Plant proteins are on the rise—and the market for them is expected to grow significantly from 2021 to 2028, according to Grand View Research.
What’s fueling the momentum? There are a few factors in play1,2:
- Consumer interest in health, and particularly more plant-based eating
- Renewed focus on immune health because of COVID-19
- Increased awareness of the impact of animal meat production and consumption
- Price volatility in the dairy and soy ingredient sectors
One of the reasons that animal proteins—including dairy—are so popular is because they are complete proteins, delivering consistent amounts of all nine essential amino acids. Essential amino acids are those that cannot be synthesized in your body, and so they must be consumed through your diet.
But there are also some plant proteins that have a high-quality amino acid profile and provide all 9 essential amino acids, such as hemp, pea, soy, and others that when combined together, can be considered more complete sources of protein (e.g., the classic example of beans plus rice). Even when a plant protein contains all the essential amino acids, it may be slightly low in an essential amino acid or two.
Here we take a look at how the essential amino acid profile of hemp compares to other popular plant proteins, and the most important protein qualities to consider for food formulations.
How Hemp’s Amino Acid Profile Compares to Other Plant Proteins
Every plant protein’s amino acid profile is a bit different - some are high in certain amino acids, but are lower in others.
For example, these four popular plant proteins are low in methionine:
Hemp protein, however, is rich in methionine and contains the most out of any other plant protein. Hemp is also rich in cysteine, another essential amino acid. This makes hemp a great complimentary plant protein to pair with pea, soy, oat, and/or microalgae. These combinations enable formulators to develop a product with a more complete amino acid profile.
These four popular plant proteins are rich in lysine:
Hemp is limited in lysine—as are wheat and oat proteins. However, pairing hemp, wheat, and oat proteins with the lysine-rich proteins above is ideal to create a product with a more robust amino acid profile.
Although when looking at the big picture, it’s not about having the most of any, or every, essential amino acid. It’s more important to have the right proportion of each. Another valuable factor to consider is protein digestibility.
How Is Protein Quality Measured?
The Protein Digestibility Adjusted Amino Acid Score, or PDCAAS—has been the FDA/FAO approved standard method of assessing protein quality since 1991. The PDCAAS score (on a scale of 0 to 1) of a protein is based on a combination of two key components - the amino acid composition and the digestibility of the protein.
Amino Acid Composition Measurement
The amino acid composition measurement as part of PDCAAS takes into consideration the first limiting amino acid compared to a standard reference value. The standard 1991 reference value is based on the amino acid requirements of a 2 to a 5-year-old child, which is considered the most nutritionally demanding age group.
The more essential amino acids the protein contains, the higher the score. This amino acid score is then multiplied by the protein digestibility score to calculate a total PDCAAS score.
Most plant-based proteins contain at least one limiting amino acid, an amino acid that contains less than the standard reference value. As mentioned in regards to its amino acid profile, hemp protein’s limiting amino acid is lysine. Victory Hemp’s V-70™ Hemp Heart Protein contains about 63% of the required amount to fit within the proper ratio of the other essential amino acids, according to a Victory Hemp Foods-funded study.*
However, this is again why it is best to combine the unique benefits of hemp with other plant proteins rich in lysine like pea protein. And since hemp is rich in methionine, this also helps complement pea protein’s low methionine content.
Another one of hemp’s unique benefits includes its superior digestibility, the second component of the PDCAAS equation.
Protein Digestibility Score
The protein digestibility score as part of PDCAAS is calculated based on the percentage of protein digested in the body. To determine this score, fecal output is measured at the end of the digestive cycle.
Hemp protein and especially our V-70™ Hemp Heart Protein scores particularly high for digestibility compared to other plant proteins. This is of interest to consumers looking for an easy-to-digest plant protein.
PDCAAS Method and Beyond - Then and Now
Of note, there are two new versions of protein quality scoring methods that have been developed since 1991—one in 2007 and the most recent in 2013. All three versions are accepted by food scientists. However, the original version is still currently the FDA standard, and thus remains the version used by food formulators.
The changes associated with the newer versions still warrant discussion into how they impact the final protein quality scores, and what may be to come in the future.
For comparison purposes, here are the protein quality scores of our V-70™ Hemp Heart Protein for each scoring period:
1991 - PDCAAS Original Version. The PDCAAS of our V-70™ Hemp Heart Protein is 0.63 based on this original method. This is based on the 1991 FAO Report reference amino acid scoring equation³. This score is as compared to the reference standard for 2-5 years olds, a more stringent measure due to the vulnerability of this age group.
2007 - PDCAAS Most Recent Version. The PDCAAS of V-70™ Hemp Heart Protein is 0.76 based on this method. This is determined as per the 2007 WHO/FAO/UNU Joint Report Reference Amino Acid Scoring⁴. This score is compared to the reference standard for both 3-10-year-olds and those who are 18-plus years old, which is closer to the nutritional requirements of an adult.
2013 - DIAAS Scoring Method, or Digestible Indispensable Amino Acid Score. The DIAAS method is the most recent method of protein quality. This was developed as per the FAO Report Reference Amino Acid Scoring⁵. This score is compared to the reference standard of those 3 years of age and older.
The FAO has recommended DIAAS as a more accurate measure of protein quality than PDCAAS, but it is significantly more expensive and requires invasive animal testing in pigs. This method is also thus not vegan-friendly.
The DIAAS method is said to be more accurate for two reasons. First, it takes anti-nutrient factors into account that are present in the protein such as phytic acid and trypsin inhibitors, which decrease protein absorption and digestibility.
Second, DIAAS samples are derived from the ileum, which gives a more accurate depiction of amino acid digestion and absorption versus testing the feces with PDCAAS methods.
However, using the DIAAS method is not feasible from a practicality standpoint, and so in reality PDCAAS currently remains the best available method of assessing protein quality.
To summarize, the chart below displays the PDCAAS values of common plant-based proteins, including dehulled hemp seeds. This chart is based on the 1991 PDCAAS standards and does not reflect the more recent methods discussed here⁶. (See chart and references below).
Amino Acid Profile Comparisons - Bottom Line
If you’re looking to meet consumer demand for a high-quality plant-based protein with enhanced digestibility, look no further than our V-70™ Hemp Heart Protein. Especially when combined with another plant protein-rich in lysine such as pea protein, the result is a complete and balanced amino acid profile for food formulations and their customers.
If you’re interested in learning more about hemp seed ingredients, book a meeting with our Hemp Ingredients Specialist today!
*The digestibility value is 0.63 for ages 2 to 5 years and is based on an in vitro study conducted on V-70™ Hemp Heart Protein, and through a third-party lab, whereas most other digestibility values are based on rat models.
- Millward DJ. Amino acid scoring patterns for protein quality assessment. Br J Nutr. 2012 Aug;108 Suppl 2:S31-43. DOI: 10.1017/S0007114512002462. PMID: 23107544. https://pubmed.ncbi.nlm.nih.gov/23107544/
- Joint FAO/WHO/UNU Expert Consultation on Protein and Amino Acid Requirements in Human Nutrition (2002: Geneva, Switzerland), Food and Agriculture Organization of the United Nations, World Health Organization & United Nations University. (2007). Protein and amino acid requirements in human nutrition: report of a Joint FAO/WHO/UNU expert consultation. World Health Organization. https://apps.who.int/iris/handle/10665/43411
- Wolfe RR, Rutherfurd SM, Kim IY, Moughan PJ. Protein quality as determined by the Digestible Indispensable Amino Acid Score: evaluation of factors underlying the calculation. Nutr Rev. 2016;74(9):584-599. doi:10.1093/nutrit/nuw022. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6322793/
- House, James D.; Neufeld, Jason; Leson, Gero (2010). "Evaluating the quality of protein from hemp seed (Cannabis sativa L.) products through the use of the protein digestibility-corrected amino acid score method". Journal of Agricultural and Food Chemistry. https://pubs.acs.org/doi/10.1021/jf102636b
- Hoffman, Jay R.; Falvo, Michael J. (2004). "Protein – Which is Best". Journal of Sports Science and Medicine. 3 (3): 118–30. PMC 3905294. PMID 24482589.
- Schaafsma, Gertjan (July 2000). "The protein digestibility-corrected amino acid score". The Journal of Nutrition.
- Boye, Joyce; Wijesinha-Bettoni, Ramani; Burlingame, Barbara (2012). "Protein quality evaluation twenty years after the introduction of the protein digestibility corrected amino acid score method". The British Journal of Nutrition. PMID: 23107529. DOI:10.1017/S0007114512002309.
- Suárez López MM, Kizlansky A, López LB (2006). "[Assessment of protein quality in foods by calculating the amino acids score corrected by digestibility]". Nutrición Hospitalaria (in Spanish). PMID 16562812