Sprouting

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Mixed bean sprouts
Soybean sprouts

Sprouting is the practice of soaking, draining and then rinsing seeds at regular intervals until they germinate, or sprout. This can be a semi-automated or fully automated process when done on a large scale for commercial use.

Contents

[edit] Seeds that can be sprouted

One of the most common sprouts is that of the mung bean (Vigna radiata); another common sprout is the Kala Chana & alfalfa sprout and the barley sprout.

Other seeds that can be sprouted include adzuki bean, almond, amaranth, annatto seed, anise seed, arugula, basil, brown rice, navy bean, pinto bean, lima bean, broccoli, buckwheat, cabbage, canola seed, caragana, cauliflower, celery, chia seed, chickpeas, chives, cilantro (coriander, dhania), clover, cress, dill, fennel, fenugreek, flax seed, garlic, hemp seed, kale, kamut, kat, leek, green lentils, lupins, pearl millet, mizuna, mustard, oats, onion, black-eyed peas, green peas, pigeon peas, snow peas, peanut, psyllium, pumpkin, quinoa, radish, rye, sesame, soybean, spelt, sunflower, tatsoi, triticale, watercress, and wheat berries.

Sprouting is also applied on a large scale to barley as a part of the malting process. Malted barley is an important ingredient in beer and is used in huge quantities. Most malted barley is distributed among wide retail sellers in North American regions.

However, many sprouts are in fact toxic when eaten, like kidney beans. Some sprouts can be cooked to remove the toxin, while others will be toxic either way and should be avoided.[1] So before eating any sprouts, find out if that species is edible as a sprout.

With all seeds, care should be taken that they are intended for sprouting or human consumption rather than sowing. Seeds intended for sowing may be treated with chemical dressings. Several countries, such as New Zealand, also require that some varieties of edible seed be heat-treated, thus making them impossible to sprout.

Many varieties of nuts, such as almonds and peanuts, can also be started in their growth cycle by soaking and sprouting, although because the sprouts are generally still very tiny when eaten, they are usually called "soaks."

[edit] Sprouting

Sprouting mung beans in a glass sprouter jar with a plastic sieve-lid

Moisture, warmth, and in most cases, indirect sunlight are necessary for sprouting. Some sprouts, such as mung beans, can be grown in the dark. Little time, effort or space is needed to make sprouts.

To sprout seeds, the seeds are moistened, then left at room temperature (between 13 and 21 degrees Celsius) in a sprouting vessel. Many different types of vessels can be used. One type is a simple glass jar with a piece of cloth secured over its rim. ‘Tiered’ clear plastic sprouters are commercially available, allowing a number of "crops" to be grown simultaneously. By staggering sowings, a constant supply of young sprouts can be ensured. Any vessel used for sprouting must allow water to drain from it, because sprouts that sit in water will rot quickly. The seeds will swell and begin germinating within a day or two.

Sprouts are rinsed as little as twice a day, but possibly three or four times a day in hotter climates, to prevent them from souring. Each seed has its own ideal sprouting time. Depending on which seed is used, after three to five days they will have grown to two or three inches in length and will be suitable for consumption. If left longer they will begin to develop leaves, and are then known as baby greens. A popular baby green is sunflower after 7-10 days. The growth process of any sprout can be slowed or halted by refrigerating until needed.

Common causes for sprouts to become inedible:

  • Seeds are allowed to dry out
  • Seeds are left in standing water
  • Temperature is high or too low
  • Insufficient rinsing
  • Dirty equipment
  • Insufficient air flow
  • Contaminated source of water
  • Poor rate of germination of seed
Sprouter

These problems are easily solved by an automatic sprouter that mists and drains the sprouts at regular intervals. To control temperature, in the winter a warming blanket can be placed under the sprouter, and in the summer small fans in the lid if it's very hot and humid.

Mung beans can be sprouted either in light or dark conditions. Those sprouted in the dark will be crisper in texture and whiter, as in the case of commercially available Chinese Bean Sprouts, but these have less nutritional content than those grown in partial sunlight. Growing in full sunlight is not recommended, because it can cause the beans to overheat or dry out. Subjecting the sprouts to pressure, for example, by placing a weight on top of them in their sprouting container, will result in larger, crunchier sprouts similar to those sold in Polish grocery stores.

A very effective way to sprout beans like lentils or adzuki is in colanders. Soak the beans in hot water for about 8 hours then place in the colander. Wash twice a day. The sprouted beans can be eaten raw or cooked.

[edit] Nutritional information

Sprouts are rich in digestible energy, bioavailable vitamins, minerals, amino acids, proteins, beneficial enzymes and phytochemicals, as these are necessary for a germinating plant to grow[1] . These nutrients are essential for human health. To clarify, the nutritional changes upon germination & sprouting have been summarized below. Chavan and Kadam (1989) concluded that - “The desirable nutritional changes that occur during sprouting are mainly due to the breakdown of complex compounds into a more simple form, transformation into essential constituents and breakdown of nutritionally undesirable constituents.”

“The metabolic activity of resting seeds increases as soon as they are hydrated during soaking. Complex biochemical changes occur during hydration and subsequent sprouting. The reserve chemical constituents, such as protein, starch and lipids, are broken down by enzymes into simple compounds that are used to make new compounds.”

“Sprouting grains causes increased activities of hydrolytic enzymes, improvements in the contents of total proteins, fat, certain essential amino acids, total sugars, B-group vitamins, and a decrease in dry matter, starch and anti-nutrients. The increased contents of protein, fat, fibre and total ash are only apparent and attributable to the disappearance of starch. However, improvements in amino acid composition, B-group vitamins, sugars, protein and starch digestibilities, and decrease in phytates and protease inhibitors are the metabolic effects of the sprouting process.”

Increases in Plant Enzyme content

According to the naturopath and herbalist Isabell Shipard (Shipard, 2005) -

“Sprouts are a tremendous source of (plant) digestive enzymes. Enzymes act as biological catalysts needed for the complete digestion of protein, carbohydrates & fats. The physiology of vitamins, minerals and trace elements is also dependent on enzyme activity.”

“Being eaten whilst extremely young, “alive” and rapidly developing, sprouts have been acclaimed as the “most enzyme-rich food on the planet”. Estimates suggest there can be up to 100 times more enzymes in sprouts than in fruit and vegetables, depending on the particular type of enzyme and the variety of seed being sprouted. The period of greatest enzyme activity in sprouts is generally between germination and 7 days of age.”

“Grains and legume seeds of all plants contain abundant enzymes. However, while grains and seeds are dry, enzymes are largely inactive, due to enzyme inhibitors, until given moisture to activate germination. It is these inhibitors that enable many seeds to last for years in soil without deteriorating, whilst waiting for moisture. Enzyme inhibitors in some grains and legume seeds (for example trypsin inhibitors in raw soybeans and certain other beans and peas) need to be inactivated by heating or other processes, before they can be safely fed. However, heating, cooking and grinding processes can also inactivate certain digestive enzymes within grains and seeds. Fortunately, during germination and sprouting of grains and seeds, many enzyme inhibitors are effectively neutralized, whilst at the same time the activity of beneficial plant digestive enzymes is greatly enhanced.”

Increases in Crude Protein content Morgan et al. (1992) found that -

“The protein content of sprouts increased from the time of germination, as shown below. The absorption of nitrates facilitates the metabolism of nitrogenous compounds from carbohydrate reserves, thus increasing crude protein levels.”

Crude protein contents of seed and 4, 6 and 8-day old barley grass mats

Crude protein (% DM)

Original seed 10.1% 4 day old 10.8% 6 day old 13.7% 8 day old 14.9%

Source: Morgan et al. (1992)

Increases in Protein Quality Chavan and Kadam (1989) stated - “Very complex qualitative changes are reported to occur during soaking and sprouting of seeds. The conversion of storage proteins of cereal grains into albumins and globulins during sprouting may improve the quality of cereal proteins. Many studies have shown an increase in the content of the amino acid Lysine with sprouting.”

“An increase in proteolytic activity during sprouting is desirable for nutritional improvement of cereals because it leads to hydrolysis of prolamins and the liberated amino acids such as glutamic and proline are converted to limiting amino acids such as lysine.”

Increases in Crude Fibre content Cuddeford (1989), based on data obtained by Peer and Leeson (1985), stated - “In sprouted barley, crude fibre, a major constituent of cell walls, increases both in percentage and real terms, with the synthesis of structural carbohydrates, such as cellulose and hemicellulose”. Chung et al. (1989) found that the fibre content increased from 3.75% in unsprouted barley seed to 6% in 5-day sprouts.”

Crude Protein and Crude Fibre changes in Barley Sprouted over a 7-day period

Crude Protein Crude Fibre (% of DM) (% of DM)

Original seed 12.7% 5.4% Day 1 12.7% 5.6% Day 2 13.0% 5.9% Day 3 13.6% 5.8% Day 4 13.4% 7.4% Day 5 13.9% 9.7% Day 6 14.0% 10.8% Day 7 15.5% 14.1%

Source: Cuddeford (1989), based on data obtained by Peer and Leeson (1985).

Increases in Essential Fatty Acids

An increase in lipase activity has been reported in barley by MacLeod and White (1962), as cited by Chavan and Kadam (1989). Increased lipolytic activity during germination and sprouting causes hydrolysis of triacylglycerols to glycerol and constituent fatty acids.

Increases in Vitamin content According to Chavan and Kadam (1989), most reports agree that sprouting treatment of cereal grains generally improves their vitamin value, especially the B-group vitamins. Certain vitamins such as α-tocopherol (Vitamin-E) and β-carotene (Vitamin-A precursor) are produced during the growth process (Cuddeford, 1989).

According to Shipard (2005) - “Sprouts provide a good supply of Vitamins A, E & C plus B complex. Like enzymes, vitamins serve as bioactive catalysts to assist in the digestion and metabolism of feeds and the release of energy. They are also essential for the healing and repair of cells. However, vitamins are very perishable, and in general, the fresher the feeds eaten, the higher the vitamin content. The vitamin content of some seeds can increase by up to 20 times their original value within several days of sprouting. Mung Bean sprouts have B vitamin increases, compared to the dry seeds, of - B1 up 285%, B2 up 515%, B3 up 256%. Even soaking seeds overnight in water yields greatly increased amounts of B vitamins, as well as Vitamin C. Compared with mature plants, sprouts can yield vitamin contents 30 times higher.”

Chelation of Minerals Shipard (2005) claims that - “When seeds are sprouted, minerals chelate or merge with protein, in a way that increases their function.”

[edit] Health concerns

[edit] Risks and Antinutritional factors

FDA Health Warning

Raw sprouts have been associated with at least eleven foodborne illness outbreaks since 1995. FDA and other public health officials are working with industry to identify and implement production practices that will assure that seed and sprouted seed are produced under safe conditions. While these efforts have improved food safety awareness within the industry and have led to a significantly better understanding of the microbial ecology of sprout-associated foodborne illness, not all industry segments have been reached and outbreaks continue to occur. Consequently, FDA released a guidance document, entitled "Guidance for Industry: Reducing Microbial Food Safety Hazards for Sprouted Seed" (the "sprout guidance"). The sprout guidance identifies a number of areas, from the farm to the sprout facility, where FDA believes immediate steps should be taken to reduce the risk of sprouts serving as a vehicle for foodborne illness and to ensure that sprouts are not adulterated under the Food, Drug, and Cosmetic Act (the act). Specific recommendations in the sprout guidance include: development and implementation of good agricultural practices and good manufacturing practices in the production and handling of seeds and sprouts, seed disinfection treatments, and microbial testing before product enters the food supply.

The agency will closely monitor the safety of sprouts and the adoption of enhanced prevention practices as set out in the sprout guidance. FDA plans to send investigators to sprouting facilities to test water used to grow sprouts (i.e., spent irrigation water) and assess the adoption of preventive controls. Failure to adopt effective preventive controls can be considered insanitary conditions which may render food injurious to health. Food produced under such conditions is adulterated under the act (21 U.S.C. 342(a)(4)). FDA will consider enforcement actions against any party who does not have effective preventive controls in place, in particular, effective microbial testing.

Salmonella and Escherichia coli O157:H7 have been the major causes of sprout-associated illness outbreaks. [2]

Seeds disinfected with contrast water resulted in better disinfection combined with better germination rate.[3]


Some legumes can contain toxins or antinutritional factors, which can be reduced by soaking, sprouting and cooking (eg, stir frying). Joy Larkcom advises that to be on the safe side “one shouldn’t eat large quantities of raw legume sprouts on a regular basis, no more than about 550g (20oz) daily”.[4] However not all legume sprouts contain these antinutritional factors and many have beneficial properties so it is recommended that the advice of a qualified nutritionist is sought before making any decisions about what to include or eliminate from a diet.[citation needed]

[edit] Reduction of Anti-Nutritional Factors

Phytic Acid occurs primarily in the seed coats and germ of plant seeds. It forms insoluble or nearly insoluble compounds with minerals including Calcium, Iron, Magnesium and Zinc, such that they cannot be effectively absorbed into the blood. Diets high in phytic acid and poor in these minerals produce mineral deficiency symptoms in experimental animals (Gontzea and Sutzescu, 1958, as cited in Chavan and Kadam, 1989). The latter authors state that the sprouting of cereals has been reported to decrease levels of Phytic Acid. Similarly, Shipard (2005) states that enzymes of germination and sprouting have the ability to eliminate detrimental substances such as Phytic Acid.

Buckwheat greens contain fagopyrin, a naturally occurring substance in the buckwheat plant. When ingested in sufficient quantity, fagopyrin is known to cause the skin of animals and people to become phototoxic, which is to say hypersensitive to sunlight, particularly if juiced or eaten in large quantities. Due to the growing popularity of sprouts in general, and a widespread ignorance as to the toxic dangers posed by buckwheat greens specifically, many people are today suffering unnecessarily.[5][6]

Also, sprouted grains,nuts and seeds should not be consumed by anyone sensitive to MSG, as sprouting naturally converts any glutamate to its free form, which immediately enters the blood stream and causes reactions. Reference: Battling the MSG Myth by Debby Anglesey.

[edit] Sprouting and the Living foods diet

Advocates of a raw food diet promote the use of sprouting as an effective way to increase vitamin content and digestibility.[citation needed] Sprouts are believed by many to be the most nutrient rich food on earth.[citation needed] This misinterpretation stems from the way nutritional content is presented. Companies that sell seeds and sprouting products compare the vitamin content of the seeds to that of the sprouts which has been shown to increase significantly. The increase is due to seeds having very little vitamin content not sprouts containing large amounts. Additionally, when sprouts are compared to commonly eaten vegetables the overall vitamin content of sprouts is shown to be substantially lower.[7] This is not to say that eating sprouts is not nutritious or healthy, but rather, to show that there is no scientific evidence that sprouts are superior to other edible plants.

Many raw food dietitians avoid unsprouted grains, nuts and seeds. While raw and unsprouted grains, nuts and seeds contain enzyme deactivators that harm the stomach[citation needed], and cooking them denatures their fats and oils, soaked or sprouted grains, nuts and seeds have natural oils and active enzymes at the same time.

Unlike most cooked foods, there are very few commercial avenues for purchasing such foods.[citation needed] Most "raw foods bars" are raw but not sprouted (and therefore do not have active enzymes) because the bars would not keep as long on the shelf.[citation needed] The same is true of most nut and seed butters.[citation needed] The fact that sprouts have a limited shelf-life is seen as a nutiritional asset, as it shows that the nutrients in sprouts are easily assimilated by the digestive system.[citation needed]

[edit] See also

[edit] References

[edit] Notes

  1. ^ "Plant-based nutrition". Spring 2002. http://www.plantbased.org/PLANT_BASED_NUTRITION_2002-02.doc. Retrieved on 2007-11-14. 
  2. ^ Food and Drug Administration Center for Food Safety and Applied Nutrition October 27, 1999,Federal Register Notice of Availability, 64 FR 57893, Guidance for Industry: Reducing Microbial Food Safety Hazards for Sprouted Seeds and Guidance for Industry: Sampling and Microbial Testing of Spent Irrigation Water During Sprout Production October 27, 1999
  3. ^ http://www.eurekalert.org/pub_releases/2009-04/sfgm-ahs032709.php
  4. ^ Larkcom, Joy ‘Salads For Small Gardens’, p.98 Hamlyn 1995 ISBN 0-600-58509-3
  5. ^ "PDF Article by Gilles Arbour" (PDF). http://www.gillesarbour.com/buckwheat_assets/Buckwheat%20Greens.pdf. Retrieved on 2004-06-15. 
  6. ^ Arbour, Gilles (December 2004). "Are buckwheat greens toxic?". Townsend Letter for Doctors and Patients. Find Articles. http://www.findarticles.com/p/articles/mi_m0ISW/is_257/ai_n7638045. Retrieved on 2007-02-04. 
  7. ^ Wright, Howard. "Sprout Nutrition and Vitamins." Howard Wright. 2007. 28 Nov. 2008 <http://jmdl.com/howard/rants/sprout-nutrition.html>.

[edit] Bibliography

  • The Raw Truth by Jeremy A Safron, (Celestial Arts, Toronto, 2003) ISBN 1-58761-172-4 (pbk.)

[edit] External links

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