In a commercial oyster mushroom farm, fruiting body base (FBB) was not harvested compared to the common cap and stem of the fruiting body parts, and thus remained as waste. In the present study, unused FBB was powdered and subjected to proximate analysis as floured FBB (FFBB). FFBB was found to contain 71.2% carbohydrate, 8.93% moisture, 7.18% fibre, 5.72% ash, 5.57% protein, and 1.4% fat, while raw-FBB (RFBB) contained 7.57% carbohydrate, 84.4% moisture, 5.17% fibre, 5.72% ash, 1.54% protein, and 0.85% fat. The high carbohydrate content of FFBB was subjected to hot-water extraction and yielded 7.40 g of FFBB polysaccharide (FFBBP). Total phenolic content (TPC) of FFBBP contained 1.80 mg gallic acid equivalents (GAE)/g, exhibiting the reducing activity of 1.74 mM Fe(II)/g by ferric reducing antioxidant power assay, and reduced the stable 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonate radical forms at IC 50 of 25.08 mg/mL, which was comparable with other parts of oyster mushroom species. Different percentages of FFBB mixtures were utilized in the production of cookies (10% and 20%) and steamed buns (10%, 20% and 30%). Thirty-seven panellists were selected for sensory testing, which showed that 10% of FFBB in a steamed bun was more acceptable than 30% of FFBB, while the overall acceptance of cookies with 10% FBB was insignificant (p > 0.05) but 20% FFBB in cookies was significantly different from control (p < 0.05). This study indicates that potential value of FFBB as an economical antioxidative flour in the development of functional foods.

A rare Malaysian tiger milk mushroom Lignosus rhinocerus strain ABI (LRSA) was morphologically identified based on its pileus, stipe, and sclerotium. LRSA (515 bp) was sequenced and found to have 99% similar to L. rhinocerus strains CH31 and CH2. Phylogenetically, evolutionary distance (Knuc) and plasmid-matching software (ApE) for sequences of matching fungal species were used to verify that the isolate belonged to the L. rhinocerus species. The strain was cultured in a stirred-tank bioreactor and a mycelial β-glucan (G) was extracted for compound characterization. The structure of exopolysaccharide extract from mycelium of LRSA was studied using Fourier-transform infrared spectroscopy (FT-IR) and one-dimensional (1D) and two-dimensional (2D) Nuclear Magnetic Resonance (NMR). FT-IR spectroscopy showed that G exhibited a similar β-glycosidic structure to the standard (laminarin), and the presence of characteristic bands at 3277, 2919, 1638, 1545, 1400, 1078, and 896 cm−1 confirmed the similarities. 1H and 13C NMR, as well as 2D NMR: homonuclear correlation spectroscopy (COSY), total correlation spectroscopy (TOCSY), heteronuclear multiple quantum coherence (HMQC), and heteronuclear multiple bond coherence (HMBC) spectra, were used for structural elucidation of the β-glucan and confirmed the extracted material as (1,3)-β-D-glucan. In addition, the G compound exhibited antioxidant activities through total phenolic content (4.47 mg gallic acid equivalents/g), 2, 2-diphenyl-1-picrylhydrazyl (11.48 mg/mL), and ferric reducing antioxidant power (0.56 mg/mL) assays. These findings may facilitate the development of rare G production in a high-scale bioreactor using LRSA.