How Do Foods Become Functional?
In nutrition science, the primary role of foods is to provide energy and supply the macro- and micronutrients necessary for survival. However, scientific research has shown that some foods may go beyond basic nutrition and play a role in supporting health. This is where the concept of “functional foods” emerges.
What Is a Functional Food?
Functional foods are natural or processed foods that contain bioactive compounds capable of providing health benefits beyond their basic nutritional value. When consumed in specific and non-toxic amounts, they are scientifically investigated for their potential to reduce the risk of chronic diseases or help manage their symptoms. Their properties often come from specific bioactive components such as phenolics, carotenoids, dietary fibers, prebiotics, and probiotics.
Why Is Green Banana Considered a Functional Food?
Bananas are commonly consumed in their ripe, sweet form; however, unripe green bananas have a unique nutritional profile. When dried and processed into flour, green bananas may contain 55.05% to 65.54% starch. One of the key characteristics that makes green banana a functional food candidate is the structure of this starch and the way it may behave in the digestive system. Saledo Green Banana Flour contains 66.83% resistant starch.
1. Type 2 Resistant Starch (RS2) and Digestion Dynamics
Green banana may contain approximately 36–40% Resistant Starch (RS) on a dry weight basis. The form found in green banana is known as Type 2 Resistant Starch (RS2) and is characterized by a tightly packed B-type crystalline structure.
This structure may show a high resistance to digestive enzymes in the human stomach and small intestine. Therefore, when green banana is consumed, the breakdown and absorption rate of carbohydrates may be reduced. The dynamics of slowly digestible starch and resistant starch may help slow carbohydrate conversion into sugars and support more balanced blood glucose responses.
2. Gut Health and Prebiotic Potential
Resistant starch that escapes digestion in the small intestine may reach the colon intact. In the large intestine, it can act as a fermentation substrate — in other words, a prebiotic source — for beneficial bacteria within the gut microbiota, such as Bifidobacterium and Bacteroides. Supporting these microorganisms may contribute positively to gut health.
3. Antioxidant Potential and Polyphenols
Green banana is not only a source of resistant starch. Scientific analyses have also shown that green banana flour contains Total Phenolic Compounds (TPC) and may exhibit antioxidant activity against free radicals, demonstrated through DPPH inhibition assays.
These phenolic compounds, which may help support cells against oxidative stress, could contribute to maintaining a healthy metabolism.
In conclusion, functional foods provide bioactive compounds that support physiological functions beyond basic nutrition. Green banana, with its hydrolysis-resistant starch structure, prebiotic potential, and phenolic compounds, can be considered a valuable functional food alternative within daily diets.
In addition, processing green bananas into flour before spoilage may also contribute to reducing food waste, as fresh bananas in their raw form are highly perishable.
References
Arshad, Z., Shahid, S., Hasnain, A., Yaseen, E., & Rahimi, M. (2025). Functional foods enriched with bioactive compounds: Therapeutic potential and technological innovations. Food Science & Nutrition. https://doi.org/10.1002/fsn3.71024
Hazarika, U., Saikia, P., Choudhury, M., Gohain, D., & Das, M. (2026). Exploring the functional food potential of Grand Naine banana flour (GBF) as a prospective weaning formulation by developing GBF-based composite flour mixes. Sustainable Food Technology, 4, 604. https://doi.org/10.1039/d5fb00335k
Banana
Martirosyan, D. (2025). Functional food science and bioactive compounds. Bioactive Compounds in Health and Disease, 8(6), 218–229. https://doi.org/10.31989/bchd.v8i6.1667