Journal of Food: Microbiology, Safety & Hygiene
Open Access

Role of Fermentation by using Streptococcus lactis and Lactobacillus plantarum of yogurt

Vicky M Jakob^{* *}Correspondence: Vicky M Jakob, Department of Microbiology, Klabat University, Manado,, Indonesia, Email:

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Description

Yogurt, a staple in diets worldwide, owes its unique characteristics to the intricate interplay of microorganisms, particularly Streptococcus lactis and Lactobacillus plantarum. These bacteria are integral to the fermentation process that transforms milk into the creamy, tangy product enjoyed for its taste and purported health benefits. Understanding the roles and contributions of Streptococcus lactis and Lactobacillus plantarum in yogurt production not only highlights their significance in the food industry but also underscores their potential impact on human health. This article explores the scientific intricacies of these bacteria in yogurt, examining their fermentation mechanisms, health-promoting properties, and implications for product quality and consumer choice. By delving into the microbial dynamics behind yogurt production, we uncover the symbiotic relationship between science and tradition in creating a beloved and nutritionally beneficial dairy product.

Microbial growth in yogurt fermentation

Yogurt fermentation is primarily driven by Lactic Acid Bacteria (LAB), which convert lactose (milk sugar) into lactic acid through fermentation. The presence of specific LAB strains, including Streptococcus lactis and Lactobacillus plantarum, is important for achieving the desired flavor, texture, and health properties of yogurt [1].

Streptococcus lactis: This bacterium is known for its ability to metabolize lactose efficiently, producing lactic acid as a by-product. It contributes to the acidity and texture of yogurt, creating a favourable

Lactobacillus plantarum: Another key LAB in yogurt fermentation, Lactobacillus plantarum contributes to flavor development and enhances the nutritional profile of yogurt through the production of various metabolites, including vitamins and antimicrobial compounds.

Fermentation process and biochemical pathways

During yogurt production, the following biochemical processes occur [2,3].

Lactose fermentation: Streptococcus lactis and Lactobacillus plantarum hydrolyze lactose into glucose and galactose, which are subsequently fermented into lactic acid.

Acid production: The accumulation of lactic acid lowers the pH of the milk, coagulating the milk proteins (caseins) and imparting yogurt's characteristic tangy taste and thick texture.

Metabolite production: Besides lactic acid, LAB produce other metabolites such as acetic acid, diacetyl (contributing to buttery flavor), and bacteriocins (natural antimicrobial agents).

Health benefits of yogurt containing streptococcus lactis and lactobacillus plantarum

Yogurt consumption has been associated with several health benefits, largely attributed to the probiotic properties of LAB strains like Streptococcus lactis and Lactobacillus plantarum [4].

Digestive health: Probiotic LAB contribute to gut health by maintaining microbial balance, enhancing digestion, and potentially alleviating symptoms of gastrointestinal disorders such as Irritable Bowel Syndrome (IBS).

Immune modulation: Certain LAB strains in yogurt may modulate immune responses, promoting resilience against infections and reducing inflammation [5].

Nutrient absorption: LAB-produced enzymes can enhance the bioavailability of nutrients such as calcium, improving bone health and overall nutritional status.

Metabolic health: Regular yogurt consumption has been linked to improved metabolic parameters, including blood sugar control and lipid profile management.

Quality attributes and consumer preferences

The presence of Streptococcus lactis and Lactobacillus plantarum influences several quality attributes that appeal to consumers:

Texture: LAB fermentation contributes to yogurt's creamy texture and smooth mouthfeel, enhancing sensory appeal [6].

Flavor: The production of lactic acid and other flavor compounds by LAB imparts yogurt with its characteristic tangy and mildly acidic taste.

Shelf life: Acidification and microbial competition during fermentation contribute to yogurt's extended shelf life by inhibiting spoilage organisms [7].

Probiotic content: Consumer demand for probiotic-rich foods like yogurt has driven research into enhancing and quantifying the probiotic content of yogurt through optimized fermentation processes.

Technological advances in yogurt production

Advancements in technology have further optimized yogurt production and quality [8,9].

Starter culture development: Selection and optimization of starter cultures, including specific strains of Streptococcus lactis and Lactobacillus plantarum, for consistent and desirable fermentation outcomes.

Fermentation control: Monitoring and controlling fermentation parameters such as temperature, pH, and inoculum size to ensure reproducibility and product consistency.

Ingredient innovation: Incorporation of prebiotics (nondigestible fibers that promote probiotic growth) and alternative milk sources (e.g., plant-based milks) to expand yogurt varieties and cater to diverse consumer preferences.

Challenges and considerations

Despite the benefits and advancements, challenges in yogurt production and consumption include [10].

Regulatory standards: Compliance with regulatory standards for probiotic claims and microbial safety in fermented dairy products.

Sustainability: Addressing environmental impacts associated with dairy production and exploring sustainable practices in yogurt manufacturing.

Consumer education: Enhancing consumer understanding of probiotics, fermentation processes, and the health benefits of yogurt to promote informed dietary choices.

Future directions and research opportunities

Future research directions in yogurt production and consumption include:

Strain selection and optimization: Continued exploration of LAB diversity and strain-specific attributes to enhance yogurt quality and health benefits [11].

Functional foods: Development of functional yogurt varieties targeting specific health conditions or nutritional needs through customized probiotic and prebiotic formulations.

Technological innovations: Integration of biotechnological tools, such as genetic engineering and metabolomics, to optimize yogurt fermentation and enhance product characteristics.

Conclusion

In conclusion, Streptococcus lactis and Lactobacillus plantarum in yogurt exemplify the intersection of tradition, science, and consumer demand for nutritious, functional foods. Streptococcus lactis and Lactobacillus plantarum play pivotal roles in yogurt fermentation, contributing to its flavor, texture, health benefits, and overall quality. As consumers increasingly prioritize natural, probiotic-rich foods, yogurt remains a versatile and nutritious choice. Advances in microbial science, fermentation technology, and consumer preferences continue to drive innovation in yogurt production. By leveraging scientific insights and technological advancements, stakeholders can further enhance yogurt's appeal, health-promoting properties, and sustainability in the global food market.

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