The increase of nutrient density by lactic fermentation is mostly due to a decrease of sugar content. Catabolism of disaccharides like sucrose or lactose has been extensively studied for many LAB species.Lactic fermentation modifies the composition of the fermented materials and by the metabolic microbial action can improve the beneficial health benefits of food.

1. Changes in Bioactive Compounds Over
Lactic fermentation
Sukhveer Singh
Ph.D.-FST

2.  The increase of nutrient density by lactic fermentation is mostly
due to a decrease of sugar content. Catabolism of
disaccharides like sucrose or lactose has been extensively
studied for many LAB species (Gänzle & Follador, 2012; Melanie
Kostinek et al., 2005; Lynch et al.,2015).
 On the opposite, sucrose, glucose and fructose were totally
depleted over cabbage or leek fermentation when fermentation
lasted several weeks (Jung et al., 2013; Wouters, Bernaet, et al., 2013;
Wouters, Grosu-Tudor, Zamfir, & De Vuyst, 2013).
 Fermentation also contributes to increase protein, peptides and
amino acid content in foods from legumes.
Increase of nutrient density

3.  One of the main mechanism that could explain antioxidant
activity variation is the release of bioactive compounds from
conjugated phytochemicals.
 Feruloyl esterase enzymes are also known as ferulic acid
esterases (FAE), cinnamoyl esterases and cinnamoyl ester
hydrolases, release ferulic acid or coumaric acid from
conjugated phenolic acids.
 Beta-glucosidase is one of the major enzymes responsible for
the hydrolysis of flavonoid conjugates during bacterial
fermentation. This enzyme was detected in many LAB species
(Lee, Han, & Kim, 2012; Michlmayr & Kneifel, 2014; Pyo, Lee, & Lee, 2005).
Hydrolysis of phenolic compounds

4.  Cabbage content in glucosinolates is high (Kusznierewicz et
al.,2008).
 The main glucosinolates hydrolysis product in fermented
cabbage is Ascorbigen.
 It was shown recently that cabbage fermentation by LAB
resulted in an increase of antioxidant activity (Kusznierewicz,
Śmiechowska, Bartoszek, & Namieśnik, 2008).
 The observed changes can be related to Lactobacillus ability
to degrade glucosinolate in allyl-isothiocyanate (Llanos Palop,
Smiths, & Brink, 1995).
Derivatives of glucosinolates

5.  Bioactive peptides have been mainly studied from milk or whey
hydrolysis during lactic fermentation (López-Fandiño, Otte, & van
Camp, 2006).
 But also from fermented soybeans (Gibbs, Zougman, Masse, &
Mulligan, 2004), and more recently from grapes (Aredes
Fernández, Stivala, Rodríguez Vaquero, & Farías, 2011) and cereal flours
(Coda, Rizzello, Pinto, & Gobbetti, 2012).
 Bioactive peptides are generated during fermentation process
through enzymatic proteolysis, performed by single or multiple,
specific or unspecific proteases, of larger protein molecules
usually not bearing any bioactivity (Humiski & Aluko, 2007).
Bioactive peptides

6.  Secondary metabolites generated during fermentation process
are notably interesting regarding health. Isoflavones from soya,
for example, were demonstrated with anti-cancer properties,
limiting the onset of breast carcinogenesis (Celligoi, Santos, da
Silva, & Baldo, 2015).
 Short chains fatty acids are produced from hydrolysis of lipids.
 Fermentation of fruits and vegetables is frequently associated
with an increased content in vitamins. They notably include
vitamins of the B group as well as others such as vitamin K.
Secondary metabolites, short chain
fatty acids and vitamins

7.  It was demonstrated that LAB belonging to the genera
Lactobacillus, Lactococcus, Leuconostoc, Pediococcus and
Weissella, in particular W. cibaria, W. confusa and W. hellenica,
are producing a large diversity of EPS, depending on the
carbon source (Fessard et al., 2016; Juvonen et al., 2015; M. J. Kim, Seo
& Park, 2008; Pan & Mei, 2010).
 The most studied health effect is indirect and called prebiotic:
EPS stimulate the growth of probiotic bacteria.
 EPS are also proposed to have direct effects, such as
immunomodulation effects, antioxidant activity and cancer
prophylaxis (Caggianiello, Kleerebezem, & Spano, 2016; Franco-Robles &
López, 2015; Kwak, Cho, Noh, & Om, 2014; Pan & Mei, 2010).
Synthesis of exopolysaccharides

8.  The content of proteases and trypsin inhibitor was also reduced
by fermentation. LAB, through their enzymatic equipment, help
neutralize anti-nutritive factors such as phytates, saponins,
tannins, cyanogens or trypsin inhibitors. (Lai, Hsieh, Huang, & Chou,
2013).
 For example, galactosidase is able to reduce anti-nutritive
factors such as phytic acid, tannins, trypsin inhibitors (Adeyemo &
Onilude, 2014).
 This effect can be associated with modification of minerals
bioavailability (Arslan & Erbas, 2015; Gaspar & Crespo, 2015) and
proteins whose digestibility is also favored (Kaur, Jha, Sabikhi, &
Singh, 2014).
Degradation of anti-nutritional
factors

9.  Use of probiotic bacteria in the non-dairy product is challenging
and important to research and industry for commercialisation of
healthy beverage.
 Masking of the medicinal taste and off flavours is the possible
solution for the nondairy probiotic.
 Probiotic cells can be stabilized with microencapsulation to
preserve them from detrimental processing and storage factors
such as high acidity and low pH.
 Lactic fermentation modifies the composition of the fermented
materials and by the metabolic microbial action can improve the
beneficial health benefits of food.
CONCLUSION

10. Food is our natural medicine