Pickles are canned vegetables, fruits, cereals, meats or fish put in brine or in vinegar and sugar. This ancestral mode of preservation concerns all regions of the world and has many recipes and manufacturing methods.
If studies have long been interested only in the effects of fermentation and food safety of these products, the health effects of this type of preparations are beginning to be studied.
The different types of fermentation
Savory pickles are made by immersing the raw materials in diluted brine (2 to 5% salt). Natural bacteria grow for 1 to 2 weeks by producing lactic acid, which prevents the growth of bacteria and other pathogenic microorganisms. The amount of salt added controls the type and speed of fermentation.
Sweet fermented pickles are preserved by a combination of lactic acid or acetic acid (vinegar), sugar and spices.
The different micro-organisms present in the pickles
Lactic acid bacteria (Lactobacillus, Pediococcus, Enterococcus, Lactococcus, Leuconostoques, Oenococcus, Streptococcus, Tetragenococcus, Carnobacterium, Vagococcus, Weissella, and Alkalibacterium) are in the majority in pickles thanks to their ability to tolerate considerable quantities of salt and sugar. There are also bacteria from the Micrococcaceae family (Micrococus and Staphylococcus) which play an important role in the fermentation of pickles.
Certain species of yeast (Brettanomyces, Candida, Cryptococcus, Debaryomyces, Dekkera, Galactomyces, Geotrichum, Hansenula, Hanseniaspora, Schizosaccharomyces, Torulaspora, Torulopsis, Trichosporon, Yarrowia, and Zygosaccharomyces) have also been observed in traditional pickle recipes.
• Filamentous mushrooms
Fungal strains (Mucor, Monilla and Rhizopus) are also responsible for the fermentation process of the pickles even if they are not very studied.
Why eat pickles?
For their nutritional richness
In addition to their conservation property, pickles have a tenfold nutritional richness through fermentation. Micro-organisms produce many protective compounds during fermentation, including vitamins (B2, B9, B12, K, B1), antioxidants (flavonoids, phenols and sterols), as well as amino acids which also change the flavor and food texture. Fermentation also improves the digestibility of fibers, especially that of root vegetables and tubers.
For their action on the microbiota
Lactobacillus are the most studied probiotics due to their role in the digestion and health of the microbiota. The doses of probiotics observed in the pickles correspond to the recommended therapeutic doses. Regular consumption of pickles allows the microbiota to be seeded with beneficial probiotic strains.
For a potential protective effect against cancer
The probiotic strains present in this type of preparation reduce the proliferative and mutagenic activity of certain enzymes involved in cancer. However, further studies are still needed to confirm these preliminary observations.
For the regulation of metabolic parameters
Several pickle preparations have shown interesting effects on certain metabolic parameters including cholesterol levels, insulin resistance and weight.
A recent study has shown that a bacteria found in kimchi (Lb.Plantarum) induced a reduction in weight in mice after 8 weeks of consumption.
The beneficial effects of pickles on blood sugar can be attributed to vinegar and acetic acid, which have already been shown to work on blood sugar.
To support the immune system
Fermentation produces molecules, especially alkyl catechols, which improve the immune system. These molecules help cells defend themselves from the oxidative stress involved in many chronic diseases (neurodegenerative diseases, cancers).
Microorganisms, including certain lactobacilli, stimulate the anti-infectious and anti-tumor activity of the immune system by modulating the inflammatory response and stimulating defense molecules (NK lymphocyte).
Considerable varieties of pickles produced from vegetables, fruits, fish or meats exist. Among the best known in Europe, we find the pickle, but also the capers, which are a typically Mediterranean condiment made from the buds of the caper plant. Other foreign preparations are widely known as Kimchi from Korea. For fruit, we can easily cite table olives, emblematic of the Mediterranean diet, lemons and many other fruits whose shelf life is very short (mango, cherry, plum …). These plants become symbiotics after fermentation because they contain both probiotics and prebiotics. As far as pickles made from animal raw materials are concerned, this preservation process has long been the safest. Indeed, meat is an excellent substrate for probiotic bacteria, as well as for fish.
Enriching your microbiota with probiotic food supplements can help, only the benefits will only last the time of treatment, as explained by Dr. Martine Cotinat “ food will always remain the key to sustainably enriching one’s microbiota by regularly consuming fermented drinks (kefir, fermented vegetable juices), fermented soybeans (miso, natto), fermented dairy products and all foods rich in prebiotics. ”