Enhancing Cordyceps Sinensis shelf life: The role of liquid nitrogen spray freezing in maintaining hypha structure and reducing metabolic degradation.

Cordyceps sinensis (C. sinensis) is a valuable edible fungus, known for its therapeutic benefits, including immune enhancement and anti-inflammatory effects, making it an important component in nutritional applications. However, its delicate nature makes long-term storage challenging, with conventional freezing often leading to the loss of bioactive compounds. This study evaluates liquid nitrogen spray freezing (LNSF) at -80 °C and - 120 °C compared to conventional freezing (CF) at -20 °C over 90 days of storage. Our findings show that LNSF at -120 °C (LNSF-120) preserved superior color quality, sensory attributes, and reduced thawing loss at endpoint, while both LNSF temperatures stabilized total sugars, amino acids, cordycepin, adenosine levels, as well as antioxidant enzyme activities and free radical scavenging capacities. These results suggest that LNSF is a superior method for the long-term preservation of C. sinensis, with diverse advantages and their corresponding shelf lives associated with the two different LNSF temperatures.