Humans have used hemp for thousands of years in the manufacture of food, cloth, paper, and various other purposes. Although related to marijuana, another type of the cannabis sativa plant, it contains very low levels – .3 percent or less – of the psychoactive substance tetrahydrocannabinol (THC). Unlike the strains people use medically or recreationally and that produce various psychological and physiological effects, industrial hemp does not offer the same results. In this piece, we are discussing the latter-- the hemp plant and its seeds.
While the hemp plant has been hyped for its varied uses, hemp seeds have received less attention, though recent studies show their nutritional benefits. Rich in nutrients, hemp seeds can be eaten raw or made into oil, flour, protein powder, milk, or even transformed into cheese substitutes.
A Brief History of Hemp Seed Production
Hemp is thought to have originated in Central Asia, as it grows wild from Iran to southern Siberia. Evidence going back thousands of years suggests it was the first cultivated agricultural crop.
Medicinal Hemp in Ancient Cultures
- Hemp seeds were consumed in ancient China, sometimes pressed with hemp stalks to make hemp oil and healing salves. The first recorded use of hemp as medicine comes from China, circa 2700 BCE, where hemp oil was extracted from the seeds to make a medicinal tea or applied topically to treat skin irritation and rashes.
- Hemp seeds are also listed in Hindu medicinal texts from ancient India from around 2000 BCE.
- Evidence also suggests hemp use in ancient Greece from around 200 BCE, where numerous burial sites were found containing hemp seeds and fiber.
Hemp in North America After the 17th Century
The first North American settlers who founded Jamestown in 1616 also brought hemp seeds with them. In 1789, George Washington promoted the growing of hemp, telling farmers of the new nation to “Make the most of Indian Hemp Seed and sow it everywhere.” Large-scale industrial cultivation of hemp was the norm by 1800, and throughout the 19th-century, cannabis could be found in many medicines in the United States.
During this time, people grew hemp mainly for its fiber, with the seeds considered a byproduct that was primarily used for animal feed.
20th Century and Beyond
The nutritional value of hemp seeds became more widely known as activists advocated for hemp’s return as a commercial crop. In 1998, Paul Benhaim introduced the 9bar, made with Hungarian hemp seeds, which became the highest-selling snack bar in Europe. As studies continue to show the nutritional and health benefits of industrial hemp seeds, the market for products made from them continues to grow.
Modern Uses for Industrial Hemp Seeds
Technological advances in processing have allowed hemp seeds to be made into a variety of foods, with whole seeds used in soups, ground into cakes, or used as animal feed. Although other parts of the plant are also edible, the seeds contain much more protein and omega-3 fatty acids. Hemp seeds can be eaten raw, roasted like other nuts, substituted for dairy or meat products shelled to allow consumption of the high-protein hemp hearts or otherwise used in cooking.
Hemp seeds can also be used to make:
- Health bars
- Non-dairy butter, cheese, milk, and ice cream
The remnants remaining after extracting oil from the hemp seed can be made into protein-rich flour or feed for animals.
Though small, the inner part of the hemp seed, called a hemp heart, contains high amounts of protein. Three tablespoons (about 44 ml) of industrial hemp seeds contain over a third of an ounce (9.5 g) of protein, almost 50 percent more than a single egg.
Hemp seed production often centers on the making of hemp oil, as the seeds themselves are between 25-35 percent oil. Though used for food, industrial hemp seed oil can also be used for a wide variety of non-food products as well.
Hemp oil can be used in:
- Cooking oil
- Food supplements
- Salad dressings
Hemp can be used in personal care products like:
- Hand cream
- Lip balm
The oil can be used for industrial purposes that include:
- Diesel fuel
- Leather conditioning oil
- Oil paints
- Printing ink
Hemp seed production of oil leaves a meal containing up to 25 percent protein, which can be used for human or animal consumption.
As the protein from hemp seeds is readily digestible, it is often pulverized and used for protein powder. A study published in the Journal of Agricultural and Food Chemistry found that the protein absorption rate of hulled hemp seeds was comparable to casein, a dairy protein supplement, and is as digestible as any other seed, grain, or nut.
Clinical research on hemp seed production confirms their health benefits. Not only are they rich in eight essential proteins, but they also have high levels of omega-3 and omega-6 essential fatty acids. Recent studies show hemp seeds can help regulate metabolism, heighten the immune system and support healthy cholesterol levels. Additionally, industrial hemp seeds are rich in the following minerals:
- Various B vitamins
- Vitamin E
The hemp heart’s high levels of thiamine (also known as vitamin B1) help the body break down carbohydrates for energy and contribute to cell function and growth. Manganese and phosphorus additionally contribute to good bone health, a healthy immune system, and assist with blood clotting.
Processing Hemp Seeds
Hemp seed production starts with the harvest, after which they are stored indoors before being carefully cleaned and dried. Several different techniques are used for this stage, including sieving, grading, and separating by gravity. One technique involves hemp seeds passing through two sieves that separate them by size, allowing the allocation of seeds for further processing in assorted applications. Hemp seeds cultivated for food require a dehulling process that involves removing the outer shells, which must be done carefully to minimize damage to the hemp hearts.
The next stage of hemp seed production involves extracting the oil, which leaves a byproduct called hemp meal or hemp cake. This is the basis for hemp protein powder, which is usually milled before being screened to separate the coarser fiber from the fine powder. The mechanisms and storage of industrial hemp seed material at this stage differ according to the type of operation and can include storage barns, dehumidifiers, fans, mechanical dryers, or drying sheds. Once the seed product becomes adequately dried, it can then be packaged or shipped for further production.
Processing Industrial Hemp Seed Oil & Powder
When it comes to extracting the oil, multiple hemp seed production techniques exist that differ regarding their yield, cost, composition, or the oil's chemical makeup. Methods for hemp seed production of oil include:
- Microwave-assisted extraction
- Supercritical fluid extraction
- Ultrasound-assisted extraction
The protein powder resulting from hemp seed production after extracting the oil can involve the remnants of dehulled seeds, hemp seed meal, and hemp cake.
Hemp Seeds Processing Equipment from Prater Industries
Prater Industries milling and processing equipment can be used separately or combined into custom systems for hemp seed production for hemp hearts, hemp protein powder, and other hemp products. As hemp seeds become more prominent in health foods and nutritional supplements, Prater will continue to design, engineer, install and maintain systems for hemp seed production.