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Section 7. Food processing industry
Eshmatov Fozil Khidirovich, Assistant, department of «Food safety» Tashkent chemical-technological institute, Maksumova Dilrabo Kuchkarovna, Tashkent chemical-technological institute, (Uzbekistan) docent, department of «Biotechnology» Dodaeva Laylo Kuchkarovna «Microbiology» institute, Academy of sciences Republic of Uzbekistan (Uzbekistan), scientific collaborator.
E-mail: sherzod_mamatov@mail.ru.
Regulation of acidity and reduction of turbidity in the clarified pomegranate juice production
Abstract: Regulation of acidity and reduction of turbidity in the clarified pomegranate juice production. From sour varieties of pomegranates may obtain normal natural pomegranate juice by anion-exchange resin. There are determined problems quantity of precipitate and unstable color in the pomegranate juice and concentrate by experimentally.
Keywords: pomegranate juice and concentrate, acidity, color, precipitate, anion-exchange process, regulation,
tannin substances.
Introduction. Pomegranate — an ancient culture, mentions of it are found in the earliest historical sources. Pomegranate grew in Iran and Armenia in 20003000 BC, its sculptural images are in ancient monument Egypt was the usual fruit trees Phoenicia and Thrace (1000 BC) on the territory of ancient Greece, the Caucasus, Central Asia, served as a symbol of abundance and fertility.
Pomegranate grows in various soils, the highest yields pomegranates with the best quality get in deep, fertile soils and water capacity with good drainage. In the northern growing areas during the winter at very low temperatures pomegranate covers.
Physical and mechanical properties of different varieties of pomegranate fruit growing in conditions of Georgia, Azerbaijan and Uzbekistan, indicate that the average fruit weight varies from 182 to 467 g, peel the septum is between 26.6 to 49.8%, the seeds coated 5 4 to 15.8, juice yield — 38,2-54,9% [2; 3].
The pomegranate juice and their concentrates containing carbohydrates, organic acids, vitamins, and minerals. They provide the human energy soothe the nervous system, support its operation regulates the excitability of the nerve muscle cells, protect mucous membranes and
the skin and the blood vessel wall and prevent anaemia, possess anti-cancer effect, help with pellagra are anti-spasm impact exhibit diuretic convergence, antibiotic properties and help the functioning of the heart, increase appetite, relieve fatigue, reduce weight, anti-inflammatory and antifungal promote the body's resistance.
Like other fruits, a significant proportion of solids contains carbohydrates presented sugars and pectin substances. With moderate combination of sugars and acids pomegranate juice is a kind of pleasant fresh taste, making it high appreciated in hot climates. The fruit juice of ripen cultural forms of pomegranate depending on the variety and location of growing contains from 8 to 20% sugar and 0.3-0.4% acids. Sugars are represented mainly glucose and fructose in a slight quantity contained sucrose. Among the predominant Citric acid. The wild and certain cultural forms of pomegranate juice acid content can achieve 5-9% in the varieties grown in Uzbekistan to 2.9%. Therefore, wild forms of pomegranate are one of the most important types of natural raw materials to produce citric acid [3].
In pomegranate juice found in about 2% of proteins and 61-95 mg% of amino acids. From aminoacids are identifies cystine, lysine, histidine, arginine, aspartic
acid, serine, threonine, glutamic acid, alanine, hydroxy-proline, a-aminobutyric acid, methionine, valine, fenilal-anin. leucine, i. e. It found 15 aminoacids, six of which are irreplaceable.
The total content of tanned and the color substances in pomegranate juice is from 0.82 to 1.13% of flavo-noids including anthocyanins — 34,0-76,5 mg%. The pomegranate juice contains a number of physiologically active compounds: vitamins, mineral substances. The pomegranate juice contains ascorbic acid (4-15 mg%), thiamin (0,04-0,36 mg%), riboflavin (0,01-0,27 mg%), pyridoxine (0.50 mg), pangamic acid, traces of vitamin A and folacin [3].
Pomegranate juice contains a number of macro- and microelements: potassium, sodium, manganese, phosphorus, magnesium, aluminum, silicon, chromium, nickel, calcium, copper, some of which are considered very deficient.
Pomegranate fruit peel is rich in tannins (18-20%), in the wild pomegranate their content reaches 28-35%, there are also pectins (4-6%), about 16% cellulose, 7-8% hemicellulose 20-25 mg% ascorbic acid, various alkaline substances such as — pelleterin, izopelleterin, metilpelleterin (up to 1.80%). Therefore pomegranate rind should be considered as a source of tannin, flavo-noid, anthocyanin and pectin, extraction technology which is known [3].
In addition to pomegranate juice as a remedy widely used rind (peel) pomegranate. Broth from pomegranate rind is used as a remedy for inflammation anticepti-cal processes and as a means against different types of worms, for some stomach disease.
In industry, pomegranate rind is used as a tanning agent for valuable high-grade leather. Of petals and fruit peels are prepared unfaded colors to the sun-ray a variety of fabrics and rugs. From pomegranate rind is obtained pomegranate pectin, which can be used in the confection industry.
Pomegranate seeds are also some nutritional value. They contain 6-20% oil, 9-12% protein, 13-18% starch, 20% cellulose, 1.54-1.65% mineral elements.
In pomegranate oil contains linoleic 40.03%, 23.75% oleic, 2.98% linoleic, 16.46% palmitic, 6.78% 1.63% stearic and behenic fatty acids. The pomegranate oil was found vitamin E. According content of tocopherol (272 mg per 100 g) oil from pomegranate seeds almost doesn't yield from wheat oil [2].
Objects and methods. Pomegranate juice and concentrate produced by the technology which will eliminate the disadvantages. As a rule, technological schemes in-
clude preparing of raw materials, juice separation, purification, clarifying by enzymatic method, filtration, juice packaging or obtaining pomegranate concentrate by evaporation, packaging in aseptic bags.
Operating experience and analysis of the line production technology of pomegranate at the operating enterprise "El-Kol», "GREEN-WORLD" and "Agromir" indicates the following deficiencies of equipment and technology itself:
— the process of separation arils from pomegranate peel needs some work, since there is a run-offjuice from damaged arils are not in, and 5-7% of the arils is not extracted from the peel at all. Total losses juice reach 8-9%, which is very much;
— advantageously provided for processing pomegranates of acidic varieties — pomegranate with a high content of organic acid negative influence fermentation of starch and pectin;
— tannin is located in the peel and the inner film part of pomegranate extracted to the juice resulting juice and flavor concentrate takes tartly and when storage process makes a precipitate;
— ruby-color of juice or concentrate in the storage changes to brown;
— processing of wastes for extracting a food color, pectin and the problem usage peels as an additive in animal feed and birds are not radically solved.
Solving the problem associated with the separation of pomegranate arils will be presented to the company «Bertuzzi» (Italy) for further improvement ofthe device.
For ensuring the normal environment of fermentation of starch and pectin in the formulation of the concentrate it is necessary to normalize the content of organic acids. 85-90% of total acid consisting of citric acid, i. e. tribasic citric acid. The chemical formula of the citric acid has a view of C6H8O7 Anhydrous acid having a molecular weight of 192 g/mol is melted at 153 °C, very hygroscopic. When heated to 175 °C citric acid loses a molecule of water and turns into unsaturated aconitic. There are studied methods for obtaining acetonedicar-boxylic acid, oxalic acid and acetic acid [2; 3; 4].
In the industrial processing of the fruit comes from the high acidity (total acidity of citric acid 2.0-3.0%). Juice and concentrate of pomegranate contain in excess of a reasonable amount of citric acid, which is unacceptable according to standart and difficult clarification technology and the use of food purpose. The starch and pectin contained in the composition of pomegranate juice clarification when cleaved, further, concentration by evaporation of the juice is adjusted to high values.
Enzyme preparations used for the purpose, function effectively with the active acidity ~ pH 4,0-4,6, which is proportional to the total acidity of the pomegranate — raw materials.
The stated problem is solved by us by removing an excessive amount of citric acid anion-exchange method, citric acid removal modes were studied experimentally. For this purpose epoxyamide resin on base epichloro-hydrine, Amberlite IRA-68, IRA-958, EDE-10P, 313, Lewatit MP-62 sterol-DVB, DVB-Acrylic, Amber-lite XAD-2.
Epoxyamide resin on base epichlorohydrine (EASE) represent polybase, reticulated synthetic polymers capable of exchanging anions upon contact with electrolyte solutions. The polymer matrix (frame) epoxyamide resin fixed positive electric charges, offset by mobile anions involved in the exchange.
Epoxyamide resin — a solid particulate material, grains which are spherical or irregular shape, and defines the size in the range 0.3-0.4 mm.
Experimental research on the separation of citric acid from sour pomegranate juice carried out in the plant operating continuously on anion exchangers EDE-10P and IRA-958. Anion-exchange resin was tested in (OH-)— form in which it was carried out with 20% NaOH solution.
For the experiments used epoxyamide resin on base epichlorohydrine grades EDE-10P and IRA-958 (Amberlite) in a hydroxyl (OH -) — form.
Experiments were conducted to determine the optimum temperature of the ion exchange by varying the temperature from 20 to 60 °C. Maximum saturation of the adsorbent is achieved with citric acid at a temperature of 40 °C.
Fig. 1. Dynamics of changes in the acidity of pomegranate juice by varying the amount of the anion exchanger EDE-10P brand when the temperature 40 °C
From the curve shown in Figure 1 shows that the total acidity of pomegranate juice decreases due to absorption of the anion of citric acid anion exchangers EDE-10P brand in the (OH) form. Moreover, the expense ratio at 40 °C GEDE/Gpj = 2/500 = 0.004 g/ml, the amount of citric acid is reduced to 1.668% to 1.25% over the 40 minutes duration of anion exchange; a ratio GEDE/G . = 4/500 = 0.008 g/ml to 1.168%; at GEDE/Gpj = 6/500 = 0.012 g/ml to 1.108%; when GEDE/Gpj = 8/500 = 0.016 g/ml to 1.056%; at GEDE/Gpj = 10/500 = 0.02 g/ml to 0.938% [3].
The difference between adjacent values of the residual amount of citric acid shows that the decrease in the number of its juice is done linearly, i. e. is directly proportional to the amount of the anion exchanger.
When using anion exchange resin IRA.-958 mark in (OH) form at 40 °C at a ratio of expenses GIRA/Gp. = 2/500 = 0.004 g/ml, the amount of citric acid decreases from 1,668% to 1,469% in the 40 min duration anion exchange process; a ratio G /G . = 4/500 = 0.008 g/ml to 1.405%; when G^/G = 6/500 = 0.012 g/ml to 1.369%; at GIRA/Gpj = 8/500 = 0.016 g/ml to 1.26%; at GIRA/Gpj = 10/500 = 0.02 g/ml to 1.142%.
Analysis shows that the best result is achieved by the removal of citric acid at 40 °C for 40 min. Anion exchanger EDE-10P brand is effective for 28% of the brand than the anion exchanger IRA.-958.
Unlike other fruits as part of a pomegranate contains a lot of tannins — tannin, comprising 0.3-0.4% juice,
and in the peel and internal film — 15-30%. The initial juice obtaining technology isn't allow to avoid the extraction of tannin from torn pieces of peel and internal film to the juice. This creates a number of problems in the production of juice and concentrate. Firstly, tannin give tart taste, and secondly, as contained in the concentrate tannin in storage last more than two months is polymerized partially react with anthocyanins that give the juice and concentrate bright ruby color, and as a result the polymer obscures color anthocyanin concentrate becomes brown shade. Besides tannin feels confers increased acidity.
Production observations show that by polymerizing tannin juice turbidity when stored for more than two months increased. This is due to the fact that tannin produced by polymerizing a substance with large molecules constituting the basis of turbidity, of the original amount exceeds 20-30 times. In this regard, the precipitate appears. All pomegranate juices conquered the world market currently have the above-mentioned lack [5; 6].
Version with respect to the harmful effects of tannin on the color and turbidity of pomegranate juice and
concentrate, verified experimentally by us. It is obtained a positive result. For a discussion of the amount of tannin, tannin concentration in the juice is reduced by half, by dilution with water, and then again twice, etc. Experiments showed that the intensity of the color of the tannin compounds with ferric chloride is reduced slightly, and hence the concentration of tannin in the pomegranate juice high.
Pomegranate juice is freed from coarse solids coarse filtration (sometimes by centrifugation) is subjected to an anion-exchange process — is passed through a filter, which performs the role of attachment we have chosen based on the results of preliminary experiments epoxy-amide resin on base epichlorohydrine.
Tannin — a complex ester residue is 5 gallic acid between one molecule of glucose. The mechanism of ion exchange is that each of tannic acid exchanges with EASE hydroxyl group, thereby forming one molecule of glucose.
Removal of the tannin from the pomegranate juice is carried out in a similar way, a chemical reaction which is as follows:
Where R2 — gallic acid residue, has the following structural formula. Tannin is a residue of 5-tannic acid, combining one molecule of glucose. The mechanism of ion-exchange is that each of tannic acid exchanges with EASE hydroxyl group, thereby forming one molecule of glucose. The balance of tannin — 5 molecules of tannic acid is absorbed by the adsorbent. The reaction carries out in 5 stages similar absorption citric acid at each stage is absorbed by one molecule of digallic acid.
OH
COO
Therefore, come to carrying out of fermentation splitting of tannin. In the world produced pure enzyme which manufacture by Ireland Belgium specialists a few amount (€ 180/g).
The resulting strain of the fungus Aspergillus niger oriented splitting tannins in the juice copes with the task. Determination of residual tannin Implemented indirect method, the essence of which is to determine the presence and amount of root-knot (tannic acid), formed in the juice from the tannin enzyme preparation by the FeCl3 Sample juice acquires burgundy color by adding a few drops of a 1% aqueous solution of FeCl3. In the initial experiment shows a juice in the juice of dark green color.
Similar experiments carried out in the treatment of peel. Peel can be considered as feed, rich in protein and carbohydrates. The frame of peel fiber, cellulose, hemicellulose. Tannin, which has a strong taste makes tartly peel inedible for animals. Therefore, it is necessary to split the tannin, which we used the resulting strain Aspergillus niger. Experiments have shown the result exceeds our expectation, split the strain of all that had turned into a breakdown product of a true solution (of the results of the experiments reported separately).
Effect of pretreatments on drying quality potato
The juice is fermented further amylase and pectinase, glued baykisolem-30, gelatin and bentonite to settle for 4-6 hours. Clarified pomegranate juice decanted by centrifugation and the final removing of weak-soluble small solid particulates molecular level ultrafiltered. The obtained clarified juice can be filled into consumer packaging or evaporated to produce a concentrate of pomegranate juice [1].
Conclusion. Anion-exchange epoxyamide resin on base epichlorohydrine adsorb the citric acid contained in pomegranate juice, but has no influence on other useful
components, such as glucose, fructose, vitamins, micro-and macroelements, and anthocyanin. The mechanism studied anion-exchange regimes, the calculation is made for the industrial process.
The method removing of tannin from pomegranate juice by anion-exchange resin is a uneffective for molecular weight of tannin exceed 1500 g/mol, up to 1800 g/mol and anion-exchange resin can't adsorb sufficiently a large molecule of tannin but expence of resin increased and the method considers expensive and unwieldy of the method.
References:
1. Shobinger W. Fruit and vegetable juices. - M.: Light and food industry, 1982.
2. Eshmatov F.Kh., Dodaev K. O., Hasanov H. T. Processing of pomegranate juices and concentrates on//Beer and beverages. 2005. - № 5. - P. 46-47.
3. Eshmatov F.Kh., Dodaev K. O., Maksumova D. K.. Removal of citric acid and tannin in pomegranate juice//Stor-age and processing of agricultural raw materials. 2012. - № 11. - P. 16-19.
4. Dodaev K. O., Abdukadirov I. T. Juraev Kh. F., Dodaeva D. K. etc., Features of processing melons//Food Industry, 2002. - № 11. C. 40.
5. Eshmatov F.Kh., Maksumova D. K., Dodaev K. O. Analysis of the chemical composition of the components of the turbidity and sediment pomegranate juice//Storage and processing of agricultural, number 11, 2012 th. -S.16-19.
6. Eshmatov F.Kh., Maksumova D. K., Dodaev K. O. The turbidity ofpomegranate juice concentrate and ways of its removing//Storage and processing of agricultural, № 8, 2013. - S. 27-29.
Mamatov Sherzod Mashrabzhanovich Tashkent Institute of Chemical Technology, Uzbekistan E-mail: sherzod_mamatov@mail.ru Dodaev Kuchkor Odilovich Tashkent Institute of Chemical Technology, Uzbekistan Kurbanova Madina Zhamshedovna Tashkent Institute of Chemical Technology, Uzbekistan
Effect of pretreatments on drying quality potato
Abstract: Implemented intensification of IR vacuum drying on the example of potatoes, by selecting one of the pilot to explore ways of preliminary IR, microwave and infrared microwave treatments. Main attention is paid to the degree of safety component material to be dried. The data on safety study native starch and ascorbic acid.
Keywords: potato starch, ascorbic acid pretreatment, drying, IR drying.
Introduction. One of the reliable methods of food Organization of drying is useful when used as a
preservation and to meet the growing demand for source of heat energy converters, which are available in them is their drying. a wide range in a variety of configurations. They are envi-
In world practice, using all methods: convection, ronmentally friendly, automatically adjustable, it is easy freeze, dielectric, conductive, thermo radiation, dry- to provide in their security measures. ing vegetable raw materials with inherent advantages and IR rays are absorbed by the active moisture in the
disadvantages. The quality of the dried product and the product, but not absorbed by the tissue of the product, economic performance of the industrial organization of so the removal of moisture can be accomplished at a tem-drying depends largely on the duration of drying. perature of40-70 °C, which allows to retain biologically
