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EP-4482879-B1 - INTEGRATED PROCESSES FOR PECTIN ACTIVATION AND MILD EXTRACTION

EP4482879B1EP 4482879 B1EP4482879 B1EP 4482879B1EP-4482879-B1

Inventors

  • ANDERSEN, Bastian
  • BUTZGE, José Júnior
  • STAUNSTRUP, Jan Aae

Dates

Publication Date
20260513
Application Date
20230223

Claims (14)

  1. A process comprising: (a) providing an aqueous alcohol mixture containing water, at least 35 wt. % alcohol, and a starting pectin-containing biomass material comprising an insoluble fiber component and an insoluble protopectin component; (b) contacting an acid with the aqueous alcohol mixture at a temperature of at least 40 °C and a pH in a range from 0.5 to 2.5 to form an activated mixture containing a liquid component and an activated pectin-containing biomass composition comprising the insoluble fiber component and a water-soluble pectin component; (c) removing at least a portion of the liquid component from the activated mixture to form a solid fraction containing the activated pectin-containing biomass composition; (d) contacting the solid fraction with water to form an aqueous mixture, wherein the aqueous mixture contains less than or equal to 10 wt. % of alcohol, and adjusting a pH of the aqueous mixture to within a range from 4 to 5, thereby forming a liquid fraction containing the water-soluble pectin component; and (e) isolating the water-soluble pectin component from the liquid fraction; wherein mechanical energy is applied to the aqueous alcohol mixture of step (a), or to the activated mixture of step (b), or both.
  2. The process of claim 1 further comprising the steps of: adjusting the pH of the activated mixture of step (b) to 2.8 to 5; and drying the solid fraction of step (c).
  3. The process of claim 1 further comprising the step of adjusting the pH of the activated mixture of step (b) to within a range from 3.5 to 6.
  4. The process of any one of claims 1-3, wherein the starting pectin-containing biomass material is obtained from citrus fruit.
  5. The process of any one of claims 1-4, wherein from 20 wt. % to 55 wt. % of the activated pectin-containing biomass composition is the water-soluble pectin component.
  6. The process of any one of claims 2-5, wherein adjusting the pH of the activated mixture of step (b) comprises adding a basic material to the activated mixture, preferably wherein the basic material comprises sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, ammonia, ammonium hydroxide, or any combination thereof.
  7. The process of any one of claims 1-6, wherein the solid fraction has a solids content of from 15 to 85 wt. % after step (c).
  8. The process of any one of claims 1-7, wherein substantially none of the water-soluble pectin component is removed in step (c).
  9. The process of any one of claims 1-8, wherein adjusting the pH in step (d) comprises contacting the solid fraction with water and a basic material to form the aqueous mixture, preferably wherein the basic material comprises sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, ammonia, ammonium hydroxide, or any combination thereof.
  10. The process of any one of claims 1-9, further comprising a step of drying the water-soluble pectin component, and/or milling the water-soluble pectin component.
  11. The process of any one of claims 1-10, further comprising a step of contacting the solid fraction after step (d) with a second aqueous mixture having a pH in a range from 1 to 2.5 to form a second liquid fraction containing additional water-soluble pectin component.
  12. The process of any one of claims 1-11, further comprising a step of washing the solid fraction after step (d) with water to form a washed liquid fraction containing additional water-soluble pectin component.
  13. The process of claim 11 or 12, further comprising a step of isolating the additional water-soluble pectin component from the liquid fraction, and/or drying the additional water-soluble pectin component, and/or milling the additional water-soluble pectin component.
  14. The process of any one of claims 1-13, wherein the process is characterized by an extraction efficiency of at least 30%, preferably at least 34%.

Description

FIELD OF THE INVENTION The present invention is directed generally to a method of pectin activation and pectin extraction, and more particularly, to a method that first converts water-insoluble protopectin into water-soluble pectin under high temperature acidic-alcohol conditions, followed by an aqueous extraction of the water-soluble pectin at a pH greater than that utilized in the activation step. BACKGROUND OF THE INVENTION Pectin is a complex polysaccharide present in the cell wall and middle lamella of plant tissues. Citrus fruit rind, also referred to as citrus peel, is the most available and widely used raw material for industrial pectin production, although apple pomace and sugar beet pulp also are employed. Chemically, the backbone of pectin consists of a linear chain formed by α (1→4) linked galacturonic acids monomers. The galacturonic acid units may be present as either free carboxylic acid groups or methyl esterified, where the fraction methylated is denoted as the degree of esterification (DE), usually presented as a percentage. Besides the backbone, the pectin molecule contains different neutral sugar groups, usually denoted as hairy regions. Pectin is widely used in food, chemical and pharmaceutical industries. Commercial pectins are conventionally classified in two categories depending on the DE, in which high methoxy pectins (HM) have a DE higher than 50% while low methoxy pectins have a DE lower than 50%. The physical and chemical properties of pectin are associated with the presence of methyl ester groups and the DE determines the functionality and, consequently, its industrial application. In addition, another important pectin quality parameter is known as intrinsic viscosity (IV). The units of IV are volume per weight, typically dL/g, and high values indicates large pectin backbones. Pectins with high IV values are desirable in a great number of pectin products, indicating its innate pectin form and having superior functionality and application performance. Pectin IV and DE can vary for natural reasons (e.g., raw material, season, maturity stage, post-harvest residence time), however, these two parameters are highly affected by the pectin activation and extraction conditions. From an economic point of view, high pectin extraction yield is desirable during the pectin production process. However, to obtain high pectin extraction yield, severe process conditions often are required (e.g., low pH and high temperature), which can lead to pectin molecule degradation and have a negative effect on quality parameters (e.g., IV and DE), and consequently, limit the use of pectin in certain applications. If pectin is exposed to alkaline conditions, or even very mild acidic conditions (e.g., pH 5-7), another route of backbone degradation may occur, called beta-elimination. Relative to degradation via acid, the beta-elimination is much faster and is generally avoided. US 2020/046008 A1 discloses methods for producing activated pectin-containing biomass compositions which may be useful in understanding the invention. Therefore, methods for activating and extracting pectin that can combine high pectin quality with high pectin yield would be beneficial. Accordingly, it is to these ends that the present invention is generally directed. SUMMARY OF THE INVENTION In accordance with an aspect of the present invention, there is provided a process for activating and extracting pectin according to claim 1. Further optional features of the invention are set out in the dependent claims. Processes for activating and extracting pectin from plant-based raw materials are disclosed and described herein. One such process comprises (a) providing an aqueous alcohol mixture containing water, at least 35 wt. % alcohol, and a starting pectin-containing biomass material comprising an insoluble fiber component and an insoluble protopectin component, (b) contacting an acid with the aqueous alcohol mixture at a temperature of at least 40 °C and a pH in a range from 0.5 to 2.5 to form an activated mixture containing a liquid component and an activated pectin-containing biomass composition comprising the insoluble fiber component and a water-soluble pectin component, (c) removing at least a portion of the liquid component from the activated mixture to form a solid fraction containing the activated pectin-containing biomass composition, and (d) contacting the solid fraction with water to form an aqueous mixture and adjusting a pH of the aqueous mixture to within a range from 4 to 5, thereby forming a liquid fraction containing the water-soluble pectin component. Mechanical energy is applied to the aqueous alcohol mixture of step (a), or to the activated mixture of step (b), or both. Another process encompassed herein can comprise (i) providing an aqueous alcohol mixture containing water, at least 35 wt. % alcohol, and a starting pectin-containing biomass material comprising an insoluble fiber component and an insoluble protopectin