WO2012169718A1

WO2012169718A1 - A method of process for edible oil reduced with 3-chloro-1,2-propanediol forming substances and product prepared thereby

Info

Publication number: WO2012169718A1
Application number: PCT/KR2012/000900
Authority: WO
Inventors: Yun Sik Kim; Sang-Bum Lee; Seung-Won Park
Original assignee: Cj Cheiljedang Corp.
Priority date: 2011-06-09
Filing date: 2012-02-08
Publication date: 2012-12-13
Also published as: KR101207413B1; CN103596445A; JP2014515940A; MY161102A

Abstract

Disclosed are a method for decreasing 3-chloro-1,2-propanediol (hereinafter, '3-MCPD') forming substances (hereinafter, '3-MCPD-FS') generated in refining edible oil, as well as the edible oil containing decreased 3-MCPD-FS. More particularly, a method for reducing a concentration of 3-MCPD-FS to 0.3 ppm or less by controlling chlorine ions contained in tap water used for edible oil refinement is provided, thereby greatly decreasing the content of 3-MCPD-FS, compared to typical edible oil known in the related art. Simultaneously, the present invention attains excellent effects of providing edible oil that has improved reliability and safety to consumers, while retaining high quality thereof such as taste, color, etc.

Description

A METHOD OF PROCESS FOR EDIBLE OIL REDUCED WITH 3-CHLORO-1,2-PROPANEDIOL FORMING SUBSTANCES AND PRODUCT PREPARED THEREBY

The present invention relates to edible oil containing reduced 3-MCPD-FS and a manufacturing method thereof and, more particularly, to a method for controlling chlorine ions contained in tap water used for oil refinement.

A 3-chloro-1,2-propanediol forming substance (hereinafter, referred to as ‘3-MCPD-FS’) generally refers to a substance producing 3-MCPD, and is classified into four species, that is, 3-MCPD, glycidol, combined 3-MCPD having fatty acid bonded thereto (‘fatty acid-combined 3-MCPD’), combined glycidol. In general, fatty acid-combined substances are detected from edible oil.

Briefly, the combined 3-MCPD means 3-MCPD fatty acid ester in mono- or di-ester type of higher fatty acid, and is well known to be naturally generated in manufacturing or processing foods containing fat and salt (sodium chloride). The foregoing substance is usually detected together with 3-MCPD in manufacturing or processing a variety of foods such as cookies (biscuits), bread (donuts), fried potato, roasted coffee bean, roasted malt, or the like. In addition, the foregoing substance is detected from marinated olive or herring, which was processed at a low temperature using acid as a medium. Moreover, it has been reported that the foregoing substance is detected from vegetable oils including refined olive (W. Seefelder et al., Esters of 3-Chloro-1,2-Propanediol (3-MCPD) in Vegetable Oils, 2008). Although toxicity and physiological characteristics of the combined 3-MCPD have yet to be more clearly disclosed, some European countries have proposed a need for reduction of combined 3-MCPD since the combined 3-MCPD may potentially be converted into 3-MCPD.

Meanwhile, 3-MCPD is a colorless or pale yellow chemical substance and one of chloropropanol species, which are produced by a reaction of trace glycerin with hydrochloric acid while hydrolyzing fat residue, which remains when vegetable protein is degraded into amino acid and fat, into glycerin and fatty acid. With regard to harmfulness of 3-MCPD to human body, it was known that this substance does not have carcinogenic potential. However, according to animal testing, it has been reported that the foregoing substance may cause infertility or have possibility for decrease in sperm production and/or genetic toxicity (C. G. Hamlet & P.A. Sadd, Chloropropanols and Chloroesters, 2009). In 1996, the foregoing substance has been detected from instant noodle soup powder, soy sauce, acid hydrolyzed-HVP, or the like, in several countries in Southeast Asia and western countries as well as Korea, in turn causing significant problems. According to regulations on content of the above substance in soy sauce, for example, the content of 3-MCPD may be controlled to 0.02 ppm in EU, 1.0 ppm in Canada, 0.2 ppm in Australia and 0.3 ppm in Korea.

Further, combined glycidol means a substance called glycidol combined with one fatty acid, and safety of the combined glycidol is not yet clearly identified. However, the foregoing substance may be digested and degraded in a human body, in turn releasing glycidol therefrom. Such glycidol has been classified by The International Agency for Research on Cancer (IARC) into one of substances to be “probably carcinogenic to humans” (group 2A). Numerous studies on safety of combined glycidol contained in processed foods have recently been executed in Europe and Japan.

At present, for the combined glycidol contained in processed foods, approved analysis methods for glycidol only have not yet been disclosed. Instead, a method of calculating a total amount of 3-MCPD after converting glycidol into 3-MCPD is usually employed, and it is reported that about 10 to 60% of 3-MCPD is derived from glycidol (ILSI Europe Report 2009).

With respect to mechanisms for production of probably harmful substances described above, many of them have yet to be disclosed. However, according to HAMLET et al., a mechanism for conversion of combined 3-MCPD into 3-MCPD, wherein: 1,3 or 1,2-diacylglycerol is generated by a reaction of triacylglycerol and salt through heating; the generated material is changed into 1,2-diacyl-3-chloropropane-1,2-diol or the like, as combined 3-MCPD, produced by hydrolysis and chlorine substitution via cyclic acyloxonium ions as an intermediate; the produced material is again subjected to hydrolysis to produce 1 or 2-acyl-3-chloropropane-1,2-diol; and, in turn being converted into 3-MCPD through hydrolysis, in the manufacture and processing of food, has been proposed.

However, for edible oil, it is presumed that trace chlorine compounds contained in a raw material or water may react with the oil at a high temperature to generate the foregoing substance during refining and, in this regard, a content of 3-MCPD-FS detected in the refined oil ranges from 0.3 to 13 ppm.

According to Korean Laid-Open Patent Publication No. 10-1999-0075193, a method of minimizing a content of 3-chloro-1,2-propanediol (MCPD), which includes controlling a concentration of hydrochloric acid by hydrolyzing animal/vegetable protein using hydrochloric acid, to thus reduce harmfulness of combined 3-MCPD in preparation of soy sauce, has been described.

However, there is still no disclosure for a method of decreasing 3-MCPD-FS from edible oil.

In view of the foregoing, the present invention has been proposed and an object of the present invention is to provide a method for effectively and safely reducing 3-MCPD-FS generated as a by-product in manufacturing edible oil, while retaining flavors and color thereof.

The foregoing purpose has been accomplished by removing chlorine ions contained in drinking top water used for refining edible oil.

As set forth above, according to the present invention, 3-MCPD-FS probably generated in processing may be principally controlled while maintaining color and flavors of existing edible oil. In addition, the inventive method may be easily applied to general oil refining processes so as to effectively and safely decrease 3-MCPD-FS, thereby attaining excellent functional effects.

The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a block diagram illustrating an overall process of a manufacturing method according to the present invention;

FIG. 2 is ionic chromatographs showing results of chlorine ion content analysis conducted according to the present invention;

FIG. 3 illustrates types of 3-MCPD-FSs produced according to the present invention and production mechanisms thereof; and,

FIG. 4 is graphs showing analyzed results of 3-MCPD-FS contents obtained in the manufacture of oil according to the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail by the following examples, however, such embodiments are proposed for illustrative purpose only and the scope of the present invention is not particularly limited to these examples.

Among terminologies used herein, edible oil means oil stated in Food Code and includes raw oil obtained from vegetables (including crushed vegetables) containing oil or fat and/or animal fat, and all products manufactured/processed therefrom, for example; soybean oil, corn oil, canola oil, rice bran oil, sesame oil, perilla oil, safflower oil, sunflower oil, cottonseed oil, peanut oil, olive oil, palm seed oil, coconut oil, mixed edible (vegetable) oil, shortening oil, margarine, red pepper seed oil, flavored edible oil, processed fat, and so forth. Further, all oil/fat products requiring deodorization in the oil refining process shown in FIG. 1 are included. From the foregoing, the processed fat means butter, margarine, shortening, etc.

Preparation of oil composition with high diacylglycerol content

According to the invention in Example 5 disclosed in Korean Laid-Open Patent Publication No. 2004-0005350, an oil composition having a high diacylglycerol content was prepared by ester synthetic reaction (‘esterification’) of glycerol with a liquid fatty acid having a high content of unsaturated fatty acid. Such esterification may be executed by a chemical method including addition of an alkaline catalyst and/or a biological method using an enzyme, that is, lipase. Such methods are well known in the related art. After completing esterification, refining processes such as molecular distillation, decoloring (or bleaching), deodorization, etc., were executed, resulting in a liquid oil composition with a diacylglycerol content of 78% or more. Constitutional composition thereof is shown in Table 1 below.

Table 1

	TAG	DAG	MAG	Others
Constitutional composition (%)	20.0	78.0	1.5	0.5

TAG: Triacylglycerol

DAG: Diacylglycerol

MAG: Monoacylglycerol

Analysis of 3-MCPD-FS Content

In order to analyze the content of 3-MCPD-FS, a gas chromatography/mass spectrometer (GS/MS) technique was used. Conditions for analysis used herein are shown in Table 2 below. After dissolving 100 mg of a sample in tBME:EA (8:2 v/v, Solvent A), 50 μL of an internal standard material having a concentration of 200 ppm and 1 mL of sodium methoxide (NaOCH₃) solution were added thereto, followed by leaving the mixture at room temperature for 5 to 10 minutes. As the internal standard material, d5-3-MCPD was used. After adding 3 mL of hexane and 3 mL of a solution of acetic acid:20% NaCl (1:30 v/v, Solvent B) to the foregoing material, an organic solvent phase which is a supernatant portion was removed. 250 μL of a derivatization reagent, that is, phenylboronic acid was added to a water phase, followed by conducting a reaction at 80℃ for 20 minutes. Here, derivatization of the standard material was simultaneously executed. After naturally cooling at room temperature, the reaction product was subjected to extraction using 3 ml of hexane and the hexane phase was subjected to GC/MS analysis. Quantification was executed using 196 m/z (3-MCPD) and 201 m/z (3-MCPD-d₅) ions, while a qualifier was 147 m/z (3-MCPD) and 150 m/z (3-MCPD-d₅) ions.

Table 2

Equipment	GC (Agilent 6890 GC,HP)/ MS (Platform, Micromass Ltd., UK)
Column	HP-5 capillary column
Amount of sample	2 L (Split 10:1)
Carrier gas	Helium (1 ml/min)
Oven temperature program	50(keeping for 1 minute) -> 200 (temperature elevation, 30/min) -> 280 (temperature elevation, 50/min) -> 280 (keeping for 15 minutes)
Detector	EI + SIM mode
Internal standard material	m/z = 201
3-MCPD	m/z = 196 (quantifier), 147(qualifier)
Amount of sample	1 L (Split 10:1)

The present invention will be better understood from the following examples and comparative examples.

[EXAMPLE 1] - Removal of chlorine ions from tap water

According to one embodiment of the present invention, in order to remove chlorine ions, any known method in the related art such as use of ion exchange resin, electrical dialysis, or the like, may be employed.

Among those, the use of ion exchange resin is a method utilizing a phenomenon wherein, when a specific material is in contact with an aqueous solution containing a salt, ions of the material enter the solution while ions of the solution are introduced into the material, that is, reverse exchange between various ions in the solution and other ions having the same charge (positive or negative) as the former, through an insoluble resin (the ion exchange resin). In order to remove chlorine ions, an anion exchange resin composed of a polymer parent exchanger combined with quaternary ammonium or primary to tertiary amines (-NH₂ primary amine, -NHR secondary amine, -NR₂ tertiary amine) are used.

Meanwhile, electro-dialysis is a method based on a principle in that a membrane selectively passing cations or anions therethrough is used, more particularly, wherein: an anionic membrane through which only cations penetrate as well as a cationic membrane through which only anions penetrate are alternately arranged; and DC voltage is applied to an electrode to allow cations pass through the anionic (exchange) membrane while passing anions through the cationic (exchange) membrane, to thereby remove ions while remaining pure fresh water.

According to one embodiment of the present invention, a content of chlorine ions in general tap water and a concentration of chlorine ions in water obtained by electro-dialysis of the drinking top water and through ion exchange resin are shown in Table 3 below. In addition, chlorine ions were analyzed by a typical ionic chromatography technique, while ionic chromatogram of the tap water was shown in FIG. 2.

Table 3

	Tap water	ED method	Anionic exchange resin method
Chlorine ion (ppm)	25.0	0.27	0.10

[EXAMPLE 2] - Reduction of 3-MCPD-FS of diacylglycerol oil deodorized using chlorine ion-free water

In food manufacturing and processing, deodorization is purposed of removing volatile materials such as free fatty acid, glycerol, oxidation products, sterol, hydrocarbon, agricultural chemicals, or the like, in turn ultimately removing foul taste and/or foul odor of a final oil product. Further, in order to remove probably remaining metal portions, a metal remover such as citric acid was added to the oil product in order to degrade a complex generated therein, which in turn removed the degraded material through filtration. Deodorization may be executed in a batch, semi-continuous or continuous way. By blowing steam into the oil under vacuum ranging from 2 to 10 mmHg while heating the oil at 240℃ or higher, ingredients other than triacylglycerol were volatilized and removed. As a result, the content of free fatty acid was reduced to 0.05% or less by deodorization, and an amount of the oxidation product was considerably reduced to a level impossible to determine in terms of peroxide value.

Among processes for manufacturing an oil composition with a high content of diacylglycerol, the deodorizing process was executed by steam deodorization at 230℃ for 2 hours. Here, as water used for steam deodorization, a control was the tap water while the water free from chlorine ions, for example, obtained using an anionic exchange resin or by electro-dialysis, or the like, was used as a test sample to conduct the deodorizing process. After deodorization, GS/MS was performed to determine acid value, peroxide value and/or color value, as indexes for quality safety, which indicate extents of reduction and/or maintenance in 3-MCPD-FS. Results thereof are shown in Table 4 below.

Table 4

	3-MCPD-FS content (ppm)	Acid value	Peroxide value	Color value (Y/R, 5_1/4)
Tap water	13.0	0.14	0.01	11/1.1
Electro-dialysis	0.30	0.13	0.01	11/1.1
Anionic exchange resin treatment	0.25	0.14	0.01	11/1.1

As a result of the foregoing experiments, it was found that the content of 3-MCPD-FS correlates with the concentration of chlorine ion residue contained in steam used for deodorization. The lower the concentration of chlorine ions in the tap water, the lower the content of 3-MCPD-FS was observed. For general tap water, the concentration of chlorine ions was 25 ppm and the content of 3-MCPD-FS after deodorization was the highest level of 13.0 ppm. In contrast, the tap water free from chlorine ions treated by electro-dialysis included 3-MCPD-FS in a content of 0.4 ppm, while the chlorine ion-free tap water treated using anion exchange resin showed a 3-MCPD-FS content of 0.31 ppm.

[EXAMPLE 3] - Reduction of 3-MCPD-FS of rice bran oil and palm seed oil which were deodorized using chlorine ion-free water

Each of the rice bran oil and the palm seed oil was used as a raw material and subjected to steam deodorization using chlorine ion-free water according to the same procedures as described in Example 2, and results thereof are shown in TABLE 5.

Table 5

	3-MCPD-FS content (ppm)
	Rice bran oil	Palm seed oil
Tap water	1.5	2.0
Electro-dialysis	0.20	0.23
Anionic exchange resin treatment	0.19	0.20

As shown in FIG. 3, results of the foregoing example demonstrated that, since combined 3-MCPD as well as 3-MCPD are compounds containing chlorine ions bonded thereto, the content of 3-MCPD-FS may be reduced by controlling a chlorine compound contained in the raw oil or during oil refinement. Specifically, it is understood that the content of 3-MCPD-FS was minimized by removing chlorine ions from tap water used in a deodorizing process, without influence upon final quality of edible oil.

Claims

A method for manufacturing edible oil by preparing a product after degumming, deoxidizing, bleaching and deodorizing raw oil, comprising:

removing chlorine ions from tap water used as usual, so as to reduce a 3-chloro-1,2-propanediol forming substance (3-MCPD-FS).
The method according to claim 1, wherein the edible oil is at least one selected from soybean oil, corn oil, canola oil, rice bran oil, sesame oil, perilla oil, red pepper seed oil, flavored edible oil, safflower oil, sunflower oil, cottonseed oil, peanut oil, olive oil, palm seed oil, coconut oil, mixed edible (vegetable) oil and processed fat.
The method according to claim 2, wherein the processed fat has a content of diacylglycerol of 10% or more.
Edible oil manufactured by any one method as set forth in claims 1 to 3, having a content of 3-MCPD-FS of 0.3 ppm or less.