Method for extracting pectin from fruit peels

Abstract

The invention discloses a method for extracting pectin from fruit peels, and belongs to the technical field of pectin extraction. The extraction method comprises: pre-treating fruit peel; adding dry ice into the peel, stirring and mixing, putting into a liquid nitrogen system, then standing the mixture of the dry ice and the peel at 20-40 DEG C, and leaving the peel after the dry ice sublimates; adding an acidic solution into the peel, adjusting the pH value to 1.5-2.0, heating to 90-100 DEG C, keeping the temperature for 1-2 hours, and filtering while the peels are hot to obtain a pectin extracting solution; after cooling to 50 DEG C, adding amylase, stirring and mixing for 20-30 minutes, heating to 80 DEG C, and carrying out enzyme deactivation; adding a decolorizing agent, keeping the temperature for 20-30 minutes, and filtering to obtain decolorized filtrate; concentrating the decolorized filtrate; and (5) performing spray drying to obtain pectin powder. According to the method, the cell walls of fruit peels are broken through low-temperature freezing and dry ice sublimation, so that pectin is convenient to extract so as to effectively improve the pectin extraction efficiency and effectively reduce the content of the impurities in the pectin extracting solution.

Description

technical field [0001] The invention belongs to the technical field of pectin extraction, in particular to a method for extracting pectin from pericarp. Background technique [0002] Natural pectin substances widely exist in the fruits, roots, stems, and leaves of plants in the form of protopectin, pectin, and pectic acid. They are a component of cell walls. They exist with cellulose and form adjacent Adhesives in the middle layer of cells, so that plant tissue cells are only glued together. Protopectin is a water-insoluble substance, but it can be hydrolyzed into water-soluble pectin under the action of acid, alkali, salt and other chemical reagents and enzymes. Pectin is essentially a linear polysaccharide polymer. [0003] Ordinary fruits, such as citrus, lemon, grapefruit and other peels contain about 30% pectin, which is the most abundant source of pectin. Vegetables and fruits with good water retention, such as apples, persimmons, pears, bananas, strawberries, dried b...

AI Technical Summary

Problems solved by technology

Since the hydrolysis of pectinases is easy to occur in the raw materials, the yield or gel degree of pectin will decrease. Therefore, it is necessary to process the fresh peels in time. Generally, high temperature is used to inactivate the activity of pectinases, and then the raw materials treated with enzymes are squeezed out. The juice is removed from the juice, and then extracted with an acidic solution. During the extraction process, it takes a long time to extract the pectin, which has a great impact on the production efficiency, and because the calcium and magnesium ion content in the peel is relatively high High, these ions will have a blocking effect on pectin, affecting the conversion of pectin into water-soluble substances, and also because of the high content of impurities in the peel, which affects the degree of gelation. Therefore, the extraction efficiency of the acid extraction method is poor and the extraction The yield is low and the quality of the extraction is also poor