14F-7 |
Comprehensive utilization of bitter apricot (Prunus armeniaca) kernels I. extracting oil with supercritical CO2 |
H. ZHANG1, T. Yu2, and J. Shui2. (1) Cereal and Food Sciences, North Dakota State University, 113 Harris Hall, Fargo, ND 58105, (2) Department of Food Science, Beijing Agricultural College, Beijing, 102206, China Bitter apricot kernels are by-products of apricot processing factories and main produces of apricot-shelter forests in China. They are rich in oil (around 50%) and protein (around 25%). Apricot kernel oil has been used in cosmetics industry or as value-added edible oil. Crude oil extracted from traditional methods requires several refining steps and equipments for several days to reach the standard for final use. The objective of this study is to investigate the parameters influencing the oil yield (percentage of oil extracted based on kernel weight) and quality from supercritical CO2 extraction. Kernels were de-shelled, peeled off, detoxicated and ground into powder of various mesh sizes for supercritical extraction. The analysis of iodine, saponification, acid values and other parameters were based on AOCS Recommended Practice. Firstly, it was found that majority of the extraction occurred at the first hour, so two hours were chosen as the maximum extraction time. Then, optimum oil yield was achieved at conditions of 42oC, 20 MPa and 10L/min with 20-mesh powder by orthogonal main effect plan. High moisture content of detoxicated kernels decreased extraction yield of oil, and drying the kernels at low temperature (<50 oC) significantly improved the yield. SiO2 powder was mixed with apricot kernel powder to obtain better extraction. This approach increased oil yield, but brought about two disadvantages: occupying the space of extraction vessel in supercritical equipment, and posing difficulty in separating SiO2 powder from the remaining kernels, which was designed to be further utilized. Lastly, mixing 5% ethanol in CO2 significantly increased the extraction yield. The acidity, iodine and saponification values, and other values of the resulting apricot kernel oil reached the corresponding oil standards. This study indicates that a comparable apricot kernel oil can be produced with supercritical extraction equipment within a short time (hours).
Session 14F, Product Development: General
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