Appropriate water blanching treatment to keep quality and color of Agaricus bisporus slices

Button mushroom (Agaricus bisporus) is one of the most popular and valuable mushrooms in the world, and it is usually processed for long-time storage. Button mushrooms are a good source of vitamins, protein, phenolics, polysaccharose and many mineral elements. The enzyme polyphenoloxidase (PPO) is the responsible cause of this deteriorative process. The production of heat-sterilized preserves represents most usual long-term preservation. Sterilization accounts for more than 60 percent of industrially processed mushrooms. In the preparation process of sterilized mushrooms, blanching is an important pre-treatment, which objectives may be: (i) to reduce enzymatic browning through thermal inactivation of PPO; (ii) to induce volume contraction (shrinkage) to avoid this occurrence at the sterilization stage; (iii) to make the product more pliable to facilitate filling operations. Results showed that blanching significantly reduced the content of ascorbic acid and total phenolic, antioxidant capacity, and color. Asc