Pumpkin protein would perhaps be more suitably named, “pumpkin seed protein”… or (if you want to get real technical) “pumpkin seed kernel protein.” Pumpkin seeds, also known as pepitas, are kernels found in the white-colored seed hull of pumpkins.
Derived from hulled pumpkin seeds, the olive-green pumpkin seed kernel is [commonly] milled, defatted (fat extracted), and made available in a concentrated protein-powder form. While supplying a quality source of protein, pumpkin seed kernels are unique in that its composition is primarily fat. Therefore, pumpkin seed protein is “isolated” from its whole form through the process of fat extraction (AKA defatting).
With plant-based protein on the rise, it's just about wherever one type (specifically, pea protein) is found, so is pumpkin protein. Pumpkin protein is commonly paired with other plant-protein sources for purpose of meeting a complete protein claim. With its many call outs and nutritional benefits, it is a welcomed member of the plant protein space, though comes secondary to other sources for several good reasons (as discussed below).
- Plant-based protein (Vegan-friendly)
- Sustainable protein ingredient
- Free from the Top 8 food allergens in the USA
- Free from the Top 12 food allergens in Canada
Pumpkin seed protein offers roughly between 35% to 65% protein content, highly dependent upon the manufacturer’s process. In its milled, partially defatted powder form, protein content ranges in the 35% - 45% range. For protein contents above this amount, additional isolation is carried out through proprietary manufacturing processes involving further extraction of fat, and in some cases, carbohydrates.
The nutritional story is flexible depending upon (1) the nutritional benefits sought and (2) the level of ingredient isolation. For example, the benefits of key fatty acids will be negligible in a defatted protein powder. With that said, pumpkin seeds as a standalone ingredient are nutritionally dense in fat and protein. Around 50% of its content is fat, followed by 25-30% protein, and 10-15% carbohydrates. Further, about ¼ C (100g) of raw pumpkin seeds can supply 80% or more of your Daily Value for Iron (that’s 15 mg of Iron, based on a 18mg DV).
Pumpkin seed protein boasts numerous benefits, but (as previously said) comes secondary to other plant protein sources for several good reasons:
(1) Color: Its color can vary from a dull grey-green, a bright yellow-green, or even a deep olive-green, depending upon the manufacturer, and in some cases, the lot. With this degree of fluctuation, formulating a product aligned with color standards can be difficult. While its nutritional story is fantastic, a combination with a primarily neutral-colored ingredient (such as pea protein) can yield the quality claims a formulator is seeking, without the havoc of significant color changes.
For example, a plant-based protein mix may be less approachable to some if the color is grey or green once mixed with water. Pumpkin protein may not yield a color issue in a chocolate flavor, but can be problematic for other flavors like vanilla or strawberry (where white or pink is expected).
(2) Taste: Pumpkin seed protein has a nutty flavor. Its critics may call out a planty/earthy taste, but again, when used secondary or tertiary in a protein blend, its flavors can be masked. Like color, its taste profile is truly unique to the proprietary processes of individual manufacturers/suppliers.
(3) Function: Pumpkin seed protein in application (thus far) has been fairly limited. Presently, it is commonly found in protein-delivery food applications, such as bars, dry beverage blends, and ready to drink beverages.
(4) Cost: Pumpkin seed protein is expensive, and rightfully so. Pumpkins require a lot of food and a long growing season. Further, pumpkins are a heavy, large fruit (affecting transport and space) that have to be cut and separated from their seeds. Those seeds are then hulled to yield a green-colored kernel which is passed through several other processes – milling, defatting, and (in some cases) mechanical separation of carbohydrates.
The USDA database reports a 25% - 30% protein content in raw pumpkin seeds (AKA pepitas). In other words, per 100g of as-is raw pumpkin seeds, there’s 25g – 30g of protein. When processed into pumpkin seed protein, pumpkin seeds are hulled, their kernels (an olive-green color) are milled (ground into a fine powder), and its macronutrients isolated (fat separated from protein and carbohydrates) to yield a higher percent protein content.
Protein contents for pumpkin protein (as opposed to stand-alone pumpkin seeds) can range between 35% - 65% at this time, generally influenced by the amount of fat and/or carbohydrates removed during manufacture. In other words, per 100g of pumpkin seed protein, there's a standardized 35g to 65g of protein. The remaining 35% - 65% is fat and carbohydrates (starch and fiber).
The amino acid profile per 100g of [solely] protein derived from pumpkin seeds is below. For comparison purposes, also included is the amino acid profile per 100g of protein derived from pea protein, an ingredient it is commonly paired with.
Pumpkin protein (derived from pumpkin seed kernels) offers nearly 3X more arginine than pea protein, and 6X more arginine than whey! Like pea protein, it is diverse in its amino acid composition, though offers twice the methionine content (pea protein’s limiting amino acid).
Sources: USDA Food Database: Yellow Split Peas, Goya; Jarrow Formulas: Organic Pumpkin Seed Protein
The first-limiting (least amount) amino acid of pumpkin seeds [kernels] is tryptophan. Tryptophan can be consumed through a variety of sources. Ironically, while tryptophan is the limiting amino acid, pumpkin seeds supply more than 2X the Reference Daily Intake (RDI) per 100g (roughly ¼ C). For purposes of reaching a protein claim, pumpkin protein can (1) be bumped, but due to its limitations in color, taste, functional versatility, and cost, it can (2) be combined with alternative protein sources (such as pea or brown rice protein), to meet the recommended intakes of the limiting essential amino acids. More on this in a later article.
Source of Origin.
Pumpkins can be grown throughout the United States, and in fact, are grown on every continent with exception of Antarctica. The top producers of pumpkins include China, India, Ukraine, the United States, Egypt, and Mexico. Within the United States, the top growing states include Illinois, California, New York, Ohio, and Pennsylvania. Illinois tops this list, where Libby’s pumpkin processing plant (located in Morton, IL, and owned by Nestle Food Company) cans more than 85% of the world’s processed pumpkin, within a 90-mile radius of Peoria, IL, (its neighboring town).
Pumpkin protein offers an impressive array of amino acids in comparison to pea protein, and further, in comparison to whey protein. Despite its nutritional advantages, four obstacles stand in the way of its easy adoption: (1) color, (2) taste, (3) limited functional versatility (so far), and (4) cost. This ingredient is a fantastic companion to other plant-based protein sources for at least its amino acid profile, and also abides by a free-from allergens statement and non-GMO criteria.
My articles are written with the consumer and food scientist in mind, and exist for the purpose of making the conversation on food (its science, process, regulations, and applications) approachable. I'm a passionate supporter of a plant-based lifestyle, believing technology today can support an optimal diet through plant-derived nutrition.