Supercritical CO2 and hydrothermal extraction of phytochemical compounds from Polygonum cuspidatum roots

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Abstracts / Journal of Bioscience and Bioengineering 108 (2009) S135–S146

This study was supported financially by the Food Nanotechnology Project of the Ministry of Agriculture, Forestry, and Fisheries of Japan, and by the Kurata Foundation. doi:10.1016/j.jbiosc.2009.09.014

FE-O7 Preparation of edible nano calcium lactate crystal from crude L-lactic acid via chemical precipitation method Zheng Li, Yinghua Zhang, and Tianwei Tan Beijing Key Laboratory of Bioprocess, Beijing University of Chemical Technology, Beijing, China Calcium lactate, is a nontoxic water-soluble food additive for making bread, soy milk, orange juice and yogurt. Calcium lactate is also reported to function as an anti-microbial, enhancer of bone mineral density, anti-caries, anti-carcinogen (1, 2). This paper is concerned with optimization of effect factors for nano calcium lactate crystal production by chemical precipitation by onefactor-at-a-time and orthogonal methods. The one-factor-at-a-time method was adopted to investigate the effects of L-lactic acid concentration, operating temperature, the ration of calcium hydroxide to lactic acid, stirring speed on the purity, the mean size, the output and crystal morphology of calcium lactate particle was determined. Among these factors, L-lactic acid concentration, stirring speed, temperature and the amount of ethanol were identified to be the most important factors. Subsequently, these factors were optimized using the orthogonal matrix method. The optimal conditions were determined as 6 mol/l L-lactic acid , 500 rpm, 50 °C and 50% ethanol (v/v). The subsequent verification experiments confirmed the validity of the models. Under this optimized conditions, the particle size of calcium lactate, the yield and the purity were 55 nm, 85% and 98%, respectively. Keywords: Nano calcium lactate crystal; L-lactic acid; Chemical precipitation References 1. Lee Y.K., and Kim S.D.: Preparation and Characteristics of Calcium Lactate from Black Snail, Nutrac. Food, 8, 166-172 (2003). 2. Shelef L.A.: Antimicrobial effects of lactates: a review. J. Food Prot., 57, 445-450 (1994).

doi:10.1016/j.jbiosc.2009.09.015

FE-O8 Supercritical CO2 and hydrothermal extraction of phytochemical compounds from Polygonum cuspidatum roots Siti Machmudah, Tomoyo Kamogawa, Mitsuru Sasaki, and Motonobu Goto Kumamoto University, Kumamoto, Japan Phytochemical compounds of the roots of Polygonum cuspidatum has been extracted using supercritical CO2 and water at hydrothermal

condition. Yield of extract was studied at various extraction conditions. The antioxidant activity of the extract obtained by hydrothermal extraction was also investigated in order to analyze the effect of temperature and pressure. Supercritical CO2 extraction was carried out at temperatures of 40–80 °C, pressures of 10–40 MPa, modifier concentrations of 1–5% and CO2 flow rate of 3 ml/min. Modifier used in the experiment was ethanol to enhance supercritical CO2 power for dissolving polyphenolic compounds. Hydrothermal extraction was conducted at various temperatures of 150–200 °C and pressures of 5–15 MPa. Phytochemical compounds were identified as polyphenolic compounds of resveratrol, quercetin and rutin. The polyphenolic compounds were analyzed quantitatively by using HPLC with diode array detector. The experimental result showed that the yields of polyphenolic compounds are significantly affected by supercritical CO2 condition. Based on the hydrothermal extraction result, extraction yields of resveratrol, quercetin and rutin significantly increased with increasing temperature and pressure. In order to determine organic compounds in the extract, watersoluble organic carbon (WSOC) of extracted solution was analyzed by TOC. As expected, amount of ion product of water resulted by increasing temperature causes increasing organic carbon dissolved in water. While the increasing pressure caused higher water penetration into cells of the roots, and resulted in higher organic carbon dissolved in water. In addition, the effect of extraction condition on the antioxidant activity of the extract was also investigated by using DPPH assay. doi:10.1016/j.jbiosc.2009.09.016

FE-O9 Solubility consideration in extraction of astaxanthin from Haematococcus pluvialis using supercritical carbon dioxide Duangkamol Ruen-ngam,1,2 Siti Machmudah,2 Motonobu Goto,2 Mitsuru Sasaki,2 Artiwan Shotipruk,1 and Prasert Pavasant1 Chulalongkorn University, Bangkok, Thailand 1 and Kumamoto University, Kumamoto, Japan 2 Astaxanthin is one of the most efficient carotenoids that a large amount of astaxanthin is available from Haematococcus. Although there were reports on the extraction of astaxanthin from this alga using high pressure CO2[1], little is known regarding its solubility in condition. This work intended to provide more insight by examining the solubility of astaxanthin in supercritical CO2. All chemical substances were purchased from Wako Pure Chemical Industries, Ltd. The experiment was prepared by dissolving 0.0030 g of astaxanthin standard in 20 ml of chloroform then was absorbed onto 3 g of cotton wool which was placed in the middle of 4 cm diameter cylindrical vessel. The column was also packed with 0.5 cm diameter glass bead at the bottom and top of the vessel. The vessel was then placed in the middle of oven where the temperature and pressure were adjusted with temperature regulator and backpressure regulator, respectively. In this experiment astaxanthin solubility was examined at 30, 50 and 80 °C and over the pressure range from 8 to 55 MPa. At equilibrium, the sample was entrained from the vessel at normal temperature and pressure (25 °C and 0.10 MPa) with CO2 flow rate of around 1 ml/min. The sample was then trapped with 10 ml dichloromethane. The amount of astaxanthin was analyzed by HPLC at the wavelength of 480 nm using methanol:acetonitrile at the volume