CS259953B1 - Edible oils ee increased stability against oxidative rancidity - Google Patents

Abstract

The solution deals with edible oils with increased stability against oxidative rancidity, which is achieved by adding up to 3 wt. of concentrates composed of a mixture of phosphatidic, lysophoefatid and bis/aylglycerol/phosphoric acids and their salts. Edible oils are prepared by mixing refined vegetable oils and animal fats with the necessary amount of phospholipid concentrate, or other additives at a temperature of 20 to 150 °C. The stability of the oils thus modified exceeds the stability of the starting oils and fats by 30 to 150%.

Description

The invention relates to edible oils with increased stability against oxidative rancidity, which is achieved by the addition of a phospholipid concentrate.

In recent years, the production and consumption of vegetable oils with an increased content of essential fatty acids, mainly linoleic and linolenic acids, has been increasing. Although these increase the nutritional value of edible oils, they oxidize relatively quickly in air and at normal storage temperatures. These processes, collectively called rancidity, deteriorate their organoleptic properties.

Edible oils are usually stabilized with a set of oxidation inhibitors. Tocopherols and related natural antioxidants are not very effective in edible oils, and the same can be said about inhibitors commonly used to stabilize animal fats, e.g. lard, such as di-tert.butylhydroxytoluene or tert.butylhydroxyanisole. A more effective substance is propyl gallate, but it is expensive and gives the oil a darker color and a noticeable odor. Tert.butylhydroquinone slows down primary oxidation reactions, but it is also expensive. Of the natural substances, soy phospholipids have proven themselves as antioxidants. However, they are in short supply on the market and to a greater extent they give vegetable oils a specific odor.

The above disadvantages are eliminated by the solution according to the invention, according to which edible oils contain up to 3% by weight of concentrates of phosphatidic, lysophosphatidic, bis/diacylglycerol/phosphoric, bis/monoacylglycerol/phosphoric, monoacylglycerol/diacylglycerol/phosphoric and mono/diacylglycerol/phosphoric acids and their salts. The above concentrates contain up to 70% by weight of these phospholipids and up to 30% by weight of fatty acid esters with glycerol,

- 2 optionally fatty acids, both free fatty acids and those bound in phospholipids and in simple lipids having 10 to 24 carbon atoms in the chain and up to 6 double bonds. The phospholipid fraction is composed of 45 to 95% by weight of phosphatidic acids, 2 to 20% by weight of lysophosphatidic acids, 2 to 50% by weight of bis/diacylglycerol/phosphoric acids, 0.2 to 10% by weight of bis/monoacylglycerol/phosphoric acids and 0.2 to 10% by weight of monoacylglycerol/diacylglycerol/phosphoric acids. The edible oils according to the invention may contain phenolic antioxidants and synergists, e.g. citric acid, phosphoric acid, ascorbic acid or acyl esters of ascorbic acid.

The advantage of the aforementioned phospholipid inhibitors is that they have a similar structure to natural phospholipids, from which they differ mainly in that they contain ammonium ions instead of choline, ethanolamine or other nitrogenous components and that they are easily available from natural raw materials.

Phospholipid concentrates having the above composition can be prepared by phosphorylation of a mixture of monoacylglycerols, diacylglycerols and triacylglycerols obtained from vegetable and animal oils and fats, e.g. by the procedures according to Czech Patent Nos. A. 0. 173 220 and 203 421.

From the crude products thus prepared, which usually contain 40 to 60% by weight of phospholipids and 40 to 60% by weight of simple lipids and fatty acids, the desired mixture of phosphatidic, lysophosphatidic and bis(acylglycerol)phosphoric acids and their salts is then prepared by a suitable method, e.g. extraction with organic solvents.

The edible oils according to the invention are prepared by mixing refined vegetable oils and animal fats with the required amount of phospholipid concentrate and optionally with other additives at a temperature of 20 to 80°C.

The examples below illustrate the composition and properties of the edible oils according to the invention and their advantages over commonly used types of inhibitors. However, these examples do not limit the scope of the invention in any way.

Example 1

Stabilized edible oil is prepared by mixing conventionally refined rapeseed oil with phospholipid concentrate at a temperature of 20 to 30 °C. The resulting oil has a light yellow color, a pleasant, characteristic taste and aroma, and its stability during storage under Schaal test conditions, depending on the concentration, exceeds the stability of the starting oil by 30 to 150 % / Table Γ>.

The phospholipid concentrate was made from refined rapeseed oil and contained 92% by weight of ammonium salts of acidic phospholipids, 1.5% by weight of free fatty acids and 6.5% by weight of triacylglycerols. Of the acidic phospholipids, 85% by weight was phosphatidic acids, 3% by weight was lysophosphatidic acids, 10% by weight was bis/diacylglycerol/phosphates and the remainder to 100% by weight was a mixture of bis/monoacylglycerol/phosphates and monoacylglycerol/diacylglycerol/phosphoric acid.

Table 1 - Effect of phospholipid concentrate on the stability of rapeseed oil against oxidative rancidity phospholipid concentration in wt. %.

stability against oxidative rancidity induction period stability in % /d/

0 18.6 100 0.05 24.9 134 0.10 26.3 141 0.20 27.6 148 0.50 36.7 197 1.00 46.8 252

Example 2

Stabilized edible oil is prepared by mixing a mixture of refined soybean and sunflower oils with a phospholipid concentrate containing a mixture of acids with ammonium salts at a temperature of 40 °C. The resulting oil is light yellow to golden yellow in color, has a pleasant taste and is 40 to 120% more stable (determined at 60 °C according to Schaal) than the starting oil, as shown in Table 2.

The phospholipid concentrate was made from sunflower oil and contained 75% by weight of a mixture of acidic phospholipids and their ammonium salts in a ratio of 1:2, the remainder up to 100% by weight was made up of fatty acids and acyl glycerol in a ratio of 1:10. The phospholipid fraction was composed of 50% by weight of phosphatidic acid,

X wt. bisZdi acylglycerolZphosphate, 5 X wt. lysophosphatidic acid, 3 X wt. bis/monoacylglycerol/phosphoric acid, and 2 X wt. monoacylglycerolZdi acylglycerolZphosphate.

Table 2 - Effect of phospholipid concentrate on the stability of a mixture of soybean and sunflower oil against oxidative rancidity

concentration of phospholipids in X mass. stability against oxidative rancidity ZdZ induction period stabi 11 ta re lat. v X 0 16.4 100 0.02 22.5 137 0.05 23.8 145 0.10 28.8 176 0.20 32.6 199 0.50 37.0 22 6

Example 3

Stabilized edible oil is prepared by mixing refined sunflower oil with a phospholipid concentrate containing a mixture of ammonium salts of ascorbic acid palmitate at a temperature of 25 °C. The resulting oil is light yellow in color, has a characteristic pleasant taste, is slightly acidic, and its stability is significantly higher than that of the original oil, as shown in Table 3.

The phospholipid concentrate had a similar composition to that in Example 1 and was made from refined soybean oil.

Table 3 - Effect of a mixture of phospholipid concentrate and ascorbic acid palmitate on the stability of sunflower oil against oxidative rancidity /determined by Schaal

test pr1 60 °C/ Concentration Stability against oxidative rancidity of inhibitors Induction period stability in X wt. /d/ re lat. X . without additives 16.6 100 0.05 X phospholipids 23.4 141 0.02 X ascorbic acid palmitate 20.9 126 mixture of 0.05 X phosphoUpids and 0.02 X ascorbic acid palmitate 28.6 172

r

Example 4

Stabilized edible oil is prepared by dissolving a mixture of phospholipid concentrate, consisting of phosphatidic acids and their ammonium salts, citric acid as a synergist and one of the following phenolic antioxidants: d1-tert. butylhydroxytoluene /BHT/, tert. butylhydroxyanisole /BHA/ or propyl gallate /PG/, in unrefined refined rapeseed oil at a temperature of 40 °C with stirring. The resulting oil has a light golden yellow color, a characteristic pleasant, slightly acidic taste and its stability significantly exceeds the stability of the oil without the inhibitor /Table 4/.

The composition of the phospholipid concentrate was the same as in Example 2, from conventional refined rapeseed oil.

Table 4 - Effect of a mixture of phospholipid concentrate, phenolic antioxidants and synergists on the stability of refined rapeseed oil against oxidative rancidity /determined according to Schaal/

Inhibitor concentration Stability against oxidative rancidity inductive /d/ per 1 person stabi11 ta relatively in X in % mass be of inhibitors 12.9 100 0.05 % Phospholipids 18.6 ¹ 144 0.05 % Phospholipids + 0.02 X BHT 19.8 153 0.05 % Phospholipids + 0.02 X citric acid 20.9 162 0.05 X phospholipids + 0.02 % citric acid + 0.02 X BHT 26.6 206 0.05 X phospholipids + 0.02 X citric acid + 0.02 X BHA 21.5 167 0.05 X phospholipids + 0.02 X citric acid + 0.02 X propyl Iga l ate 48.6 377

Claims (2)

Edible oils having an oxidative rancid stability having a trincylglycerol of from 1 to 24 carbon atoms in the acyl group with an increased oxidation rancidity, characterized in that they contain up to 3% by weight. phosphate, lysophosphatide concentrate, bs / dlacylglycerol / phosphoric acid, bs / monoacylglycerol / phosphoric acid, monoacylglycerol / dlacylglycerol / phosphoric acid and mono / dlacylglycerol / phosphoric acid and their ammonium salts, said concentrates containing up to 70% by weight. and up to 30 wt. fatty acid esters of glycerol or fatty acids, wherein the fatty acids bound in phospholplases, single lipids 1 of free fatty acids have 10 to 24 carbon atoms in the chain and up to 6 double bonds. 2. Edible oils according to claim 1, characterized in that the phospholester portion is comprised of 45 to 95% by weight. phosphatldic acid, 2 to 20 wt. % lysophosphatldic acid, 2 to 50 wt. % bs / diacylglycerol / phosphoric acid, 0.2 to 10 wt. % bis (monoacylglycerol) phosphoric acid and 0.2 to 10 wt. monoacylglycerol / dlacylglycerol / phosphoric acid.