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Ismatov S. Sh.
Bukhara engineering-technology institute Associate Professor Mamatkulov Farrukh Golibzhonovich the teacher of Karshi engineering-economics institute.
E-mail: [email protected]
RESEARCH OF CHANGES IN THE QUALITY INDICATORS OF BLEACHED COTTONSEED OIL AND ITS PRODUCTS
Abstract. The optimal technological regimes for the partial neutralization of raw cottonseed oil were determined, ensuring the maximum elimination of phospholipids, gossypol and its derivatives, tocopherols from the raw material at the preliminary refining stage. Technique and technology of refining fats continuously improved. On the basis of the work of scientists and the experience of the foremost workers, original technological schemes have been created that ensure a high oil purification effect with a significant reduction in waste and losses. Refining production is equipped with modern high-performance equipment of continuous action, due to which the capacity of workshops is increased and labor costs are significantly reduced.
Key words: phospholipids, gossypol, cotton fat, alkaline refining.
The refinement of vegetable oils and fats is one ers, original technological schemes have been cre-
of the most important technological processes of fat processing. The technology of refining, namely, alkaline neutralization of raw cottonseed oil consists of a complex of complex physical, chemical and physi-cochemical processes, on which the physic-chemical characteristics and quality indicators of refined oil mainly depend. Technological regimes, yield and quality indicators of refined cottonseed oil are also due to the nature and method of production of raw oil, the composition and the quantitative content of impurities in it, as well as related substances. Selection of an effective adsorbent for the improvement of cotton fat requires a deep study of its mineral and chemical composition, as well as structural properties. The optimal technological regimes for the partial neutralization of raw cottonseed oil were determined, ensuring the maximum elimination of phospholipids, gossypol and its derivatives, tocopherols from the raw material at the preliminary refining stage. Technique and technology of refining fats continuously improved. On the basis of the work of scientists and the experience of the foremost work-
ated that ensure a high effect of refining oils with a significant reduction in waste and losses. Refining production is equipped with modern high-performance equipment of continuous action, due to which the capacity ofworkshops increases and labor costs are significantly reduced [1].
The issue of the development and research of the technology of refining oils and fats, as well as the study of the scientific and theoretical foundations of this process, both in the domestic and foreign literature and patent information, is a lot of work. Given this, the issues that are directly related to the topic of my work are analyzed.
For alkaline neutralization of raw cottonseed oil, sodium hydroxide solutions with various concentrations and excess are mainly used as alkaline agents. Refining of raw pre-press and extraction cottonseed oil proceeds at high concentrations and an excess of alkaline sodium hydroxide solution. This technology of refining is accompanied by a low yield of the final product, as well as a significant consumption of material and technological resources. Along with
this, the oil and fat industry of the republic is experiencing a deficiency of sodium hydroxide due to its high cost. Taking this into account, in recent times, advanced technological processes of alkaline neutralization of raw cotton oil have been proposed using new types of alkali-replacing chemical reagents. In this direction, a special place belongs to the use of alkaline-berybamide and other solutions. However, the technological processes of purification of raw cotton oil with these types of alkaline reagents are also not without some drawbacks [1].
It should be noted that the chemical and oil refining industries of the republic use various alkaline solutions in technological processes. At the same time, alkaline compounds of various metals accumulate as industrial wastes and in wastewater. This is especially noticeable with the activation of stationary catalysts used in technological processes of oil refining, cracking and catalytic hydrogenation of oils and fats. Alkaline activation of alloyed stationary aluminum-containing catalysts is carried out using sodium hydroxide solutions. As a result of catalyst activation, alkaline solutions of sodium aluminates are formed, which later, being industrial waste, are discharged into wastewater [2]. However, alkaline solutions of sodium aluminate have a high neutralizing and adsorption capacity. This is especially important when neutralizing the free fatty acids of raw cotton oils. At the same time, alkaline solutions of sodium aluminate react with the substances associated with cottonseed oil. In addition, aluminum compounds and aluminosilicates have high adsorption proper-
ties, which is important when combining methods of neutralization and adsorption purification of raw materials. All this determines the prospects and effective use of alkali-containing industrial waste, in particular, sodium aluminate solutions in the oil and fat industry of the republic, namely, in technologies for alkaline neutralization of raw cotton oil. Considering the above, the main objectives of the research on the subject of this thesis were established:
- study of technological processes of alkaline neutralization of raw cotton oil with sodium aluminate solutions of different concentrations and excess;
- determination of the possibility and effectiveness of the use of alkaline solutions of sodium aluminate in the industrial technology of cotton oil refining;
- development of technological regimes and conditions for improving the quality and nutritional value of refined cottonseed oil.
In studies on the alkaline neutralization of raw materials with solutions of aluminates and sodium hydroxide, cotton oil samples were used, obtained by forpressing and extracting oil seeds of cotton of different quality.
The feedstock differed in quality indicators and physico-chemical characteristics [4].
Crude cottonseed oil obtained by forpressing cotton pulp ofvarious varieties of cotton seeds under production conditions was estimated by acid number, color, humidity, content of phospholipids, gossypol and its derivatives. The physic-chemical characteristics of pre-press cotton oils are given in (table 1).
Table 1. - Physic-chemical characteristics of samples of prepress cotton oils
Sample, № Cotton seed grade Crudeoilperformance
Acid number, mg KOH / g Humidity,% Chromaticity, kr.ed. at 35 went. in 1 cm.sl. Content in %
Phospholipids Free gossy-pol Bound Gossypol General to-copherolcon-tent, mg 100
1 2 3 4 5 6 7 8 9
1. I 3.5-4.7 0.20-0.21 17-21 0.3-0.4 0.09-0.17 0.12-0.20 90-100
1 2 3 4 5 6 7 8 9
2. I-II 4.8-6.3 0.22-0.24 23-34 0.5-0.7 0.19-0.23 0.26-0.29 80-90
3. III - IV 6.9-10.8 0.25-0.27 not supervised 0.8-1.4 0.29-0.35 0.34-0.39 75-85
4. Nonstandard 12.2-14.0 0.28-0.31 not supervised 1.3-1.7 0.44 0.50 0.50-0.65 60-70
As shown by the data given in( table 1). The used samples of pre-press cotton oils differ among themselves by their quality and physic-chemical parameters. At the same time, in raw cottonseed oil obtained from low-grade and non-standard oil seeds, there is an increase in color, the content of free fatty acids and bound gossypol, as well as a decrease in the total amount of tocopherols. In order to obtain extraction oil, the cake of the above samples (Table 1.) Cotton seeds were extracted under production conditions. Physic-chemical character-
istics of the obtained extraction of cotton oils are given in (table 2).
It has been established that, in contrast to raw prepressions, extraction oils are characterized by a higher content of free fatty acids, free and bound gossypol, and also phospholopids.
The purpose of this section is to study the effect of the concentration of alkaline solutions on the change in the content of the main accompanying substances of raw cotton oil with the processing of solutions in the electromagnetic field and without it.
Table 2. - Physical and chemical indicators of samples of extraction cotton oils
Sample, № (On the table 2) Crudeoilperformance
Acid number, mg KOH / g Humidity,% Chromaticity, kr.ed. at 35 went. in 1 cm.sl. Content in %, The residual content of the solvent,%
Phospholipids Free gossypol Bound Gossypol The total content of tocopherols, mg 100 g
1. 4.2-5.8 0.22-0.26 34-41 0.7-0.9 0.13-0.22 0.16-0.28 70-80 traces
2. 6.1-7.6 0.26-0.30 46-52 1.3-1.6 0.27-0.38 0.30-0.43 60-70 traces
3. 7.9-12.3 0.34-0.35 not supervised 1.9-2.6 0.45-0.55 0.50-0.61 50-90 traces
4. 12.6-14.8 0.36-0.41 not supervised 2.0-2.8 0.60-0.70 0.75-0.93 40-50 traces
Evaluation of technological methods of purifying raw cotton oil suggests that the quality and nutritional benefits of refined oil mainly depend on the content of free fatty acids, phospholipids, gossypol and its derivatives, as well as other substances. The reduction and complete removal of some oil-related substances can significantly improve the performance of the final product. Purification of raw oil
and ensuring high levels of final products also depend on the nature of the raw materials and methods ofproducing cottonseed oil [3,4]. When processing raw cottonseed oil with an alkaline solution of sodium aluminate of various concentrations, the raw materials are partially neutralized and some of the associated substances are removed.
The most significant decrease in the content of free fatty acids and related substances is observed at an alkali concentration of 15%.
When this is achieved by improving the color of the partially neutralized cottonseed oil. The most acceptable technological data is obtained by partially neutralizing raw cottonseed oil with an initial acid number of not more than 4.1 mg KOH / g. This suggests that alkaline solutions of sodium aluminate exhibit their reactivity to a certain level of acid number and the content of substances accompanying the original oil [3].
For the first time, compositions of adsorbents from local materials were created for the purification of cotton fat from the residues of gossypol and its derivatives, catalyst metals and other impurities. Technological regimes have been developed for the transesterification of high-melting cotton fat with rosehip oil and corn germ, which makes it possible to obtain suppository bases of the required quality [4]. Thus, the optimal technological conditions for the refining of crude oil using the recommended new technologies were determined, and the pos-
sibilities for increasing the yield and quality of refined oil were established.
The technological parameters have been established, which allow to significantly reduce the content of substances accompanying the oil and improve its color.
The chemical interactions of the main components of crude oil with an alkaline solution of sodium aluminate are determined and their correspondence with known chemical phenomena is established.
A technology is proposed to intensify the partial alkaline neutralization of raw cotton oil with a solution of sodium aluminates activated by treatment in an electromagnetic field.
The technological parameters were optimized and the modes were determined to improve the quality of partially neutralized oil.
Obviously, the final process of alkaline refining of raw materials with low acid number and improved color can be reduced by reducing the consumption of sodium hydroxide, which increases the yield of refined oil and improves its quality.
References:
1. Harutyunyan N. S. and others. Technology of processing fats. - M .: Pishepromizdat. 1999.
2. Ilyasov A. T., Serkaev K. P., Vakhabova D. Z. Fractional refining of cottonseed oil // Fat-and-oil industry. 1999. - No. 4. - P. 30-31.
3. Abdurakhimov. Investigation of the influence of heterogeneous nickel catalysts on the process of liquidphase hydrogenation of fats and fatty acids Abstract. Diss., Dr. tech. Sciences.- Tashkent, 1975. - 55 p.
4. Mazhidov K. Kh. Research and improvement of the technology ofhydrogenation of cotton oil on modified alloyed stationary catalysts. Author. Diss., Doctor of Engineering. Science-L. VNIIZh 1989.- 54 p.
