In recent years, scientific research—responding to the interests and needs of food companies and consumers—has been developing ever-new fermented functional foods that take various factors into account, such as:
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The ongoing pursuit of healthy diets and lifestyles;
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Food intolerances;
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New eating habits like vegetarianism or veganism;
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Sensitivity to environmental impact issues.
In addition to these factors, which have driven the development of processes and technologies for creating new food matrices to be fermented, studies on the beneficial effects of postbiotics have also played a role. The results obtained have led to the search for products different from traditional dairy-based ones.
Thanks to the absence of live microorganisms—which makes them more stable over time than probiotics—postbiotics have proven to be safe and suitable for consumption by vulnerable individuals such as the elderly, pregnant women, and children. Recent data also indicate that postbiotic functional foods play a fundamental role in maintaining a balanced and stable immune system, as well as in strengthening and improving gastrointestinal functions. Moreover, they have demonstrated their effectiveness as:
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Anti-inflammatory agents;
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Immunomodulators;
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Antihypertensives;
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Cholesterol-lowering agents;
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Antioxidants.
Postbiotic Functional Foods and Ingredients from Legume Matrices
Producing postbiotic functional foods and ingredients from legume matrices currently seems to be the best choice to provide valid solutions to the aforementioned variables, especially because it is possible to obtain functional products with a high content of plant-based proteins. These represent a valid alternative to animal proteins, which have long been under scrutiny for their nutritional limitations.
The reasons for choosing legume substrates, in addition to those already mentioned, can also be attributed to two further factors:
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Legumes are relatively inexpensive and are excellent raw materials from a nutritional standpoint, due to their low lipid content, low glycemic index, high fiber, resistant starch, and protein content;
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Legume matrices are excellent fermentation substrates thanks to their high content of carbohydrates, proteins, fibers, vitamins, and minerals.
Their functionalization can occur through the production of functional metabolites such as organic acids, γ-aminobutyric acid (GABA), short-chain fatty acids (SCFAs) like butyrate, acetate, and propionate, bioactive peptides, polyphenolic compounds with high antioxidant activity, polyamines, and serotonin.
Fermentation of Legumes
The fermentation of legumes enriches these foods with valuable proteins, reduces the concentration of antinutritional factors—particularly certain complex oligosaccharides, including α-galactosides such as raffinose, stachyose, and verbascose, which can cause gastrointestinal discomfort—increases antioxidant activity, and generally improves their nutritional properties.
During the fermentation process, not all microorganisms are capable of breaking down and metabolizing these oligosaccharides. Therefore, to ensure good efficiency in the functionalization process, it is necessary to select an appropriate bacterial strain and control:
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pH;
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Temperature;
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Fermentation time;
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Recipe used in the formulation of the fermentative substrate.
Fermentation, combined with common domestic processes such as soaking and controlled cooking, allows for further improvement of the entire process.
Legumes also contain other types of compounds that, while not truly toxic, are classified as antinutrients because they reduce the digestibility of various proteins and the bioavailability of minerals. Examples include certain protease and trypsin inhibitors, saponins, and phytates. Fermentation can also be used in this case to limit their excessive presence.
Conclusions
In conclusion, fermenting a widely consumed product such as legumes would be an excellent strategy for obtaining new postbiotic functional foods and ingredients with a high protein content, enriched with functional compounds that offer various beneficial properties in terms of nutritional profile and digestibility.
