8.1. Microbes in Household Products

You would be surprised to know that we use microbes or products derived from them every day. A common example is the production of curd from milk.

Microbes, particularly certain bacteria, are utilized in our daily food preparation, often without us realizing it. The most common example is the transformation of milk into curd, which is done by lactic acid bacteria, mainly Lactobacillus. These bacteria ferment the lactose in milk, producing lactic acid, which causes milk proteins to coagulate and gives curd its texture.

Think of curd as a product similar to magic – you start with milk, and by adding just a spoonful of curd (which is full of LAB) and leaving it in a warm spot, you watch it transform into delicious curd. Just like a little seed can grow into a big tree given the right conditions, a small inoculum of LAB can multiply to transform a whole batch of milk into curd.

Micro-organisms such as Lactobacillus and others commonly called lactic acid bacteria (LAB) grow in milk and convert it to curd. During growth, the LAB produce acids that coagulate and partially digest the milk proteins.

Lactic acid bacteria ensure that as they grow, they produce acids that not only help in the coagulation process – turning milk into curd – but also begin digesting milk proteins, enhancing the nutritional value. This process of fermentation not only preserves the milk but also improves the availability of nutrients for our bodies. Furthermore, these bacteria also promote health in our digestive systems by helping fight off harmful pathogens.

Imagine LAB as tiny chefs that not only create a dish (curd) from basic ingredients (milk) but also ensure that it's nutritious and good for you. They prepare the food not just for flavor but also to make sure it's easier for our body to digest and utilize.

The dough, which is used for making foods such as dosa and idli, is also fermented by bacteria. The puffed-up appearance of dough is due to the production of CO2 gas.

When making traditional foods like dosa and idli, the dough is fermented, primarily through the action of specific bacteria and yeast. As these microbes metabolize sugars in the dough, they produce carbon dioxide (CO2) gas, which causes the dough to rise and creates a fluffy texture. This gas production is vital as it helps give bread and similar products their lightness and aeration necessary for proper cooking and eating.

Think of the dough as a living sponge. When microbes feast on the sugars in the dough, they create bubbles (like a balloon) because of the CO2 they produce. It’s the cheerful bubbles that make your idli fluffy and light – almost like there’s a party happening inside the dough!

A number of traditional drinks and foods are also made by fermentation by the microbes. ‘Toddy’, a traditional drink of some parts of southern India, is made by fermenting sap from palms.

Fermentation is a traditional method of processing food and beverages around the globe. For instance, the sap of certain palm trees can be fermented by natural yeasts and bacteria to produce 'toddy,' a popular beverage in southern India. This process highlights not only the culinary use of microbes but also the diversity of fermentation products that exist in different cultures. Other examples include fermented fish, soy products, and various alcoholic beverages where microbial fermentation plays a critical role.

Consider fermentation like a cultural recipe passed down through generations. Just as a family might have a secret recipe for their special cake, different cultures have unique ways of using fermentation to create traditional foods and drinks, like how 'toddy’ is cherished in southern India.

Cheese is one of the oldest food items in which microbes were used. Different varieties of cheese are known by their characteristic texture, flavour and taste, the specificity coming from the microbes used.

Cheese production is a perfect example of how different microbes can create a diverse array of flavors and textures. For instance, the bacterium Propionibacterium sharmanii helps create the characteristic holes in Swiss cheese through gas production. Meanwhile, other cheeses like Roquefort are ripened with specific fungi, giving them unique flavors. This showcases the varying roles different microbes play in flavor development and texture of cheese, impacting its culinary use.

Think of cheese as a treasure chest of flavors, where each microbe represents a different artisan, crafting its specialty. Just like how different artists would create pieces with unique styles, each type of cheese derives its own unique taste and texture from the different microbes involved in its making.

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