MD1453Z - Process for producing dyes from Safflower petals (Carthamus tinctorius L.) - Google Patents

Abstract

The invention relates to the food industry, namely to a process for producing dyes from Safflower petals.The process, according to the invention, comprises treating the petals with 3…5% sodium carbonate solution and subsequently pressing them, separating the solution obtained after pressing and treating it with citric acid to a pH of 4.8…6.3, followed by the separation of the cardamine sediment from the luteolin solution.

Description

The invention relates to the food industry, in particular to the production of natural dyes for their use in the manufacture of harmless food products, namely to a process for obtaining dyes from Safflower petals.

A process for obtaining natural dyes from Safflower is known that includes microwave pretreatment of the raw material, followed by sealing and preservation for its use in subsequent stages, which consist of the extraction of yellow and red pigments, concentration of the pigments by reverse osmosis, and their drying by sublimation [1].

The disadvantage of this process is the use of five technological operations that require expensive equipment, significant energy expenditure for freezing and drying the samples, and the process is also long-lasting.

One of the closest processes for separating dyes from Safflower petals is the process that includes the use of polar solvents, adjusting the pH of the extract between 4...5, in which the concentration of the extract is carried out in vacuum at temperatures of 60...70°C. The purification of the extract containing the carthamin pigment is done with one of the non-polar solvents, including: n-hexane, petroleum ether, heptane and cyclohexane [2].

The disadvantage of this process is that the organic solvents: n-hexane, petroleum ether, heptane and cyclohexane, are highly flammable and pose a risk in the production process. Also, the use of these solvents poses a risk to food safety.

The problem solved by the present invention consists in obtaining natural, harmless red (carthamine) and yellow (luteolin) dyes, intended for the manufacture of food products, safe for consumption.

The proposed process for obtaining dyes from Safflower petals (Carthamus tinctorius L.) includes treating the petals with a 3...5% sodium carbonate solution and their subsequent pressing, separating the solution obtained after pressing and treating it with citric acid to a pH of 4.8...6.3, followed by the separation of the cartamine sediment from the luteolin solution.

Wetting the petals with the sodium carbonate solution helps reduce the amount of water used for extraction, thus avoiding the costs of evaporation and concentration.

Pressing the moistened and swollen petals contributes to the efficient extraction of dyes from the petals and ensures increased process efficiency.

Adjusting the pH within the limits of 4.8...6.3 allows the separation of purified cartamine in solid state and luteolin in liquid form.

The individual state of the obtained pigments is confirmed by UV-Vis spectra (see figure).

Examples of embodiments of the invention

Example 1

5 grams of dried petals were moistened with 25g of 5% sodium carbonate solution, after which the swollen petals were pressed. After pressing, a brown solution was obtained. The pressed petals were treated again with 5% sodium carbonate and subjected to repeated pressing. Thus, 3 cycles were performed. The brown solutions were collected, treated with citric acid to pH 6.3, obtaining solid carthamin (the red pigment) and luteolin in the form of a yellow-orange solution. The yield of carthamin is about 3.0%.

Example 2

15 grams of dried petals were moistened with 50 g of 2% sodium carbonate solution, after which the swollen petals were pressed. After pressing, a dark brown solution was obtained. The pressed petals were treated again with 2% sodium carbonate and subjected to repeated pressing. Thus, 5 cycles were performed. The dark brown solutions were collected, treated with citric acid to pH 4, obtaining solid carthamin (the red pigment) and luteolin in the form of a yellow-orange solution. The yield of carthamin is about 2.0%.

Example 3

10 grams of dried petals were moistened with 40 g of 3% sodium carbonate solution, after which the swollen petals were pressed. After pressing, a dark brown solution was obtained. The pressed petals were treated again with 3% sodium carbonate and subjected to repeated pressing. Thus, 4 cycles were performed. The dark brown solutions were collected, treated with citric acid to pH 4.8, obtaining solid carthamin (the red pigment) and luteolin in the form of a yellow-orange solution. The yield of carthamin is about 3.2%.

1. CN 102031014 A 2011.04.27

2. IN 215351 2008.02.26

Claims (2)

1. Process for obtaining dyes from Safflower petals (Carthamus tinctorius L.), which includes treating the petals with a 3...5% sodium carbonate solution and their subsequent pressing, separating the solution obtained after pressing and treating it with citric acid to a pH of 4.8...6.3, followed by separating the cartamine sediment from the luteolin solution. 2. Process according to claim 1, which includes triple, quadruple or quintuple treatment of the petals with their pressing after each treatment and subsequent unification of the obtained solutions, at the same time the petals and the sodium carbonate solution are taken in a respective ratio of (1...3) : (5...8).