Health & Nutrition
Sprouting for Birds
Benefits of sprouting - myth and reality
Germination and sprouting set off a biochemical reaction in seeds and grains. It is widely reported on the internet that sprouts are a superfood, and that sprouting causes a significant improvement in the quality and quantity of many beneficial nutrients, along with a decrease in the amount of fat. Unfortunately this is a myth; scientific studies indicate that the nutritional content changes but it doesn't change very much. The last section of this article provides more information on the nutritional changes.
Even though sprouts aren't a superfood, they are beneficial in other ways. Sprouting improves the digestibility of the seed/grain by making it softer and easier to process, and it improves the bioavailability of some nutrients by removing anti-nutrients like phytate. Our birds would have easy access to living, growing foods in the wild, and sprouting helps us approximate this part of their diet. Variety in the diet adds interest and enrichment to our birds' lives, and the texture of moist sprouts is very different from that of dry seeds and grains. Grocery-store sprouts aren't recommended for birds due to problems with bacteria and mold.
You can buy an inexpensive commercial sprouter if you like, but it's easy to make your own sprouter using simple materials. Basically, you need something that will let you rinse and drain the seeds easily without making a mess or having seeds go down the sink.
A mason (canning) jar with plastic canvas mesh in the lid works very well. The smaller jelly jar size is convenient for small batches. In the US mason jars can be found in large grocery stores, sold in multi-packs. Plastic canvas can be found in the needlework department of craft stores like Michaels. The standard size seems to be #7 (the size indicates the number of holes per inch), which is fine for bigger seeds. But for small seeds like millet it's best to use a finer mesh (#10). This equipment will not retain really tiny seeds like amaranth.
A strainer that fits comfortably inside a bowl also works well. Recently a 3-in-1 "berry bowl" that comes with its own strainer has become available, and it is very well suited for sprouting. The slots in the strainer are small enough to retain millet seeds, although for really tiny seeds you'd need to put something in the strainer (like a coffee filter) to keep the seeds in.
Grains and Seeds
You can sprout your bird's regular seed (including sunflower), and sprouting is actually an excellent way to test the quality of the seed. If less than half of it sprouts it's old and stale and should be discarded. Human-quality grains (usually found in the bulk food bins at the local natural-foods grocery) are excellent for sprouting. Things like wheat, kamut, spelt, barley, oats, rye, etc - anything that looks like a seed. Quinoa is a great addition, and raw rice can be added to the mix. Lentils, mung beans, garbanzos, and adzuki beans are good, but other beans are best avoided unless you're willing to cook them after they've sprouted, due to natural toxins in the beans that are eliminated by cooking but not by sprouting. Even the acceptable beans need to have the tails sprouted out to a length of 1/4" to 1/2" to neutralize toxins. Grains don't have this issue, and are considered to be at their nutritional peak when the root is just barely starting to stick out of the seed. For bigger birds you can include bigger items like pumpkin seeds and popcorn.
How to Sprout
The mason jar technique: at night, put the seeds/grains in the jar and put the lid on. Rinse them a few times by pouring in some cool water, swirling it around a little, and draining. Don't drain the water the last time; let the grains soak overnight. A few drops of vinegar can be added to the soaking water to discourage mold and bacteria. You need enough water that the seeds will still be covered with it after they've been soaking for several hours. You also need to allow space for air circulation in the jar, so the jar should not be more than about half full of seeds after they've soaked. There's no problem with having smaller amounts of seed in the jar.
In the morning, rinse and drain. It's recommended that you leave the jar tilted downward at an angle so it can continue draining, but simply laying the jar on its side may work for people in dry climates. In any case, there must be some open space above the seeds so air can flow in through the mesh. Rinse and drain again in the middle of the day (optional) and once again at night (not optional). Success is somewhat dependent on the climate in your house; some people will get better results from keeping the sprout jar in a dark place (like a cupboard) and others won't need to do this.
In the morning rinse it one last time and give it to the birds. Right before feeding you can add supplemental items if you want, such as chopped veggies. Total prep time: about 36 hours. Total time actually spent working on it: about three minutes.
The bowl and strainer technique
is the same as above, except that you put your sprouting seeds in the
strainer, which is then put in the water-filled bowl. When you're ready to rinse
you just lift out the strainer.
Storage and Safety
It's possible to store sprouts in the refrigerator for a few days, although making a new batch is so easy that this will be a better option for many people. You can't just put the sprouts in the fridge and ignore them because it takes some vigilance to avoid problems with bacteria and mold. The technique that is usually recommended is to continue rinsing them daily, drain them well, then store them in the refrigerator in a covered container with a paper towel in the bottom.
To avoid storage issues, you can start a new batch every night. You will have two jars (or bowls) going every night: the one that was just started, and the one that was started the previous night and will be served in the morning.
Vigilance is also needed both before and after serving the sprouts. Like any moist food, they provide a nice environment for mold and bacteria. So you have to make sure they haven't spoiled before you serve them - if they smell sour throw them away. Be sure to take them out of the cage before they go bad. The amount of time that they stay good will vary depending on the humidity and temperature in your house. It could be anywhere from a couple of hours to all day long, and the safe period will fluctuate from day to day and season to season.
The procedure described above will work in most situations, but some people have a lot of problems with the sprouts spoiling during the sprouting process. In those cases, more air circulation might be helpful; use the bowl and strainer approach instead of the mason jar. If all else fails, just soaking the seed overnight is usually safe and effective. The procedure is the same as above except that the process ends immediately after the overnight soak, and you drain, rinse, and serve at that point.
In most respects the nutritional/chemical content of a soaked or lightly sprouted seed is pretty similar to that of the dry seed. Chavan et al provides a list of beneficial changes caused by sprouting but then tells us that the improvements are not significant. Lorenz & D'Appolonia also provide a list of beneficial nutrient increases, but then tell us that this is mostly a phantom increase; the base for computing percentages has changed since the amount of dry matter (carbohydrates) has decreased, so the percentage of everything that remains will automatically get bigger even if the actual quantity doesn't change at all.
There is a real reduction in the carbohydrate level, since carbohydrates are used as the main source of energy during germination and early growth (at least in high-carbohydrate seeds) (Ziegler, McDonald). But the magnitude of the change isn't clear. I couldn't find any information on how much the biochemistry of germination varies from one plant species to another. But Satyanarayana et al reported an increasing rate of carbohydrate depletion during the first 6 days of germination, ranging from 0.19% on day 0 to 0.286% on day 6 for Sterculia urens (not a food plant). This is a relatively small change, adding up to a cumulative total of 1.2% to 1.7% after 6 days.
They also reported slow protein depletion during this same time period, and said that similar protein depletion had been observed in several sprouts used as food. In contrast to this, Taraseviciene et al reported an increase in several amino acids during the first 72 hours of germination for broccoli sprouts, but all were amino acids that are already plentiful in the diet and therefore not of any particular use. They calculated a 16% decrease in calories after 5 days of germination but their speculation that this was due to a fat decrease is at odds with other sources, and casts doubt on the accuracy of their information.
Marton et al report that there's little difference in the fat content of sprouted and unsprouted seed, apparently referring to the relative percentages of saturated and unsaturated fatty acids. But in contrast to other sources who report that carbohydrates are the main energy source during sprouting, Table 1 of the Marton paper makes it seem likely that the energy source used during germination and sprouting depends to some degree on what type of energy was stored in the seed to begin with. The table shows that the amount of fat in wheat and lentils hadn't changed at all after three days of sprouting, but there was a slight decrease in the amount of fat in sunflower seed after this time period. Wheat and lentils are relatively high in carbohydrates and low in fat, while the reverse is true of sunflower. 100 grams of wheat contains 71g of carbohydrate and 2g of fat. 100 grams of lentils contains 60g of carbohydrate and 1 g of fat. And 100 grams of sunflower seed contains 20g of carbohydrate and 51g of fat.
Here's another paper on sunflower sprouts by Balasaraswathi et al, but most of it isn't available for free online viewing. The preview does let you see Table 1 however which is interesting (and also hard on the neck since it's displayed sideways). It shows an irregular pattern of decreases in dry matter, fats, protein, and carbohydrates over a period of five days. But I'm not quite sure what to make of it all, since this paper only looks at the cotyledon of the seed. Other sources indicate that there are other parts that need to be considered in measuring the total nutrients in the seed.
Yet another paper on fats in sunflower sprouts by Munshi et al tested fast-growing and slow-growing seeds. Apparently all were the same type of seed, and some just sprouted faster than others. The faster-growing seeds had a faster rate of lipid (fat) depletion than the slower-growing seeds did, which makes sense because you'd expect faster growth to use more energy than slower growth. The density of the writing and the amount of detail in the tables are a bit much for me, but it looks like the results are generally the same as the other sources: most of the fat decrease comes sometime after day 3.
The last sentence of the paper indicates that the germination speed of the seed is determined by where in the sunflower head it came from, and the faster-growing seeds are "filled with enhanced amount of lipids and soluble sugars". It's hard to interpret Table 1, but it looks like the slow-growing seeds might contain less total fat than the fast-growing seeds on the same day of development, in spite of the fact that the fast-growing seeds use their fat stores faster.
The changes caused by sprouting are not always beneficial; sorghum (milo) produces a large amount of prussic acid (cyanide) when it is sprouted, and should not be sprouted as a food for this reason (Panasiuk & Bills, Ikediobi et al). Unripe sorghum seed and mature dry sorghum seed are safe and beneficial, but the sprouts are not safe and neither are the green leaves and stems of the plant. Dried-out yellow sorghum stalks and stems are safer than fresh green ones, but are best avoided to be on the safe side.
Case study using mung beans. Here's a crude approximation of the nutritional changes that sprouting causes in mung beans, the most common type of bean sprouts. This discussion uses NutritionData's nutritional analyses for dry mung beans and mung bean sprouts so you need to click on those links and look at the charts. In both cases, look for the little drop down arrow under the name of the food and change the serving size to 100 grams so you're comparing the same amount of food. At first glance the sprouts look a lot worse compared to the dry beans, but this is caused by the difference in water weight. 100 grams of sprouts contains 90 grams of water and the same weight of dry beans has only 9 grams, so you have to adjust for this to make them reasonably comparable. The change in water weight is a convenient 10-fold increase, so you can either multiply the sprout nutrients by 10 or divide the dry-seed nutrients by 10 to provide a rough estimate of the real differences between them.
Now let's look at the differences reported by NutritionData, keeping in mind that this is a crude approximation and shouldn't be taken as hard facts. I'll use the reported numbers for dry beans, and multiply the amount for the sprouts by 10 to adjust for the water weight.
Also keep in mind that, as reported earlier, some of the apparent increase in percentages is a numerical phantom caused by the loss of dry matter, not a real increase in the amount of nutrients. As an example of the "phantom increase" effect, look at the fat content. It goes from 1.2 g in the dry seed to an adjusted value of 2.0 in the sprouts, which is an increase of 66%. But the plant is using up its stored energy, not taking in fresh nutrients from outside sources, so we can be pretty sure that this didn't really happen. The scientific sources say the fat content either stays the same or decreases, but the tricky nature of statistics makes it look like there's been a big increase. There are probably some rounding effects in there too. The size of the phantom increase might vary from one nutrient to another depending on a variety of factors.
The gross protein analysis on NutritionData shows an apparent large increase in protein, from 24 grams in dry beans to 30 grams (adjusted value) in sprouts. This is a big increase (33%) if it's real. But some of the amino acids that are counted as protein are more important than others, so there's more at play here than the issue of how accurately they measured the amounts. The three most limiting (and therefore most important) amino acids for birds are methionine, lysine, and threonine (Karaalp), so click on the More Details tabs on the NutritionData site to look at those; the other amino acids don't matter because they're either nonessential or already plentiful in the diet. Methionine increases from 286 milligrams to 340; lysine remains essentially the same, declining from 1664 to 1660; and threonine goes from 782 to 780. So even if this is a real increase, the only protein difference worth talking about is the increase in methionine, which has gone up by about 50 milligrams in a 100-gram sample. That's not very much.
What about the calories? The amount given for kJoules is more precise than the number for calories, and shows a decrease caused by sprouting of about 13%. Since obesity is a big problem in pet birds, it's not bad to lose some of the calories while keeping everything else more or less the same. Keep in mind though that we're talking about "grocery store" style sprouts, which have been sprouted longer than the typical homegrown sprouts for birds. "Barely sprouted" seeds and beans will not have used up as many calories as long sprouts that have been growing for a longer time.
The carbohydrates decrease from 63 g to 59, a difference of about 6% which is more or less in the middle of the range reported in the scientific literature. There's no doubt that there's a real decrease in the carbs, and the only question is how big the change really is.
The vitamin C changes significantly, from about 5 mg to 132; but it doesn't matter because birds manufacture their own vitamin C and don't need it in the diet. There's a nice increase in vitamin K, which looks like it could be more than a statistical fluke. Vitamin K is present in VERY small amounts (measured in micrograms, which are a millionth of a gram), so I'm not sure how easy it is to measure the amount accurately. The other increases are small enough to be probably be a numerical wobble. If the "phantom increase" effect was strong enough, these statistics could be masking an actual decrease in the total amount of many vitamins and minerals. The beans had to be soaked in water to sprout them, so some loss of water-soluble nutrients is expected.
Copyright 2014 Carolyn Tielfan all rights reserved