Although sprouts have traditionally been used as a food source in some cultures, this area has only recently been investigated and the first obtained results are very promising. As there is an increasing consumer demand for health promoting foods, sprouted whole-grain foods emerge as a new trend in the food market. Studies have reported that sprouting not only significantly increased antioxidant activity, vitamin C, E, β -carotene, minerals, and folate content but also reduced antinutrients, such as phytic acid, which might result in greater bioavailability of nutrients (Liu et al., 2017).
Traditionally, edible bean sprouts, such as mung bean and soybean sprouts are popular in some developing countries, such as some eastern Asian countries (Gan et al., 2017). Recent studies show that germination can enhance the nutritional and medicinal values of edible seeds. This leads to degradation of main macronutrients, such as carbohydrates, protein and fatty acids, accompanied with the increase of simple sugars, free amino acids and organic acids (Shi et al., 2010; Wang et al., 2005). It also reduces anti-nutritional and indigestible factors, such as protease inhibitors and lecithin (Aquilera, 2013).
Accumulation of secondary metabolites in edible seeds, such as Vitamin C and polyphenols has also been observed (Gan et al., 2016). Germination can accumulate different bioactive compounds, such as vitamins, γ-aminobutyric acid and polyphenols, and this can be dependent on de novo synthesis and transformation. In addition, germinated edible seeds and sprouts possess many bioactivities, such as their antioxidant capacity, which is significantly increased after germination. Taking all this into account, germination could be considered as a green food engineering method to accumulate natural bioactive compounds, and those germinated edible seeds and sprouts rich in natural bioactive compounds can be consumed as functional foods to prevent chronic diseases (Gan, et al., 2017).
The original composition of the seeds essentially changes during germination. The quantity of the protein fractions changes, the proportion of the nitrogen containing fractions shifts towards the smaller protein fractions, oligopeptides and free amino acids. Beyond this changes the quantity of amino acids (some of them increase, others decrease or remain the same) during germination, and non-protein amino acids are also produced. In consequence of these changes, the biological value of the sprout protein increase, and greater digestibility was established in animal experiments. The composition of triglycerides also changes, owing to hydrolysis of free fatty acids, which can be considered as a certain kind of predigestion. Generally, the ratio of the saturated fatty acids increases compared to unsaturated fatty acids, and the ratio within the unsaturated fatty acids shifts to the essential linoleic acid (Marton et al., 2010).
Sprouts could be considered as mini bio-factories which not only produce vitamins and antioxidants, but also make the nutrients such as proteins in the seed more readily available for digestion.