A DETERGENT COMPOSITION APPLICABLE TO FOODSTUFF USE

Abstract: The invention relates to a washing formula suitable for use with foodstuffs, intended for washing fruits, vegetables, and edible roots. The washing formula contains surface-active agents and wax-dissolving agents. The wax-dissolving agent comprises a vegetable-oil based substance and the surface-active agent comprises a sorbitan-derived substance.

Description: A DETERGENT COMPOSITION APPLICABLE TO FOODSTUFF USE The present invention relates to a washing formula suitable for use with foodstuffs, which is applicable to washing fruits, vegetables, edible roots or the like foodstuffs for removing pesticide residues in an effective and safe fashion. In this context, the term fruits is conceived to include various types of berries as well. Efforts have been made for decades for preventing the microbiological spoilage of fruits and vegetables with chemical substances, such as e.g. copper salts. Currently, several countries also make use of organic compounds, imidazoles, benzimidazoles, and triazoles for pesticidal or preservation purposes. Imported fruits and vegetables are being checked for pesticide or preservative residues in order to offer the consumer an access to high-quality and clean products. However, due to sampling, the markets may end up with shipments containing loads of pesticides. In all cases, the best guarantee for sufficient purity is to clean or peel the products prior to use. The peel or skin of fruits and vegetables protects the inner portion thereof from the evaporation of water and the effects of oxygen, which impair the taste, nutritive value, and vitamin content thereof. If it is necessary to peel the products, it is most preferable that such products be used immediately or be put in a freezer. The best storage wrapping for fruits and vegetables is their very own peel or skin. The skin of several fruits and vegetables contains plenty of ceraceous or waxy substances which are soluble in fat. In several cases, the organic pesticides or preservatives are also soluble in fat and, hence, impregnate effectively in the surface of these products. In these cases, washing with plain water is not sufficient to remove pesticide residues. Many fruits and vegetables have a very uneven skin with its furrows and crevices. As a result of its surface tension, water is not able to penetrate sufficiently into these furrow areas. However, the pesticides or preservatives, which contain surface-active agents, are in aqueous dilutions capable of penetrating and spreading everywhere in the skin layers. It is common knowledge that the surface tension of water can be reduced by adding surface-active agents therein. On the other hand, it is known that fat- soluble substances dissolve in oils and may emulsify or dissolve also in surface- active agents. It is also known that oils, containing solids dissolved therein, can be emulsified in water by means of surface-active agents. The surface-active agents accepted in food and pharmaceutical industries include esters of sorbitan derivatives of fatty acids, e.g. Span 20, and the ethoxylated derivatives thereof, e.g. Tween 80. Edible oils contain abundant amounts of triglycerides, which due to unsaturated fatty acids are liquid at room temperature (+ 20°C). Those are nutrients absorbed from the alimentary canal and decomposing in the organism first into fatty acids and glycerol. Due to the oily nature thereof, the vegetable oils often function as a solvent for hydrophobic, water-insoluble substances. Although triglycerides themselves are fats and not miscible in water, the hydrolysis products thereof, fatty acids, mono- and diglycerides, can be miscible in water. They also have surface-active characteristics, especially if the mixture is neutral or alkaline. In acidic conditions, they function as oil-containing solvents. The adjustment of acidity in foodstuffs can be effected by using citric acid, which is also a physiological compound. It has been surprisingly discovered that nutritionally applied or physiological fat- soluble substances and nutritionally accepted surface-active agents can be used for preparing a mixture which, when diluted in water, enhances the removal of pesticide or preservative residues from the skin surface and the ceraceous layer. Thus, according to the present invention, there is provided a washing formula suitable for use with foodstuffs and intended for washing fruits, vegetables, and edible roots and which is characterized by containing surface-active agents and wax-dissolving agents. The wax-dissolving agent comprises preferably some vegetable-oil based substance, e.g. a vegetable-oil based ester, such as triglyceride, and/or the hydrolysis product of an ester. Triglyceride is obtained e.g. from sunflower, turnip rapeseed, rapeseed, or soybean oil or mixtures thereof. The concentration of triglycerides in the washing formula is 0 - 50 %, preferably 2 - 20 %. The hydrolysis products of triglycerides are prepared by an alkali, acid, or enzymatic treatment of triglycerides to effect a complete or partial hydrolyzation thereof. The hydrolysis products of triglycerides have a concentration in the washing formula within the range of 0 - 100 %, preferably 20 - 40 %. The surface-active agent comprises preferably a sorbitan-derived substance, which is the ester of a fatty acid and sorbitan or an ethoxylated derivative thereof, wherein the fatty acid has an average carbon chain length within the range of 8-20 carbons. The sorbitan-derived surface agent has a concentration within the range of 0 - 100 %, preferably 30 - 60 %. Furthermore, the washing formula of the invention preferably contains an acid which particularly enhances the removal of heavy metal residues, such as copper compounds, from the surface of products. The acid comprises preferably tetra- acetic acid, e.g. ethylenediamine tetra-acetic acid. The washing formula may contain also isopropanol, e.g. about 0,1 - 5 %, which functions a.o. as an anti-precipitant and contributes to the penetration of the washing medium into wax. The washing formula of the invention is used as a solution diluted in water, said formula having a concentration in aqueous solution of about 1 % to about 10 %, preferably from about 2 % to about 5 %. Another object of the present invention is the use of a food-compatible washing formula, containing surface-active agents and wax-dissolving agents, for washing fruits, vegetables, and edible roots in an aqueous solution, wherein the washing formula has a concentration of about 1 % to about 10 %, preferably from about 2 % to about 5 %. The washing formula is used e.g. by blending the same in water in a sink or washbowl.. The washing formula can also be used e.g. by spraying a pre-mixed aqueous solution. The washing formula of the invention is non-toxic and contains biodegradable substances and removes effectively pesticide or preservative residues, nor does it itself leave other harmful agents in the product. Table 1 shows a few examples of washing formulae of the invention. The table discloses various trade names, whereof Arlacel and Tween 80 are various sorbitan oleates. Tween 20 is one sorbitan laurate and Trilon B flussig contains ethylenediamine tetra-acetic acid and tetrasodium salt in water. The agents shown in the table have concentrations preferably within the following ranges: Arlacel 28-67 %, preferably about 45-50 %; Tween 80 6-20 %, preferably about 10 %, Tween 20 0-20 %, preferably about 1-5 %, more preferably about 2 %; a fatty acid mixture about 10-45 %, preferably about 25-30 %, more preferably about 28 %; a vegetable oil about 1-13 %, preferably about 5 %; Triloβ Flussig about 3-22 %, preferably about 5-10 %, more preferably about 8 %. Patent Blue contained in the compositions (about 0,001 %) contributes to appearance and colour, water (about 0,08 % - about 1 ,1 %) to consistency, and cotric oil (about 0,175 %) to scent; these have no effect on washing power. Table 1 EXAMPLE: The washing solution containing a combination 1 of table 1 was tested in the customs laboratory on mandarin oranges which, on the basis of preliminary testing, contained residues in amounts sufficient in terms of testing. Equal numbers of mandarins were included in two samples (12 pieces/sample). One sample was analyzed as such, while the mandarins of the other sample were washed intact with a 10 % washing solution by keeping them in the washing solution and by brushing with a dish-washing brush. The analyzing method was TLAB-PE1 Modif. AOAC 985.22, 1990. The gas chromatographic determination of pesticides from fruits, berries, vegetables, and grains (a method accredited by FINAS). Results: Unwashed Washed Pesticides applied before harvest Methidathion 0,20 mg/kg 0.09 mg/kg Malathion 0,16 mg/kg 0,06 mg/kg Chlorpyrifos 0,14 mg/kg 0,08 mg/kg Dimethoate 0,03 mg/kg 0,02 mg/kg Pesticides applied after harvest Thiabendazole 0,55 mg/kg not detectable Imazalil 0,58 mg/kg not detectable Washing removed 85 % of the residues.

Claims: Claims 1. A washing formula suitable for use with foodstuffs, intended for washing fruits, vegetables, and edible roots, characterized in that it contains surface-active agents and wax-dissolving agents. 2. A washing formula as set forth in claim 1 , characterized in that the wax- dissolving agent comprises a vegetable-oil based substance. 3. A washing formula as set forth in claim 1 , characterized in that the wax- dissolving agent comprises a vegetable-oil based ester and/or a hydrolysis product of the ester. 4. A washing formula as set forth in claim 3, characterized in that the ester comprises triglyceride. 5. A washing formula as set forth in claim 4, characterized in that triglyceride is obtained from sunflower, turnip rapeseed, rapeseed, or soybean oil or mixtures thereof. 6. A washing formula as set forth in claim 4 or 5, characterized in that the concentration of triglycerides is not higher than 50 %, preferably 2 - 20 %. 7. A washing formula as set forth in claim 3, characterized in that the hydrolysis product of the ester comprises a hydrolysis product of triglyceride, which is prepared by means of the alkali, acid, or enzymatic treatment of triglyceride in such a way that it has hydrolyzed completely or partially. 8. A washing formula as set forth in claim 7, characterized in that the concentration of the hydrolysis products of triglycerides is up to 100 %, preferably 20 - 40 %. 9. A washing formula as set forth in any of claims 1-8, characterized in that the surface-active agent comprises a sorbitan-derived substance. 10. A washing formula as set forth in claim 9, characterized in that the sorbitan- derived surface-active agent comprises an ester of a fatty acid and sorbitan or its ethoxylated derivative, wherein the average carbon chain length of the fatty acid is within the range of 8-20 carbons. 11. A washing formula as set forth in claim 9 or 10, characterized in that the concentration of the sorbitan-derived surface-active agent is up to 100 %, preferably 30 - 60 %. 12. A washing formula as set forth in any of the preceding claims, characterized in that it further contains an acid. 13. A washing formula as set forth in claim 12, characterized in that the acid comprises tetra-acetic acid, e.g. ethylenediamine tetra-acetic acid. 14. A washing formula as set forth in any of the preceding claims, characterized in that its concentration in an aqueous solution is from about 1 % to about 10 %, preferably from about 2 % to about 5 %. 15. The use of a food-compatible washing formula, containing surface-active agents and wax-dissolving agents, for washing fruits, vegetables, and edible roots in an aqueous solution, wherein the washing formula has a concentration of about 1 % to about 10 %, preferably from about 2 % to about 5 %.

Inventors: KIRJAVAINEN HARRI, MYLLYKYLAE JUKKA, KIRJAVAINEN, HARRI, MYLLYKYLAE, JUKKA
Applicants: FRUIT WASH OY, KIRJAVAINEN HARRI, MYLLYKYLAE JUKKA, KIRJAVAINEN, HARRI, MYLLYKYLAE, JUKKA
Application year: 1998
Main classification: A23P1
IPC codes: A23L1, C11D1, C11D3