# The Role of Fungi in Food Production and Processing
## 1 Introduction
### Historical Perspectives and Milestones in the Study of Fungi in Food  
For millennia, humans have relied on fungi as a source of sustenance [28], even though only a small amount of fungi is edible and can be used in food processing. Since early agricultural practices, men have used the natural ability of fungi to ferment various grains and fruits in order to enhance the sensory and beneficial traits in the production of specific foods such as alcoholic beverages and bread [29]. Fungi are used in the production of beverages (like beer, cider, and wine) and fermented food items (like bread, cheese, and rice, including other foods) [30]. _Saccharomyces_ yeasts are mostly utilized to maintain the safety and quality of foods and beverages because, in contrast to other microorganisms, they can withstand high amounts of ethanol. Initially, fungal species were accidentally used to ferment and produce alcohol, which ultimately resulted in the identification of efficient strains. Although _S. cerevisiae_ is the primary species used in wine production, other species also play important roles. Numerous types of fungi can infect grapes before they are harvested, with the main culprits being species from the genera _Alternaria_, _Aspergillus_, _Botrytis_, _Plasmopara_, _Penicillium_, _Rhizopus_, _Oidium_, _Uncinula_ and _Cladosporium_ impacting the wine flavor and quality [31]. These species are considered domestic because they have adapted and possess improved traits in comparison to their wild ancestors [32]. Edible mushrooms are globally cultivated and considered a component of a healthy human diet [33]. Fungi, as mentioned above, are considered a source of nutrients since they produce important proteins and high-value biochemicals [7; 34]. For a century, there has been intense interest in the production of proteins from fungi. Indeed, vigorous efforts are being made to replace animal-derived proteins with proteins produced by fungal cells [35]. In numerous instances, fungi are employed in food products due to their capability to decompose biomass and generate improved flavors and textures. It is noteworthy to mention some examples of the milestones achieved through the utilization of fungi and their enhanced biochemical products in food production and cultivation. _Aspergillus awamori_, which is one variant of _Aspergillus niger_, since 1919, has been commercially utilized for large-scale submerged culture fermentations to produce citric acid [36]. _Penicillin_, derived from _Penicillium_ mold, revolutionized food safety, alongside the advancement of mycoprotein as a meat alternative due to its nutritional benefits [37]. Some phytopathogenic edible portions of fungi are also consumed, such as a delicacy comprised of _Ustilago maydis_. In Mexico, this fungus induces the formation of black tumors on maize, resulting in a delicacy known as huitlacoche [38]. One of the earliest documented instances of using fungi for human consumption was reported in China. Since then, its utilization has continued in various forms [39]. For over 3000 years, the fungus _Aspergillus sojae_ has been utilized in the production of soy sauce because of its capacity to secrete enzymes, break down soybeans, and impart a distinctive flavor to the sauce [40]. _Aspergillus oryzae_ has also been employed in the production of koji, using solid-state cultivation (koji is used as a starter for secondary fermentations). This technique is believed to have originated in China and has been utilized for centuries in Japanese fermentations. The commercialization of koji can be traced back to the Heian and Muromachi periods (13 th to 15 th century) [41]. This filamentous fungi is also utilized for the production of traditional alcoholic beverages, sauces, and sediments. In Japan, _A. awamori_ has been extensively employed in the production of an alcoholic beverage called awamori, converting starch into glucose.