Nowadays, we are forced to spend more and more time in our homes, which has increased people's appetite for fermented foods that they can prepare themselves at home. The range of foods that can be fermented is very wide, with well-known and tested recipes (pickled cucumber, sauerkraut) and many other ingredients (courgette, carrot, garlic, carbonated juice, etc.). UC Davis University has a project to test home-made products, both for safety and quality.

The aim of fermentation is to modify raw materials of animal or plant origin through the metabolic activity of micro-organisms (bacteria, yeasts, filamentous fungi). Fermented foods have many advantages, some of which are: increased shelf-life, increased variety of food products (thousands of different types of cheese can be made from milk), increased nutritional value and quality.

However, food safety issues should also be mentioned. It is very important that the raw material and the culture used are microbiologically sound. The technological steps must be strictly followed, and it is important to apply the technologically prescribed heat treatment and temperature correctly. During fermentation, the microbial growth and metabolic products of the microbes not only affect the texture, flavour and odour of the product, but also participate in the production of biogenic amines by the starter culture in some lactic acid fermented products.

Biogenic amines are mildly toxic compounds (most of them cause allergy-like symptoms), and their formation is facilitated by low pH and high NaCl content. Biogenic amines are most abundant in soft cheeses, meat products, sauerkraut and olives.

To produce safe and high-quality fermented food at home, it is important to follow recipes that are already well-established and based on science. If you suspect that your fermented product is not suitable, do not consume it under any circumstances.

More information on fermented foods and related food safety issues:

https://ucfoodsafety.ucdavis.edu/consumers/food-safety-home/home-food-preservation

https://nchfp.uga.edu/how/can6a_ferment.html

Updates

Home canning predisposes Italy to botulism infections

Italian researchers through the national surveillance system have reported 1,039 suspected cases of botulism from 2001 to 2020, with a predominance in the Southern part of the country. The main reason for this high botulism rate is he nation’s long-standing habit of home canning. The year with the most suspected instances was 2013, with 137, but the year with the most confirmed cases was 2020, with 74. An average of 50 reports of suspected cases are submitted to the national botulism surveillance system each year, with roughly half receiving lab confirmation. Most occurrences of botulism are associated with meat and fish, as well as vegetables preserved in oil, water, or brine.