Orange oil is composed largely of terpene hydrocarbons but is a source of flavor and fragrance compounds (oxygenated) that are present in low concentrations. To increase the ratio of oxygenated compounds to terpene hydrocarbons, orange oil was partially fractionated by adsorption of the oxygenated compounds onto porous silica gel, with full utilization of its adsorbent capacity, and then further purified by desorption into supercritical carbon dioxide. The desorption of 24 compounds was monitored by GC and GC-MS. Adsorption alone removed three-fourths of the terpene hydrocarbons, and fractional extraction by supercritical carbon dioxide (SC-CO2) improved the separation further. Response surface methodology was used in the experimental design, and regression analysis was used to determine the effects of process variables. Extraction at low temperatures and flow rates improved separation by SC-CO2. Decanal was concentrated to 20 times that of the feed oil by using SC-CO2 at 13.1 MPa, 35 °C, and 2 kg/h. The ...

Use of adsorbent and supercritical carbon dioxide to concentrate flavor compounds from orange oil

Supercritical Fluids – Fundamentals for Application. Von E. Kiran und J. M. H. Levelt Sengers. Kluwer Academic Publishers, Dordrecht 1994. 771 Seiten, zahlr. Abb. u. Tab., US‐$ 292,–.

Solubility of cholesterol in bile (proceedings)

A styrene-divinylbenzene (SDVB) resin was used in a sorption column process to concentrate volatile flavor con stituents from aqueous orange essence. The resin XAD-16 was chosen for the study based on its oil sorption capacity and additional evaluations. Aqueous orange essence was passed through a downflow fixed-bed column resin system. The sorbed essence was desorbed using 95% ethanol, and the qualitative and quantitative compositions of the recovered essence were determined by capillary gas chromatographic analysis. Major compounds concentrated from aqueous orange essence were ethyl butyrate, octanal, linalool, octanol, neral and geranial. Other components concentrated in lower levels were ethyl 3-hydroxyhexanoate, terpinen-4-ol, a-terpineol, and carvone. Ethyl acetate and methyl butyrate were concentrated at very low levels. The concentrated essence product should be useful as a flavor for citrus juice and beverages. Natural aqueous orange essence is the distillate collected during orange juice concentration using a thermal acceler ated short time evaporator (T. A.S.T.E.) (Johnson and Vora, 1983). Major flavor constituents of aqueous orange essences have been previously reported (Kealey and Kinsella, 1979; Moshonas and Shaw, 1990; Shaw, 1977). Aqueous orange essence is widely used by citrus processors to improve the flavor of frozen concentrated orange juice, and orange con centrate containing added aqueous orange essence has been found to maintain acceptable essence flavor for periods up to 30 months of frozen storage (Dougherty et al., 1974). Although increasingly used in the industry, the full com mercial potential of aqueous orange essence has not been determined. Many factors affect the quality of orange es sence including cultivar, season of harvest, maturity and processing methods. Different types of commercially available granular polymeric adsorbents have been tested to remove organic compounds from waste water (Weber and Van Vliet, 1981; Patterson and Patzelt, 1981). The styrene-divinylbenzene (SDVB) resin is one of the most commonly used resins. They are durable non-polar styrene polymers crosslinked with different percentages of divinylbenzene. The ad sorbed solutes can be easily desorbed with organic solvents (Gustafson etal., 1968). The applications of styrene-divinyl benzene resins in the food industry include grapefruit juice debitterment (Manlan et al., 1990), and concentration of apple and tomato volatiles (Di Cesare et al., 1987; Moshonas and Shaw, 1990) from aqueous solutions. A recent study done by Ericson et al. (1990) evaluated the capacity of SDVB resins to recover grapefruit oil from processing waste water. Since SDVB resins may have a potential application for concentrating the flavor constituents of aqueous orange essence, this study was conducted to assess this possibility. The high level of ethanol (13-15%) in the aqueous essence could interfere with the sorption process. The XAD-16 resin was chosen for the column operations due to its high sorption capacity. Materials and Methods Several commercially available resins were tested for their sorption rates and capacities for total esters and total aldehydes from model solutions. Resin XAD-16 exhibited high sorption rate and high sorption capacity, and was selected for the subsequent column processes to recover essence components from model solutions. Some of the physical properties of the XAD-16 resin are listed in Table 1. Ten ml of the pretreated XAD-16 resin (dry base) which had been soaked overnight in 10% ethanol for hydration was packed into a glass column (11 mm x 30 cm. Five to 10 bed volumes (BV) of water was added to rinse the sorp tion column before the model solution (85% water, 13% ethanol, 1400 to 1600 ppm ethyl butyrate and 65 to 70 ppm octanal) was pumped downflow through the column at room temperature. The concentration of octanal in the model solution was limited by its solubility. The flow rate of the model solution was controlled at 25 to 30 bed volume (BV)/hr. Fractions were collected by an ISCO Model GYGENT fraction collector (Instrumentation Specialties Co., Lincoln, NE) at a constant volume of 10 ml. The influent and effluent concentrations were monitored. When the sorption resin was saturated (effluent concentration equal to influent concentration), the operation was discontinued. Breakthrough curves were developed by plotting effluent concentration versus elution volume. The sorbed con stituents were eluted from the column with 7 to 8 BV of 95% ethanol. The eluted total esters and total aldehydes of all model solutions in the study were determined by using colorimeteric methods reported by Attaway et al. (1967) and modified by Ismail et al. (1970). Aqueous orange essence samples were obtained from a Florida citrus flavor supplier. Essence constituents were sorbed from aqueous orange essence samples using the column process described for the model solution. Total

Concentration of aqueous orange essence by sorption on styrene-divinylbenzene resin

The crude oil extracted from soy flakes with supercritical carbon dioxide (SCCO2) was characterized for color, free fatty acid, phosphorus, neutral oil loss, unsaponifiable matter, tocopherol and iron content and compared to a commercial hexane-extracted sample of crude degummed oil. Characterization and processing studies indicate that SCCO2 extraction yields a product comparable to a hexane-extracted degummed oil. However, hexane-extracted degummed soybean oils exhibit better oxidative stability because phosphatides, which are natural antioxidants, are essentially absent in SCCO2-extracted oils.

Processing Characteristics and Oxidative Stability of Soybean Oil Extracted with Supercritical Carbon Dioxide at

This study investigated the use of dense carbon dioxide, in both liquid and supercritical states, to extract and fractionate food by-product oils dispersed in porous
matrices. Two oils were studied - Rice bran oil and Orange oil

Zhiping Shen

Papers

The use of dense carbon dioxide extraction and fractionation to recover and refine natural food ingredients from food processing wastes