Can the fermentation of foods enhance their antioxidant properties?

In a recent editorial published in Fermentation, researchers examined the use of fermentation as a means to increase the antioxidant potential of foods.

Free radicals such as reactive oxygen species (ROS) cause oxidative stress, potentially leading to various conditions like cancer and cardiovascular and neurodegenerative diseases. Dietary antioxidants may help to protect cells from free radicals.

Fermentation, which began as a means to extend the shelf-life of foods, has been investigated for its health benefits, including those provided by antioxidant compounds.

About the editorial

In the present editorial, researchers examined the potential of fermentation and the use of microbial enzymes to enhance the activity of bioactive constituents in foods, enhancing their antioxidant potential.

The important contribution of antioxidant molecules to food longevity and their health-promoting effects, along with growing concern about synthetic antioxidants, are causing scientific researchers to show interest in natural antioxidants. Bioactive peptides, polyphenols, vitamins, and amino acids are the most prevalent antioxidant molecules found in meals naturally.

Nonetheless, permitting future advances in dietary antioxidant activities in the in vitro settings, which might potentially reflect in the in vivo settings, is a critical subject. Biological conversion induced by microbial enzymatic substances and fermentation with chosen starter molecules could be viewed as a technique for potentiating the activities of bioactive substances by promoting their expression or modifying their structural configuration.

Recent studies have explored the health benefits of fermentation, including those conferred by antioxidants. Much of the research published included in vitro experiments to investigate ways in which spontaneous or chosen starter fermentation might enhance the antioxidant properties of legumes, by-products of milling, cereals, and other vegetable matrices. Animal studies were used in several articles to elucidate the in vivo effects of fermented foods.

In most cases, lactic acid bacterial organisms (LAB) and yeast activities increased the biological accessibility of phenol-containing molecules, resulting in increased antioxidant activity, often evaluated using 2,2-difenil1-picrylidrazyl (DPPH), based on its radical scavenging activities, and increased anti-platelet and anti-inflammatory potential.

Although using in vitro assays has generated controversy over several years due to their limitations, they remain of considerable importance in selecting compounds with antioxidant potential and analyzing conspicuous microbes and matrices, so they are frequently combined with other techniques, including those based on cellular modeling.

This was used in a study conducted by Polo et al. (2023) to evaluate the impact of fermentation using various LAB initiators for fermenting ice cream. They observed fermentation of the ice cream with the Lacticaseibacillus casei F14 strain, inhibiting the activity of pro-inflammatory cytokines such as interleukin-6 and interleukin-8, as well as ROS, in human colon carcinoma (Caco-2) cells, demonstrating anti-inflammatory and anti-free radical properties.

However, in vitro as well as ex vivo experiments can only estimate antioxidant activities in the in vivo settings, and human-based clinical studies are lengthy and severely controlled by ethics committees. Indeed, exposing rats to oxidative stress and administering lactic acid bacteria or yogurt as a probiotic led to statistically significant reductions in triglyceride (TG), total cholesterol (TC), and low-density lipoprotein-cholesterol (LDL-C) levels.

In addition, remarkably elevated high-density lipoprotein (HDL-C) levels were observed, indicating fermentation as a feasible approach to enhance food functionality. However, novel bioconversion routes must be identified, bio-accessibility and bioavailability of different antioxidant compounds must be evaluated, and their roles associated with digestion in vivo must be explored.

Implications

Based on the findings, microbial enzymes and fermentation with certain starters can enhance the activities of bioactive chemicals in foods by stimulating their secretion or changing their structural form, resulting in increased antioxidant capacity. Incorporating fermented foods into one’s diet can provide a natural supply of antioxidants, hence improving one’s general health and well-being.

Food makers might investigate the use of fermentation and microbial enzymes to boost the antioxidant activity of their goods, providing healthier alternatives to customers. Further research and development in this field may result in the development of innovative food items with enhanced antioxidant qualities, meeting the rising demand for natural and functional foods.

Future research must address potential limitations or challenges associated with the use of natural antioxidants in fermented foods, assess the efficacy or effectiveness of various fermentation techniques in increasing the antioxidant activity of bioactive compounds, and investigate the potential impact of fermentation on the bioavailability or absorption of antioxidant compounds in the human body.