Fermented Food - part 2

(Upham, 2021)

There is a variety of fermented foods across the world. Based on the key microorganism, fermentation can be divided into four segments: bacterial fermentation, yeast fermentation, fungal fermentation, and mixed culture fermentation (Hui and E Özgül Evranuz, 2012). Those methods allowed to manufacture various types of products such as soy products, vegetables, and dairy products.

Soy sauce is an example of a fermented soy product. It is a popular oriental fermented condiment made by a two-step fermentation process known as koji which is a solid-state fermentation, and moromi which is a brine fermentation (Devanthi and Gkatzionis, 2019). There are various types of soy sauce depending on the ingredient proportions, fermentation and extraction methods, and other flavoured ingredients.

Vegetables started to be fermented in different cultures to preserve them longer or from climatic limitations. Salt is used to store vegetables. The main microbial activity in these processes is natural lactic acid fermentation, which produces enough lactic acid to reduce the pH. These two substances combine to make lactic acid, which creates an environment that can prevent the growth of other spoilage microorganisms (Hui and E Özgül Evranuz, 2012). Sauerkraut and Kimchi are the fermented vegetables. Sauerkraut is a German fermented product produced with cabbage and it uses lacto-fermentation (Christensen, 2013). Kimchi is a Korean traditional cabbage side dish. It is made by a lacto-fermentation as well (Baechu Kimchi, 2023).

Fermented dairy products can be categorised into three sectors: cheeses, yogurts, and milks (Hui et al., 2004). Majority of cheeses are produced with pasteurised and standardised milk. Yogurts are made with milk; bacteria break some of the proteins in milk down into amino acids. In fact, the bacterial strains in yogurt prevent the growth of other germs that would normally contaminate milk (Moyano, 2020). Fermented milks are similar to plain yogurt drinks. The final product maintains the liquid form. There are many types of fermented milk such as Kefir and sour milk.

Fermentation of cereal is helpful to the health as it improves the nutrition value. Fermentation decreases the level of carbohydrates and non-digestible polysaccharides and oligosaccharides in cereals and increases the synthesis of certain amino acids and the bioavailability of the vitamins of group B (Blandino et al., 2003). Cereal products fermentation is typically used in bread. Major ingredients such as flour, yeast, salt, and water make dough and fermentation happens when the dough bulk. From regular bread, chilled dough, to croissant bread, fermentation was crucial. Another example is Tarhana. It is a traditional and popular cereal-based cuisine fermented with lactic acid bacteria, is often cooked as a soup and consumed in Turkey throughout the winter (Sengun et al., 2009).

Fermentation used in drink as well. There are various types of fermented drinks around the world. The method used to make Typically wine and beer are commonly consumed fermented alcoholic drinks (Ahn et al., 2017). European barley beer, as well as the biochemical and microbiological changes that occur during malting, fermentation, and subsequent processing and storage (Blandino et al., 2003).

Some examples were discussed and there are a lot more fermented products including vinegar, Kombucha, and sourdough bread. The fermentation is a mega trend that meets the demand for organic food which is beneficial to health. Given that fermentation is a natural process, it meets consumers' demands for "clean labelling" and their desire to stay away from artificial additives and preservatives (Askew, 2018). Despite its benefits, several literatures have suggested that health care providers promote fermented foods containing living bacteria as part of public health policy (Sanders et al., 2014; Hill et al., 2017). The advantages outweigh the disadvantages, fermentation has become popular and is definitely one of the highlight food trends around the world.