Study of Biochemical Changes on Freeze-Dried and Conventionally Dried White Button Mushroom as a Sustainable Method of Food Preservation

Abstract

The conventional biotechnology and the advanced agricultural practices may not be sufficient to meet the rising and expected high protein demands. Presently mushroom has occupied a high status because of its nutritive value, i.e. it is rich in protein and fibre along with several vitamins and minerals contents, it contains virtually no fat and cholesterol. However, preservation of mushroom during its storage and distribution has always been a challenge. Cryogenic freezing of food material is the only valuable option for its preservation. The principle behind the freeze drying involves the triple point of water. It occurs at 0 °C temperature and 4.7 mm of Hg pressure. Dehydration of food material has taken place by sublimation process. A comparative study on freeze-dried and other conventional dried mushrooms has been performed. White button mushrooms were preserved by hot air oven method and freeze-drying method. Nutritional parameters like moisture, protein, crude fat, reducing sugars, ash content, crude fibre, ascorbic acid content and sensory evaluation like texture, flavour, aroma, shape, rehydration ratio, particle nature and storage stability of samples dried by different methods have been studied by different chemical methods. The freeze-drying technique has been found excellent for mushroom dehydration, since the quality of product is found to be the best in terms of its colour, flavour, texture and nutritive value. Therefore, this method is found to be useful for preservation of mushrooms.