Most plant-based proteins do not contain high levels of all of the nine essential amino acids, soy, is one of the exceptions, along with quinoa and buckwheat. Of the plant-based protein powders on offer, soy-based products contain the greatest amount of leucine (1) and they do pretty well when considering their amino acid composition and speed of absorption. Soy protein has a nutty taste more grainy texture when compared with whey protein. For a 30g serve, soy protein powder provides ~ 27g of protein. To consume the same amount of EAAs ingested when consuming 25 g whey protein, 40g of soy protein would need to be digested (2).
Like many other plant-based proteins soy is limited by the EAA methionine so should not be used as the sole protein source and could be combined with the likes of hemp, corn or potatoes elsewhere in the diet (2).
There is conflicting information out there about soy; some concern among health professionals remains that it’s consumption is unsafe. Isoflavones found in soy products have been thought to mimic the effect of estrogen and increase the risk of hormone-related cancers. These studies were however carried out in rodents, who process soy differently to humans. A recent shift in thinking has deemed soy food to be not only safe but potentially protective of cancer. The American Cancer Society claims the evidence suggests a moderate intake of whole soy foods is safe and possibly protective against cancer. The safety of soy protein isolate consumed in large quantities as in protein powder is not so well studied and therefore any supplementation should be done in moderation alongside other protein sources as part of a balanced diet. Whole soy foods remain the recommended way to consume this type of protein.
Soy protein powder also sparks a whole new debate related to its frequent genetic modification.
Brown rice protein powder is made by removing the majority of carbohydrates and fat from the rice product leaving a concentrated source of protein. For a 30g serve, brown rice provides ~ 24g of protein that is quickly absorbed. To consume the same amount of EAAs ingested when consuming 25 g whey protein, 39g of brown rice protein would need to be digested (2).
Brown rice is low in the EAA lysine but has a good supply of methionine. This means it makes a good protein powder when combined with other protein sources as part of a well-balanced diet. Pairing brown rice protein with the likes of pea protein (low in methionine) at a 50/50 would yield a protein blend with a more ‘complete’ amino acid composition Brown rice protein powder is also allergen-free.
One of the real ups to brown rice protein is that is it is relatively inexpensive and accessible. However, brown rice protein powder is pretty fresh to the scene and not a lot of studies have been done. Preliminary studies suggest that it could be as successful as a whey protein powder in improving body composition and exercise performance.
Hemp protein powder is made from hemp seeds and has a subtle nutty flavour. Hemp is around 50% protein and each 30g serves provides ~15 g of protein so is therefore much lower in protein content than the likes of brown rice, soy and pea protein. To consume the same amount of essential amino acids ingested when consuming 25 g whey protein, 48g of hemp protein would need to be digested (2). Therefore if you are using this protein powder for building or repairing muscles, you will need a much larger dose.
Hemp protein is lacking when you consider its composition of essential amino acids. However, its main asset is its healthful nutrition package. Hemp is a great source of dietary fibre, healthy fatty acids as well as iron, zinc and magnesium.
Similar to brown rice, hemp is low in the amino acid lysine so consuming it as part of a diet containing pea and soy proteins would ensure a complete amino acid composition is obtained.
Pea protein powder is a great low-allergen option for all plant-based goers, including gluten-free, lactose-free and dairy-free. It is an easy to grow resource, and despite it being available for years, is growing in popularity. Pea protein powder is made using dry peas as they are higher in protein content than green peas. Dry peas may be green or yellow and are rich in phytochemicals which are thought to provide health benefits.
Peas have a protein content of around 75-85% and each 30g serve provides around 23g of protein. To consume the same amount of essential amino acids ingested when consuming 25g whey protein, 37g of pea protein would need to be digested (2).
Pea protein contains a great level of amino acids, particularly, the essential branched-chain amino acids (BCAAs) leucine, isoleucine and valine. These amino acids help energise the muscles and signal the body to begin muscle growth and repair through a process called muscle protein (3). Like soy protein, pea protein is limited by the essential amino acid methionine.
Similar to Hemp protein, pea protein boasts a rich nutrition package. Peas are a great source of fibre, vitamin K, manganese, folate, copper, phosphorous and also contain vitamins B6, B2, zinc, magnesium, iron, and potassium.
Sachi Inchi seeds, which are also referred to as ‘Inca Peanuts’ have grown in the Amazon Rainforest of Peru for centuries. Like pea protein, it is a dairy-free, gluten-free option that is very well digested. So if you’re someone who may have struggled to digest protein powders in the past, Sacha Inchi protein powder could be a good option for you.
Sacha Inchi protein powder is most noted for its great omega-3 fatty acid profile. It also contains some omega-6 and omega-9 and has a balance of these fatty acids that supports inflammation and other disorders.
Despite its long history of use, not much is known about Sacha Inchi protein. In a 28g of serve of Sacha Inchi protein powder, there is 17g of protein. One serve of protein powder also provides you with around 16% of your daily iron requirements (4).
The following table rank the most popular types of plant-based protein powders by protein concentration.
Type Of Protein | Protein Concentration |
---|---|
Soy protein powder | 90% |
Pea protein powder | 80 to 90% |
Brown Rice protein powder | 70 to 75% |
Sacha Inchi protein powder | 60 to 65% |
Hemp protein powder | 50% |
The following table presents the most common plant-based protein powders ranked by their digestibility index (Protein digestibility-corrected amino acid score or PDCAAS).
A PDCAAS value of 1 is the highest and shows excellent digestibility, and 0 the lowest, which represents poor digestibility.
Type Of Protein | Protein Concentration |
---|---|
Soy protein | 1.0 |
Mycoprotein | 0.996 |
Pea protein | 0.893 |
Sacha Inchi protein | 0.870 |
Hemp protein | 0.660 |
Brown Rice | 0.500 |
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The biological value or quality of a protein is determined based on both its amino acid composition, and how well it is digested. Therefore, not all proteins are created equal. Regardless of whether a protein comes from a plant, or animal source, the types of amino acids, as will its digestibility will vary between foods. Let’s explore these concepts a little further.
All proteins are made up of amino acids. When a protein is consumed it breaks down into amino acids and these are used by the body for different processes, like building muscle. If you happened to read our earlier protein guide, you may recall that a complete protein contains all of the 9 Essential Amino Acids (EAAs) that your body needs for optimal function. Typically, all animal proteins – meat, dairy, eggs and fish – are complete proteins or ‘high quality’. Plant foods more often than not have a lower percentage of at least one essential amino acid, commonly lysine. Legumes, don’t fall too far short of being a ‘complete proteins’ but have a lower methionine content.
Protein digestibility refers to how much of the absorbed protein is consumed by the organism.
The measure of a protein’s quality is referred to as its PDCAAS (Protein Digestibility Corrected Amino Acid Score). The score ranges from 0-1 with 1 being the highest quality, and 0 being the lowest. Our body can’t digest protein with a low PDCAAS very well.
Digestibility is related to the presence of EAAs. If food is lacking in one of them - we talk about a limiting amino acid. Animal foods are more digestible because they are complete and contain all the EAAs, which improves the utilisation of these components so that the body can manufacture its own proteins. Animal protein have very high digestibility, with eggs and milk protein being the easiest to absorb.
Those consuming a plant-based diet have somewhat higher protein requirements as plant proteins are slightly less digestible when compared with animal proteins. Since they generally have one limiting essential amino acid, the use of plant protein by the body rarely is rarely over 85%.
Here is a ranking of common food ranked by PDCAAS score.
Source Of Protein | PDCAAS |
---|---|
Whey Protein | 1 |
Cow's Milk | 1 |
Caseine (Milk Protein) | 1 |
Eggs | 1 |
Mycoprotein (From Fungi) | 0.99 |
Beef | 0.92 |
Pea Protein | 0.89 |
Sacha Inchi Powder | 0.87 |
Chickpeas / Soybeans | 0.78 |
Black Beans | 0.74 |
Vegetables | 0.73 |
Legumes | 0.70 |
Hemp Seeds | 0.66 |
Fresh Fruit | 0.64 |
Cooked Peas | 0.59 |
Peanuts | 0.52 |
Rice | 0.50 |
Wheat | 0.42 |
Wheat Gluten | 0.25 |
The digestibility of a protein is also in part determined by how processed the food is. The less processed the food, the less digestible its protein is. Generally speaking, plant proteins are digested at rates of 70-90% whereas soy, casein and egg have values of around 97% and above (2). Protein requirements are therefore around 10-20% higher for plant-based eaters to account for this.
For a protein to be used by the body, it is necessary that the protein contains all the EAAs in the required proportions. Animal protein are of high biological value because they are complete. Vegetable protein are of lower quality because they contain EAAs but some of them in small amounts.
To avoid these shortcomings when following a plant-based diet, various plant foods have to be combined. Today it is thought that the liver has the ability to store EAAs throughout the day so complementing plant proteins do not need to be consumed in the same meal so long as a variety of foods are consumed across the day. Eating complete proteins is therefore not essential, you’ve just got to eat a little more tactically. People who consume a well-balanced diet will consume all of the EAAs throughout the course of the day without too much extra effort. Eating a variety of different plant foods like grains, legumes and vegetables, will make sure you’re getting all of the EAAs your body needs.
While animal proteins are highly regarded for their quality, they have also been associated with higher intakes of saturated fats and cholesterol, particularly when they come from processed meat. While fat is an essential nutrient for the body, saturated fat should be consumed in small amounts as it increases LDL cholesterol - also known as ‘bad cholesterol’. LDL cholesterol carries cholesterol from the liver to other parts of the body where it risks building up and causing a blockage in the blood vessels which increases the likelihood of strokes and heart attacks. On the flip side, animal protein has been shown to result in greater gains in lean body mass in the elderly when compared to plant protein (KK). Foods that are rich in animal protein are generally high in vitamin B12, vitamin D, heme-iron, zinc and DHA (an omega-3 essential fatty acid), some of these nutrients are often lacking in plant foods.
Plant proteins are associated with a frequent reduction in intakes of saturated fats and cholesterol. People on plant-based diets tend to have lower Body Mass Indexes (BMIs), diabetes and obesity risk, favourable lipid profiles, and reduced risk of oesophageal, lung, stomach and colorectal cancers. Plant proteins are often accompanied by carbohydrates and fibre, which are important energy sources as well as having a significant role in maintaining a healthy gut environment and managing cholesterol levels. Plant foods like legumes, nuts and seeds also contain the essential fatty acids omega-3 and omega-6, and are rich in vitamins and minerals including vitamin C, potassium, magnesium and calcium.
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Simply put, whey protein powder is a by-product of the cheese-making industry. Whey protein originally starts with cow’s milk, which naturally contains two main types of protein, casein and whey, at respective ratios of 80% and 20%. During the cheese-making process, the milk is heated to kill unwanted bacteria. The rise of temperature splits the milk into curds and liquid whey.
After separation the curds are strained, the leftover is liquid whey. In its original liquid state, whey is a mixture of mostly water with some protein, fat, carbohydrates and lactose. Whey then undergoes a multi-step filtering and drying process to be turned into protein powder.
From cows grazing the lush pastures of New Zealand to flavoured protein blend canister delivered to your door, let’s dive deeper into each step of how whey protein powder is made.
Whey protein is an animal-based product obtained from the dairy industry. Fresh milk is collected from cow’s who, in our case, live most of their life in the open air in New Zealand. This is particularly important as it means these cows are farmed without any antibiotics and growth hormones (Rgbh) and are only grass-fed. It ensures the quality of the milk is as high as can be. In its raw state, milk contains about 5% lactose, 4% fat and 3.5% protein.
Cooled milk is transferred to the closest factory in large refrigerated tanks.
Freshly milked from cows, milk contains bacteria that can be harmful to humans. It needs to be pasteurized before it is ready for consumption. To kill pathogens, the milk is briefly heated to high temperature (~73°C), then cooled rapidly. The important nutrients in milk are not affected by heat, only bacteria is removed during the process. After pasteurization, the milk obtained has 20 % whey and 80 % casein and is ready for transformation.
Enzymes such as Chymosin are added to the pasteurized milk to alter the casein micelle structure and make the milk curdle. The main part of the milk turns into curds. This solid part of milk is used as the base product for a long list of different cheeses. The remaining part is the liquid whey.
Liquid whey is sent to be filtered to high-protein liquid whey. During this step, whey goes through further purification to remove fats, carbohydrates and water. In a protein manufacturing plant, liquid whey is filtered through an array of ceramic micro-filters. This process happens in a cold environment and is completely natural. This process removes most fat and lactose from the liquid whey. The resulting product is the base of whey protein concentrate.
Whey concentrate is ultra-filtered to make whey protein isolate. Working by size exclusion, the ultra-filtration membrane lets the lactose-rich solution go though but retains the larger whey complex. At this stage, virtually all fat and lactose are removed.
The high-protein whey liquid is put into a dryer. Under the influence of hot and cold air, the water is rapidly removed. The correct spray drying process also ensures that whey doesn’t lose its nutritional value and the protein doesn’t get denatured. When the residual moisture has evaporated.
The unflavoured whey protein powder is then tested for quality. The amount of protein is strictly measured. The final product contains 80 to 90% protein.
The plain whey protein powder is packaged and transferred to the last facility, where it gets blended with other ingredients. Go Good only add organic flavours sourced from fruits and superfoods, thaumatin - a potent natural sweetener and non-GMO sunflower lecithin (for better solubility in liquids).
Finally, the flavoured whey protein powder is packaged and sealed into 1Kg recycled cardboard canisters. A sample of every batch is sent for testing to a lab, which uses an infra-red machine to precisely measure the amounts of protein, fat, carbs, amino acids, etc.