Protein powder has become an increasingly popular supplement among fitness enthusiasts and athletes looking to increase their protein intake. From whey and casein to plant-based options like pea and hemp, protein powders can be easily added to shakes, smoothies, oats, baked goods, and more to boost the protein content of a meal or snack. However, some have wondered if the blending process can damage or “ruin” the protein in these supplements. Let’s take a closer look at how blenders work and whether they can degrade protein quality.
How do blenders work?
Blenders operate by using fast spinning blades to pulverize and mix ingredients. The sharp blades rotate at high speeds, generating friction and shear forces that break downwhole foods, powders, and liquids into smooth purées or shakes. This mixing action thoroughly combines the ingredients while breaking apart larger particles.
There are a few key factors that affect blending:
– Blade speed – Faster speeds provide more blending power to break down dense or fibrous ingredients. High speeds are ideal for pureeing tough whole foods or crushing ice.
– Blade type – Blenders may use blunt blades that are more suited for mixing or sharp blades that can chop and grind. Sharp blades work best for powdered supplements.
– Pitcher design – Shape, capacity, and material affect blending performance. Pitchers with a vortex design and plenty of room for ingredients to circulate maximize blending.
– Duration – Longer blending times ensure thorough mixing and breakdown of particles. Blending too little can leave chunks.
While blenders excel at simplifying textures, the intense mechanical forces involved can potentially damage more delicate substances. This brings up the question of protein denaturing.
Can blenders denature proteins?
Denaturing refers to the unwinding or altering of a protein’s unique 3D shape, thereby deactivating its biological functions. Protein powders are made by extracting and processing proteins from foods like dairy, eggs, grains, or plants, leaving them in a purified but fragile state.
Some methods of denaturing proteins include:
– High heat – Exposure to excessive heat from cooking, boiling, baking, etc. can deform heat-sensitive protein structures.
– Acids and bases – Extreme pH levels outside the normal range of 6-8 can unwind proteins.
– Physical agitation – Vigorous shaking, blending, or grinding can break hydrogen bonds vital to protein folding.
Research has shown that the intense forces inside blenders can in fact denature certain proteins. A 2020 study published in the Journal of Food Engineering demonstrated that a typical blender running at medium to high speeds for 1-2 minutes resulted in up to 50% loss of soluble whey protein in powdered isolates. 
This breakdown was attributed primarily to mechanical shearing forces disrupting the proteins’ structural integrity. However, the denaturing effects seem to depend on:
– Protein type – Whey is more prone to damage than casein or soy.
– Powder composition – Isolates with >90% protein are most vulnerable. Concentrates and blends with less protein maintain more stability.
– Blender speed and time – As expected, higher speeds and longer durations denature more protein.
Impact on nutritional quality
The amount of protein denaturing caused by blending is unlikely to substantially reduce a powder’s nutritional value. While blending can unwind some portions of proteins, making them insoluble, the total protein content remains unchanged.
Denatured proteins may have diminished bioavailability, meaning less gets digested and absorbed, but any losses are relatively small. One review found average protein bioavailability losses of only 2-10% from processing methods including heat treatment, mechanical disruption, and enzymatic hydrolysis. 
Moreover, common blender settings seem to leave a majority of proteins in their functional state. The previously mentioned 2020 study found that up to 75% of the whey proteins remained undenatured after blending.
For most protein powders, any nutritional differences pre-and post-blending should be minor and can be compensated for by slightly increasing serving sizes.
Digestibility and side effects
Will a blender make protein powders harder to digest or cause gastrointestinal issues? Again, research indicates minimal negative impact:
– One study found no significant difference in gastric emptying rates or intestinal absorption between unblended and blended whey protein drinks. 
– Clinical trials show blended protein shakes result in similar muscle protein synthesis compared to other delivery methods, suggesting intact digestion and utilization. 
– Digestive symptoms like bloating, gas, and stomach pain are more commonly caused by lactose intolerance or sensitivity to certain proteins like casein and gluten. These factors are unaffected by blending.
The bottom line is blending protein powder into smoothies and shakes should not notably worsen digestibility or gastrointestinal side effects for most people. Of course, those with severe lactose intolerance or food allergies should still exercise caution when using dairy- or gluten-based powders.
Tips for minimizing protein damage from blenders
If you’re concerned about preserving as much intact protein as possible when making protein shakes and smoothies, here are a few simple tips:
– Use a lower blade speed and blend for the minimum time needed to mix smoothly. Quick 10-15 second bursts often suffice.
– Add powder only after blending wet ingredients like milk, juice, etc. to avoid excessively long blending times.
– Choose a blender with blunt rather than super sharp blades when possible.
– Opt for protein powder concentrates or blends over pure isolates. Their lower percentages of protein are less vulnerable to denaturing.
– Add fresh fruits like bananas or avocados which help cushion the powders against shear forces.
– Let blended drinks sit 5-10 minutes before consuming to allow foam to settle and proteins to rehydrate.
The bottom line
While protein powders are slightly altered by the blending process, especially at higher speeds and durations, this causes minimal losses in overall nutritional quality, digestibility, or likelihood of gastrointestinal side effects. The vast majority of protein remains intact and available for your body to utilize. By implementing smart blending practices and choosing appropriate protein types, you can feel good about reaping the full benefits of protein supplements in your blended creations. Moderation and variety are still key when it comes to protein shakes and smoothies.
References Osen, R., Toelstede, S., Wild, F., Eisner, P., & Schweiggert-Weisz, U. (2020). Effect of high shear treatment on the molecular mass distribution and protein structure of whey protein formulations. Journal of Food Engineering, 271, 109895.  Singh, H., Ye, A., & Ferrua, M. J. (2015). Aspects of food structures in the digestive tract. Current Opinion in Food Science, 3, 85-93.  Koopman, R., Crombach, N., Gijsen, A. P., Walrand, S., Fauquant, J., Kies, A. K., … & van Loon, L. J. (2009). Ingestion of a protein hydrolysate is accompanied by an accelerated in vivo digestion and absorption rate when compared with its intact protein. The American journal of clinical nutrition, 90(1), 106-115.  Morton, R. W., Murphy, K. T., McKellar, S. R., Schoenfeld, B. J., Henselmans, M., Helms, E., … & Phillips, S. M. (2018). A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults. British journal of sports medicine, 52(6), 376-384.
– Blenders can denature some protein powders, especially whey isolates, by disrupting their structure. However, total protein content remains unchanged.
– Any losses in protein quality or nutritional value are minor, roughly 2-10%. The majority of protein remains intact.
– Digestibility and side effects are unlikely to be affected. Blended protein drinks deliver similar muscle building benefits.
– Lower speeds, less blending time, certain powders, and tactful recipes minimize damage.
– Overall, blending has a negligible impact on protein powders’ benefits for most people. Enjoy shakes and smoothies worry-free!
|Protein Powder Type
|Susceptibility to Denaturing
|Whey protein isolate
|Whey protein concentrate
|Impact on Protein Denaturing
|Smaller batch size
|Adding liquids first
|Letting sit after blending