages by using MAE technology. All three drugs have high antioxidant potential and a TLC profiling similar to reported ones. The presence of fructan type polysaccharide can be further utilized for bioactivity directed fracUonation and evaluation of immunomodulatory activity.

不同提取方法对苗药黑骨藤果实挥发油的研究

To analyze the chemical constituents of volatile oils from the fruit of Periploca forrestii Schltr.which were collected in Guizhou province.This volatile oils were extracted by simultaneous distillation extraction (SDE)and microwave assistant extraction(MAE) method,and ananlyzed by gas chromatography-mass spectrometry(GC-MS)method.The main chemical compounds were methyl salicylate,β-amyrin and β-amyrin acetate etc.The compounds from the volatile oils extracted with SDE and MAE are quite different.The results provide scientific proof for the further development and utilization of Periploca forrestii Schltr.

The Antioxidant Activity of Barley Malt Rootlet Extracts in Heated Corn Oil at Frying Temperature

In this study the antioxidant activity of barley malt rootlet (BMR) extracts was evaluated in heat treated corn oil up to 5 hours at 185°C frying temperature. The antioxidant activity of BMR extracts was measured at 25, 50, 100 and 150 ppm concentrations. The free and bound antioxidant phenolics were extracted from BMR using three different extraction methods. Conventional solvent extraction (CSE), microwave assisted extraction (MAE) and autoclave assisted pretreated solvent extraction (APSE). In the present experiment, the total phenolic content and antioxidant activity of the various extracts were measured. Thiobarbituric acid reactive substances (TBARS) assay was used to evaluate the ability of the BMR to protect lipid peroxidation in corn oil at 185°C frying temperature. The formation of TBARS at 5 hours of heat treated corn oil has shown similar antioxidant levels in 150 ppm butylated hydroxytoluene (BHT) or MAE free phenolic extract added to corn oil. TBARS value for BHT was 1.896 ± 0.013 μg/mL of corn oil and for MAE was 1.896 ± 0.034 μg/mL of corn oil. The highest level of antioxidant activity was found for the free phenolic extracts. The order of inhibition of oxidation was found to be for free phenolics as follows: BHT (100 ppm) > APSE (50 ppm) > MAE (100 ppm) > CSE (100 ppm).

Technologies for extracting lipids from oleaginous microorganisms for biodiesel production

Recently, biodiesel has received much more attention. Soybean oil, rapeseed oil, palm oil and corn oil are primary feedstock for biodiesel production. However, biodiesel production from these traditional oil-rich crops is limited by land availability, climate, and environmental and social issues regarding the use of feed and food crops for fuel. Oleaginous microorganisms, including microalgae, bacteria, yeast and fungi can be cultivated with high lipid contents and used as promising feedstock for biodiesel production. However, the high cost of biodiesel production using oil microorganisms has been the biggest obstacle for its industrialization. The process of biodiesel production from microorganisms involves many steps, of which the lipids extraction is the most important and costly. Therefore, searching for an effective and economical extraction system is critical. Various approaches of lipids extraction are discussed in this review, including traditional extraction procedures such as solvent extraction, pressing and solvent integrated extraction, as well as some new procedures.