Name of indicator | Sheepskin processing options | Normative documentation on research methods | |||
---|---|---|---|---|---|
1 | 2 | 3 | 4 | ||
Organoleptic indicators | |||||
Appearance | The hairline of the skin is slightly damp. The skin is soft, not elastic | The hairline of the skin is dry. There is some moisture at the junction of the skin and hair. The skin is elastic | The hairline of the skin is dry. The skin is elastic | The hairline of the skin is dry. There are places with a small touch of salt. The skin is elastic | GOST 28509-90. Leather raw material. Sheepskins are undressed. Specifications |
Mezdra (a layer of subcutaneous fatty tissue, meat, fat, and pieces of tendons that are removed from the skin in the process of preparatory operations) color | Mezdra gray shade | Mezdra light milky color | Mezdra light milky color | Mezdra with a milky yellow tint | |
Chemical indicators | |||||
NaCl concentration, g/l | 70 (20% of saturated solution) | 100 (30% of saturated solution) | 125 (40% of saturated solution) | 150 (50% of saturated solution) | GOST 13105-77 Leather raw materials. Methods for determining the components of preserving |
Moisture, % | 17,8 | 16,2 | 15,5 | 15,1 | GOST 13104-77. Leather raw material. Methods for determining salt and net weight |
NaCl, % | 6,7 | 10,6 | 11,7 | 12,8 | GOST 13105-77 Leather raw materials. Methods for determining the components of preserving |
pH | 5,4 | 5,1 | 4,9 | 4,7 | GOST 32165-2013. Dressed fur and sheepskin skins. Method for determining the pH of an aqueous extract |
microbiological indicators | |||||
QMAFAnM, CFU/g | 5×102 | 6×102 | 2×102 | 2×102 | GOST 25311-82. Feed flour of animal origin. Methods of bacteriological analysis. GOST 26670-91. Food products. Methods of cultivation of microorganisms. GOST 10444.15-94. Food products. Methods for determining the number of mesophilic aerobic and facultative anaerobic microorganisms |
Mold, CFU/g | 1 | Not detected | Not detected | Not detected | |
Halophiles | Not detected | Not detected | Not detected | Not detected |
Name of indicator | Combination serum options | Normative documentation on research methods | |||
---|---|---|---|---|---|
1 | 2 | 3 | 4 | ||
Appearance and texture | Homogeneous translucent liquid with the presence of a protein precipitate | The determination of organoleptic indicators is carried out visually and organoleptically at a whey temperature of (22 ±2) °C according to GOST 343522017 “Whey - raw materials. Specifications» | |||
Color | Pale green | ||||
Taste and smell | Characteristic of whey, sour | ||||
Mass fraction of fat, % | 0,4 | 0,2 | 0,2 | 0,3 | GOST 5867-90 “Milk and dairy products. Methods for determining fat « |
Mass fraction of solids, % | 5,1 | 5,7 | 5,4 | 5,9 | GOST 33957-2016 “Whey and drinks based on it. Acceptance rules, sampling and control methods» |
Density, kg/m3 | 1025 | 1024 | 1026 | 1028 | |
Titratable acidity, °T | 88 | 90 | 87 | 91 | |
Active acidity, pH | 3,96 | 3,85 | 3,98 | 3,98 | |
Temperature, °C | 6±2 | 6±2 | 6±2 | 6±2 |
Experienced options | Sheepskins after preservation | |
---|---|---|
QMAFAnM, CFU/g | mold, CFU/g | |
Sheepskins after 5 days of preservation | ||
paired | 8×106 | 30 |
1 option (20%) | 14×103 | 18 |
2 option (30%) | 12×103 | 10 |
3 option (40%) | 9×103 | 2 |
4 option (50%) | 5×103 | 1 |
Control | 13×103 | 16 |
Sheepskins after 7 days of preservation | ||
1 option (20%) | 3×103 | 18 |
2 option (30%) | 2×103 | 10 |
3 option (40%) | 1,2×103 | 2 |
4 option (50%) | 1,1×103 | 1 |
Control | 5×103 | 19 |
Sheepskins after 10 days of preservation | ||
1 option (20%) | 2×103 | 20 |
2 option (30%) | 2×103 | 12 |
3 option (40%) | 1×103 | 2 |
4 option (50%) | 1×103 | 1 |
Control | 3×103 | 20 |
Sheepskins after 15 days of preservation | ||
1 option (20%) | 1,1×103 | 24 |
2 option (30%) | 1,3×103 | 13 |
3 option (40%) | 9×102 | 3 |
4 option (50%) | 5×102 | 2 |
Control | 1×103 | 26 |
Name of indicator | Norm according to normative documentation | Actual performance | Normative documentation on research methods |
---|---|---|---|
Quantity of mesophilic aerobic and facultative anaerobic microorganisms (QMAFAnM), CFU/g | no more than 1×105 | 3,9×104 - 6,5×104 | GOST 34352-2017. Whey - raw material. Specifications |
Bacteria of the Escherichia coli group (Coliform bacteria) in 0.1 g | not allowed | not detected | |
Pathogenic, including salmonella in 25 g | not allowed | not detected | |
S. aureus in 0.1 g | not allowed | not detected | |
Yeast, CFU/g | not allowed | not detected | |
Molds, CFU/g | not allowed | not detected |
Indicators | Shrinkage temperature of leather tissue by days of storage in experimental batches and control | |||
---|---|---|---|---|
5 days | 7 days | 10 days | 15 days | |
Experimental variant 1 - (20 %) (n=8) | ||||
M | 67,13 | 67,75 | 64,75 | 67,88 |
±δ | 0,22 | 0,38 | 0,38 | 0,22 |
CV (%) | 0,33 | 0,56 | 0,59 | 0,32 |
Experimental variant 2 - (30 %) (n=8) | ||||
M | 67,25 | 67,88 | 67,13 | 64,13 |
±δ | 0,38 | 0,22 | 0,22 | 0,22 |
CV (%) | 0,57 | 0,32 | 0,33 | 0,34 |
Experimental variant 3 - (40 %) (n=8) | ||||
M | 67,5 | 68,13 | 67,63 | 68,88 |
±δ | 0,5 | 0,22 | 0,47 | 0,22 |
CV (%) | 0,74 | 0,32 | 0,69 | 0,32 |
Experimental variant 4 - (50 %) (n=8) | ||||
M | 66,88 | 63,63 | 68,5 | 66,63 |
±δ | 0,22 | 0,47 | 0,5 | 0,47 |
CV (%) | 0,33 | 0,74 | 0,73 | 0,71 |
Control (n=8) | ||||
M | 67,13 | 62,63 | 62,88 | 62,13 |
±δ | 0,22 | 0,47 | 0,22 | 0,22 |