Vegetables Preserved In Vinegar, Brine, Oil And Mushrooms
VEGETABLES PRESERVED IN VINEGAR, BRINE AND OIL
These products can be divided into two broad categories:
“Acid preserves”, in that the production and stabilization methods, as well as the preservation times and conditions of the same, maintain the pH at a maximum of 4.6: 1. Acid preserves covered with liquid: mainly one vegetable or mixed vegetables, whole or cut, covered with preserving liquid consisting of aqueous solutions of vinegar and/or acidity regulators.
2. Oil preserves: mainly one vegetable or mixed vegetables, whole or cut, previously acidified by immersion in aqueous solutions of vinegar and/or acidity regulators, then covered with oil.
3. Liquid-free vegetable preserves: one vegetable or mixed vegetables, whole or cut, previously acidified by immersion in aqueous solutions of vinegar and/or acidity regulators, and then packaged without any liquid or sauce.
“Non-acid preserves”, preserves with pH> 4.6:
1. Products with reduced water activity: mainly vegetable-based preserves that undergo one or more technological processes to reduce the activity of the water present in the preserves themselves.
2. Non-acidic vegetable preserves with or without liquid or oil: one vegetable or mixed vegetables, with pH> 4.6 and stabilised by sterilisation.
The practice of preserving food in salt, vinegar and oil has ancient origins. The action of these substances makes it possible to maintain the main organoleptic characteristics (consistency, flavour, smell, colour) of the vegetables for various lengths of time, and to protect them from alterations that would compromise their edibility.
In 2017, the Italian production of vegetables in oil, vinegar and brine was 81,300 tonnes, divided as follows:
Sweet and sour vegetables: 5,000 t
Vegetables preserved in vinegar: 10.900 t
Vegetables preserved in oil: 32,700 t
Table olives: 23,100 t
Rice seasonings: 9,600 t
“Dried mushrooms” refers to the product that after natural or mechanical drying, has a moisture content not exceeding 12% + 2% m/m. Only mushrooms belonging to the Boletus edulis species and related group can be placed on the market with the name “porcini mushrooms”. Only the commercialisation of the wild and cultivated fresh mushroom species listed in Annex I of Presidential Decree no. 376 of 14 July 1995 is permitted. The mushroom species listed in Annex II of Presidential Decree no. 376 of 14 July 1995, can be preserved in oil, vinegar and brine, frozen, or otherwise prepared.
The use of the fruiting bodies of fungi for food purposes can be traced back to our prehistoric ancestors, who ̶ driven by hunger and curiosity ̶ discovered that some of the fruiting bodies of higher fungi were edible. The preservation and trade of edible mushrooms arose soon after, and there is evidence of the mushroom trade dating back to the Ancient Greeks and Romans. More than a thousand edible ectomycorrhizal mushrooms are currently consumed around the world, and many more species have yet to be registered, particularly those in Africa and South America.
Freezing processes make it possible to maintain excellent organoleptic properties in most species of ectomycorrhizal mushrooms, and guarantee the availability of frozen mushrooms throughout the year. Frozen mushrooms are sold in different forms: sliced, diced and whole. The continuity of the cold chain is a critical control point in all stages of the production, storage, transport and sale of frozen mushrooms, and must always be strictly monitored by the food industries within their self-control systems, based on risk analysis and critical control points (HACCP). Deep freezing is a process that makes it possible to exceed the temperature zone of maximum ice crystal formation at the necessary speed – depending on the nature of the product – and to continuously maintain the temperature, after thermal stabilisation, at -18 °C (or lower) throughout the product.
Preservation in brine
The preparation of pickled mushrooms consists of a short amount of time cooking in salted water, usually slightly acidified with citric acid, followed by cooling and soaking in strong brine. After 10-15 days of fermentation in the brine, the mushrooms are drained and soaked in fresh brine. A different salting process is used in some countries: after harvesting, the mushrooms are immediately pressed, salted (solid salt) in small barrels and then transported to processing plants, where they are washed under running water, classified and immersed in strong brine. Mushrooms preserved in brine are normally used for industrial processes, i.e. to produce mushrooms in oil, sauces, or other mushroom-based products.
The mushrooms are dried by reducing the moisture content through moderate heating and air exchange. The maximum water content for dried mushrooms is set by international quality standards (FAO/WHO 1981) and Italian regulations, and must not exceed 12-14% of the total weight. The drying process has significant effects on the colour, texture and smell, and consequently determines the commercial value of dried edible ectomycorrhizal mushrooms. A constant flow of hot air is required (no higher than 60 °C). Edible ectomycorrhizal mushrooms are not usually blanched or pre-treated chemically, just cleaned and sliced, manually or mechanically. Edible ectomycorrhizal mushrooms can be dried at home (often roughly chopped with varying thicknesses, and dried in ovens or in the sun), or processed in apposite collection/processing centres, where they are cut by machine and systematically dried in large drying ovens equipped with air flow and temperature controls.
In 2017, wild mushroom imports were divided as follows:
fresh mushrooms: 7,360 t
dried mushrooms: 1.355 t
mushrooms preserved in brine: 9,662 t
frozen mushrooms: 20,019 t
mushrooms preserved in vinegar: 234 t