Physiological and textural response of truffles during low-temperature storage

Truffles (Tuber aestivum Vitt.) were stored at 0 degrees C, 5 degrees C and 10 degrees C for 40 d, and ethylene, carbon dioxide and ethane production was measured. No difference was observed between samples kept at 0 degrees C and 5 degrees C while at 10 degrees C truffles underwent decay and produced high amounts of ethylene, ethane and carbon dioxide. When truffles were stored in either low oxygen (1%) or high CO2 (60%) at 5 degrees C and 10 degrees C, ethylene was better controlled by high CO2 than low O-2. Even the weight loss of truffles treated in high CO2 was reduced. Studying the rheological characteristics by using TPA (Texture Profile Analysis), we observed that truffles stored in high CO2 at 5 degrees C kept values of hardness, gumminess and chewiness similar to those of fresh samples. Frozen-thawed samples, as a commercial comparison, showed completely altered texture. The shape of TPA peaks are useful for the definition of truffle pulp texture. Carbon dioxide treatment at 5 degrees C could be a good technique for storing fresh truffles because truffles keep their strong, typical odour better than samples kept in low oxygen which in addition was not able to control weight loss.