IAS Gyan

Daily News Analysis


29th January, 2024 Science and Technology


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In many cultures, the issue of food wastage during events has been addressed through traditional methods of food preservation, one of which is lactofermentation.


  • An example often cited is the preservation of leftover potato sabji through this age-old technique.
  • The process involves mixing the sabji with water, ground red mustard seeds (rai), and salt.
  • Over a period of two to three days, the starch in the potatoes undergoes conversion into lactic acid by the lactic acid bacteria (LAB) present in the mustard seeds.
  • This natural acid acts as a preservative, inhibiting the growth of spoilage bacteria and fungi, giving the sabji a spicy, tangy flavor.

Scientific Basis

Role of Lactic Acid Bacteria (LAB):

  • LAB in mustard seeds convert starch to lactic acid.
  • Lactic acid acts as a natural preservative and enhances flavor.

Anaerobic Conditions:

  • Submersion in water creates anaerobic conditions.
  • Only LAB can thrive, inhibiting spoilage microorganisms.

Lactofermentation in Global Cuisines


  • Curd: Commonly fermented in households.
  • Regional Specialties: Kasundi (spiced mustard sauce), dal vadis (dried lentil fritters).

Global Examples:

  • Eastern and Central Europe: Sauerkraut (fermented cabbage).
  • Korea: Kimchi (fermented vegetable dish).

The Science of Probiotics and Fermented Foods

  • Fermented Foods: Result from microbial growth and enzymatic conversions.
  • Probiotics: Live microorganisms conferring health benefits.

Beneficial LAB Microbes:

  • Identification: Ongoing efforts to identify LAB providing distinct tastes.
  • Example: Lactobacillus plantarum in North Indian black carrot kanji.

Health Benefits:

  • Cardiovascular and Metabolic Health: Studies suggest fermented products reduce disease risk.
  • Anti-Obesity and Anti-Diabetic Effects: Noted in dishes like kimchi.
  • Inflammatory Bowel Disease: Fermented foods may alleviate symptoms.
  • Cholesterol Reduction and Anti-Cancer Properties: Linked to LAB-associated fermented milk.

Mood and Cognitive Function:

  • Recent Studies: Fermented foods associated with mood and cognitive improvements.
  • Gut Microbiota and Health: Links between microbiota and overall health.
  • LAB Fermentates: Potential for target-specific modulation of gut microbiota.

About Fermentation

  • Fermentation is a metabolic process that converts carbohydrates, such as sugars and starches, into alcohol or organic acids using microorganisms such as bacteria, yeast, or fungi.
  • This process has been utilized by humans for thousands of years in various cultural practices like brewing, baking, and the production of fermented foods.

Historical Perspective:

  • Ancient Practices: Humans have been using fermentation for millennia, with evidence of early fermentation in the production of beer and bread.
  • Discovery of Microorganisms: Louis Pasteur's work in the 19th century established the role of microorganisms in fermentation, laying the foundation for modern understanding.

Importance of Fermentation:

  • Food Production: Fermentation is crucial in the production of various foods like yogurt, cheese, sauerkraut, and kimchi.
  • Beverage Production: Brewing, winemaking, and distillation all involve fermentation processes.
  • Industrial Applications: Fermentation is used in the production of biofuels, pharmaceuticals, and various industrial chemicals.

Microorganisms Involved in Fermentation:


  • Lactic Acid Bacteria: Common in dairy fermentation (e.g., yogurt), sauerkraut, and pickles.
  • Acetic Acid Bacteria: Involved in vinegar production.


  • Saccharomyces cerevisiae: Widely used in baking, brewing, and winemaking.
  • Other Yeasts: Different yeast strains contribute to the diversity of fermented products.


  • Molds: Used in the fermentation of certain cheeses (e.g., blue cheese).
  • Filamentous Fungi: Play a role in traditional fermentation processes.

Biochemical Pathways in Fermentation:

Alcoholic Fermentation

  • Overview: Conversion of sugars into alcohol and carbon dioxide.
  • Yeast Metabolism: Glycolysis, followed by alcohol fermentation.

Lactic Acid Fermentation

  • Overview: Conversion of sugars into lactic acid.
  • Bacterial Metabolism: Glycolysis, followed by lactic acid fermentation.

Acetic Acid Fermentation

  • Overview: Conversion of ethanol into acetic acid.
  • Bacterial Metabolism: Acetic acid bacteria play a crucial role.

Factors Affecting Fermentation:


  • Optimal Range: Each microorganism has a specific temperature range for optimal fermentation.
  • Thermophiles and Psychrophiles: Some microorganisms thrive at extreme temperatures.

pH Levels

  • Acidic and Alkaline Conditions: Microorganisms exhibit specific pH preferences.
  • Buffering: Understanding and controlling pH is essential for successful fermentation.

Substrate Availability

  • Types of Substrates: Different microorganisms have preferences for specific sugars and substrates.
  • Nutrient Requirements: Adequate nitrogen, vitamins, and minerals are essential for microbial growth.

Industrial Applications of Fermentation:

  • Yogurt Production: Lactic acid bacteria fermentation in milk.
  • Bread Making: Yeast fermentation in dough.
  • Brewing: Saccharomyces cerevisiae fermentation in beer production.
  • Winemaking: Yeast fermentation of grape sugars.
  • Antibiotic Production: Fermentation processes for the synthesis of antibiotics.
  • Insulin Production: Genetically engineered microorganisms used in insulin fermentation.


Lactofermentation, as a sustainable and traditional practice, not only addresses the issue of food wastage but also contributes to the creation of flavorful and health-promoting dishes.


Q. Examine the environmental and health implications of fermentation practices. (250 Words)