Relevance of the topic Improving the efficiency of using secondary production resources to obtain a valuable food product — pectin, based on non-waste environmentally friendly technologies, is an important and urgent problem. Today, in winemaking and other branches of the food industry (processing fruit raw materials), secondary resources for the production of pectin are used extremely unsatisfactorily. This is due to several reasons, and first of all, the lack of highly efficient environmentally friendly technologies for pectin production.
Keywords: pectin, pulp, cultivated, extraction, hydration
The invention relates to methods for obtaining pectin from pectin-containing raw materials and can be used in the food industry and medicine, as well as in other sectors of the economy. A known method of obtaining pectin from the pomace of cultivated and wild apples [1] This method includes hydrolysis-extraction of apple raw materials with an aqueous solution of nitric acid at a hydrolysis mixture temperature of 70–80°C for 3.0–3.5 hours and subsequent isolation of pectin. The disadvantage of this method is the duration of the hydrolysis-extraction process, as well as the impossibility of wide industrial use of the method due to the very limited raw material base due to the use of apple pomace for the production of fruit flour, which is a valuable food additive in the confectionery industry. Closest to the claimed is a method for obtaining pectin from beet pulp [2] The method includes hydrolysis-extraction of raw materials (beet pulp) with an aqueous solution of hydrochloric acid at an HCl concentration of 1.1–1.5 % at a temperature of the hydrolysis mixture of 75–76 ° C for 120 min and subsequent isolation of pectin, consisting of successive operations of purification of liquid extract, separation of pectin from solution, purification of pectin and drying. The disadvantage of this method is a sharp increase in the consumed volumes of hydrochloric acid at the stage of hydrolysis-extraction, especially with wide industrial use of the method, as well as a relatively long duration of the hydrolysis-extraction operation and, accordingly, the energy costs associated with this.
This goal is achieved by the fact that in the method for obtaining pectin, including hydrolysis-extraction of plant raw materials at an elevated temperature, followed by isolation of purification and drying of pectin, pomegranate fruit processing wastes are used as vegetable raw materials, and hydrolysis-extraction is carried out with water at 70–75 ° C for 70 -90 min.
The method includes the following operations: hydrolysis-extraction of the raw material by exposing it to hot water at a temperature of 70–75°C; purification of the liquid extract by passing through a mechanical filter; isolation of pectin from the solution by exposing the solution to salts of light metals; purification of pectin by dehydration with an alcohol solution; drying. Hydrolysis-extraction is carried out for 70–90 minutes at a mixture temperature of 70–75°C. With the specified time and temperature parameters, the isolated pectin has an increased gel-forming ability. A decrease in temperature, in addition to a decrease in the quality of pectin (does not become gel), leads to a sharp decrease in the activity of the hydrolysis-extraction process, and its increase makes the process much less economical. After hydrolysis, the mixture is cooled to 56°C. At 56°C, the hydrolysis mixture is cooled quickly, and after a 10-minute rest, a filter layer is installed, then the extractor pectin solution is decanted, which is filtered through a filter press. A 25 % ammonia solution is introduced into the filtered extract for neutralization, the pH of the mixture is in the range of 5.0–6.0. Upon reaching a uniform pH value, a standard solution of aluminum chloride (density 1.22) is introduced into the pectin solution at the rate of 22–27 ml per 1 liter of extract. When the mixture is stirred for 2 minutes, pectin precipitates in the form of a pectin-aluminum coagulant. The end of the process of precipitation of pectin is established by monitoring the precipitation of the alcohol sample of the mother liquor. After complete precipitation of pectin, the mother liquor is decanted through a filter press. After that, the pectin coagulant is unloaded into the cages for preliminary squeezing out of the pectin coagulant, which is carried out using a hydraulic batch press. The resulting cakes are crushed and subjected to finer grinding, followed by pressing. The coagulant pressed to a moisture content of 73–75 % and sieved is subjected to drying using ethyl alcohol with a strength of 94, 95, 96 according to the IV-phase purification scheme. The multiple ratios of coagulant and alcohol are 1:4.0, the duration of treatment in all four phases is 15 minutes. After the fourth phase, the pressed pectin is washed with alcohol, laid out in a thin layer on trays, and sent to a dryer at a temperature of 45°C. The final moisture content of the pectin powder should be no more than 14 % since with it the dried pectin is preserved for a long time and qualitatively and meets the requirements of Industry Standard 18 62 72. The advantages of the invention in comparison with the prototype are that due to the implementation of hydrolysis-extraction with hot water, the need for the use of acids is eliminated, which greatly simplifies the process and increases its economy as a whole, especially in large-scale production, and also improves working conditions and significantly enhances safety. The use of pectin-containing raw materials as a pectin-containing raw material allows obtaining new sources of pectin-containing raw materials, both in the form of fruits of cultivated varieties and wild-growing pomegranate, as well as expanding the range of pectins. Reducing the duration of the operation of hydrolysis-extraction allows you to reduce the duration of the entire process, respectively, reduce the associated energy costs and thereby increase the efficiency of the method for producing pectin.
References:
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