Journal of Food: Microbiology, Safety & Hygiene
Open Access

Lactic Acid Bacteria for the Production of Functional Cultured Dairy Products

Salihu Arimie^{* *}Correspondence: Salihu Arimie, Department of Dairy Sciences, Federal University of Technology, Gaga, Nigeria, Email:

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Description

Lactic Acid Bacteria (LAB) are a diverse group of gram-positive bacteria that play a pivotal role in the fermentation of dairy products. These microorganisms are integral to the production of various cultured dairy products, including yogurt, cheese, kefir, and fermented milk. Beyond their traditional role in fermentation, LAB are increasingly recognized for their potential health benefits, making them key players in the development of functional dairy products. This article explores the types, mechanisms, and health implications of LAB in the production of functional cultured dairy products.

Characteristics of LAB

LAB are characterized by their ability to ferment carbohydrates, primarily lactose, into lactic acid. This fermentation process not only preserves dairy products but also enhances their flavor and texture. LAB can be classified into two primary groups based on their metabolic pathways:

Homofermentative LAB: These bacteria primarily produce lactic acid from glucose fermentation, resulting in a high yield of lactic acid. Common homofermentative LAB include Lactobacillus delbrueckii and Streptococcus thermophilus.

Heterofermentative LAB: These bacteria produce lactic acid along with other by-products such as ethanol, carbon dioxide, and acetic acid. Examples include Lactobacillus brevis and Leuconostoc mesenteroides.

LAB are Generally Recognized as Safe (GRAS) and are known for their probiotic potential, contributing to gut health and overall well-being.

The role of lactic acid bacteria in fermented dairy products

Yogurt production

Yogurt is one of the most widely consumed fermented dairy products, produced through the fermentation of milk by specific LAB strains, primarily Lactobacillus bulgaricus and Streptococcus thermophilus. The fermentation process involves the following steps:

Milk preparation: Whole milk is pasteurized to eliminate harmful bacteria and denature proteins.

Inoculation: Selected LAB strains are added to the cooled milk, initiating fermentation.

Fermentation: The mixture is incubated at temperatures between 40°C and 45°C for several hours, during which LAB metabolize lactose to produce lactic acid. This acidification leads to the coagulation of milk proteins, resulting in the characteristic texture of yogurt.

Functional aspects: Yogurt made with specific probiotic strains can provide health benefits, including improved digestion, enhanced immune function, and the potential reduction of lactose intolerance symptoms.

Cheese production

Cheese production also relies heavily on LAB, which contribute to the fermentation and flavor development of various cheese types. The process typically involves:

Milk preparation: Similar to yogurt, milk is pasteurized.

Inoculation with starter cultures: Various LAB strains, such as Lactococcus lactis and Lactobacillus helveticus, are introduced.

Coagulation: Rennet is added to coagulate the milk, forming curds.

Fermentation and aging: The curds are processed, molded, and aged. LAB play an essential role in developing the flavor and texture of the cheese during aging.

Functional aspects: Certain cheeses, especially those containing live cultures, can confer health benefits similar to yogurt, including probiotic effects and improved nutrient absorption.

Kefir production

Kefir is a fermented milk drink characterized by its tangy flavor and effervescence, produced by a complex community of LAB and yeasts. The production process involves:

Milk preparation: Like yogurt and cheese, milk is pasteurized.

Inoculation with Kefir Grains: Kefir grains, which contain a symbiotic matrix of LAB and yeast, are added to the milk.

Fermentation: The mixture is incubated at room temperature, allowing fermentation to occur, producing lactic acid, carbon dioxide, and alcohol.

Functional aspects: Kefir is known for its high probiotic content, which may enhance gut health, improve lactose digestion, and boost immune function.

Challenges in the use of lactic acid bacteria

Despite the benefits, several challenges exist in the application of LAB for producing functional dairy products:

Strain selection: Choosing the right LAB strain is evaluative for achieving desired sensory and functional properties. Variability in strain performance can lead to inconsistent product quality.

Shelf stability: The survival of LAB in dairy products during storage is a concern. Factors such as temperature, pH, and oxygen availability can affect the viability of probiotics. Ensuring that products maintain their probiotic content throughout their shelf life is essential for delivering health benefits.

Consumer acceptance: The sensory characteristics of cultured dairy products, including taste, texture, and aroma, are influenced by LAB. Achieving a balance between health benefits and consumer preferences is essential for market acceptance.

Future directions

Research into LAB and their applications in dairy production continues to evolve. Future directions may include:

Genetic engineering: Modifying LAB strains to enhance their probiotic properties, resistance to adverse conditions, and nutrient synthesis capabilities.

Functional foods: Developing novel cultured dairy products fortified with additional bioactive compounds or prebiotics to further enhance health benefits.

Personalized nutrition: Exploring the role of specific LAB strains in personalized nutrition, customizing dairy products to meet individual health needs.

Conclusion

LAB are active for the production of functional cultured dairy products, offering numerous health benefits while enhancing flavor and texture. Through the fermentation process, LAB contribute to the creation of products that promote gut health, aid in lactose digestion, and improve nutrient absorption. As research continues to unveil the complexities of LAB, the potential for developing innovative, health-promoting dairy products remains vast. With growing consumer interest in functional foods, the future of LAB in dairy production is promising, paving the way for healthier dietary options.