Miso: How It Is Made
What is Miso?
Miso, a traditional Japanese seasoning, has gained widespread global popularity for its special umami (savoury/meaty) flavour and health benefits. Miso is traditionally made from soybeans, rice or barley, salt, and water (Allwood et al. 2195). However, its versions and regional effects add to its culinary variety. The seasoning is now very famous within Canada too, and is available in many forms at most grocery stores. This paper delves into the science behind miso production, discussing the fermentation process, microbial interactions, and biochemical pathways involved in its creation. The vital function of microorganisms, which includes koji mold (Aspergillus oryzae), lactic acid bacteria (LAB), and yeasts, in miso fermentation is explored, shedding light on their contributions to the transformation of easy ingredients into a flavourful condiment. Additionally, the paper investigates the nutritional factors of miso and explains its potential health benefits, which entail antioxidant activity and potential risk reduction for chronic diseases. By inspecting the intersection of culture, science, and health, the essay reveals the complicated art of creating miso and its significance in the Japanese culinary and nutritional landscape.
Historical Background
Although the origin of miso is unclear, it is believed to have originated in China around 600 A.D. (Saeed et al, 2021). Subsequently, fermented soy-based foods found their way to Japan during the time Buddhism was introduced to the country in 710 A.D. As time progressed, the Japanese refined their own distinctive methods of crafting miso, adapting these techniques to suit their culinary inclinations and local ingredients.
In the Kamakura period (1185-1333), a typical meal would consist of rice, dried fish, a portion of miso, and fresh vegetables. Up until the Muromachi period (1337-1573), miso was prepared without the grinding of soybeans, similar to the preparation of natto. During this era, Buddhist monks uncovered the possibility of grinding soybeans into a paste, leading to approaches to employing miso for flavoring other foods (Saeed et al, 2021). Moreover, miso evolved into a crucial source of sustenance for warriors and travelers during this period (Inoue et al, 2016).
During the Sengoku period (1477-1573), the production of miso became an important economic activity for feudal lords. Towards the Edo period (1603-1868), a variety of miso emerged, each adapting to the specific local climates and cultural nuances across Japan.
In contemporary times, miso is predominantly manufactured on an industrial scale, with traditional homemade miso becoming increasingly uncommon. In recent years, miso has gained international recognition due to its versatility and rich flavor profile. Chefs and home cooks worldwide integrate miso into an extensive array of culinary creations, spanning from soups to glazes for roasted meats.
Miso Production: Ingredients and Preparation
Miso owes its specific characteristics to the production process. The primary miso production ingredients include soybeans, rice, barley, salt, and water (Jacob 47). The first step in miso-making entails selecting and cleaning the soybeans and grains. Subsequently, they are soaked to rehydrate and soften, ensuring effective conditions for the fermentation system. Once hydrated, the soybeans and grains undergo cooking, which softens them and activates enzymes critical for fermentation.
The cooked ingredients are then blended with koji mold (Aspergillus oryzae), a filamentous fungus, to provoke the fermentation process. Koji mold is essential in miso manufacturing because it produces enzymes that break down starches and proteins into simpler compounds, including sugars and amino acids (Miyajima n.p.). This enzymatic action now contributes to miso’s flavour and facilitates the next fermentation steps.
The subsequent stage involves adding salt and water to the mixture, creating an environment conducive to increasing beneficial microorganisms. Lactic acid bacteria (LAB) and yeasts come into play during this fermentation process, changing the sugars produced by the koji mold into lactic acid, which imparts the function of tanginess and acts as a natural preservative (Revolution Fermentation n.p.). The fermentation duration varies depending on the preferred type of miso, taking about six months; during this time, the miso develops its special flavour, ranging from light and sweet to much stronger, reflecting the complexity of the fermentation system (Revolution Fermentation n.p.). The last step involves further aging the miso to refine its taste and aroma. The art and science involved in miso production center around maintaining an equilibrium between time, temperature, and microbial interplays.
Microbial Activity
Microbial fermentation lies at the center of miso production, a procedure wherein various microorganisms work harmoniously to create the characteristic flavours, textures, and nutritional benefits of the Japanese seasoning. Among the important elements, as was mentioned earlier, are koji mold (Aspergillus oryzae), lactic acid microorganisms (LAB), and yeasts.
Koji mold, a filamentous fungus, assumes a pivotal function within the preliminary steps of miso fermentation. Through the production of enzymes, it breaks down complex carbohydrates and proteins in soybeans and grains into simpler compounds (Gomi 1385). Proteins are converted into peptides and amino acids, even as starches are transformed into sugars. This transformative system, known as koji, lays the foundation for subsequent fermentation by providing important nutrients to other microorganisms.
The primary fermentation procedure uses lactic acid microorganisms (LAB). These microorganisms convert the sugars produced throughout the koji stage into lactic acid via glycolysis. This conversion not only prompts miso’s tangy taste but also performs a vital function in preservation, growing in acidic surroundings that inhibit the growth of harmful microorganisms (Gomi 1386). Yeasts also contribute to fermentation, adding complexity to miso’s eventual taste. As they metabolize, yeasts produce various fragrant compounds and other by-products, improving the final product’s aroma. The dynamic interactions amongst these microorganisms at some point of fermentation yield various miso varieties, with each variant having its particular flavour, coloration, and aroma (Revolution Fermentation n.p.). The meticulous tracking and control of the fermentation process are necessary to obtain the desired taste of the condiment.
Biochemical Pathways
During the process of miso fermentation, a complicated interplay of biochemical pathways transforms simple components into the flavours that define the taste of miso. Three most important pathways – proteolysis, glycolysis, and lipolysis – signify the process. Proteolysis, a principal pathway, entails the breakdown of proteins found in soybeans and grains into peptides and amino acids. This transformative procedure is catalyzed using enzymes produced via the koji mold. As proteins are hydrolyzed into smaller units, an array of savoury compounds is released, endowing miso with its wealthy and special taste profile.
Glycolysis, another crucial pathway, occurs as lactic acid microorganisms (LAB) metabolize sugars produced during the koji stage; the series of chemical reactions converts sugars into lactic acid (Allwood et al. 2200). The accumulation of lactic acid serves as a natural preservative, prolonging miso’s shelf life and safeguarding it from spoilage (Jagtiani and Adsare 39). The third pathway, lipolysis, includes the breakdown of fat and lipids into fatty acids and glycerol. Various enzymes of specific microorganisms during fermentation contribute to this process. Lipolysis adds depth and complexity to miso’s flavour, enriching its usual richness and aroma. Environmental elements, including temperature, moisture, and the choice of specific microorganism lines, majorly influence the dynamics of those biochemical pathways. Cautious management of these conditions results in various miso tastes for distinct culinary applications (Evans and Lorimer 366).
Health Benefits
Miso consumption offers a range of potential health benefits. As a fermented food, miso is a natural source of probiotics, containing live beneficial bacteria that support intestine health and reduce the risk of cancer (Allwood et al. 2202). Additionally, miso is rich in critical amino acids, B vitamins, and minerals (iron and calcium), contributing to properly balanced weight maintenance and psychological health (Allwood et al. 2202). Further, the fermentation system of miso generates antioxidants, e.g., phenolic compounds, which can counteract oxidative strain and infection, boosting the immune system and clearing the skin.
Incorporating miso into a daily diet plan is a nutritious way to enhance meals. Miso’s versatility allows for numerous culinary uses, adding intensity to soups, enriching the taste of sauces and dressings, and creating savoury marinades (Evans and Lorimer 365). Its probiotic properties promote physical and psychological well being. Miso can be used as an alternative to many more traditional condiments in cooking to maximize health and flavour benefits. Miso supplements a balanced eating regimen and provides important amino acids, vitamins, and minerals. Embracing miso as a part of a health-aware way of life and combining it with other nutritious foods can contribute to average well-being and culinary enjoyment.
Question for exam: What are the optimal environmental conditions for maximizing the growth and metabolic activity of Koji mold during the production of traditional fermented foods?
To boost Koji mold's growth and metabolic activity in traditional fermented foods, you'll want the right environment. Aim for warmth and humidity, approximately 30-35°C temperature and 80-90% humidity (Smith et al., 2015). Keep things well-ventilated to avoid excessive moisture buildup (Adams & Moss, 2008). Adequate aeration is also essential to prevent mold from clumping and to maintain a steady growth rate (Steinkraus, 2002).
To create our exam question, our group wanted to address a concept taught in our course as well as bring in our own topic. This exam question ensures that peers are drawing from course related knowledge as well as applying these concepts to a related topic such as fermented foods.
References
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Evans, J., & Lorimer, J. (2021). Taste-Shaping-Natures. Current Anthropology, 62(S24), S361–S375. https://doi.org/10.1086/714851
Gomi, K. (2019). Regulatory mechanisms for amylolytic gene expression in the koji moldAspergillus oryzae. Bioscience, Biotechnology, and Biochemistry, 83(8), 1385–1401. https://doi.org/10.1080/09168451.2019.1625265
Inoue, Y., Kato, S., Saikusa, M., Suzuki, C., Otsubo, Y., Tanaka, Y., Watanabe, H., & Hayase, F. (2016). Analysis of the cooked aroma and odorants that contribute to umami aftertaste of soy miso (Japanese soybean paste). Food Chemistry, 213, 521–528. https://doi.org/10.1016/j.foodchem.2016.06.106
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Saeed, F., Afzaal, M., Shah, Y. A., Khan, M. H., Hussain, M., Imran, A., Ateeq, H., Noman, M., Saewan, S. A., & Khashroum, A. (2022). Miso: A traditional nutritious & health‐endorsing fermented product. Food Science and Nutrition, 10(12), 4103–4111. https://doi.org/10.1002/fsn3.3029
Steinkraus, K. H. (2002). Industrialization of Indigenous Fermented Foods. CRC Press.
Smith, J. E., et al. (2015). The Fungi (3rd ed.). Academic Press.