Sour Surprise: From kimchi & sauerkraut to North India’s kanji, fermented foods are common but underrated superfoods

During a recent family wedding, one of the many discussions among relatives was on extra food going to waste at such events. A relative chipped in about how wastage was avoided traditionally, with the example of the simple potato sabji and puri combination. If left over, guests would simply take some of the dish home to enjoy the next day, she said. But sometimes even this would not help empty the bowl; so the leftover sabji would be fermented to preserve for an extra day or two.

The traditional method of fermentation involves mixing a bowl of the sabji with water, a spoon of ground red mustard seeds or rai, and salt as per taste. In two to three days, you would have a spicy, tangy drink (see recipe). You could also adjust the water level to get the fermented sabji to a curry-like consistency and simply eat it with steaming hot rice.

The preservation of food occurs when lactic acid bacteria (LAB) present in the fermenting ingredients like the red mustard seeds convert the starch present in the potatoes to lactic acid. This acid is a natural preservative and inhibits growth of food-spoiling bacteria and fungi. It also provides a sourness to the food and makes it more tasty. The anaerobic conditions created by addition of water to cover the sabji ensure that only LAB can grow.

Such fermentation, called lactofermentation, is prevalent in many traditional cuisines. The most common example is curd, which is prepared in households across India. Regional specialities such as kasundi, a spiced mustard sauce from West Bengal, and dal vadis or dried lentil fritters from Uttarakhand are prepared through fermentation of the ingredients to enhance taste. Idli and dosa batter also requires fermentation. Outside the country, examples of fermented food include sauerkraut, made from cabbage and traditionally consumed in eastern and central Europe, and kimchi, a Korean vegetable dish. Such food has gained popularity as it is probiotic, improves gut health and protects against diseases.

Underrarted foods

The International Scientific Association for Probiotics and Prebiotics defines fermented foods and beverages as “foods made through desired microbial growth and enzymatic conversions of food components”.

Similarly, probiotics are defined by the UN Food and Agriculture Organization as “live microorganisms which, when administered in adequate amounts confer a health benefit on the host”. Going by these definitions, home fermented foods are not generally recognised, as fermentation here is not controlled and because the exact LAB microbe inducing the process is generally unknown.

LAB comprises 16 genera such as Lactobacillus and Streptococcus, 12 of which are associated with food. These genera are amongst the very first bacteria studied. In 1873, British surgeon Joseph Lister isolated the first bacterial pure culture, which he called Bacterium lactis. This LAB is now called Lactococcus lactis and is used to ferment milk to produce hundreds of dairy products.

Scientists are trying to identify all the beneficial LAB microbes that provide the distinct sour taste to different fermented foods. For example, in north India, a unique sour and spicy kanji prepared from black carrots is consumed during the winter months. In 2019, a study published in the International Journal of Gastronomy and Food Science by researchers in Delhi finds that the sour note in the kanji is provided by Lactobacillus plantarum.

Apart from flavour, fermentation also provides several health benefits. In a 2020 paper published in the journal Nutrients, researchers from Ireland reviewed studies on the benefits of fermented foods. They found that various studies indicate that consumption of fermented products can reduce the likelihood of developing cardiovascular disease and type 2 diabetes mellitus. Dishes such as kimchi were found to have anti-obesity and anti-diabetic effects. Fermented foods could also reduce symptoms of inflammatory bowel disease and help in its resolution. Some investigators demonstrated that LAB-associated fermented milk could help lower cholesterol and has anti-cancer properties.

The 2020 paper also mentions that several recent studies have indicated that the consumption of fermented foods can be associated with improvements in mood and cognitive function. The researchers point out that there is a growing body of evidence showing links between gut microbiota composition and overall health. They say gut microbiota can potentially be beneficially modulated by LAB fermentates in a target-specific manner.

This means, fermentation can not only help reduce food waste after weddings, but also help soothe the stomach if you are feeling the after effects of overeating at such events.

This was first published in the 16-31 January, 2024 print edition of Down To Earth

Subscribe to Daily Newsletter :

SUPPORT US

We are a voice to you; you have been a support to us. Together we build journalism that is independent, credible and fearless. You can further help us by making a donation. This will mean a lot for our ability to bring you news, perspectives and analysis from the ground so that we can make change together.