Optimization of a Continuous Preparation Method of Arthrospira platensis γ-linolenic acid by supercritical carbon dioxide technology using response surface methodology

γ-linolenic acid is an essential omega-6 unsaturated fatty acid made in the human body from linoleic acid. It can be metabolized to various important eicosanoids and it is also a precursor of prostaglandin E and several other active substances that are associated with anti-inflammatory properties. Arthrospira platensis is known to contain relatively large quantities of γ-linolenic acid. The aim of this study was to investigate the optimal parameters under a continuous preparation method of γ-linolenic acid from A. platensis using supercritical carbon dioxide technology. A Box-Behnken experimental design and response surface methodology were used to optimize combinations among pressure (10, 20 and 30 MPa), temperature (40, 50 and 60°C) and flow rate of A. platensis extract liquor (1, 2 and 3 mL/min) for yield of γ-linolenic acid. The results showed that the extraction of γ-linolenic acid from A. platensis was optimized at a temperature of 60°C, a pressure of 30 MPa and a flow rate of 3 mL/min. These parameters could be used as a basis for facilitating future scale-up industrial applications

Bioactive constituent characterization and antioxidant activity of ganoderma lucidum extract fractionated by supercritical carbon dioxide

Ganoderma lucidum has been recognized as a precious fungus in both Chinese and Japanese traditional medicine for centuries. It contains many bioactive ingredients such as triterpenoids and polysaccharides. The present study used supercritical carbon dioxide (SC-CO2) fractionation to fractionate Ganoderma lucidum extract into four fractions (R, F1, F2, & F3) and evaluate the correlation between the content of functional components and their antioxidant ability. Relatively high concentrations of the three types of bioactive constituents were simultaneously partitioned into different fractionation collecting vessels. The free radical scavenging ability was greatest in F1. The IC50 of DPPH scavenging ability was 0.90 mg/mL and that of ABTS radicals scavenging activity was 0.45 mg/mL. The correlation analysis of antioxidant ability with total triterpenoids and total polyphenols showed a positive relationship. In conclusion, this study showed that fractionation of Ganoderma lucidum extract using SC-CO2 fractionation technology was able to effectively partition its bioactive components including triterpenoids, polysaccharides and phenolic compounds and also to increase the antioxidant activities of the fractions

Effects on blood glucose, insulin, lipid and proatherosclerotic parameters in stable type 2 diabetic subjects during an oral fat challenge

Abstract Background Restriction of fat intake has been effective in improving insulin sensitivity in obese and type 2 diabetic subjects, but what effects the recommended diet (less than 30% of total calories from fat) have not been elucidated in subjects with type 2 diabetes. The purpose of this study was to test the effects of oral fat challenge, composing 30% calories of a meal, on blood glucose, insulin, lipid, leptin, plasminogen activator inhibitor-1 (PAI-1) and tumor necrosis factor-α (TNF-α). Design and Methods Blood glucose, insulin, lipid, leptin, TNF-α and PAI-1 were compared in 14 type 2 diabetic patients and 10 normal subjects after an oral fat challenge upto 2 hours (fasting, 15 min, 30 min, 45 min, 60 min, 90 min and 120 min). Results Postprandial glucose, total cholesterol, leptin, PAI-1 levels did not differ significantly from levels at fasting. Serum triglyceride increased significantly from baseline only in diabetic patients (P = 0.042). Serum insulin increased postprandially in both groups (P = 0.028 in diabetic group and P = 0.055 in normal group), with displaying a prolonged insulin response in diabetic subjects. TNF-α decreased postprandially in both groups without significant difference, although diabetic patients have higher baseline levels (P = 0.024 compared to normal subjects). Conclusions Oral fat load does not have an acute effect on blood glucose, total cholesterol, leptin and PAI-1 levels in both type 2 diabetic and normal subjects. TNF-α value showed decreased trend in both diabetic and normal subjects. The tendency of a delayed postprandial insulin response and elevated serum triglyceride level in diabetic subjects might be related to insulin resistance at the level of adipose tissue. Additional research is needed to assess the impact of the use of fat contents on the macronutrient composition of the diet, and potentially healthy and nutritional benefits for patients with diabetes.</p

Extraction temperature affects the activities of antioxidation, carbohydrate-digestion enzymes, and angiotensin-converting enzyme of Pleurotus citrinopileatus extract

AbstractExtraction temperature can potentially affect the chemical compositions and bioactivities of the extracts obtained. The objective of this study was to investigate the effect of extraction temperature on the distribution of bioactive compounds and the bioactivities of Pleurotus citrinopileatus. The antioxidant activities (2,2-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)+ scavenging capabilities) and the inhibitory capabilities on pancreatic α-amylase, intestinal α-glucosidase, and hypertension-linked angiotensin-converting enzyme of hot water P. citrinopileatus extract and cold water P. citrinopileatus extract were determined. The results showed that the antioxidant capabilities and inhibitory effects on α-amylase, α-glucosidase, and angiotensin-converting enzyme of cold water P. citrinopileatus extract were significantly higher than those of hot water P. citrinopileatus extract. The cold water P. citrinopileatus extracted was further precipitated with 100% ammonium sulfate to obtain a polysaccharide fraction or with 75% ethanol to obtain a protein fraction. The inhibitory activities of the protein fraction of the cold water P. citrinopileatus extract on α-amylase, α-glucosidase, and angiotensin-converting enzyme were significantly higher than those of the polysaccharide fraction. In conclusion, the protein fraction of the cold water P. citrinopileatus extract could be responsible for its bioactivities

Fractionation for Biodiesel Purification Using Supercritical Carbon Dioxide

In recent years, biodegradable and alternative biodiesel has attracted increased attention worldwide. Producing biodiesel from biomass involves critical separation and purification technology. Conventional technologies such as gravitational settling, decantation, filtration, water washing, acid washing, organic solvent washing and absorbent applications are inefficient, less cost effective and environmentally less friendly. In this study supercritical carbon dioxide (SC-CO2) with few steps and a low environmental impact, was used for biodiesel fractionation from impure fatty acid methyl ester (FAME) solution mixes. The method is suitable for application in a variety of biodiesel production processes requiring subsequent stages of purification. The fractionation and purification was carried out using continuous SC-CO2 fractionation equipment, consisting of three columns filled with stainless steel fragments. A 41.85% FAME content solution mix was used as the raw material in this study. Variables were a temperature range of 40–70 °C, pressure range of 10–30 MPa, SC-CO2 flow rate range of 7–21 mL/min and a retention time range of 30–90 min. The Taguchi method was used to identify optimal operating conditions. The results show that a separated FAME content of 99.94% was verified by GC-FID under optimal fractionation conditions, which are a temperature of 40 °C of, a pressure level of 30MPa and a flow rate of 7 mL/min of SC-CO2 for a retention time of 90 min

Panax ginseng Fraction F3 Extracted by Supercritical Carbon Dioxide Protects against Oxidative Stress in ARPE-19 Cells

In our previous work, the ethanolic extract of Panax ginseng C. A. Meyer was successively partitioned using supercritical carbon dioxide at pressures in series to yield residue (R), F1, F2, and F3 fractions. Among them, F3 contained the highest deglycosylated ginsenosides and exerted the strongest antioxidant and anti-inflammatory activities. The aim of this study was to investigate the protective effects of P. ginseng fractions against cellular oxidative stress induced by hydrogen peroxide (H2O2). Viability of adult retinal pigment epithelium-19 (ARPE-19) cells was examined after treatments of different concentrations of fractions followed by exposure to H2O2. Oxidative levels (malondialdehyde (MDA), 8-hydroxydeoxyguanosine (8-OHdG), and reactive oxygen species (ROS)) and levels of activity of antioxidant enzymes were assessed. Results showed that F3 could dose-dependently protected ARPE-19 cells against oxidative injury induced by H2O2. F3 at a level of 1 mg/mL could restore the cell death induced by H2O2 of up to 60% and could alleviate the increase in cellular oxidation (MDA, 8-OHdG, and ROS) induced by H2O2. Moreover, F3 could restore the activities of antioxidant enzymes suppressed by H2O2. In conclusion, F3 obtained using supercritical carbon dioxide fractionation could significantly increase the antioxidant capacity of P. ginseng extract. The antioxidant capacity was highly correlated with the concentration of F3

Extraction and Separation of lO-hydroxy-δ-decenoic acid from Royal Jelly by Supercritical Carbon Dioxide

本研究之目的在於萃取與分離蜂王乳中葵烯酸（10-hydroxy-δ-decenoic acid ; 10-HDA ）成分。超臨界二氧化碳（supercritical carbon dioxide ; SC-CO2 ）是一種較其它溶劑（如水、乙醇、己院、乙醚、丙酮）安全、無毒、不易燃，而且萃取物與超臨界二氧化碳很容易利用降壓方式將其分離。葵烯酸是一種抗癌、抗氧化和抗菌之物質，食用後有強烈辛辣味，使得蜂王乳不易為消費者接受。為了提高產品接受性與價值性，此研究以超臨界二氧化碳為溶劑，萃取與分離蜂王乳中葵烯酸成分做為醫學用品，與去除不悅味道後之去葵烯酸蜂王乳產品做為食品、飲料與健康食品等用途。實驗操作選擇溫度40℃，壓力10 、20 、30MPa 與添加或不添加10 ％乙醇／蜂王乳（體積/重量比）當為輔溶劑等條件，求得最適溶解度（g 葵烯酸／g CO2）、分配係數（氣相與液相之溶解度比）與選擇性（葵烯酸與蜂王乳之分配係數比）。由實驗之最佳結果，採用溫度40℃ 、壓力25MPa 、添加10％乙醇之條件下，於連續式超臨界二氧化碳萃取系統進行實驗後，顯示此條件下可去除蜂王乳中之90％葵烯酸成分。 The objective of this study was to extract and separate lO-hydroxy- -decenoic acid (10-HDA) from royal jelly. A static and a continuous extraction methods using the solvent of supercritical carbon dioxide (SC-C02) or ethanol ¡Ò SC-CO2 were designed to rearch the objective and to measure the solubility of 10-HDA in SC-CO2 or in ethanol ¡Ò SC-CO2. The extraction were performed at 40¢XC and at pressures 10, 20, and 30 MPa. Results showed distribution coefficient of 10-HDA increased with pressure. Two products, 10-HDA and non- or low 10-HDA content of royal jelly products, were obtained at 25 MPa and 40¢XC in the ethanol + SC-CO2 continuous extraction system