# The Role of Fermented Vegetables as a Sustainable and Health-Promoting Nutritional Resource
## 3. Femented Vegetables
### Fermentation and Food Safety  
Several studies have shown that microbial fermentation improves food safety, on the basis that the fermented foods contain significant amounts of organic acids, low water activity, nitrite, and other salts, all of which have antimicrobial properties that minimize the risk of foodborne illness linked to their intake [244]. Many LAB, whether naturally occurring in the microbiota or introduced as starter cultures, are recognized for their production of bacterios that effectively inhibit harmful bacteria, including _Clostridium_, _Listeria_, and _Staphylococcus_[245]. Food fermentation can also improve food safety and nutritional quality by eliminating toxic compounds from the fermentation of cereals, legumes, and other vegetables [246; 247]. For example, several vegetables contain cyanogenic glycosides which need to be neutralized through fermentation, soaking, or other appropriate methods to prevent acute toxicity upon consumption [248; 249]. Throughout sourdough fermentation, certain LAB promote the breakdown of phytate, a compound linked to cereal grains that binds divalent cations and hinders their absorption in the gastrointestinal tract [250]. It is also thought that sourdough fermentation decreases the levels of other immunoreactive proteins, such as the amylase-trypsin inhibitor found in wheat, which may lead to better tolerance in individuals with non-celiac wheat sensitivity or irritable bowel syndrome compared to traditional breads [251]. Fermented foods are rarely associated with intestinal disorders, although any food product may present safety concerns related to pathogenic microorganisms and their toxins or metabolites that may have adverse effects. For example, biogenic amines (e.g., histamine and tyramine) are produced by some LAB through the decarboxylation of amino acids during the fermentation of vegetables and soybeans [252]. In the absence of detoxification systems mediated by the host, these amines can lead to mild or severe effects, including nervous system problems, headache, hypertension, fever, and sometimes vomiting and sweating [253]. Diverse strategies have been implemented to decrease or mitigate the formation of biogenic amines, such as hygiene to limit the presence of microorganisms that produce these compounds and the use of decarboxylase-negative starter cultures [254; 255]. Several factors of fermented foods have been proposed for health promotion, including the nutritional modification of raw materials, the biosynthesis of bioactive compounds, the modification of the human gut microbiota, and the modulation of the immune system [126; 256]. Microbial activity during food fermentation leads to a reduction in the levels of high-calorie monosaccharides and disaccharides, such as fructose, glucose, and sucrose, found in plants through catabolic pathways. The reduction in determinate sugars may also lower the glycemic index and enhance food tolerance (e.g., fructas or raffinose found in wheat, as well as stachyose and verbascose present in legumes and soybeans) [257]. Additional enzymatic processes with significant nutritional consequences also take place, encompassing detoxification reactions and the removal of anti-nutritive factors (e.g., deactivation of trypsin inhibitors in soybeans and the breakdown of phytic acid in cereals like sorghum) [258; 259; 260]. In foods rich in phenolics, the transformation of phenolic compounds by lactobacilli enhances the bioavailability of flavonoids, tannins, and various other bioactive substances [140]. Furthermore, the biosynthesis of vitamins, amino acid derivatives, and organic acids produced during fermentation may have beneficial effects on the gastrointestinal system [261]. Several human studies have indicated that microorganisms in plant-fermented foods are capable of surviving gastric passage and of reaching the colon [262; 263], on the basis that fermented foods have intrinsic properties that enhance their ability to survive gastric transit (i.e., acid and bile tolerance) [264].