Beneficial microbes in food industries

 

Beneficial microbes in food industries

Beneficial microbes play a vital role in the food industry, contributing to the production, preservation, safety, and enhancement of food products. These microorganisms are utilized in various processes, from fermentation to probiotics, and are essential in creating some of the world’s most popular foods and beverages.

Beneficial microbes are indispensable in the food industry, playing critical roles in fermentation, preservation, safety, flavor, and texture development. Their application enhances the quality and safety of food products and contributes to sustainability by reducing the need for chemical preservatives and processing aids.

1. Beneficial microbes in food industries - Fermentation

Fermentation is one of the oldest and most important processes in the food industry, where beneficial microbes convert sugars and other substrates into alcohol, acids, gases, or other desirable compounds. This process helps in preserving food and enhances its flavor, texture, and nutritional value.

1. Microbial Fermentations:

Lactic Acid Fermentation:

Microbes Involved: Lactic acid bacteria (LAB) such as Lactobacillus, Leuconostoc, Pediococcus, and Streptococcus species.

Dairy Products: LAB are essential in the production of yogurt, cheese, kefir, and other fermented dairy products. They convert lactose into lactic acid, which gives these products their characteristic tangy flavor and thick texture.

Vegetable Fermentation: Sauerkraut, kimchi, and pickles are produced through lactic acid fermentation, where LAB convert sugars in vegetables into lactic acid, acting as a natural preservative.

Meat Products: Fermented sausages like salami rely on LAB to produce lactic acid, which lowers the pH and helps in preserving the meat while enhancing flavor.

In Homolactic fermentation glucose molecule is converted into two molecules of lactic acid and in Heterolactic fermentation, glucose molecule is converted into lactic acid, carbon dioxide, and ethanol. 

Alcoholic Fermentation:

Microbes Involved: Yeasts, particularly Saccharomyces cerevisiae.

Bread making - In bread dough yeast ferment and produce alcohol and carbon dioxide, this causes leavening of the dough causing it to expand. 

Brewing: Yeasts ferment sugars in grains (like barley) to produce beer. The fermentation process generates alcohol and carbon dioxide, giving beer its alcohol content and carbonation.

Winemaking: Yeasts ferment sugars in grapes to produce wine. The type of yeast and fermentation conditions significantly influence the flavor and character of the wine.

Production of other alcoholic beverages: Yeasts are also used to produce alcoholic spirits like whiskey and vodka through fermentation, followed by distillation to concentrate the alcohol.

Acetic Acid Fermentation:

Microbes Involved: Acetic acid bacteria (AAB), such as Acetobacter and Gluconobacter species.

Vinegar Production: AAB oxidize ethanol (produced by yeast fermentation) into acetic acid, which gives vinegar its sour taste. This process is used to produce various types of vinegar, including apple cider vinegar and balsamic vinegar.

Kombucha: A fermented tea where AAB and yeasts work together to convert sugars into ethanol and acetic acid, resulting in a tangy, effervescent beverage.

Propionic Acid Fermentation:

Microbes Involved: Propionibacterium species.

Cheese Production: Propionic acid bacteria are involved in the fermentation of Swiss cheese, where they produce propionic acid and carbon dioxide. The carbon dioxide forms the characteristic holes, or "eyes," in the cheese, while propionic acid contributes to its nutty flavor.

2. Beneficial microbes in food industries - Probiotics

Probiotics are live microorganisms that confer health benefits when consumed in adequate amounts. They are often added to foods or dietary supplements to enhance gut health and overall well-being.

Microbes Involved:

Common probiotic bacteria include species of Lactobacillus, Bifidobacterium, Streptococcus, and Enterococcus.  Some yeasts, like Saccharomyces boulardii, are also used as probiotics.

Applications in Food Products:

Dairy Products: Yogurts, kefir, and some cheeses are often fortified with probiotic cultures. These products support gut health by promoting the growth of beneficial bacteria in the intestines.

Functional Foods: Probiotics are added to various functional foods, including juices, cereals, and snack bars, to provide health benefits.

Dietary Supplements: Probiotics are available in capsule, tablet, and powder forms, often recommended for digestive health, immune support, and other benefits.

Probiotics help balance the gut microbiota, alleviate symptoms of irritable bowel syndrome (IBS), and reduce the incidence of diarrhea, especially after antibiotic use.  Regular consumption of probiotics can enhance the immune response and reduce the risk of infections.

3. Beneficial microbes in food industries - Food Preservation

Beneficial microbes are used in the preservation of food by producing compounds that inhibit the growth of spoilage organisms and pathogens.

Lactic Acid Bacteria (LAB) - These produce lactic acid and other organic acids that lower the pH of the food environment, creating unfavorable conditions for spoilage microbes and pathogens.  They are used in the production of Fermented Vegetables and Fermented Dairy Products where they help to prevent the growth of spoilage organisms and pathogens and extend the shelf life of products.

Bacteriocins - Bacteriocins are antimicrobial peptides produced by certain bacteria that can kill or inhibit the growth of closely related or specific harmful bacteria.  Examples are Nisin produced by Lactococcus lactis, used in the preservation of dairy products, meats, and canned foods to inhibit the growth of spoilage organisms and pathogens and Pediocin Produced by Pediococcus species and is used in meat products to inhibit Listeria and other harmful bacteria.

Fungi like Penicillium roqueforti and Penicillium camemberti are used in Blue cheese and Camembert cheese production, respectively. These molds create unique flavors and contribute to the preservation of the cheese.   Aspergillus oryzae are used in the fermentation of soybeans to produce soy sauce and miso, which have extended shelf lives due to the antimicrobial properties of the fermentation by-products.

4. Beneficial microbes in food industries - Food Safety

Beneficial microbes are used to enhance food safety by outcompeting or inhibiting the growth of pathogenic microorganisms.

Beneficial microbes, particularly in fermented foods, can outcompete harmful pathogens for nutrients and space, reducing the likelihood of contamination.  In fermented sausages, LAB prevent the growth of pathogens like Salmonella and Listeria.

Certain beneficial microbes produce substances that directly inhibit or kill pathogens. Lactobacillus species in yogurt can inhibit the growth of Escherichia coli and Staphylococcus aureus by producing lactic acid and bacteriocins.  Probiotic strains like Lactobacillus rhamnosus and Bifidobacterium bifidum can inhibit the adhesion of pathogens to the gut lining, reducing the risk of infections.

5. Beneficial microbes in food industries - Flavor and Texture Development

Beneficial microbes contribute significantly to the flavor, aroma, and texture of various food products, enhancing their sensory qualities.

Microbes produce various metabolites during fermentation that contribute to the complex flavors and aromas of food. For example, Yeasts produce ethanol and esters during beer and wine fermentation, which contribute to the fruity and floral aromas while LAB produce diacetyl, a compound that gives a buttery flavor to dairy products and certain types of cheese.

Microbial activity can influence the texture of food products, making them more appealing to consumers.  For example, In yogurt production, LAB ferment lactose into lactic acid, which causes milk proteins to coagulate, forming the thick texture characteristic of yogurt and In bread making, Saccharomyces cerevisiae ferments sugars in the dough, producing carbon dioxide that makes the dough rise and gives the bread its light, spongy texture.