Comparative physicochemical characteristics of virgin coconut oil produced by different methods

Issue Date

12-2005

Abstract

Virgin coconut oil (VCO) was produced using three methods termed desiccated coconut meat-40 C incubation method, coconut milk-40 C incubation method and coconut milk-freeze-and-thaw method during which the highest temperature attained was 47 C for the first method. Two varieties and one hybrid of coconut were used to obtain VCO using the first two methods while coconuts of unknown variety were used for the third method. Six commercial VCO products and one refined, bleached and deodorized coconut oil (RBDCO) sample were included for comparison. All VCO samples had water clear transparent physical appearance and coconut-like aroma and taste. The melting point of laboratory-produced VCO samples ranged from 24.5 to 25.5 C, which is similar to the melting point of RBDCO. Their specific gravity ranged from 0.9176 to 0.9192. The saponification number of the laboratory-produced VCOs ranged from 264 to 274 mg KOH g -1 while the iodine values were from 4.35 to 6.85 g I2 100 g-1. The free fatty acid (FFA) ranged from 0.09% to 0.18% lauric acid while the peroxide value (POV) ranged from 0.24 to 0.50 meq peroxide kg-1. The moisture content ranged from 0.06% to 0.12%. For commercial sample VCOs, the range of values of the said properties were 24.0 to 25.7 C, 0.9169 to 0.9193, 266 to 272 mg KOH g-1, 4.86 to 7.61 g I2 100 g-1, 0.06 to 0.32% lauric acid, 0.48 to 2.07 meq peroxide kg-1 and 0.10% to 0.42%, respectively. The fatty acid composition showed slight variation among oil samples and the lauric acid content ranged from 47.63% to 52.55%. α-Tocopherol was not detected in the VCO samples by HPLC analysis. The total phenolic content of the laboratory-produced VCOs ranged from 22.88 to 91.90 mg catechin equivalent kg-1 oil while that of the commercial VCOs was 35.26 to 49.07 mg catechin kg-1 oil. The antioxidant activity of the VCO samples ranged from 47.4% to 78% relative peroxidation compared with 46% obtained using 200 mg á-tocopherol. The crude protein for laboratory-produced VCOs was 0.06% to 0.11% compared to 0.07% to 0.12% for the commercial VCOs. The study showed that the VCOs produced by the three methods or using different varieties exhibited differences in chemical and quality properties but these may not be large enough to affect the overall quality of the VCOs. Further, the levels of such properties were still within the CODEX and proposed Philippine standards for coconut oil and for VCO, respectively, probably due to the relatively mild process (with temperature not exceeding 47 C) used in the study.

Source or Periodical Title

Philippine Agricultural Scientist

ISSN

317454

Volume

88

Issue

4

Page

462-475

Document Type

Article

Language

English

Subject

Cold processing, Desiccated coconut route, Incubation at 40 C, Physicochemical characteristics, Virgin coconut oil

Digital Copy

none

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