# Physicochemical, Functional, and Antioxidative Characteristics of Oyster Mushrooms
## 3 Physicochemical Properties of Oyster Mushroom
### Physical Properties  
Oyster mushrooms exhibit a firm but flexible texture, with hardness, springiness, and chewiness that can vary depending on how they are processed. Studies using texture profile analysis (TPA) found that compression tests on mushroom stems show their ability to retain structure when compressed, making them suitable as meat substitutes in some culinary applications. Processing methods like drying also affect the texture, with sun and vacuum drying showing the least effect on firmness compared to hot air drying, which can increase hardness levels due to moisture reduction [26; 27; 28; 29]. The colour profile of oyster mushrooms is typically measured using the L*, a*, and b* values, indicating lightness, red-green, and yellow-blue scales, respectively. Fresh oyster mushrooms generally display a light, off-white colour with slight yellowish hues. However, drying can darken them; for example, vacuum drying helps retain a closer-to-fresh colour; sun drying or hot air drying can result in browner shades, impacting visual appeal and potential application in food products [30; 31]. Oyster mushrooms are known for their high moisture content, often around 85-90% in fresh samples, making them highly perishable. Drying methods significantly impact water retention, where methods like vacuum and hot air drying reduce moisture to below 10%, making mushrooms less prone to spoilage and lighter in weight. This high water retention also affects their rehydrated texture and enhances their utility in foods that require water absorption, such as soups or sauces [32; 33]. \begin{table}
\begin{tabular}{c c c c c c} \hline
**Species/family** & **Group** & **Compound** & **Properties** & **Content/1000 g DM** & **Refs. ** \\ \hline _Patents overtants_ & & Beta-glycans & Immunomodulatory anti-inflammatory, anti-cancer, cholesterol-lowering & -6 g-7 g & [20, 21] \\ _Patents traits traits_ & Polysaccharides & Complex sugars & Antioxidant, immune-boosting, anti-tumor effects & -50 g-60 g & [22, 23, 24] \\ _Singer_ & & Polysaccharides & Total dietary fibre & Stimulation of intestinal bacterial flow, regulation of intestinal function, prevention of intestinal disease, stabilization of blood glucose levels. & 42.87 g-52,31 g \\ \hline \multirow{6}{*}{_Plarantana_ *} & Saccharomyces/ & Total carbohydrates & Macroutrients & 45.25 g-63.22 g \\  & Products & Total proteins & Macroutrients & 2.48 g-33.16 g \\  & Lipids & Total fats & Macroutrients & 0.91 g-26.6 \\ \cline{2-6}  & & Sodium (Na) & Electrolyte balance of body fluids, ensuring the functioning of muscles and & 42.07 mg-338.65 mg \\  & & Potassium (K) & Nerve function and regulation of muscle contractions, including the heart & 722.24 mg-1139.40 mg \\  & & Calcium (Ca) & Influence on the blood pressure, influence on muscle contractility, functioning of the nervous system and heart muscle. & 155.21 mg-1110.11 mg \\  & & Iron (Fe) & Conti is known; it determines the delivery of oxygen to tissues and organs, and present in myoglobin, it determines the oxygenation of muscles.