Tartary Buckwheat Protein Yields 42 Blood Pressure-Lowering Peptides, Including 14 Never Identified Before | Research

The takeaway

Researchers identified 42 ACE-inhibitory peptides from Tartary buckwheat albumin — 14 of them novel — with the albumin fraction achieving nearly 80% ACE inhibition at just 0.2 mg/mL.

79.89% ACE inhibition
Tartary buckwheat albumin hydrolysate achieved this inhibition rate at just 0.2 mg/mL — comparable to some synthetic ACE inhibitor drug concentrations

What the researchers found

Four protein fractions from Tartary buckwheat (albumin, globulin, prolamin, glutelin) were hydrolyzed with pepsin and trypsin. All showed ACE inhibitory activity, with albumin hydrolysate (AH) strongest:

- AH: 79.89% ACE inhibition at 0.2 mg/mL with the highest peptide yield (82.28%)

- Globulin hydrolysate: 71.84% inhibition

- Prolamin and glutelin hydrolysates: lower inhibition rates

After gel filtration and reversed-phase HPLC purification of the most active AH fraction, nano-LC-MS/MS identified 42 ACE inhibitory peptides. Of these, 14 were completely novel discoveries. Computational analysis confirmed potent ACE inhibitory potential for all 14 new peptides.

Why it matters

ACE inhibitor drugs (like lisinopril and enalapril) are among the most prescribed medications worldwide for hypertension. Finding natural food-derived ACE inhibitory peptides could lead to functional foods or supplements that support blood pressure management as part of a healthy diet. Tartary buckwheat is particularly attractive because it's already consumed as food in many Asian countries and is gaining popularity as a health food globally.

How the study worked

Albumin, globulin, prolamin, and glutelin were extracted from Tartary buckwheat flour. Each fraction underwent sequential pepsin-trypsin hydrolysis to simulate gastrointestinal digestion. ACE inhibitory activity was measured for all hydrolysates. The most active fraction (albumin hydrolysate) was further purified using gel filtration chromatography and reversed-phase HPLC. Individual peptides were identified by nano-LC-MS/MS (nanoscale liquid chromatography-tandem mass spectrometry). Novel peptides were validated through computational molecular docking analysis.

What this study cannot tell us

All testing was performed in vitro — ACE inhibition in a test tube does not guarantee blood pressure reduction in humans. The peptides need to survive absorption through the intestinal wall intact and reach the bloodstream at sufficient concentrations. Many food-derived ACE peptides lose activity after further metabolism. No animal or human blood pressure studies were conducted. The computational validation of novel peptides provides theoretical support but not experimental proof of activity. The specific sequences of the 14 novel peptides are not listed in the abstract.

How to read the evidence

This is an in vitro biochemical study with computational validation. The peptide identification is rigorous (nano-LC-MS/MS), but no biological efficacy beyond enzyme inhibition in a test tube has been demonstrated. Evidence is at the basic research level.

When this study was published

Published in 2023, this study adds to the growing catalog of plant-derived ACE-inhibitory peptides. Interest in plant-based bioactive peptides continues to accelerate alongside the plant-based food movement.

The bigger picture

Food-derived ACE-inhibitory peptides are one of the most commercially successful categories of bioactive peptides. Lactotripeptides from milk (IPP and VPP) are already sold as functional food ingredients in Japan and Europe with regulatory approval for blood pressure claims. This study expands the plant-based ACE peptide repertoire, which is important for vegan/vegetarian markets and for diversifying peptide sources beyond dairy. The 14 novel peptides could represent unique intellectual property for nutraceutical development.

Questions still open

Can the most potent Tartary buckwheat ACE-inhibitory peptides survive gastrointestinal absorption and reach bioactive concentrations in the blood?
Would regular consumption of Tartary buckwheat products produce measurable blood pressure reduction in hypertensive individuals?
How do these buckwheat-derived peptides compare in potency and bioavailability to commercially available dairy-derived ACE-inhibitory peptides?

Common questions

What is Tartary buckwheat and is it the same as regular buckwheat?

Tartary buckwheat (Fagopyrum tataricum) is a close relative of common buckwheat but has a more bitter taste and higher levels of beneficial compounds like rutin and flavonoids. It's widely grown in mountainous regions of China, Nepal, and other Asian countries. Despite the name, buckwheat is not related to wheat — it's a pseudocereal that's naturally gluten-free. This study shows its proteins also contain blood pressure-regulating peptides.

Could buckwheat foods replace blood pressure medication?

No — this study only shows that buckwheat proteins can inhibit ACE in a test tube, not that eating buckwheat lowers blood pressure. Even if some peptides survive digestion and absorption, the concentrations would likely be much lower than pharmaceutical ACE inhibitors. Buckwheat consumption might complement a heart-healthy diet, but it should never replace prescribed blood pressure medication. Anyone with hypertension should follow their doctor's treatment plan.

Read the original research

Isolation and identification of angiotensin-converting enzyme inhibitory peptides from Tartary buckwheat albumin.

Journal of the science of food and agriculture, 103(10), 5019-5027

View on PubMed ↗Publisher’s paper ↗

Citation

Li, Yongfu; Yang, Nan; Shi, Feng; Ye, Fei; Huang, Jinrong. (2023). Isolation and identification of angiotensin-converting enzyme inhibitory peptides from Tartary buckwheat albumin.. Journal of the science of food and agriculture, 103(10), 5019-5027. https://doi.org/10.1002/jsfa.12573