The production of defatted peanut protein powder involves mechanically pressing and extracting oil from peanut kernels using either mechanical pressing or organic solvent extraction. After this process, the peanut cake residue is ground to produce peanut protein powder.
1. Batch Hydraulic Pressing Process
To reduce the fat content (energy) in peanuts for food applications, a partially defatted or semi-defatted peanut product is produced using a hydraulic oil press. This method operates at 14 MPa for 50 minutes, extracting 50% to 70% of the peanut oil. The defatted peanut press cake is then expanded in boiling water at 100°C for 3 to 8 minutes, followed by drying in a hot air oven.
During production, whole, peeled peanuts are placed in a specially designed cloth bag and positioned in a processing cylinder. The hydraulic oil pump is activated to raise the oil cylinder piston, applying pressure to the peanuts within the cylinder. The oil is released as small droplets during extraction from broken peanut cell membranes, resulting in partially defatted peanuts.
Different roasting temperatures can be applied to the peeled peanuts after partial defatting to create various grades of semi-defatted peanuts, catering to the specific needs of other food products. Peanuts roasted at low temperatures in natural-gas ovens can be used for marinating, baking salty peanut snacks, or ground to varying particle sizes for semi-defatted peanut powder. Peanuts roasted at medium (120°C) or high (160°C) temperatures develop a distinct roasted peanut aroma and are used as an ingredient in confectionery.
The natural structure of peanut cells, composed of protein and starch, clearly demonstrates the reduction in oil content after pressing. When partially defatted peanuts are boiled, the cell structure expands significantly, while the fat content decreases. Thus, the primary constituents in these cells are protein, starch, and minor amounts of peanut oil. Using these partially defatted peanut products enables the creation of low-fat peanut foods and peanut protein powders with fat contents of 14% or 28% for medium, heavy, and super heavy roasting. The quality parameters for the peanut protein powder produced from partially defatted peanuts are summarized in Table 1.
Table 1: Quality Parameters for Peanut Protein Powder from Partially Defatted Peanuts
| Item | 14% Fat Medium Roast | 14% Fat Super Heavy Roast | 28% Fat Medium Roast | 28% Fat Heavy Roast |
|---|---|---|---|---|
| Moisture/% | 1-3 | 1-3 | 2-4 | 2-4 |
| Protein/% | 42-46 | 42-46 | 33-39 | 33-39 |
| Fat/% | 12-15 | 12-15 | 26-30 | 26-30 |
| Carbohydrates/% | 35 | 35 | 26-32 | 26-32 |
| Ash/% | 5 | 5 | 5 | 5 |
| Aflatoxin/ppb | <15 | <15 | <15 (<4B2) 2-4 | <15 (<4B2) 2-4 |
| Total Bacterial Count | 5000 CFU/g | 5000 CFU/g | 5000 CFU/g | 5000 CFU/g |
| Mold/Yeast | 200/g (max) | 200/g | 200/g | 200/g |
| Coliform Bacteria | 10 MPN/g | 10 MPN/g | 10 MPN/g | 10 MPN/g |
| E. coli presence | Not specified | Not specified | Not specified | Not specified |
| Pathogenic Bacteria | Not specified | Not specified | Not specified | Not specified |
The hydraulic press can be used to produce partially defatted peanuts; however, this method requires high labor intensity and operates in batches. For larger-scale and industrial processing, continuous single or twin-screw oil presses are recommended.
- Color: Brownish-yellow
- Flavor: Distinct peanut aroma
- Water Absorption: Each 100g of dry product absorbs approximately 134-170g of water, resulting in a spongy, elastic texture.
- Bulk Density: 133g to 169g/L
- Moisture: Approximately 9%
- Fat: 2.76% (on a dry basis)
- Total Protein: 56.89%
- Ash: 5.83%
- Residual Solvent Oil: <50*10-6
The texture and flavor of peanut protein are crucial parameters. For defatted peanut protein, an important indicator is whether a fibrous structure forms internally during processing. This affects the taste of extruded products. To eliminate off-flavors, reduce anti-nutritional factors present in peanuts, and enhance the sensory attributes of peanut protein, additional ingredients such as food-grade alkali, vegetable oil, lecithin, salt, flavorings, and colorants may be required.
Peanut protein can be incorporated into vegetarian dishes with various flavors or combined with meats to create diverse savory dishes. Often, it is used as a substitute in dumplings and buns, increasing the protein content while reducing cholesterol levels from animal sources. Significantly, it also diminishes the beany flavor associated with soy protein.
The production processes, equipment, and quality indicators for peanut protein are similar to those of soy protein, with differences mainly in the raw material composition and properties. The source materials for peanut protein production include low-denaturation pre-pressed extraction cakes, blended defatted peanut powder (combined with concentrated peanut protein), and cold-pressed peanut meal.
Production Process of Defatted Peanut Protein Powder
The production of defatted peanut protein powder involves mechanically pressing and extracting oil from peanut kernels using either mechanical pressing or organic solvent extraction. After this process, the peanut cake residue is ground to produce peanut protein powder.
1. Batch Hydraulic Pressing Process
To reduce the fat content (energy) in peanuts for food applications, a partially defatted or semi-defatted peanut product is produced using a hydraulic oil press. This method operates at 14 MPa for 50 minutes, extracting 50% to 70% of the peanut oil. The defatted peanut press cake is then expanded in boiling water at 100°C for 3 to 8 minutes, followed by drying in a hot air oven.
During production, whole, peeled peanuts are placed in a specially designed cloth bag and positioned in a processing cylinder. The hydraulic oil pump is activated to raise the oil cylinder piston, applying pressure to the peanuts within the cylinder. The oil is released as small droplets during extraction from broken peanut cell membranes, resulting in partially defatted peanuts.
Different roasting temperatures can be applied to the peeled peanuts after partial defatting to create various grades of semi-defatted peanuts, catering to the specific needs of other food products. Peanuts roasted at low temperatures in natural-gas ovens can be used for marinating, baking salty peanut snacks, or ground to varying particle sizes for semi-defatted peanut powder. Peanuts roasted at medium (120°C) or high (160°C) temperatures develop a distinct roasted peanut aroma and are used as an ingredient in confectionery.
The natural structure of peanut cells, composed of protein and starch, clearly demonstrates the reduction in oil content after pressing. When partially defatted peanuts are boiled, the cell structure expands significantly, while the fat content decreases. Thus, the primary constituents in these cells are protein, starch, and minor amounts of peanut oil. Using these partially defatted peanut products enables the creation of low-fat peanut foods and peanut protein powders with fat contents of 14% or 28% for medium, heavy, and super heavy roasting. The quality parameters for the peanut protein powder produced from partially defatted peanuts are summarized in Table 1.
Table 1: Quality Parameters for Peanut Protein Powder from Partially Defatted Peanuts
| Item | 14% Fat Medium Roast | 14% Fat Super Heavy Roast | 28% Fat Medium Roast | 28% Fat Heavy Roast |
|---|---|---|---|---|
| Moisture/% | 1-3 | 1-3 | 2-4 | 2-4 |
| Protein/% | 42-46 | 42-46 | 33-39 | 33-39 |
| Fat/% | 12-15 | 12-15 | 26-30 | 26-30 |
| Carbohydrates/% | 35 | 35 | 26-32 | 26-32 |
| Ash/% | 5 | 5 | 5 | 5 |
| Aflatoxin/ppb | <15 | <15 | <15 (<4B2) 2-4 | <15 (<4B2) 2-4 |
| Total Bacterial Count | 5000 CFU/g | 5000 CFU/g | 5000 CFU/g | 5000 CFU/g |
| Mold/Yeast | 200/g (max) | 200/g | 200/g | 200/g |
| Coliform Bacteria | 10 MPN/g | 10 MPN/g | 10 MPN/g | 10 MPN/g |
| E. coli presence | Not specified | Not specified | Not specified | Not specified |
| Pathogenic Bacteria | Not specified | Not specified | Not specified | Not specified |
The hydraulic press can be used to produce partially defatted peanuts; however, this method requires high labor intensity and operates in batches. For larger-scale and industrial processing, continuous single or twin-screw oil presses are recommended.
- Color: Brownish-yellow
- Flavor: Distinct peanut aroma
- Water Absorption: Each 100g of dry product absorbs approximately 134g to 170g of water, resulting in a spongy and elastic texture.
- Bulk Density: 133g to 169g/L
- Moisture: Approximately 9%
- Fat: 2.76% (on a dry basis)
- Total Protein: 56.89%
- Ash: 5.83%
- Residual Solvent Oil: <50*10-6
The texture and flavor of peanut protein are crucial parameters. For defatted peanut protein, an important indicator is whether a fibrous structure forms internally during processing. This affects the taste of extruded products. To eliminate off-flavors, reduce anti-nutritional factors present in peanuts, and enhance the sensory attributes of peanut protein, additional ingredients such as food-grade alkali, vegetable oil, lecithin, salt, flavorings, and colorants may be required.
Peanut protein can be incorporated into vegetarian dishes with various flavors or combined with meats to create diverse savory dishes. Often, it is used as a substitute in dumplings and buns, increasing the protein content while reducing cholesterol levels from animal sources. Significantly, it also diminishes the beany flavor associated with soy protein.
The production processes, equipment, and quality indicators for peanut protein are similar to those of soy protein, with differences mainly in the raw material composition and properties. The source materials for peanut protein production include low-denaturation pre-pressed extraction cakes, blended defatted peanut powder (combined with concentrated peanut protein), and cold-pressed peanut meal.
