Understanding Fermentation: From Microbes to Modern Food Science

Fermentation is a foundational biochemical process with deep historical roots, diverse scientific principles, and broad applications in food, health, and education.

---

Table of Contents

1. Definition and Scientific Principle

2. Historical Background

3. Science Behind Fermentation

4. Common Examples of Fermented Foods

5. Health Benefits

6. Cultural and Global Perspective

---

Definition and Scientific Principle

Fermentation is a metabolic process where microorganisms—such as bacteria, yeasts, or molds—convert sugars and other organic compounds into acids, gases, or alcohol in the absence of oxygen. This process is a form of anaerobic respiration, where organic molecules serve as both electron donors and acceptors, yielding energy for microbial growth and producing various end products like lactic acid, ethanol, or acetic acid [2, 3, 6, 7].

For example, the general equation for lactic acid fermentation is:

Glucose → 2 Lactic Acid + Energy (ATP)

For alcoholic fermentation:

Glucose → 2 Ethanol + 2 CO₂ + Energy (ATP)

Historical Background

Fermentation is one of the oldest food preservation techniques, practiced by ancient civilizations such as the Egyptians, Chinese, and Koreans. Archaeological evidence shows beer brewing from cereals over 13,000 years ago, and fermented dairy, bread, and alcoholic beverages were staples in ancient diets across Asia, Africa, and Europe [5, 6, 8, 9, 12]. The technique was essential for food security, flavor enhancement, and cultural rituals [5, 6, 9].

Science Behind Fermentation

Microorganisms Involved

• Lactic Acid Bacteria (LAB): Key in yogurt, kimchi, sauerkraut, and cheese (e.g., Lactobacillus, Streptococcus) [1, 5, 6, 7, 11].

• Yeasts: Central to bread, beer, wine, and kombucha (e.g., Saccharomyces cerevisiae) [6, 7, 9].

• Molds: Used in tempeh, soy sauce, and some cheeses (e.g., Rhizopus, Aspergillus) [5, 6, 7].

Chemical Reactions

• Lactic Acid Fermentation:

  C₆H₁₂O₆ (glucose) → 2 CH₃CHOHCOOH (lactic acid) + energy

• Alcoholic Fermentation:

  C₆H₁₂O₆ (glucose) → 2 C₂H₅OH (ethanol) + 2 CO₂ + energy

Environmental Factors

Fermentation is influenced by pH, temperature, oxygen levels, and time. For example, lactic acid production is optimized at specific pH and temperature ranges, and oxygen absence is crucial for anaerobic fermentations [2, 6, 7, 12].

Common Examples of Fermented Foods

• Cheese

• Kimchi

• Kombucha

• Miso

• Pickles

• Sauerkraut

• Sourdough bread

• Tempeh

• Vinegar

• Yogurt

Health Benefits

Fermented foods improve digestion by supporting the gut microbiome with probiotics, enhance nutrient absorption, boost immunity, and contain bioactive compounds with antioxidant and antimicrobial properties. They also reduce spoilage and increase food safety by inhibiting pathogens [1, 6, 7, 9, 10, 11].

Cultural and Global Perspective

Fermentation is integral to regional cuisines—kimchi in Korea, kefir in Eastern Europe, bagoong in the Philippines—and reflects traditional knowledge and indigenous practices. It supports sustainable food systems by reducing waste and valorizing by-products, contributing to food security and zero-waste goals [5, 6, 8, 9].

Fermentation is a multifaceted process with ancient origins, scientific complexity, health benefits, and global cultural significance, making it a vital topic in both research and education.

References

1. Anumudu, C., Miri, T., & Onyeaka, H. (2024). Multifunctional Applications of Lactic Acid Bacteria: Enhancing Safety, Quality, and Nutritional Value in Foods and Fermented Beverages. Foods, 13. https://doi.org/10.3390/foods13233714.

2. Buckel, W. (2021). Energy Conservation in Fermentations of Anaerobic Bacteria. Frontiers in Microbiology, 12. https://doi.org/10.3389/fmicb.2021.703525.

3. Hackmann, T. (2024). The vast landscape of carbohydrate fermentation in prokaryotes. FEMS Microbiology Reviews, 48. https://doi.org/10.1093/femsre/fuae016.

4. Khubber, S., Martí-Quijal, F., Tomašević, I., Remize, F., & Barba, F. (2021). Lactic acid fermentation as a useful strategy to recover antimicrobial and antioxidant compounds for food and by-products. Current Opinion in Food Science. https://doi.org/10.1016/j.cofs.2021.11.013.

5. Lee, C., Ahn, J., & Son, H. (2024). Ethnic fermented foods of the world: an overview. Journal of Ethnic Foods. https://doi.org/10.1186/s42779-024-00254-2.

6. Mannaa, M., Han, G., Seo, Y., & Park, I. (2021). Evolution of Food Fermentation Processes and the Use of Multi-Omics in Deciphering the Roles of the Microbiota. Foods, 10. https://doi.org/10.3390/foods10112861.

7. Praveen, M., & Brogi, S. (2025). Microbial Fermentation in Food and Beverage Industries: Innovations, Challenges, and Opportunities. Foods, 14. https://doi.org/10.3390/foods14010114.

8. Shoda, S. (2021). Seeking Prehistoric Fermented Food in Japan and Korea. Current Anthropology, 62, S242 - S255. https://doi.org/10.1086/715808.

9. Siddiqui, S., Erol, Z., Rugji, J., Taşçı, F., Kahraman, H., Toppi, V., Musa, L., Di Giacinto, G., Bahmid, N., Mehdizadeh, M., & Castro‐Muñoz, R. (2023). An overview of fermentation in the food industry - looking back from a new perspective. Bioresources and Bioprocessing, 10. https://doi.org/10.1186/s40643-023-00702-y.

10. Terefe, N., & Augustin, M. (2020). Fermentation for tailoring the technological and health related functionality of food products. Critical Reviews in Food Science and Nutrition, 60, 2887 - 2913. https://doi.org/10.1080/10408398.2019.1666250.

11. Wang, Y., Zhang, C., Liu, F., Jin, Z., & Xia, X. (2022). Ecological succession and functional characteristics of lactic acid bacteria in traditional fermented foods. Critical Reviews in Food Science and Nutrition, 63, 5841 - 5855. https://doi.org/10.1080/10408398.2021.2025035.

12. Yang, L., Chen, L., Li, H., Deng, Z., & Liu, J. (2021). Lactic acid production from mesophilic and thermophilic fermentation of food waste at different pH.. Journal of environmental management, 304, 114312 . https://doi.org/10.1016/j.jenvman.2021.114312.