Abstract

Introduction

At the present time in Ukraine there are many different types of confectionery products, including caramel holds the leading position. Mainly this is due to the ever-increasing consumer demand for this product. High quality products can be released only if all the technological conditions of production and the rapid correction of all possible deviations. This requires a constant operational information on the process, which provides office technochemical control based on ongoing systematic analysis and testimony of instrumentation.

Caramel mass - is an amorphous mass, obtained by boiling of highly concentrated solutions of sugars in the mixture with other carbohydrates to the concentration (96-99)% of dry matter. Depending on the recipe of the caramel mass include: sucrose, maltose, glucose, fructose, dextrin and other oligo-saccharides - products of incomplete hydrolysis of starch [1].

Caramel mass gradually passes from liquid in the noncompressed plastic state, and then in the hard amorphous or crystalline state depending on a temperature. At temperatures higher 100 °C a caramel is a homogeneous, multicomponent viscid liquid.

Caramel mass can be regarded as a fusion of dissimilar materials, which are distributed separately hydrated water molecules. The molecules of sucrose, glucose, maltose and other substances that make up the caramel, are compact packing of particles bound by forces of molecular interaction. These forces are large enough, as evidenced by high viscosity of the caramel mass (110 Pa ? s at 115 ° C).

For a manufacturer the enormous importance has viscidity of caramel mass. Than viscidity is higher, that a caramel is less subject to crystallization – sugaring. Caramel mass is a very unstable structure: sucrose, a part of it, tends to take her peculiar crystalline state.Thus speed of crystallization of saccharose depends on speed of cooling and with the drop in a temperature (by the increase of viscidity) falls quickly. Crystallized mass loses its plastic properties, which further leads to the impossibility of the subsequent processing of mass.

To measure the viscosity of the caramel mass used different methods, the main ones are the method of the capillary end, the method of the falling ball, rotational and vibrational methods. However, all these methods is characterized by a significant disadvantage - in the process of measuring the caramel stick to the measuring element and must be constant cleaning. It is therefore advisable to carry out viscosity measurement using indirect methods, taking into account that the viscosity depends on temperature, mass fraction of solids (moisture) and recipes cooking caramel

The analysis of publications and workings out on a theme

Overview of existing tools measuring the viscosity of sludge mixtures showed that the most widely used contact methods of control. However, caramel is a sticky substance with rigidly-defined indicators of quality of finished products, therefore it is expedient to use contactless express methods of determining the composition of substances . Such methods include the method for determining the viscosity and indirectly through pryamoopredelyaemyh parameters by constructing a self-organizing model based on the theory Ivakhnenko [6]. The most important aspect in the studies undertaken is to identify the most significant indicators of the quality of caramel. It is necessary to take into account the complexity of the choice of methods for determining moisture caramel mass and temperature measurements, since in the process of boiling syrup temperature can be changed in the range from 100 to 120 ° C, and the percentage of dry matter - in the range (80-86)% [2].

Statement of research problems

During implementation of this research it is necessary to decide the following basic tasks:

• to conduct the analysis of technological process of production of caramel mass;
• to define basic parameters influencing on quality of caramel;
• to choose methods and facilities measurings of indexes of quality of caramel mass in accordance with the technological requirements of caramel production.

The basic material and research results

Getting caramel mass consists of two processes: preparation of caramel syrup and boiling caramel mass. At the confectionery factories used periodic and continuous methods of cooking caramel syrup. Sugars, included in the compounding mixture of caramel syrup, unsteady at long influence of high temperatures.Glucose and fructose rapidly decompose into anhydrides, hydroxymethylfurfural, organic acids, pigments. The products of decomposition of sugars lowers the pH of syrup, which accelerates the process of hydrolysis of sucrose, increases color syrups, degrade their quality.

In the analysis of key factors influencing the characteristics of the caramel mass, it is important to take into account the peculiarities of the process. The analysis of technology and production techniques for confectionery enterprises showed that the preparation of caramel mass by the technological scheme shown in Picture 1. The scheme fully covers the main stages of the process: preparation of syrup and boiling (part I), the filling (part II), cooling of the caramel mass and molding of her products (part III), as well as candy wrapping, and wrapping it (part IV).

Production line normally consists of the following major groups of equipment, intended: to prepare caramel mass, cooling and processing caramel mass; molding candy, cooling and finishing of caramel [9].

This scheme differs from the circuit shown in draw. 1, the presence of equipment for shortcrust, polishing, packing and packaging of caramel. Caramel from the cooling rack 1 on a tray 2 is fed into the unit 3 for finishing (continuous polishing or shortcrust). Since finishing caramel type "puff" or "ball" inclined conveyor 4 is sent to the filling and packaging machine 5 for packing in cardboard boxes, which are then placed into cardboard boxes

For caramel given quality necessary to control the temperature of the cooking caramel mass. The raised temperature of caramel mass in the process of shaping brings structure formation over to slow, and at a lower temperature accelerates the crystallization of sucrose. In the process of boiling syrup temperature may vary from 100 to 120 ° C, while the accuracy of temperature measurement should be no worse than ± 1 ° C. The best conditions of molding are those in which the caramel mass is easily taken to a form and at the same time has such rheological properties for which this form is maintained for a long time. Accordingly, the processing of caramel mass is necessary to strictly observe the recommended temperature parameters.

In general, the temperature dependence of viscosity is as follows:

where - dynamic viscosity at temperature t,°С, kg/(m*s), , , - constant characteristic of the liquid.

Concerning the dependence of viscosity of caramel on the temperature must be considered that caramel mass goes from liquid to solid in a wide temperature range. At temperatures above 100 ° C caramel is a viscous liquid solution cools, it becomes viscous-plastic, amenable to molding, and then at a temperature below 40 ° C is transformed into the fragile transparent amorphous (glassy) mass. At high temperature amorphous caramel mass is unstable due to the desire to move sugars into the crystalline state. When the temperature increases the viscosity of the mass and decreases the possibility of crystallization of sugars, so boiled caramel mass rapidly cooled to 85 - 90° C. Given all the features discussed above technology of caramel, observe the change of viscosity of caramel mass depending on the temperature (drawing 3).

Consequently, in order to obtain the viscosity of the caramel mass, it is necessary to introduce the production line of caramel feed temperature, which at this stage is a non-contact temperature measurement tool - pyrometer. Action principle of the pyrometer is based on measuring the temperature of the thermal radiation of the object. Thanks to the simplicity in work, to a wide range of measured temperatures, small time of the response, absence of necessity to contact to object, contactless gauges of temperature find of the functionality wide application practically at any enterprise. Besides pyrometers measure the temperature with an accuracy up to 0,3% of the measured value, which is valid for measuring the temperature of the caramel mass.

Humidity caramel mass - the major technological parametre that determines the course of the process and the quality of the finished product. Humidity caramel mass can be determined by knowing the percentage of dry matter content of sucrose. At higher content of solids in bulk finished caramel ceteris paribus longer retains its amorphous properties. However, due to the fact that the viscosity of the caramel mass increases sharply with increasing solids content, processing of such a mass, for example, in the manufacture of caramel with filling, interbedded caramel mass loss. Therefore, to obtain candy with fillings dry matter in the caramel mass is somewhat lower. Depending on the filling content of dry matter in caramel mass is 96.5 - 98%. For definition of humidity of caramel (in percentage) it is necessary to subtract from 100 maintenance of solids of caramel [3].

Density of the caramel mass is also a function of dry matter content and recipes and can be calculated by the following formula:

where - relative density of the caramel mass; - Content of dry matter, %; - - the ratio of solids to sugar syrup in the caramel recipe mass.

The dependence of the viscosity of the caramel mass percentage of solids is shown in drawing 4:

To determine humidity caramel mass use infrared thermogravimetric method [4]. This standard applies to sugar confectionery, and can be applied to the rapid analysis of humidity on the production line caramel mass. This method consists in measurement of weight of the sample of analyzed substance before its drying under the influence of infra-red radiation. Infrared thermogravimetric moisture of different types are characterized by different sources of infrared radiation, their geometry, the radiation power, range and accuracy of maintaining the temperature in the chamber, the range and accuracy of weighing. Effects of infrared radiation is the result of its acquisitions and is heating, remove moisture and physical-chemical transformations in the irradiated substances, while the penetration depth of infrared radiation up to several millimeters. The used method provides reception of results of measurements of humidity of confectionery products with an accuracy indicator in a range from 0,5 to 1,3 with confidential probability 0,95. Thus the range of measurements of IR-hydrometers makes from 10-4 to 100 %, temperature influences on result of measurements are insignificant. Prominent features of IR-hydrometers are sharp selectivity, sensitivity, accuracy and reproducibility. Methods for IR moisture metering allow you to analyze multi-component mixture, creating automatic and semiautomatic equipment. In drawing 4 is resulted the block diagramme of a two-wave IR-hydrometer of the foodstuff based on on the diffusion reflectance spectroscopy in near infra-red area of a spectrum of absorption of the analyzed material.

Infrared radiation from the source 1 is projected onto the capacitor 2 bihromator 3, in which there is an allocation of two rays with a wavelength of 1.73 microns (reference wavelength) and 1.95 microns (measuring wavelength). The infrared beam with a wavelength of 1.73 microns is not absorbed by water, situated in the test sample 5. Between sample 5 and bihromatorom 3 is a modulator 4 with filters, which in turn pass on the sample infrared rays from the reference and measurement wavelengths. The reflected measurement and reference signals are sent to a photodetector 6, the output of which electrical signals are transmitted to an amplifier 7 and then - by detectors 8 and 9. Detectors distinguish the reference and measuring signals and feed them to the markers 10 and 11. The reference signal is constant. Moisture content in the investigated sample is described by dependence

which is realised by means of the measuring block 12.

The researches allow to execute realisation of structure of the device of measurement of the viscosity based on indirect dependence of viscosity of caramel from indicators of quality which is presented in drawing 6.

Conclusions

Summing up, it should be noted that for determining the viscosity of the caramel mass necessary to take into account the temperature of the caramel. For this purpose, use channel temperature measurement, which is represented by a non-contact measurement tool - pyrometer. Also an important parameter in measuring the viscosity is the value of humidity caramel mass, which at this stage is determined by using infrared thermographic technique.. On the basis of the executed researches there are preconditions for the further working out of the corresponding device.

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3. GOST 5900 - 73. Confectionary. Methods for determining moisture content and dry matter.
4. GOST R 8.626 - 2006 GSI. Sugary confectionery. Infrared Thermogravimetric method for determination of moisture.
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