They would develop a disagreeable odour and they become spongy and dry. Truffles showing this kind of characteristics are no longer ideal for consumption. When looking for truffles, make sure that they are harvested in their right age. There are truffles which are preserved so that it could be distributed. Here are some varieties of truffles which are very much popular: Oregon white truffle this truffle is firm and could even be brittle. It is white when still young and would develop an orange-brown color as it matures. Oregon brown truffle- it is reddish-brown on the outside, and sort of grey in the inside. They are low in calories but contain high amount of vegetable protein, chitin, iron, zinc, fiber, amino acids, vitamins and minerals. Calcium, minerals, vitamins B and C are commonly found in several mushrooms. Truffles are different from other mushrooms since it is a hypogean or an underground mushroom. With its strong flavor and rich aroma, you can t go wrong with using gourmet truffles as an enhancer in any dish, turning it from bland to flavorful. It s no wonder why chefs and savvy food connoisseurs love to experiment different dishes with truffles as an ingredient. Why don t you use one in your own kitchen? Then you re in luck because commercially significant truffles are more abundant in European countries than in America. If you are located in California, the most popular and abundant truffle variety there is the Oregon truffle, whose popularity is comparable to that of the Italian truffle. The Oregon truffle is less expensive than other truffle types, as it usually costs about $150 per pound. Summer white truffle - Even if it has a milder aroma than its winter counterpart, the summer white truffle still has the pungent smell that is a trademark of white truffles. It is exactly the same species of truffles as the winter type, except that it is harvested in summer from January through April.