Why Sprout?

Sprouting is not a new thing, but in recent years, there has been an increase in interest and popularity of sprouted edible seeds as a part of a healthy diet, especially as more and more people worldwide look to introduce foods to improve their immune system function³. Sprouting does just that, by contributing immensely to enhance the nutritional and medicinal value of edible seeds⁶.

When a seed is sprouted, it becomes a young plant. This process usually starts with the soaking of the seeds, which can last for several hours. Then, under the right temperature and humidity, the seeds will grow into tiny plants, in a process that can take in general two to seven days. The sprout ready-to-eat measures ideally between 1/8–4 inches long, depending on which seed is being sprouted^1,4,6.

So, the question is: why is sprouting beneficial and why is it better to eat sprouted seeds than raw seeds?

Seeds have indeed many health-benefiting properties, such as antioxidant, anticancer, and antidiabetic, however, these benefits are highly increased when the seed is germinated compared to the raw seed⁶.

What happens during germination/ sprouting?

• Sprouting or germination “leads to the catabolism and degradation of main macronutrients, such as carbohydrates, protein, and fatty acids, accompanied by the increase of simple sugars, free amino acids, and organic acids⁶.”
• It also contributes to reducing anti-nutritional and indigestible factors (the called anti-nutrients), such as protease inhibitors and lectins⁶.
• Bioactive compounds, such as vitamins, γ-aminobutyric acid (GABA), and polyphenols, can accumulate in edible sprouted seeds, increasing their nutritional value⁶.

So, sprouting by decreasing the amount of antinutrients in seeds also helps improve the bioavailability of many nutrients, including minerals and protein. According to a 2022 study, “The sprouting process activates hydrolytic enzymes and releases nutrients from their phytate chelates, making them bioavailable; in addition, vitamins are synthesized and accumulate¹.”

The nutritional benefits of sprouted seeds are¹:

• Seed activation through imbibition, favorable temperature, oxygen, light, or darkness.
• Enhanced respiration and metabolic activities.
• Enzymes mobilize stored seed reserves and convert starch to sugar.
• Hydrolysis of storage proteins, release of essential amino acids.
• Accumulation of phenolic compounds with antioxidant ability.
• Accumulation of vitamins (C, folate, thiamin, pyridoxin, tocopherols, niacin, etc.).
• Reduction of antinutritional factors: phytate, oxalate, and tannin degradation, leading to enhanced palatability, improved bioaccessibility of iron and calcium, and enhanced digestibility of proteins.

Microgreens have also been shown to have many of the same beneficial health effects of sprouts, such as anti-inflammatory, anti-cancer, anti-bacterial, and anti-hyperglycemic properties^1,7.

Nutritional benefits of microgreens are¹:

• Photosynthetic activity in microgreens further enhances vitamin C, phylloquinone, and tocopherol accumulation compared to sprouts.
• Accumulation of carotenoids is often higher than in mature vegetables.
• Increased accumulation of chlorophyll and phenolic compounds with antioxidant ability, compared to sprouts.
• Often higher content of macro and micronutrients and lower content of nitrate in microgreens compared to the adult growth stage.
• Biofortification with specific elements (iodine, iron, zinc, selenium) made easy in hydroponic systems.
• Microgreens are consumed raw, hence thermolabile ascorbic acid content can be fully utilized, unlike in cooked mature vegetables.

Reduction of Antinutrients with Sprouting

As reported by several studies, the germination and sprouting process of seeds decreases the content of antinutrients (compounds that have an antinutritive effect), such as trypsin inhibitor, phytic acid, pentosan, tannin, and cyanides¹. On the other hand, germination increases palatability and nutrient bioavailability, and the content of beneficial phytochemicals, such as glucosinolates and natural antioxidants¹.

A 2022 study published in the Nutrition Bulletin highlights that sprouting has been associated with increased bioaccessibility of iron, zinc, and calcium⁸. One of the reasons may be the reduction of phytates present in seeds when using the sprouting method. As this study explains, “phytate is the primary storage form of phosphorus in plants. It is long recognised to affect human health as it forms insoluble complexes with minerals such as iron and zinc in cereals and legumes, thereby preventing their absorption in the body.” Since sprouting contributes to the activation of the enzyme phytase, which degrades phytate, it highly contributes to improving the bioaccessibility and bioavailability of minerals naturally present in the seeds of cereals and legumes⁸.

Another study evaluating the effect of food processing on phytate hydrolysis and availability of iron and zinc, concluded that “food processes including soaking, germination and fermentation were under optimal conditions demonstrated to completely reduce the phytate content of cereals and vegetables⁹.” Considering that phytate is considered one of the major inhibiting factors for zinc and iron absorption, sprouting, by reducing phytate, will also help to increase the availability of these minerals⁹.

However, the extent by which phytate is reduced with sprouting can vary considerably, “depending on the sprouting conditions, cereal/legume species, cultivar and native phytase activity⁸.” Differences between different cereals and legumes may also be related to the presence of other ‘antinutrients⁸.’ However, sprouting does seem to increase nutrient bioavailability, and sprouting seeds, cereals, and legumes may be an excellent and simple method to increase the nutritional value and health benefits of these foods. Furthermore, protein digestibility also appears to be positively correlated with phytate reduction⁸, which means that sprouting foods contributes to improved digestion of proteins. seeds.

Increased Bioavailability of Nutrients with Sprouting

The germination or sprouting process “activates enzymes in dormant seeds and triggers various enzymatic activities leading to the breakdown of stored proteins, carbohydrates, and lipids into simpler forms³.” The germination process increases the degradation of free amino acids, sugars, and organic acids, and ultimately enhances the bioavailability of nutrients and bioactive compounds in sprouted seeds³.

Researchers also suggest that “germination can be widely applied to other seeds, such as vegetable, fruit, flower and medicinal plant seeds, in order to improve their phytochemical composition and biological functions⁶.”

References

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2. Abdallah M.M.F. Seed sprouts, a pharaoh’s heritage to improve food quality. Arab Univ. J. Agric. Sci. 2008;16:469–478. doi: 10.21608/ajs.2008.15018.
3. Aloo SO, Ofosu FK, Kilonzi SM, Shabbir U, Oh DH. Edible Plant Sprouts: Health Benefits, Trends, and Opportunities for Novel Exploration. Nutrients. 2021 Aug 21;13(8):2882. doi: 10.3390/nu13082882. PMID: 34445042; PMCID: PMC8398379.
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10. Drozdowska M., Leszczyńska T., Koronowicz A., Piasna-Słupecka E., Domagała D., Kusznierewicz B. Young shoots of red cabbage are a better source of selected nutrients and glucosinolates in comparison to the vegetable at full maturity. Eur. Food Res. Technol. 2020;246:2505–2515. doi: 10.1007/s00217-020-03593-x.
11. Gawlik-Dziki U., Jeżyna M., Świeca M., Dziki D., Baraniak B., Czyż J. Effect of bioaccessibility of phenolic compounds on in vitro anticancer activity of broccoli sprouts. Food Res. Int. 2012;49:469–476. doi: 10.1016/j.foodres.2012.08.010.
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