Table of contents
Truffle oil is made from vegetable oil to which truffles or truffle flavors are added. Depending on the base oil, it is available raw . It is rarely found in organic quality.
Use in the kitchen
The basis of truffle oil is either a neutral-tasting vegetable oil such assunflower oil or a mild cold-pressed olive oil . Depending on which type of truffle you use to flavor the oil, you get truffle oil made from dark truffles or white truffles. The latter is characterized by a honey-sweet hay scent with a light garlic note. The smell is very intense, whereas the taste is more subtle. Truffle oil made from dark truffles has an earthy, nutty aroma. It has an intense flavor and a less strong scent. Truffle oil is used as a seasoning oil to give salads or other dishes a truffle flavor. It is mainly used in cold cuisine. If heated to a high temperature, the oil loses its pleasant taste. The smoke point of the oil depends largely on the underlying oil.
Truffle oil can be found as part of a vinaigrette in salads (raw zucchini salad with truffle oil), as a component of sauces or drizzled on soups. It goes excellently with pasta or pasta alternatives such as celery linguini with mushrooms, pumpkin seeds and sage . Truffle oil is used in marinades, which can give meat alternatives such as tofu or seitan a truffle note. It is also used to round off vegetable carpaccio made from beetroot , kohlrabi, zucchini, carrots, etc. It is also used with mushrooms /mushroom salads, with asparagus, lentils or with cabbage ( cauliflower and white cabbage ) . Black truffle oil is particularly suitable as an addition to mashed potatoes, as the earthy aroma harmonizes excellently with the potato . You can also add a few drops to boiled potatoes to refine them. In the same way, you can round off rice dishes such as risotto. In addition to its savoury use, truffle oil is also popular in desserts - especially in combination with honey and in pralines. Although truffles (oil) are now mainly used in haute cuisine, truffles used to be part of rural cuisine.
Making your own truffle oil
Truffle oil can be made at home. You need either 10 g of white or black truffle and 200 ml of cooking oil.Sunflower oil, safflower oil or rapeseed oil are suitable because of their mild taste. If you use the oil especially for pasta dishes, mild cold-pressed olive oil is a good base.
First, clean the truffle and cut/slice it into very thin slices. Put the slices in a sterilized bottle and pour in the desired oil. Store in a cool, dark place. After about a week, the oil will have absorbed the truffle aroma and you can eat it. The truffle slices can either be left in the oil or you can remove them and use them.
Vegan recipe for hummus with truffle oil
Ingredients (for 6 people): 500 g chickpeas, cooked, 1-2 cloves of garlic, 3 tsp truffle oil, 2 tsp cold-pressed olive oil, 2 lemons (raw, organic), 2 tsp tahini, drinking water (depending on consistency), salt ,pepper .
Preparation: Squeeze the lemons. Mix the lemon juice, garlic cloves and salt, add the chickpeas, tahini, truffle and olive oil and puree again until a creamy mixture is formed. If the consistency is too thick, add a dash of water and mix again. Season with salt and pepper. Chill briefly before serving.
Vegan recipes with truffle oil can be found under the note: " Recipes that have the most of this ingredient ".
| Not only vegans or vegetarians should read this: Vegans often eat unhealthily. Avoidable nutritional errors . |
Purchasing - Storage
Truffle oil can be found all year round in supermarkets (such as Coop, Migros, Spar, Rewe, Edeka, Billa ); information on the season for fresh truffles can be found in the linked article. The oil is often based on cold-pressed olive oil . Depending on the manufacturer, this is mixed with truffle flavoring and/or small amounts of truffles. Certain supermarkets (e.g. Aldi, Lidl, Hofer, Denner or Volg ) offer truffle oil as part of selected promotions. These usually only contain flavoring and no real truffles. Organic supermarkets ( Denn's Biomarkt and Alnatura ) also occasionally offer truffle oil. The most common truffle oil available for purchase is made from white truffles (truffle flavor), but oil made from black truffles (flavor) can also be found.
Some types of truffles that grow in Europe are among the most expensive foods on the food market. Truffle oil can also be sold at a high price, which makes it lucrative to use truffle flavoring instead of real truffles. Truffle oil labels often contain terms such as "flavoring," "natural flavoring," or "truffle flavoring." These terms mean that no real truffle was used to make the oil. Truffle oil made from real truffles has a full flavor, but is more expensive. A good alternative is homemade truffle oil. In addition to truffle flavoring, cheaper truffles are used. This means that the term "truffle" can be used, but it cannot compete with high-quality truffles in terms of aroma.
The availability of truffle oil varies depending on the size of the store, catchment area, etc. You can find our recorded food prices for the DA-CH countries above under the ingredient image - and by clicking you can see their development at various suppliers.
Cold-pressed oils (laws)
In Switzerland, an oil is considered cold-pressed if the oilseed was not heated, the pressing temperature did not exceed 50 °C and no problematic post-treatment was carried out. According to the Federal Department of Home Affairs ( EDI ), an edible oil is considered cold-pressed (or may contain synonyms such as (extra) virgin, unrefined, cold-pressed or natural) if it is obtained by pressing or centrifuging from previously unheated raw materials, the temperature during pressing did not exceed 50 °C and there was no refining, i.e. no neutralization, no treatment with adsorbents, bleaching earth and no steaming.
An oil can be called gently steamed if the refining process was limited to steaming and did not exceed 130 °C. 21
In the EU and the USA, there does not appear to be a generally applicable temperature limit set by law for cold-pressed oils. In Germany, similar values apply to those in the EDI regulation in Switzerland. However, the guidelines in Germany do not specify a permissible maximum temperature for general cold pressing. They only refer to products whose labelling and composition are not conclusively set by law (eg not for olive oil or spreadable fats). 22
On the other hand, both the EU directives and the EDI regulation on foods of plant origin, mushrooms and table salt (and their amendments) provide for special rules for the labelling of olive oils. 23,24
The terms "raw food" and "raw" are not state-protected terms, such as "organic". Although the pressing temperatures in purely mechanical cold pressing do not usually exceed 40 °C, one should not naively assume that edible oils are raw food quality. There is a suspicion that the measuring method used does not indicate the temperature in the press cylinder, where the heating is highest. In addition, the pressing pressure, the pressing speed and the moisture content of the oilseed influence the pressing temperature. If the moisture content is too low, the temperature rises during pressing and can even exceed the maximum limit of 50 °C.
With water-cooled olive oil presses (so-called "water-cooled 37°" oil presses), it is probably not even possible to say with any certainty what the exact temperature is inside the press cylinder, because the entire press cylinder is surrounded by cooling sleeves. 25
Storage tips
Store truffle oil in a cool, dry place, and it will last around 12 months unopened. Once opened, store in the refrigerator and use within a few weeks. In the refrigerator, the oil can become cloudy and flake, but this does not change the taste. If the truffle oil is warmed to room temperature, it will regain its usual properties. The aroma fades after a few weeks, even if you always close the oil tightly after use. You can continue to use it. However, if it starts to smell rancid/musty, you should stop using it. Homemade truffle oil will last around two to three months in the refrigerator.
Ingredients - Nutritional values - Calories
The ingredients of truffle oil depend on the underlying oil. The most commonly used oils are cold-pressed olive oil ,sunflower oil or a neutral-tasting vegetable oil such as rapeseed oil .
What nutritional values does truffle oil have? Regardless of the base oil, the macronutrients in truffle oil consist exclusively of fat (100%), depending on the oil , saturated fats may also be included. Carbohydrates and protein are not present. The calorie content is therefore very high and amounts to around 900 kcal/100g. 27
The fatty acid ratio depends on the base oil. Both cold-pressed olive oil andsunflower oil have a poor (unbalanced) ratio of linoleic acid (omega-6 fatty acid = 58 g/100g) to alpha-linolenic acid (omega-3 fatty acid = 0.3 g/100g). In this case, the LA:ALA ratio of the selected truffle oil is 191:1. The ratio of olive oil is 12:1. Sunflower oil has no alpha-linolenic acid and therefore an even poorer fatty acid ratio (>999:1). 12 Ideally, you should consume a ratio of 1:1 through your diet. However, the Western diet assumes an intake of 15:1 to 20:1. 4 This shows that we usually consume enough or too much linoleic acid, whereas we should consciously ensure that we consume sufficient alpha-linolenic acid. If you find a truffle oil based on rapeseed oil, this is preferable because it has a fatty acid ratio of 2:1. 12
The vitamin E content is very high at 62 mg/100g (520% of the daily requirement), while hazelnut oil has slightly less at 47 mg/100g and hemp oil at 41 mg/100g.
It contains 5.9 µg of vitamin K per 100g - similar to safflower oil (7.1 µg per 100g) or palm oil (8 µg per 100g). Pumpkin seed oil contains a lot of the vitamin at 112 µg per 100g.
The complete ingredients of truffle oil, the coverage of the daily requirement and comparison values with other ingredients can be found in our nutrient tables. In the article Nutrients explained you will get a detailed insight into the topic.
Health effects
Is truffle oil healthy? Whether truffle oil is healthy depends on the base oil, as this determines most of the bioactive components. Bothsunflower and olive oil have a poor fatty acid ratio (LA:ALA) and can therefore have a negative impact on health. 12 Too much linoleic acid is said to have a potentially pro-inflammatory character. In addition, our body can only synthesize the omega-3 fatty acids DHA and EPA from alpha-linolenic acid, which is considered to have anti-inflammatory properties. 6, 12 This rarely used base oil made from rapeseed oil has a good fatty acid ratio (2:1). 12 In this context, it should be mentioned that cold-pressed olive oil contains natural antioxidants that are said to have anti-inflammatory effects, similar to certain anti-inflammatory, fever-reducing painkillers. 2,3 However, poor quality olive oil is often used in truffle oil. 5
Please note: Truffle oil is a concentrated food that has gone through various processing steps. In general, whole, unprocessed foods such as nuts or seeds are preferable (and much healthier for losing weight !). Truffle oil is often used to add flavor. Alternatively, you can add small amounts of a real truffle - but the price is very high.
Various American doctors and authors take an even stricter approach, rejecting oil on principle and recommending switching to nuts and seeds. We are talking about Dean Ornish, T. Colin Campbell, John A. McDougall, Michael Klaper, Caldwell Esselstyn, Michael Greger, Joel Fuhrman and Neal D. Barnard, who basically explain that a diet high in animal fats and proteins (like the standard American diet) is bad for your health. You can find details in the text " Vegans often eat unhealthily. Avoidable nutritional mistakes. "
Secondary plant substances
Many of the health effects of truffle oil can be attributed to the secondary plant substances it contains. Our article on secondary plant substances provides an overview of the classification of substance groups, their occurrence in food and possible effects on humans. Truffles, the basis of truffle oil, contain the following secondary plant substances, among others:
- Isoprenoids: Tetraterpenes: Carotenoids (beta-carotene); Tritrepenes: Steroids: sterols (ergosterol, brassicasterol, campesterol, stigmasterol,beta-sitosterol, fungisterol, lanosterol), steroids, saponins (tuberoside); monoterpenes (carveol, p-cymene, limonene); Sesquiterpenes (Guaiene) 17,20, 28
- Polyphenols: Phenolic acids: hydroxybenzoic acids (syringic acid), hydroxycinnamic acids (ferulic acid, p-coumaric acid, cinnamic acid); flavonoids: anthocyanins, flavanols (catechin) 17,18, 28
- Organic sulphur-containing compounds: sulphides (dimethyl sulphide, bis(methylthio)methane 18
- Other organic compounds: aldehydes; ketones; esters 18
However, it should be noted that the composition of the secondary plant substances in truffle oil can vary depending on the variety, time of harvest, cultivation conditions and production process. Therefore, quantities are only of limited use and should only be understood roughly.
In the case of truffle oil made from real truffles, the base oil absorbs the truffle's volatile aromatic components. 19 Depending on the type of truffle, this is composed of different components, some of which are secondary plant substances. Dimethyl sulfide, bis(methylthio)methane and sterols are examples of these aroma components. 18,20 The volatile aromatic substances in truffle oil consist mainly of terpenes, esters, aldehydes, ketones and sulfur-containing components. 18 We do not know to what extent the aroma components contained in them affect health. Depending on the type, truffles themselves are said to have antioxidant, antimicrobial, antiviral, antimutagenic, anti-inflammatory, antidepressant and hepatoprotective properties. 17, 18,28
However, real truffles are often not used to flavor the oil, but synthetic flavorings are used instead. These are mixed with the oil and imitate the flavor. 14 In the finished truffle oil, the added flavor components are found instead of the natural ones.
Folk medicine - natural medicine
Desert truffles are used in traditional medicine to treat infections, weakness, wounds, colds, arthritis, rheumatism or to increase fertility in men. 7,8 Traditional Arabic medicine uses the juice of the desert truffle to clean the eyes and to treat eye inflammation. Today, desert truffles are known as an aphrodisiac. Juices from certain truffles are considered beneficial for the skin. 8
Ecological footprint - animal welfare
The ecological footprint and the water footprint of truffle oil depend on the base oil. The CO 2 footprint of olive oil andsunflower oil is around 3.2 kg CO 2 eq/kg, similar to that of rapeseed oil . 11 We are not aware of any directly comparable figures for the finished truffle oil.
The water footprint of olive oil is 900,000 l water eq/kg, for sunflower oil it is 7,000 l water eq/kg and for rapeseed oil it is 800 l water eq/kg. 11 These figures come from a German calculation "at the supermarket checkout" by the IFEU ( Institute for Energy and Environmental Research Heidelberg ), and in some cases they differ greatly from another source: Mekkonnen (Netherlands) calculates 4,300 l/kg for rapeseed oil, 6,800 l/kg for sunflower oil and 14,500 l/kg for olive oil. 26 We are not aware of any comparable figures for the finished truffle oil. However, the water footprint of olive oil is so significant that truffle oil made from olive oil has the worst water footprint, regardless of the source and further processing.
As a result of global warming, it is expected that there will be less rainfall in the Mediterranean region. This decrease may increase water stress and limit truffle growth in these regions. 9 Truffle plantations face the challenge of finding suitable water management without increasing water stress in the region. Another option is to cultivate truffles further north, where there is more rainfall. 9 A study of black truffles in this region found that they produced higher yields in years with lower average summer temperatures than in years with higher temperatures. This sensitivity of truffles to high summer temperatures and other climate-dependent factors, such as forest fires or pests, makes truffle production more difficult. 1 0
For detailed explanations of various sustainability indicators (such as ecological footprint, CO2 footprint, water footprint), see our article: What does the ecological footprint mean?
Worldwide distribution - cultivation
Truffles grow wild in much of Europe, Australia, the USA and in some regions of China, Japan and North Africa. 1,8,13 The species that grows there varies from region to region. Truffles prefer forests with mixed trees and some undergrowth to maintain moisture. They are often found along streams, hiking trails and under pine or poplar trees.
In general, truffles can be divided into two groups: the real truffle (genus: Tuber ) and the desert truffle (genera: Termania, Terfezia ). 8 Each type of truffle requires different soil and climatic conditions, which is why the desert truffle can also grow in very dry areas. A few tree families, such as maple or cedar, are not associated with truffle-forming fungi. 1
Research into truffle cultivation began in the mid-19th century, and in 1885 ectomycorrhiza, a symbiosis of the fungus with a host tree, was discovered. It was not until the late 1970s that the first truffles were harvested in French and Italian truffle plantations using artificially inoculated seedlings. The most commonly cultivated truffle is Tuber melanosporum - the French truffle. 13 The truffle species T. melanosporum, T. aestivum and T. brochii are cultivated in North America, China, Chile, Argentina, New Zealand, Australia and Europe. 8
Despite successful cultivation, most truffles are collected in natural areas and not in artificial truffle plantations. Truffle cultivation could be an alternative source of income for abandoned land and to promote underdeveloped areas. 13
Cultivation - Harvest
Truffles usually grow 2.5 to 15 cm below the ground (hypogeous). 1,13 The soil should have a pH of around 7 to 8. 19 Truffles are the fruiting body and reproductive organ of various types of fungi. 1,13 In nature, the spread of spores depends on animals that eat the truffles and their spores and then spread them through their excretions. 13 Truffles therefore develop very intense aromas to attract animals. 14 In truffle cultivation, however, the host plant is artificially "inoculated" with truffles. 8
Truffles live in symbiosis with certain host plants. The fungus covers the fine roots of the host with a layer of fungal tissue. The hosts receive water and minerals from the truffles, and in return the truffles receive carbohydrates and a habitat from the tree. Truffles have not yet been able to produce fruit outside of the host plant. 8, 13 Possible hosts of the genus Tuber include birch, hazelnut, beech and oak. 18
The growth of the truffle depends on the humidity and warmth of the soil. Under ideal conditions, the first truffles can be harvested on plantations after three years. It usually takes five to ten years. After this time, the harvest increases for up to 20 years. A harvest of 15 to 20 kg/ha is considered good. 13 T. magnatum (white truffle) is harvested between mid-October and the end of January, T. melanosporum (black truffle) from the end of November to the beginning of March, T. aestivum (summer truffle) in September, late December or the end of January, Termania nivea and Terfezia claveryi (desert truffle) from February to April. 18
Industrial production
When producing truffle oil, no direct pressing process is used: truffles are added to a base oil (often olive oil orsunflower oil ). The oil takes on the truffle aroma after a short time through direct contact with the truffle. It can then be sold or eaten. Aroma transfer via ultrasound is also possible, and other methods without direct contact are currently being researched. 16
However, truffle oil is often not flavored with real truffles. Certain nature-identical flavorings are used to imitate the taste/smell of truffle oil from real truffles. The volatile component that is largely responsible for the aroma of white truffles has been identified. This substance (2,4-dithiapentane) is originally known from the oil industry as a solvent. It is cheap, has good stability and low toxicity, which is why it is used as a natural flavor in truffle oil. However, it is not only used to enhance the aroma of white truffles, but also in truffle oils from other types of truffles, which are actually characterized by a different smell/aroma. 14
They were also able to identify the main aroma components of the black truffle ( T. melanosporum ) and summer truffle ( T. aestivum ). 15 A mixture of dimethyl sulfide (DMS) and 2-methylbutunal is said to mimic the aroma of the black truffle. It is used as a "truffle flavor" in truffle products such as truffle oil, which can confuse consumers and diminish the reputation of the truffle. 16
Further information
Truffles are the fruiting bodies of various ascomycetes (Ascomycota). True truffles ( Tuber ) are a genus of fungi from the Tuberaceae family. 1 Another important truffle family is the Terfeziaceae family (desert truffles). 8 The most valuable truffles include T. magnatum (white truffle), T. melanosporum (black truffle) and T. aestivum (summer truffle). They all belong to the Tuber genus. Truffle oil is made from true truffles ( Tuber ) or the aromatic substances found in them. 13
Alternative names
Truffle oil is called truffle oil in English. White truffle oil is sometimes also available with the label "olio al tartufo bianco", truffle oil made from black truffles with "olio al tartufo nero".
Other uses
The aroma of truffles is also used in the cosmetics and perfume industry. Here, almost exclusively truffle extracts or truffle aromas are used, not real truffles. Truffles are considered an aphrodisiac due to their aroma. Truffles have been said to have this effect since the 18th century and have been used as such. 17 Chocolate truffles are a popular dessert. They were named after the mushroom because of their appearance. However, they do not contain any truffles.
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