Effect of Fermentation on the Nutritional Quality of the Selected Vegetables and Legumes and Their Health Effects

Vegetables are rich in many vitamins, mineral components, antioxidants, and macronutrients. However, they also contain high levels of anti-nutrients, which reduce the bioavailability of some nutritionally essential components such as zinc or iron. The processing of vegetables, including microbial fermentation, reduces or neutralizes tannins and phytates, which results in greater bioavailability of vitamins and minerals. Another effect of bacterial processing is an increased antioxidant potential, which has been linked to the release of polyphenols from complexes with anti-nutritional ingredients. Moreover, there were identified bioactive substances such as γ-aminobutyric acid or inhibitors of an angiotensin-converting enzyme in fermented vegetables. These substances may support the treatment of lifestyle diseases, such as depression or hypertension. However, there are still no data about these substances’ bioavailability after the consumption of fermented vegetables. Additionally, fermented foods are rich in probiotic microorganisms, where the main group is lactic acid bacteria. The effect of fermentation on each vegetable is different. This should be a reason to expand our knowledge as more innovative and untested fermented products appear on the market.