RU2247731C2 - Method for isolating pectin from sunflower heads - Google Patents

Abstract

FIELD: vegetable raw technology.

SUBSTANCE: invention relates to a method for isolating pectin from the vegetable raw. Method for isolating pectin from sunflower heads involves their milling, denaturation of proteins by heating, hydrolysis-extraction of solid phase, separation of liquid phase and its concentrating and drying. Extraction with dimethylformamide is carried out before hydrolysis-extraction stage followed by extraction with liquid carbon dioxide under above atmosphere pressure. The second extract is separated without change of pressure followed by abrupt drop of pressure over the solid phase up to atmosphere value and feeding the solid phase to hydrolysis-extraction stage. Invention provides improving safety due to exclusion contact of toxic solvent with the end product, reducing time process of hydrolysis-extraction stage and reducing loss of pectin substances.

EFFECT: improved isolating method.

Description

The invention relates to a technology for the isolation of pectin from plant materials.

A known method of separating pectin from baskets of sunflower, providing for their grinding, heating to protein denaturation, extraction with acetone, hydrolysis-extraction of the solid phase, separation of the liquid phase and its concentration or drying (I. Sobol. Biochemical substantiation of the technology for producing pectin of increased biological value from inflorescences sunflower.Abstract of thesis of candidate of technical sciences - Krasnodar: KubSAU, 1997, pp. 8-21).

The disadvantages of this method are the high fire and explosion hazard of production and the transition of acetone to the target product.

The technical result of the invention is to improve safety, eliminating the ingress of toxic solvent into the target product, reducing the duration of hydrolysis-extraction and, thereby, reducing the loss of pectin substances.

This result is achieved by the fact that in the method of separating pectin from sunflower baskets, which involves grinding, heating to protein denaturation, extraction, hydrolysis-extraction of the solid phase, separation of the liquid phase and its concentration or drying, the extraction is carried out according to the invention with dimethylformamide and then liquid dioxide carbon at a pressure above atmospheric, the second extract is separated without changing the pressure, then the pressure over the solid phase is sharply reduced to atmospheric with the direction of solid second phase hydrolysis-extraction.

The method is implemented as follows.

Sunflower baskets are crushed and heated until protein denaturation, as in the closest analogue, to ensure long-term storage and facilitate the extraction of pectin substances. The raw material prepared in this way is extracted with dimethylformamide and the extract is separated according to well-known methods (Bykova S.F. Theoretical and experimental foundations for creating a fundamentally new resource-saving technology for the production of vegetable oils. Abstract of thesis, Doctor of Technical Sciences - St. Petersburg: VNIIZh, p.21- 26; Demchenko P.P. Improving the technology of extracting oil from sunflower seeds.Abstract of dissertation, candidate of technical sciences - L .: VNIIZh, 1982, p. 6-14) containing high molecular weight non-polar substances, as in the closest analogue with a bitter taste. Next, the solid phase is extracted with liquid carbon dioxide at a pressure above atmospheric pressure corresponding to the saturated vapor pressure of the extractant at the extraction temperature, for example at room temperature, and the extract is separated without changing the pressure (G. Kasyanov et al., Processing of plant materials with liquefied and compressed gases - M .: AgroNIITEIPP, 1993, 40 pp.). Residues of dimethylformamide pass into the extract, which excludes the further transition of dimethylformamide according to the stages of the process and its entry into the target product. The pressure over the solid phase is sharply dumped to atmospheric. This leads to a sharp boiling of liquefied gas and explosive grinding of plant materials, accompanied by the destruction of cell membranes. Next, the solid phase is directed to hydrolysis-extraction.

It should be noted that pectin substances are not soluble in either dimethylformamide or carbon dioxide, which eliminates their loss with separated extracts and, accordingly, increases the yield of pectin substances in comparison with the closest analogue. Despite the fact that the initial pectin content in sunflower baskets is from 12 to 24% by dry matter, and its content of water-soluble fraction is from 30 to 40% (L. Donchenko, Technology of pectin and pectin products - M .: DeLi, 2000, p. .53, 55), the loss of pectin as a result of its deep hydrolysis can be estimated for the proposed method and the closest analogue according to the known dependences (Altunyan MK, Kinetics of the destruction of the polysaccharide in the process of producing pectin. Abstract of thesis. Ph.D. Krasnodar: KPI, 1988) and is 3-4% against 12-16% in the pro totipe.

Hydrolysis-extraction is carried out at parameters selected according to well-known recommendations (the closest analogue is L. Donchenko, Technology of pectin and pectin products - M .: DeLi, 2000, p.143-142) or calculated according to known dependencies (I. Ilyina Scientific basis of the technology of modified pectins - Krasnodar: SKZNIISiV, 2001, p. 88-156). The absence of a volatile organic solvent at this stage of the process eliminates the possibility of contact with acid and fire or explosion, which increases the safety of production. At the same time, due to the preliminary destruction of cell membranes, the contact surface of the phases and the availability of protopectin substances for hydrolysis-extraction are increased. This reduces the duration of the process and reduces the possibility of deep hydrolysis and loss of pectin. After completion of the hydrolysis-extraction, the liquid phase containing pectin is separated, which is concentrated or dried. The absence of a volatile organic solvent at this stage of the technological process excludes the possibility of its contact with the surfaces of heating and ignition or explosion, as well as getting into the target product.

Thus, the proposed method can improve production safety, eliminate the ingress of toxic solvent into the target product, reduce the duration of hydrolysis-extraction, and thereby reduce the loss of pectin substances.

Claims (1)

A method for isolating pectin from sunflower baskets, which involves grinding, warming up to denature the proteins, hydrolysis-extraction of the solid phase, separation of the liquid phase and its concentration or drying, characterized in that extraction is carried out with dimethylformamide before hydrolysis-extraction, and then extraction is carried out with liquid carbon dioxide at a pressure above atmospheric, the second extract is separated without changing the pressure, then the pressure over the solid phase is sharply dropped to atmospheric from the direction lowering the solid phase for hydrolysis-extraction.