Method for extracting beet pectin by using protopectinase

Abstract

The invention discloses a method for extracting beet pectin by using protopectinase. The method comprises the following steps: 1, weighing 10kg of 80 mesh beet pulp, adding water with the amount 5-10 times the mass of beet pulp, carrying out immersion washing at 80-90DEG C for 5-15min to remove soluble sugar and impurities and passivate enzymes in the beet pulp, and filtering by using gauze to obtain wet beet pulp; 2, adding 100-300L of a citric acid-sodium citrate buffer solution with the pH value of 4.0-6.0 to the wet beet pulp, adding 1-2.5L of a crude protopectinase solution, and reacting at 40-70DEG C under 150rpm for 2-4h; 3, sequentially respectively carrying out plate and frame filtration and filter core filtration on a pectin extraction liquid to obtain a pectin stock solution, wherein a plate and frame filter has 20 layers of a filter membrane, the filtration precision of the plate and frame filter is 20[mu]m, a filter core filter is a PP folding-20-3 type filter core filter, and the precision of the filter core filter is 0.1[mu]m; 4, carrying out concentrating filtration on the filtered pectin stock solution through using a 8-tube tubular ultrafilter membrane to thoroughly remove impurities and concentrate the pectin stock solution to 3-5%; and 5, drying the concentrated and impurity-removed pectin stock solution through using an experimental high-speed centrifugal spray drier.

Description

Technical field: [0001] The invention relates to food processing and treatment, in particular to a method for extracting sugar beet pectin by protopectinase. Background technique: [0002] It is well known that pectin substances are high molecular weight, negatively charged acidic polysaccharide molecules. The main chain of the pectin molecule is connected by D-galacturonic acid with α-1,4-glucosidic bonds, which is the so-called "smooth region". The carboxyl groups of galacturonic acid on the main chain have different degrees of methyl groups ylated, while unmethylated carboxyl groups are associated with K 1+ 、Na 1+ and C 2+ The side chain is composed of polyrhamnogalacturonic acid, and neutral sugars such as polyarabinose, polygalactose and polyarabinogalactose are phased with the rhamnose in the side chain through α-1,4-glucosidic bonds connect. [0003] Pectin substances widely exist in the roots, stems, leaves and fruits of higher plants, and the pectin content is ...

AI Technical Summary

Problems solved by technology

[0007] At present, the physical methods for extracting pectin mainly include ultrasonic method, high pressure sterilization method, pressing method and subcritical water extraction method, etc. The physical method is relatively simple and efficient, but it consumes a lot of energy and is difficult to apply industrially.

Enzymatic pectin extraction has also received widespread attention. Enzymatic pectin extraction has mild reaction conditions, low pollution, and low energy consumption. However, the quality of pectin obtained by enzymatic methods reported so far is poor and the extraction rate is low. An enzyme capable of efficiently extracting pectin is imperative