Mushroom Protein Research Articles

King Boletus mushroom‐derived bioactive protein hydrolysate: characterisation, antioxidant, ACE inhibitory and cytotoxic activities

SummaryThe enzymatic‐bromelain King Boletus mushroom protein hydrolysate (eb‐KBM) was determined in terms of the biological properties (antioxidant, antihypertensive and cytotoxic activities) and compared with unhydrolysed or water‐soluble King Boletus mushroom extract (ws‐KBM). The eb‐KBM showed high antioxidant activities, as assessed by ABTS (70.9%), DPPH (60.9%) assays and hydroxyl radicals (66.0%) scavenging method. Angiotensin‐I converting enzyme (ACE) inhibitory activity of eb‐KBM was 21.1% at 1 mg protein mL−1. Anticancer activity‐relevant cytotoxicity of eb‐KBM in ChaGo‐K1 (undifferentiated lung carcinoma) and HEP‐G2 (hepatocarcinoma) cells was higher than that of ws‐KBM, with lower IC50 values (6.43 and 6.35 µg mL−1, respectively). The great biological activities of eb‐KBM were related to its amino acid composition, with high contents of hydrophobic amino acids and aromatic amino acids. These results indicate that King Boletus mushroom protein hydrolysate or bioactive peptide could be used as natural antioxidative, ACE inhibitory and anticancer activities in the nutraceutical and pharmaceutical industries.

Effect of wheat bran and maize straw substrates on the agronomic traits and nutritional content of Auricularia cornea cv. Yu Muer

Auricularia cornea cv. Yu Muer is a new edible mushroom with high nutritional value and economic value. In this study, we determined the effect of maize straw (MS) and wheat bran (WB) on the agronomic traits and nutritional content of A. cornea cv. Yu Muer, Thirteen substrate formulations of WB and MS, supplemented with oak sawdust, were compared. The addition of 15% WB to sawdust and a C/N ratio of 55-70 was found optimal for the cultivation of A. cornea cv. Yu Muer. The first flush yield was significantly higher for substrate C1 containing only MS (83%). The mushroom cultivated on substrate C4 (25% MS + 29.05% CS + 29.05% FS) had the highest yield (521.26 g) and biological efficiency (130%) compared to control. The protein content ranged from 10-12.5 g/100 g and total polysaccharide content from 24-32 g/100 g. Substrate formulas with different MS proportions had a significant increase in crude protein, crude fiber, total polysaccharides, crude fat, and ash content. The amount of MS added was positively correlated with protein and ash content of mushrooms. Based on agronomic traits and nutrient contents, MS could be used as a substitute for sawdust in cultivating A. cornea cv. Yu Muer.

What Can Mushroom Proteins Teach Us about Lipid Rafts?

The lipid raft hypothesis emerged as a need to explain the lateral organization and behavior of lipids in the environment of biological membranes. The idea, that lipids segregate in biological membranes to form liquid-disordered and liquid-ordered states, was faced with a challenge: to show that lipid-ordered domains, enriched in sphingomyelin and cholesterol, actually exist in vivo. A great deal of indirect evidence and the use of lipid-binding probes supported this idea, but there was a lack of tools to demonstrate the existence of such domains in living cells. A whole new toolbox had to be invented to biochemically characterize lipid rafts and to define how they are involved in several cellular functions. A potential solution came from basic biochemical experiments in the late 1970s, showing that some mushroom extracts exert hemolytic activities. These activities were later assigned to aegerolysin-based sphingomyelin/cholesterol-specific cytolytic protein complexes. Recently, six sphingomyelin/cholesterol binding proteins from different mushrooms have been identified and have provided some insight into the nature of sphingomyelin/cholesterol-rich domains in living vertebrate cells. In this review, we dissect the accumulated knowledge and introduce the mushroom lipid raft binding proteins as molecules of choice to study the dynamics and origins of these liquid-ordered domains in mammalian cells.

Comparative study on the physical entrapment of soy and mushroom proteins on the durability of bacterial cellulose bio\u2010leather

This study aimed to develop eco-friendly bacterial cellulose (BC) bio-leather with improved durability using plant-based proteins, namely soy protein isolate (SPI) and mushroom protein (MP), which were physically entrapped inside the BC, respectively. The amounts of the plant-based proteins were determined by evaluating the tensile strength of BC bio-leather, and were found to be 20 wt% and 50 wt% of BC for SPI and MP, respectively. The enhanced properties of mechanical strength and durability of BC bio-leather were measured in terms of changes in water resistance, tensile strength, flexibility, crease recovery, and dimensional stability. The durability of BC was improved after the entrapment of proteins, and moreover, the durability of BC entrapped with plant-based proteins was further improved by the addition of glycerol. Especially, BC entrapped with MP and glycerol had better water resistance, tensile strength, flexibility, and crease recovery compared to cowhide leather. The chemical and physical structures of BC bio-leathers were studied using Fourier transform-infrared spectroscopy, X-ray diffraction, field-emission scanning electron microscopy, and energy dispersive X-ray spectroscopy analyses. From the results, it was confirmed that BC entrapped with MP and glycerol could be a suitable leather substitute.

Physicochemical and emulsifying properties of protein isolated from Phlebopus portentosus

Edible mushroom proteins have attracted increasing interest due to their high content and nutritional quality. In the present work, Phlebopus portentosus protein isolate (PPI) was extracted from P. portentosus fruiting bodies using alkali extraction and isoelectric precipitation method, and the physicochemical and emulsifying properties of PPI were systematically investigated. PPI had a good balance of essential amino acids, but showed low solubility in water. Therefore, a protein nanoparticulation strategy was used to prepare stable PPI nanoparticle (PPIP) dispersions. PPIP showed an average diameter of 225.91 nm, an oil-in-water three-phase contact angle (θo/w) of 95.62°, and fast adsorption behavior at the oil-water interfaces. The near-neutral wettability and high interfacial ability facilitate PPIP as a single emulsifier to fabricate a double Pickering emulsion via the one-step homogenization. The properties of PPIP-stabilized double emulsions were dependent on the protein concentration and oil content. For example, an increase in protein concentration resulted in the decrease of small internal droplet number, droplet size, and storage modulus; an increase in oil content also led to the decrease in the droplet size. These results suggest that PPI has a great potential to be used as emulsifiers for preparing double emulsions.

Edible Mushroom Protein Content and Antioxidant Capacity Increase the Longevity of Anastrepha ludens Fruit Flies.

This study aimed to determine the effect of the protein and antioxidant contents of edible mushrooms on the longevity of the fruit fly (Anastrepha ludens). The contents of protein (Bradford assay), antioxidants (DPPH and ABTS assays), total phenols, and flavonoids in nine strains of different edible mushroom species were determined. Freeze-dried and finely ground complete mushroom fruiting bodies were used to feed the flies, with a concentration of 0.5% in the diet. Male and female fruit flies, both fertile and sterile, were used in this study. Two controls were used: the standard fly diet and a diet supplemented with cinnamon as a food rich in antioxidants. Differences in protein and antioxidant contents were found among the evaluated strains. Differences were also observed in the responses of female and male flies as well as between the responses of fertile and sterile flies. Overall, the sterile flies lived longer. The addition of mushrooms in the diet resulted in greater longevity than in the controls. The use of sterile flies allowed observation of the effect of proteins and antioxidants on reproduction and the subsequent effect of reproduction on longevity.

Digestibility of proteins from different sources

In vitro protein digestibility can be useful for estimating protein nutritional quality. Eight protein sources were chosen to study in vitro protein digestibility, namely: sodium caseinate, whey, mushrooms, pea, soy, oat, hemp and sea buckthorn. Trypsin was used to achieve the enzymatic hydrolysis and the pH-drop technique was employed to determine in vitro protein digestibility. Substrate hydrolysis was rapidly initiated after enzyme addition in the case of pea protein, sodium caseinate, soy and whey proteins, whereas a slower pH decrease was registered in the case of mushroom proteins. The in vitro protein digestibility decreased in the following order: pea (87.2%) > soy (85.9%) > whey (85.6%) > caseinate (85%) > hemp (78.5%) > oat (77.5%) > sea buckthorn (76.2%) > mushrooms (68.2%). The sea buckthorn and mushrooms samples with the lowest protein contents (15.6% and 18.3%, respectively) had the lowest protein digestibility. However, no correlation between protein content and protein digestibility was found.

In vitro digestion of spermidine and amino acids in fresh and processed Agaricus bisporus mushroom

Mushrooms are significant sources of amino acids and bioactive amines; however, their bioaccessibility can be affected by processing and during in vitro digestion. Fresh Agaricus bisporus mushroom was submitted to cooking and canning and samples were submitted to in vitro gastric and gastric-intestinal digestions. An UHPLC method was used for the simultaneous determination of 18 free amino acids, 10 biogenic amines and ammonia in the samples. Fresh mushroom contained 14 free amino acids, with predominance of alanine and glutamic acid; spermidine was the only amine detected; and ammonia was also detected. Spermidine levels were not affected by cooking, but there was a significant loss (14%) after canning. Spermidine levels were not affected by the in vitro gastric and intestinal digestion, suggesting full bioaccessibility. There was a significant decrease on total amino acids levels after cooking and canning, with higher losses for aspartic and glutamic acids in cooked and for aspartic acid and valine in canned mushrooms. After the in vitro gastric and intestinal digestions, the total levels of amino acids increased and two additional amino acids (arginine and methionine) were detected. During in vitro digestion many of the amino acids were released mainly in the intestinal phase. After in vitro digestion, amino acids per gram of protein of mushrooms are adequate for most FAO amino acid pattern for adults. Multivariate analysis confirmed that protein hydrolysis in processed mushrooms is higher in intestinal phase. Bioaccessibility data for spermidine in A. bisporus is a novelty and increase the value of this food.

The ribotoxin-like protein Ostreatin from Pleurotus ostreatus fruiting bodies: Confirmation of a novel ribonuclease family expressed in basidiomycetes

Fungi produce several toxins active against plants, animal or humans. Among them, ribotoxins are enzymes that specifically attack ribosomes irreparably compromising protein synthesis, useful as insecticides or as anticancer agents. Here, a novel ribotoxin from the edible mushroom Pleurotus ostreatus has been purified and characterized. This ribotoxin, named Ostreatin, is a specific ribonuclease releasing α-fragment when incubated with yeast or rabbit ribosomes. Ostreatin shows IC50 of 234 pM in rabbit reticulocyte lysate, and metal dependent endonuclease activity. Following the completion of Ostreatin primary structure, we ascertained that this toxin is homologous to Ageritin, the first ribotoxin-like protein from the basidiomycete Agrocybe aegerita, with which it shares 38.8% amino acid sequence identity. Ostreatin consists of 131 amino acid residues with an experimental molecular mass of 14,263.51 Da ([M+H+]+). Homology modeling revealed that Ostreatin and Ageritin share a similar fold in which the common catalytic triad is conserved. Purified Ostreatin lacks N-terminal and C-terminal peptides, which instead are present in the Ostreatin coding sequence. Such peptides are probably involved in protein sorting and for this they could be removed.Our findings confirm the presence of ribotoxin-like proteins in basidiomycetes edible mushrooms, that we propose as novel tool for biotechnological applications.

Antioxidant properties of peptides obtained from the split gill mushroom (Schizophyllum commune).

This study sought to assess the ideal conditions under which hydrolysate can be produced from the split gill mushroom proteins through the microbial protease, Alcalase. The research employed a central composite design and response surface methodology. Three specific parameters were varied for the purposes of the experimental process, while a fixed pH value of 8 was used in all cases. The variables were hydrolysis temperature (set as 45°C, 50°C, or 55°C), hydrolysis time (set as 60min, 120min, or 180min), and the ratio of enzyme to substrate (set as 2%, 4%, or 6% w/v). The variables under investigation exert a significant influence upon degree of hydrolysis (DH) in addition to 2,2'-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical-scavenging activity (p < 0.05). Fractionation of the hydrolysate was accomplished using molecular weight (MW) cut-off membranes, while the greatest radical-scavenging capability was observed in the < 0.65kDa fraction. The MW < 0.65kDa fraction underwent separation through RP-HPLC in order to create five sub-fractions. Among these, the greatest ABTS radical-scavenging capability was observed in the F5 sub-fraction, which was therefore chosen to undergo additional examination using quadrupole-time-of-flight-electron spin induction-mass spectrometry-based de novo peptide sequencing. Via this process it was possible to determine five antioxidant peptides. Furthermore, the MW < 0.65kDa fraction was able to demonstrating cellular antioxidant activity in the context of a human intestinal cancer cell line (HT-29). The extent of this activity was shown to depend upon the concentration levels of the peptide.

FORMULASI MEDIA PRODUKSI JAMUR TIRAM (Pleurotus ostreatus) DENGAN SUPLEMENTASI AMPAS SAGU

This study aims to know the basic media with sago pulp supplementation which can be formulated into a medium for producing white oyster mushrooms and also to know the comparison of the right media and supplements in the formulation to give maximum oyster mushrooms production. In this study using a comparison with sawdust substrate and sago pulp to see how effective the sago pulp substrate as a supplement media for the oyster mushroom production. the program used is experimental designed in Completely Randomized Design (CRD), consists of three replications so that twelve experiments were obtained. The treatment arrangement is M1: Base media without supplements (controls), M2: 90% base media + 10% sago pulp, M3: 80% basic media + 20% sago pulp, M4: base media 70% + sago pulp 30%. The observation parameters used in the study are mycelium growth, fruit body growth, biological efficiency and measurement of protein levels in the fruit body of the oyster mushroom. The results showed that the addition of sago pulp in the media of oyster mushroom production had no effect on the growth of oyster mushrooms. This can be seen from the media of production of M1 (without the addition of sago pulp) experiencing a higher growth rate of mycelium compared to other treatments. The addition of sago pulp has an effect on the levels of oyster mushroom protein. This can be seen from the protein content of oyster mushrooms in M2 production media which have high protein content. Normal levels of white oyster mushrooms in sawdust media range from 18% -20%. This is due to the mixing of wood powder as a production medium and 10% sago pulp as supplementation to produce more nutrient levels.

Odorants from the Thermal Treatment of Hydrolyzed Mushroom Protein and Cysteine Enhance Saltiness Perception.

Innovative approaches to develop flavors with high sensory appeal are critical in encouraging increased consumer preference and adoption of low sodium foods. Gas chromatography-olfactometry, coupled with stable isotope dilution assays and sensory experiments, led to the identification of the odorants responsible for an enhancement in saltiness perception of chicken broth prepared with thermally treated enzymatically hydrolyzed mushroom protein and cysteine, then reacted under kitchen-like cooking conditions. Comparative aroma extract dilution analysis revealed 36 odorants with flavor dilution factors between a range of 1 and 256. Sixteen odorants were quantitated and odor activity values (OAVs) calculated. Important odorants included 2-furfurylthiol (coffee, OAV 610), 1-(2-furyl)ethanethiol (meaty, OAV 78), 3-sulfanylpentan-2-one (catty, OAV 42), sotolon (maple, OAV 20), indole (animal, OAV 8), 2-methyl-3-(methyldithio)furan (meaty, OAV 3), and p-cresol (barnyard, OAV 1). An odor simulation model was evaluated in two consumer sensory studies. These studies confirmed that the addition of the aroma model increased the perceived saltiness of low sodium chicken broth (p < 0.05).

Influence of varying preservation methods on the shelf life and proximate composition of Pleurotus plumonarius (Fr) Quel cultivated on Andropogon gayanus substrate

The objective of the work was to evaluate the influence of preservation methods on the storability and proximate composition of Pleurotus pulmonarius. The experiment was laid out in a completely randomized design (CRD) with three replicates. Freshly harvested mushrooms grown on Andropogon gayanus substrate and analyzed for its proximate composition were divided into four portions: sun dried (SD), oven dried (OV), blanched and stored directly in citric acid solution at varying concentrations (conc.). The microbial load count of the preserved samples and sensory evaluation carried out were significant (P&amp;lt;0.05) with sun and oven dried samples most preserved followed by blanched samples stored in citric acid solutions, with 0.5% conc. taking the lead. The proximate results showed that the protein, fat, and ash contents of mushroom preserved in citric acid solution decreased while sun and oven dried samples increased significantly with increase in fibre and carbohydrate. The result of the sensory evaluation on colour, texture and flavour showed that blanched sample stored in 0.5% citric acid solution was most preferred for colour, odour and texture.

Determination of Total Protein, Vitamin and Fatty Acid Content of Pleurotus ostreatus and Agaricus bisporus Mushrooms Collected from Nature and Cultured

Bu çalışmada, kültür ortamında yetiştirilmiş ve&#x0D; doğadan toplanmış olan Pleurotus&#x0D; ostreatus (Jacq.) P. Kumm. ve Agaricus&#x0D; bisporus (J.E. Lange) Imbach mantarlarının toplam protein, vitamin ve yağ&#x0D; asidi bileşimleri, vitaminleri tespit edilmiştir. Araştırma materyallerinde 11&#x0D; çeşit yağ asidi (miristik asit, pentadekanoik asit, palmitik asit, palmitoleik&#x0D; asit, margarik asit, stearik asit, oleik asit, linoleik asit, eikosenoik asit,&#x0D; behenik asit, nervonik asit) belirlenmiş olup, bu yağ asidlerinin arasında linoleik&#x0D; asidin&amp;nbsp; %40.31-%54.44 ile en yüksek&#x0D; içeriğe sahip olduğu bulunmuştur. Her iki türün doğadan toplanan örneklerinde&#x0D; toplam protein miktarlarının kültürü yapılanlara göre daha yüksek olduğu&#x0D; saptanmıştır. En yüksek A ve E vitamini içeriği Agaricus bisporus türünün kültür ortamında yetiştirilmiş örneklerinde en&#x0D; yüksek C vitamini içeriği ise Pleurotus&#x0D; ostreatus türünün doğadan toplanan örneklerinde tespit edilmiştir. Bu&#x0D; çalışmada kullanılan mantar örneklerinde doymamış yağ asidi miktarının doymuş&#x0D; yağ asidi miktarından daha fazla olduğu belirlenmiştir.

Повышение биологической ценности белка и увеличение сроков хранения полуфабриката из вешенки обыкновенной методом электронной стерилизации

The question of the biological value of mushroom protein is not limited to the study of its composition. In addition, the associated problem of its digestibility and assimilability is widely discussed in the scientific community, including in the scientific publications discussed in this article. Mycoprotein derived from proteinrich unicellular fungi biomass is commonly used in contemporary food-production processes. In Russia, however, an alternative source of protein consists in the higher fungi including the common oyster mushroom (Pleurotus ostreatus). It is known that fungal proteins having a rich amino acid composition are absorbed at the level of plant proteins, since they are “packed” in the intercellular chitinous membrane. Various technological methods are used in the processing of raw fungi materials in order to destroy the membrane and release the protein macromolecule. These include traditional processing methods, such as grinding, thermal exposure, etc. In the present article, electromagnetic sterilisation of convenience foods is considered as a means of improving product safety. The authors studied the effect of ionising electron radiation on the physicochemical properties of mushroom products using the example of a heat-treated, vacuum-packaged, semi-finished oyster mushroom product. The applied radiation doses were 1, 3, 6 and 9 kGy. The obtained data showed that, when a semifinished product is irradiated with a dose of 1 to 6 kGy, a greater amount of protein is released compared to unirradiated samples; moreover, that the content of a number of essential amino acids also increases. Therefore, this method allows the biological activity of the nutrients to be increased. The sterilising effect of ionising radiation was achieved with a dose of 6 kGy due to slowing the growth of microorganisms: no pathogenic microorganisms were detected and no growth was observed over a period of 21 days. Thus, electronic ionising radiation as part of the technological process of processing mushrooms allows the biological value of the protein to be increased, preventing the growth of microorganisms and thereby extending the shelf life of mushroom products.

Production of Different Mushroom Protein Hydrolysates as Potential Flavourings in Chicken Soup Using Stem Bromelain Hydrolysis.

SUMMARYThe pleasant taste of edible mushrooms, which is attributed to their high protein content, makes them an attractive source for the production of protein hydrolysates with good taste properties. In the present work, different mushroom protein hydrolysates were produced from shiitake, oyster, bunashimeji and enoki mushrooms using stem bromelain hydrolysis at 0.5% (m/m) enzyme/substrate ratio at pH=6.5 and 40 °C for 20 h. The produced liquid mushroom protein hydrolysate yielded 0.77–0.92% crude protein (p>0.05). Bunashimeji mushroom protein hydrolysate was the lightest in colour, while shiitake mushroom protein hydrolysate was the darkest (p<0.05). Enoki mushroom protein hydrolysate had the highest dry matter content. There was no significant difference in the degree of hydrolysis among different mushroom protein hydrolysates (53.52–67.13%, p>0.05), with the highest yield of bunashimeji and the lowest of shiitake mushroom protein hydrolysate (p<0.05). Preference test of chicken soup with added different mushroom protein hydrolysates was performed using 58 untrained panellists to evaluate their taste-enhancing effect, compared to monosodium glutamate (MSG). Soup with MSG had the highest score for the tested attributes, while soups with bunashimeji and oyster mushroom protein hydrolysates showed higher aroma, taste, mouthfeel and overall preference scores than negative control, which contained neither MSG nor any of the hydrolysates (p<0.05). This finding suggests that bunashimeji and oyster mushroom protein hydrolysate have the potential to be used as taste enhancers in food applications.

Preliminary results on the feasibility of producing selenium-enriched pink (Pleurotus djamor) and white (Pleurotus ostreatus) oyster mushrooms: Bioaccumulation, bioaccessibility, and Se-proteins distribution

The consumption of white (Pleurotus ostreatus) and pink (Pleurotus djamor) oyster mushrooms has been highlighting due to nutritional value and ability to accumulate essential elements, such as selenium (Se). Therefore, the aims of the present study were to evaluate the Se-enriched mushrooms production and enrichment effects on the bioaccessibility of Ca, Cu, Fe, K, Mg, Mn, P, S, Se, and Zn, and proteins and Se-proteins distribution. The Se enrichment of edible mushrooms (white and pink) with different Se(IV) concentrations did not alter the moisture (77 to 89%) and biological efficiency (21 to 27%). The Se total concentration increased significantly in mushrooms cultivated in enriched medium, ranging from 19 ± 1 μg g−1 (white) to 76 ± 2 μg g−1 (pink). It was verified that Se enrichment did not significantly change the total concentration of Ca, Cu, Fe, K, Mg, Mn, S, and Zn of both mushroom species. However, the Se enrichment promoted an increase in the bioaccessible percentage of Fe (7 to 11%), Mg (12 to 13%), P (4 to 6%), S (7 to 12%), and Zn (10 to 14%) for pink oyster mushroom and a decreased in Fe (18 to 28%) and P (7 to 13%) of the white oyster mushroom. In the distribution of proteins, it was verified that the enrichment changed the solubility and distribution of proteins in white oyster (prolamins and glutelins) and pink oyster mushrooms (globulins). Lastly, Se is mainly associated to albumins (white oyster: 4.5 ± 0.4 μg g−1, pink oyster: 9.5 ± 0.7 μg g−1) and glutelins (white oyster: 4.2 ± 0.6 μg g−1, pink oyster: 11.1 ± 0.4 μg g−1). These results demonstrate the ability of these fungi to absorb and bioaccumulate Se, favoring the formation of Se-proteins that are more bioaccessible species.

Toxicity of Potential Fungal Defense Proteins towards the Fungivorous Nematodes Aphelenchus avenae and Bursaphelenchus okinawaensis.

Resistance of fungi to predation is thought to be mediated by toxic metabolites and proteins. Many of these fungal defense effectors are highly abundant in the fruiting body and not produced in the vegetative mycelium. The defense function of fruiting body-specific proteins, however, including cytoplasmically localized lectins and antinutritional proteins such as biotin-binding proteins, is mainly based on toxicity assays using bacteria as a heterologous expression system, with bacterivorous/omnivorous model organisms as predators. Here, we present an ecologically more relevant experimental setup to assess the toxicity of potential fungal defense proteins towards the fungivorous, stylet-feeding nematodes Aphelenchus avenae and Bursaphelenchus okinawaensis As a heterologous expression host, we exploited the filamentous fungus Ashbya gossypii Using this new system, we assessed the toxicity of six previously characterized, cytoplasmically localized, potential defense proteins from fruiting bodies of different fungal phyla against the two fungivorous nematodes. We found that all of the tested proteins were toxic against both nematodes, albeit to various degrees. The toxicity of these proteins against both fungivorous and bacterivorous nematodes suggests that their targets have been conserved between the different feeding groups of nematodes and that bacterivorous nematodes are valid model organisms to assess the nematotoxicity of potential fungal defense proteins.IMPORTANCE Our results support the hypothesis that cytoplasmic proteins abundant in fungal fruiting bodies are involved in fungal resistance against predation. The toxicity of these proteins toward stylet-feeding nematodes, which are also capable of feeding on plants, and the abundance of these proteins in edible mushrooms, may open possible avenues for biological crop protection against parasitic nematodes, e.g., by expression of these proteins in crops.

Enrichment of meat emulsion with mushroom (Agaricus bisporus) powder: Impact on rheological and structural characteristics

Mushrooms are considered to be a next-generation health food due to their rich protein content with high biological value, fiber and bioactive compounds. Utilization of the protein and fiber contents of mushroom for the production of functional meat products with better emulsion characteristics was the aim of this study. Therefore, the influence of mushroom powder (MP) addition (0–3%) on the properties of a model meat emulsion was investigated. Dynamic and creep-recovery analyses were conducted to reveal the effect of MP on emulsion stability by evaluating internal structure variations. Samples with 2% MP added exhibited higher resistance to applied stress and higher gel-like behavior, complex viscosity, pseudoplastic behavior, heat resistance and emulsion strength compared with other samples. Modifications of the chemical structure of emulsions with MP included were confirmed by examination of Fourier-transform infrared spectra. The addition of 2% MP provided a higher protein adsorption at the lipid interface, resulting in a well-ordered emulsion structure. As a final product, cooked meat emulsion exhibited improvement in textural properties with the addition of 2% MP. Therefore, supplementation of emulsions with mushroom powder may help to obtain a functional product with better characteristics.

The influence of the drying method for food properties and hypolidemic potential of oyster mushrooms (Pleurotus ostreatus)

The aim of this research was to study the influence of two drying methods: freeze-drying sublimation and dry-air drying on the selected nutritional properties and hypolipidemic potential of fruiting bodies of oyster mushroom (Pleurotus ostreatus). The criteria for evaluation of the food properties were the color, the morphological structure, regidratation capacity, the total level of soluble proteins, fats, polysaccharides, free amino acids and monosaccharides. Lipid-lowering potential of oyster mushroom was evaluated by the concentration of lovastatin and the level of antioxidant activity. It has been experimentally revealed that the value of optical density of hydro-alcohol extracts of dried oyster mushrooms at a wavelength of 295 nm most clearly characterized its color which intensity was almost twice less in sublimated mushrooms, than шт the sample dried by dry-air method. Histological data showed that dry-air drying lead to the destruction of the mushroom cells and to the formation of a dense layered structure. Sublimation drying preserved the ordered cell structure and provided less deformation and shrinkage of the tissues. Using X-ray microtomography it was reported that freeze-dried mushrooms had uniform pore volume distribution. Dry-air dehydration method lead to the formation of larger cavities. The average percentage of the open pores was: 29.41±0.52% (after dry-air method), 11.10±0.41% (after freeze-drying method). Respectively the number of closed pores, which reflected the true value of porosity, was 0.99±0.01 and 1.75±0.01%. Structural differences of the samples of the dry oyster mushroom combined with their unequal hydration ability. Indicator of rehydration for oyster mushroom dried by sublimation method was 5.4±0.1, and for samples obtained by dry-air method it was 3.2±0.1. Respectively the average time of maximum water absorption was 22.7±1.8 and 45.3±2.9 minutes. It was found that the freeze-drying sublimation conditions were more conducive for the preservation of the biologically active protein and polysaccharide components of oyster mushrooms and on the other hand dry-air drying method increased the nutritional value of oyster mushrooms due to the reactions of polysaccharides autohydrolysis. The number of proteins and polysaccharides of the Oyster mushrooms samples dried by dry-air method and freeze-drying method was 72.0% and 56.0% respectively. Concentrations of free amino acids and glucose in the samples dried by freeze-drying and dry-air methods were 11.60±0.31%; 175.20±6.10 mg% and 7.00±0.28%; 144.0±5.7 mg% respectively. It has been experimentally recorded that the conditions of freeze drying were optimal in terms of ensuring the preservation of the content of natural statin and the antioxidant capacity of oyster mushrooms that provided its hypolipidemic potential. The amount of lovastatin in an the freeze-dried samples was 342±9.0 mg/kg, and was significantly higher than in the samples received by dry-air method - 190±6.0 mg/kg. The level of antioxidant activity of the oyster mushrooms samples were respectively 3.83±0.02 against 2.0±0.03 mmol/100 g. The conducted researches proved that for the production of dry oyster mushroom as a potential biologically active feedstock for the functional food products with lipid-regulating directivity the choice of the drying method had a fundamental importance.