Nutritional Quality and Biological Application of Mushroom Protein as a Novel Protein Alternative.

PURPOSE OF REVIEW: Global concerns about population growth, economic, and nutritional transitions and health have led to the search for a low-cost protein alternative to animal origins. This review provides an overview of the viability of exploring mushroom protein as a future protein alternative considering the nutritional value, quality, digestibility, and biological benefits. RECENT FINDINGS: Plant proteins are commonly used as alternatives to animal proteins, but the majority of them are low in quality due to a lack of one or more essential amino acids. Edible mushroom proteins usually have a complete essential amino acid profile, meet dietary requirements, and provide economic advantages over animal and plant sources. Mushroom proteins may provide health advantages by eliciting antioxidant, antitumor, angiotensin-converting enzyme (ACE), inhibitory and antimicrobial properties over animal proteins. Protein concentrates, hydrolysates, and peptides from mushrooms are being used to improve human health. Also, edible mushrooms can be used to fortify traditional food to increase protein value and functional qualities. These characteristics highlight mushroom proteins as inexpensive, high-quality proteins that can be used as a meat alternative, as pharmaceuticals, and as treatments to alleviate malnutrition. Edible mushroom proteins are high in quality, low in cost, widely available, and meet environmental and social requirements, making them suitable as sustainable alternative proteins.

Bioactive composition and modulatory effects of Hed-Tean-Rad Mushroom, Macrocybe crassa on gut microbiota.

Macrocybe crassa (or Tricholoma crassum) is a nutrient-dense wild edible mushroom native to Thailand. The mushroom extract and its constituents have remarkable biological characteristics, but the influence of the powder on the human gut microbiota is unknown. This study investigated the bioactive composition and modulatory properties of M. crassa powder on gut microbial composition and short-chain fatty acids (SCFA) production. The fermentation of M. crassa powder by human intestinal microbiota released SCFA, mainly acetic acid, propionic acid and butyric acid. M. crassa powder significantly modulated the microbiota by increasing the relative abundances of Bifidobacterium, Lactobacillus/Enterococcus group, Atopobium, Bacteroidaceae/Prevotellaceae, and C. coccoides. F. prausnitzii, Roseburia genus, C. histolyticum and C. cluster IX, similar to that of Fructooligosaccharides (FOS). With M. crassa powder, high content of propionic acid was observed, as well as a number of Bacteroidaceae/Prevotellaceae and C. cluster IX. On the other hand, FOS caused a high acetic acid concentration and a population of Bifidobacterium spp., Atopobium cluster, Bacteroidaceae/Prevotellaceae, and C. coccoides. Therefore, this work will significantly contribute to filling the knowledge gap and revealing the significance of M. crassa in the pharmaceutical industry.

Selection of pretreatment method and mannanase enzyme to improve the functionality of palm kernel cake.

Palm kernel cake (PKC) is a by-product of palm kernel oil extraction with moderate nutritional value, containing 30-35% ß-mannan, which is indigestible, slows growth, and reduces feed efficiency. PKC can be improved by mannanase hydrolysis, but the effectiveness of mannanase is dependent on the microbial source. Thus, the effect of steam pretreatment and bacterial mannanases on PKC quality was investigated. PKC was pretreated by steaming and hydrolyzed in the small intestine by various mannanases. The contents of reducing sugar, total sugar, and protein release were measured. Steamed PKC had a significant increase in protein (16.95 ± 0.14 to 20.98 ± 0.13%) and a substantial decrease in hemicellulose (29.52 ± 0.44 to 3.46 ± 0.88%) and lignin (8.94 ± 0.28 to 1.40 ± 0.22%). Mannanases from Escherichia coli-KMAN-3 and E. coli-Man6.7 recorded the highest activities, followed by commercial mannanase, Bacillus circulans NT6.7 and B. amyloliquefaciens NT6.3 mannanases, orderly. B. circulans NT6.7 and B. amyloliquefaciens NT6.3 had multi-activities that include glucanase (3.10 ± 0.04% and 2.47 ± 0.02%) and amylase (1.74 ± 0.03% and 1.38 ± 0.04%), respectively. B. amyloliquefaciens NT6.3 mannanase hydrolyzed steamed PKC to release more reducing sugar, total sugar, and protein than hydrolyzed raw PKC. In raw and steamed PKC, B. amyloliquefaciens NT6.3 mannanase produced the highest reducing sugar release. As a result, steam pretreatment and mannanase hydrolysis, particularly from B. amyloliquefaciens, can be used to increase the functioning of PKC and develop new feed ingredients for monogastric animals at a reasonable cost.

In vitro gastrointestinal digestion of Lentinus squarrosulus powder and impact on human fecal microbiota.

Humans have long-used mushrooms as food and medicine, but digestion and colonic fermentation of most mushrooms, including Lentinus squarrosulus is markedly unknown. Here, nutritional profile, digestion and colonic fermentation of L. squarrosulus powder (LP) were determined. The powder contained mainly carbohydrate and protein. SEM and F-TIR analysis of the resistant hydrolysate (RH) revealed that the structure and ratio of carbohydrate and protein components were altered, and released known immunomodulation agents; beta-glucans and mannose. Both LP and RH promoted selected probiotic bacteria, especially Bifidobacterium strains. Using fecal microbiota of five volunteers (V1, V2, V3, V4 and V5), RH stimulated the microbiota of all used volunteers, via decreasing the ratio of Firmicutes/Bacteroidetes ranging from 1.3 to 8.2 times. Also, RH increased the relative abundance of vital immunomodulators; Bacteroides, Bifidobacterium, Clostridium cluster XIVa and IV, and Sutterella. Additionally, RH fermentation enriched the content of branch-chain fatty acids (BCFA) and short-chain fatty acids (SCFA), indicating protein and carbohydrate usage. Notably, propionic and butyric acids were abundant in V1, V2 and V3, while in V4 and V5, acetic and butyric acids were most enriched. Suggesting L. squarrosulus as functional mushroom to improve health and prevent diseases by enhancing gut health.

Functional composition and antioxidant property of crude polysaccharides from the fruiting bodies of Lentinus squarrosulus.

Lentinus squarrosulus (Hed Khon Khao) is a source of bioactive polysaccharides. Three L. squarrosulus crude polysaccharides (LSPs) were subjected to cold water (LSP-CP), hot water (LSP-HP), and aqueous alkaline (LSP-AP) extractions, and their functional compositions and radical scavenging activities were compared. Synchrotron radiation FTIR (SR-FTIR) spectra and PCA plot analysis in the bio-regions (4000-400 cm-1) revealed that functional composition LSPs differ significantly (P < 0.05). All LSPs had lipids, protein, and polysaccharides such as ß-glucan. The major monosaccharides in LSP-CP and LSP-HP are d-galactose, d-glucose, and d-mannose at different proportions, while LSP-AP contained mainly d-glucose. Also, fucose and xylose were present in all the LSPs. LSP-CP, LSP-HP and LSP-AP induced maximum 1,1-diphenyl-2- picrylhydrazyl (DPPH) radical scavenging activity of 78.93 ± 0.42% at 3 mg/mL, 79.16 ± 1.43% at 3 mg/mL and 65.26 ± 1.74% at 5 mg/mL, whiles on 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS), their maximum activities were 98.94 ± 0.16% at 3 mg/mL, 97.42 ± 0.76% at 3 mg/mL and 47.24 ± 0.045% at 5 mg/mL, respectively. The results showed that LSP-CP and LSP-HP are good ABTS scavengers, whiles LSP-AP is poor ABTS scavenger. In overall, LSPs consist of essential functional compositions and could be used as natural antioxidants. This exploitation of fungal fruiting body extracts increased the potential use of L. squarrosulus in food and medicinal industries.