Resource-saving melon processing technology

Fig. 3. Graph of the dependence of the cutting force on the movement of the knife when cutting the melon flesh of the type Myrzachulskaya Table 6 The Values of the specific cutting force for different types of melon Type
Specific cutting force, N/m
Pulp	Ctust
Iliyskaya	225	2,418
Myrzachulskaya	206	2,386
Kolkhoznytsa	227	2,421
Gurbek	216	2,410
Ameri	236	2,479
SaryGulyabi	214	2,387
Zhyldyz	218	2,412
Inzhirnaya	234	2,485
Average	222	2,424.75
More deviation	+6.31 %	+2.50 %
Less deviation	-7.20 %	-1.60 %

Thus, the conducted studies allow to conclude that the average value of the specific cutting force for the studied melon varieties with an error not exceeding 7.2 % for pulp and 2.5 % for the peel can be used in engineering calculations for different varieties, with condition of using safety factor [14-17].
3. 1. 6. Efforts of puncturing the melon crust
Determination of the piercing force of the melon crust was carried out using a CT-2 structu- rometer. For the construction of graphs, a linear model is used, as the most convenient for practical applications.
The obtained dependences are the initial data for calculating the energy expenditure for puncturing the melon peel when determining the engine power for the installation. Fig. 4 shows the dependence of the force of the crust destroying the crust of various kinds of melons by the lateral surface of indenters of different diameters. The results presented in Fig. 4 show a directly proportional dependence of the fracture force on the diameter of the rod of the indenter. The degree of approximation R is close to 1, which indicates the applicability of the obtained dependences.
The next stage of our research was the building of non-linear regression of melon skin piercing process. Using the estimates of b-factors it is possible to record the following qua­dratic regression equations for two parameters of melon skin piercing: Y - force of melon skin piercing F, N.


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Y = 10.07333 +1.22767x1 -0.09300x1^2 + 5.17933x2 + 0.41800x2^2 + 0.73200x1 x2, (1) х 1 - pin sharpening angle, deg; х 2 - pin diameter, mm. 100 90 80 Z ^70 § 60 «s S 50 I 40 30 20 10 y = 21.416x + 29.524 R2 = 0.9167 y = 21.936x + 29.755 R2 = 0.9181 y = 15.6x + 34.83 R^2 = 0.9951 y = 15.804x + 32.632 Ж y = 14.901x + 32.484 ^R2 = ^0.9963 R2 = 0.9798 y = 20.378x - 0.7799 R2 = 0.8691 0 1 1.5 2 2.5 3 Indenter diameter, mm 4 - Gurbek, - Gulyabi, A - Inzhinrnaya, M - Amiri, Ж - Zhuldyz, — - Myrzachulskaya Puncture force versus diameter for indenters with tip angle a=45° 1. 7. Physical and mechanical characteristics for volumetric compression After processing the results of the experiments, the elastoplastic properties of melon pulp of various varieties, in particular the Myrzachulskaya and Ameri varieties of the most common varieties were calculated. Analysis of the data made it possible to conclude that such indices as plasticity, softness, relative residual compression with an increase in the compression rate from 20 to 100 mm/min decrease slightly, and recoverability and bulk modulus of elasticity increase. Graphs of the dependence of the change in the bulk modulus of elasticity on the compression rate for melons of the above varieties are given in Fig. 5. The dependence with a high degree of accuracy is described by the equations of the straight line, which are shown in the graphs, which also give the reliability values of the approximation. The values of which indicate a good corre­spondence of the equations to the experimental data. According to the experimental data, the values of the effective viscosity and bulk modulus of elasticity for the melon pulp of various grades were calculated for different values of the com­pression rate. The equations describing this dependence, the reliability of the approximation and the deviation of the experimental values of these quantities from the calculated values are given in Table 7 [17, 18]. Table 7 Average values of effective viscosity and bulk modulus of mash melon of various grades at separation of 50 % juice-gravity Index	Equation (v, m/s)	Reliability of the approximation	Deviation of average value
Effective viscosity, kPa	2,086+6.767v	0.97	(+5.3; -4.1) %
Bulk modulus of elasticity, kPa	5,898+2.023v	0.96	(+3.2; -2.2) %

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Compression rate, mm/min
—■—Myrzachulskaya —♦—Amiri

4. 
   Graph of the dependence between bulk modulus and compression rate
   

3. 
   1. 8. Chemical composition of melon fruits
   

Research work was carried out in the accredited testing laboratory “Food safety” of the Al­maty Technological University. Where the following indicators of melons of late-ripening varieties were determined: mass fraction of solids, protein mass fraction, mass fraction of fat, mass fraction of pectin substances, vitamin C content, carotenoids, potassium, magnesium, iron, organic acids and antioxidant activity, using modern standard research methods.
The chemical composition of melons of late-ripening varieties is presented in Table 8. The table confirms that the Myrzachulskaya melon variety is more balanced in composition, the vegeta­ble protein content is almost 3.8 times higher in comparison with the Zhuldyz variety and 1.9 times with the Ameri type [18].
The Myrzachulskaya variety contains more fat - 0.26 %, which is 0.134 % higher than the Zhuldyz variety and 0.17 % higher than the Ameri variety. According to the content of the mass fraction of pectin substances, the Myrzachulskaya variety is inferior to the Zhuldyz grade by 0.11 g/100 g, but does not exceed the Amerite grade by 0.045/100 g.
The Myrzachulskaya grade for ascorbic acid, vitamin C content is 2.78 mg/100 g higher than that of Zhuldyz and 6.61 mg/100 g higher than that of Ameri variety.
The content of carotenoids is approximately at the same level, with a small lead the Zhuldyz variety, then the Myrzachulskaya and Ameri variety (0.12, 01124, 0.104 mg/100 g, respectively). Melons are rich in potassium, magnesium and iron, which are so necessary to maintain the tone of the cardiovascular system of the body.
These tables show that the best indicator is Ameri variety, it contains 117.38 mg/100 g of potassium, 10.846 mg/100 g of magnesium and 1.193 mg/100 g of iron. The second place is tak­en by the Myrzachulskaya variety - 116.64 mg/100 g of potassium, 10.812 mg of magnesium and 1.007 mg/100 g of iron. In the Zhuldyz variety, respectively, 113.0 mg/100 g of potassium, 10.43 mg/100 g of magnesium and significantly lower in iron content - only 0.353 mg/100 g.
In Ameri variety, the content of malic acid is 348.8 mg/kg, which is much higher than in the Zhuldyz strain at 47 mg/kg and at 58.8 mg/kg - the Myrzachulskaya variety.
According to the content of citric acid, the Zhuldyz variety is 47.5 mg/kg, then the Myr- zachulskaya variety is 27.0 mg/kg and the Ameri grade is 18.0 mg/kg.


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