Introduction
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Data SheetWalnut peptide is a small molecular collagen peptide which is extracted from walnut by targeted bio-enzyme digestion and low temperature membrane separation technology.
There are 18 amino acids in walnut protein, and the content of eight kinds of essential amino acids meets the needs of the human body, which is close to the standard recommend by the World Health Organization, Food and Agriculture Organization and United Nations University in 2007 and it is considered to be an important plant protein source for human food and a plant protein with great development potential (Table 1)[1].
Tab. 1 Amino acid composition (g/100 g) of walnut protein
(WPC: walnut protein concentrate, WPI: walnut protein isolate)
| Amino Acids | WPC | WPI | Amino Acids | WPC | WPI |
| methionine | 0.99±0.08 | 1.44±0.10 | tyrosine | 2.30±0.13 | 3.21±0.09 |
| valine | 3.50±0.18 | 4.62±0.10 | proline | 2.33±0.04 | 3.18±0.01 |
| threonine | 2.55±0.09 | 3.30±0.12 | alanine | 3.31±0.15 | 4.29±0.11 |
| histidine | 1.89±0.09 | 2.30±0.10 | argnine | 11.24±0.18 | 14.81±0.11 |
| isoleucine | 3.03±0.09 | 3.99±0.06 | glycine | 3.54±0.11 | 4.18±0.08 |
| leucine | 5.64±0.12 | 7.29±0.08 | serine | 3.96±0.22 | 5.15±0.07 |
| lysine | 2.01±0.07 | 2.13±0.11 | glutamic | 15.78±0.20 | 19.49±0.11 |
| cysteine | 0.70±0.12 | 0.81±0.15 | aspartic acid | 6.95±0.19 | 9.38±0.11 |
| phenylalanine | 3.49±0.07 | 4.61±0.12 | tryptophan | ~5.5 | ~5.5 |
Extraction Process
There are many methods for the preparation of bioactive peptides from plants, such as enzymatic methods, fermentation methods and chemical methods. Chemical methods involve hydrolyzing protein to produce active peptides by acid or alkali catalysis. The reaction process is difficult to control, and the environmental friendliness is low, so it is not suitable for the industrialization of walnut active peptide. At present, the bioactive peptides from walnut meal are mainly prepared by enzymatic and fermentation methods[1].
Our walnut peptide is extracted by targeted bio-enzyme digestion and low temperature membrane separation technology, and the detail procedure is as below.
Fig. 1 Walnut peptide extraction procedure
Properties of Walnut Peptide
Walnut peptide is received increasing interest as nutraceutics mainly due to the fact that their regular consumption has been reported to reduce the risk of coronary heart disease. In addition, many biological activities for walnut peptide have been reported, such as anti-inflammatory and antioxidant properties, anti-cancer properties, anti-hypertensive etc.
- Anti-inflammatory and antioxidant properties
Researchers[2-3] had obtained peptides from walnut protein hydrolysates, and these peptides exhibited the high anti-inflammatory and anti-oxidant activities by mice experience and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay.
Increasing level of inflammation and oxidative stress could lead to memory impairment. It has been demonstrated that walnut peptide could ameliorate the memory deficits induced by lipopolysaccharide via normalizing the inflammatory response and oxidative stress in brain.
- Anti-cancer
Several efforts have been made during the last decade to advance novel broad-spectrum anticancer peptides into clinical use. Walnut peptide had cancer cell inhibitory activity (63±1.73 % inhibition using 1 h chymotrypsin hydrolysis). And the varying results in inhibition of cancer cell growth may be attributed to the variations of the amino acid sequences of these peptides[4].
- Anti-hypertensive
Angiotension-converting enzyme (ACE) is a kind of dipeptidyl carboxypeptidase, which plays a role in the renin-angiotension system and the kallikrein-kinin system, leading to the rise of blood pressure.ACE inhibitory peptide can inhibit the activity of ACE, reduce the tension of blood vessels, blood volume and blood pressure, and play an important physiological role in regulating human blood pressure.
Wang et al. used the Lineweaver-Burk plot analysis method to explore the inhibition mode of walnut short peptide walnut short peptide on ACE, and found that walnut short peptide showed a mixed inhibition mode on ACE. Specifically, walnut short peptide can not only combine with ACE at the active site to prevent ACE lyses, but also combine with ACE at the inactive site and prevent the interaction of ACE with the substrate through spatial bit resistance effect, so as to achieve effective suppression of ACE activity.
Alfa Chemistry supplies walnut peptide with molecular weight less than 1000Dal. Which can be used in food, beverage, liquid dairy products, medicine and health care products. You can access to technical data for detail information. Please feel free to contact us if you have any questions.
References
- Xiangyang Li, Manli Guo, Jingtian Chi, et al. Bioactive Peptides from Walnut Residue Protein. Molecules 2020, 25, 1285.
- Ming-Chuan Liu, Sheng-Jie Yang, Da Hong, et al. A simple and convenient method for the preparation of antioxidant peptides from walnut (Juglans regia L.) protein hydrolysates. Chemistry Central Journal volume 10: 39 (2016).
- Shuguang Wang, Lin Zheng, Tiantian Zhao, et al. Inhibitory Effects of Walnut (Juglans regia) Peptides on Neuroinflammation and Oxidative Stress in Lipopolysaccharide-Induced Cognitive Impairment Mice. J. Agric. Food Chem. 2020, 68, 8, 2381-2392.
- Raheleh Jahanbani, S. Mahmood Ghaffari,Maryam Salam, et al. Antioxidant and Anticancer Activities of Walnut (Juglans regia L.) Protein Hydrolysates Using Different Proteases. Plant Foods Hum Nutr, 2016.
