Nutritional composition of underutilized bayberry (Myrica rubra Sieb. et Zucc.) kernels

The kernels of five bayberry cultivars (Biqi, Zaodamei, Ding-ao, Dongkui and Wandao), grown in Zhejiang Province, China, were analyzed for their proximate composition, protein fractionation, amino acid profile, fatty acid composition and mineral contents. The antinutritive compounds, tannin and cyanide, were also quantified. These bayberry kernels possessed 25.0–27.64% DW protein. A majority of storage protein in bayberry kernels was of the globulin form. The kernel protein was rich in methionine, arginine, aspartic and glutamic acids while limiting amino acid was lysine. The most outstanding feature was the abundant fat content (62.5–68.1% DW) of kernels. Approximately 84.9–90.1% of the fatty acids were unsaturated with oleic acid (43.3–50.7%) and linoleic acid (34.1–46.8%). Bayberry kernels were good sources of magnesium, potassium and calcium. These results may offer a scientific basis for use of the under-exploited bayberry seeds.     

Physico-chemical properties of alcohol precipitate pectin-like polysaccharides from Parkia speciosa pod

Alcohol precipitate polysaccharides (i.e. E_pH2, E_pH4.5 and E_pH7) from Parkia speciosa were extracted at 95 °C for 5 h using 0.1 M citrate phosphate buffers of pH 2, pH 4.5 and pH 7, respectively. Comparison between the extracts and commercial citrus pectin (CP) was also performed. Uronic acid and protein content of E_pH2 were higher followed by E_pH4.5 and E_pH7. FTIR analysis showed that E_pH2 and E_pH4.5 gave comparable pattern compared to CP with DE values of 83% and 64%, respectively, whereas E_pH7 was slightly different. E_pH2 obtained a lower solubility (∼60–70%) compared to other extracts (>90%) whereas E_pH7 obtained the highest oil holding capacity (OHC) value (3.9 g/g). Flow analysis showed that E_pH2 produced a higher viscosity gel solution at pH 2 followed by E_pH4.5 and E_pH7, however the gelling properties decreased as pH increased. Different colour of the gels was also found, ranging from yellowish to purplish colour; and the colour changed with the alteration of pH. Antioxidative properties were also shown in the extracts. E_pH2 consisted of 382.8 mg gallic acid equivalent (GAE)/100 g of samples and exhibited percent of 2,2-diphenyl-1-picrylhydrazyl free radical scavenged (%DPPH_sc) of 47.5% whereas E_pH4.5 and E_pH7 consisted of 294.8 and 74.5 mg GAE/100 g sample, respectively, and gave %DPPH_sc values of 42.8 and 6.0, respectively. Therefore, it was suggested that P. speciosa has the potential in producing functional polysaccharides that could be imparted into the food system.     

Studies on the requirements for vegetative growth of Pleurotus tuber-regium (Fr.) Singer, a Nigerian mushroom

Growth requirements of Pleurotus tuber-regium (Fr.) Singer, a Nigerian edible mushroom, were studied. Among the carbohydrates tested, glucose was the most utilised. This was followed in order by mannitol, maltose, and dextrin, which significantly enhanced mycelial growth (P < 0·01). Cellulose was the least stimulatory. Of the nitrogen compounds tested, yeast extract supported the greatest growth, which was comparable with that induced by glucose. This was followed in order by asparagine, casein, glycine, and calcium nitrate. Sodium nitrate, potassium nitrate, and ammonium sulphate supported the poorest growth. The best C/N ratio that sustained good growth was 1 : 4. This was followed by 4 : 1. Similarly, thiamine, pyridoxine, GA₃ (1 and 10 ppm), 2,4-D (10 ppm), Ca, K, Cu, and Zn supported relatively good mycelial growth. The implication of these results is discussed in relation to the cultivation of P. tuberregium in Nigeria.     

Extraction of antioxidative and antihypertensive bioactive peptides from Parkia speciosa seeds

Antioxidative and antihypertensive bioactive peptides were successfully derived from Parkia speciosa seed using alcalase. The effects of temperature (25 and 50 °C), substrate-to-enzyme ratio (S/E ratio, 20 and 50), and incubation time (0.5, 1, 2 and 5 h) were evaluated based on 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP) and angiotensin-converting enzyme (ACE) assays. Bioactive peptide extracted at a hydrolysis condition of: temperature = 50 °C, S/E ratio = 50 and incubation time = 2 h, exhibited the highest DPPH radical scavenging activity (2.9 mg GAE/g), reducing power (11.7 mM) and %ACE-inhibitory activity (80.2%). The sample was subsequently subjected to fractionation and the peptide fraction of <10 kDa showed the strongest bioactivities. A total of 29 peptide sequences from peptide fraction of <10 kDa were identified as the most potent contributors to the bioactivities. These novel bioactive peptides were suggested to be beneficial to nutraceutical and food industries.     

Characterization of a heterogalactan: Some nutritional values of the edible mushroom Flammulina velutipes

Production and consume of mushrooms have grown in the world, and beside these, the nutritional properties and biological active components of fungi have received more attention by researchers. Considering these, a mannofucogalactan was isolated from Flammulina velutipes, and characterized using ¹³C and ¹H (obs.), ¹³C HMQC nuclear magnetic resonance spectroscopy and methylation analysis. The monosaccharide composition of this polymer was determined by GC–MS and showed Fucp, Manp, and Galp in the molar ratio 20:16:64, respectively. ¹³C NMR and ¹H (obs.), ¹³C HMQC indicated an anomeric region containing signals (C-1/H-1) at δ 102.9/5.19, 102.0/5.16, and 98.8/5.05 corresponding, sequentially, to non-reducing end of α-d-Manp, 3-O-substituted α-l-Fucp, and 6-O- and 2,6-di-O-substituted α-d-Galp units. Along with methylation analysis, these data showed a structure with a main chain composed of 6-O-substituted Galp units, partially substituted at O-2 by 3-O-d-mannopyranosyl-l-fucopyranosyl, α-d-mannopyranosyl, and in a minor proportion, α-l-fucopyranosyl groups. Furthermore, some nutritional values of this edible mushroom were evaluated, like amino acid and mineral nutrient contents.     

Progress towards a lure to attract three stored product weevils, Sitophilus zeamais Motschulsky, S. oryzae (L.) and S. granarius (L.) (Coleoptera: Curculionidae)

The behavioural responses of Sitophilus granarius, S. oryzae and S. zeamais to synthetic 4S,5R-sitophinone alone and in combination with volatiles from kibbled carob have been investigated with a view to the development of a single lure to attract all three species. Sitophilus zeamais and S. oryzae were shown to respond to 4S,5R-sitophinone at amounts as low as 0.025 ng. Sitophilus granarius gave a significant response to 50 ng 4S,5R-sitophinone. Volatiles from kibbled carob were also shown to attract all three species. This is the first time that attraction of S. zeamais and S. oryzae to carob volatiles has been demonstrated. Fresh lures containing 4S,5R-sitophinone and carob volatiles attracted significantly more insects in pitfall bioassays for all three species than when either component was used alone. However, after 6 weeks a significant increase in response compared to the control was found only for S. oryzae and S. zeamais. The effect of insect age on response to the pheromone and carob volatiles was also studied for all three species. The response to carob volatiles decreased with increasing insect age for all three species. A significant response to 4S,5R-sitophinone was found only for 1-2-day-old adults of S. oryzae and S. zeamais but for all ages tested of S. granarius. The effect of the combination of pheromone and carob volatiles also decreased with increasing insect age.     

Comparative characterization of monophenolase and diphenolase activities from a wild edible mushroom (Macrolepiota mastoidea)

In this study, Macrolepiota mastoidea, a wild edible mushroom, was evaluated for its polyphenol oxidase potential. Native electrophoresis, stained by l-dihydroxyphenylalanine, of the crude extracts from this species showed two bands having R_f values of 0.38 (minor) and 0.50 (major), supporting a polyphenol oxidase potential. The crude extracts showed monophenolase activity against 3-(4-hydroxyphenyl)-propionic acid and diphenolase activity against 4-methylcatechol as substrates. Monophenolase and diphenolase activities of enzyme extract prepared from M. mastoidea showed pH optimum values at pH 6.0 and pH 4.0, respectively. The extracts retained about 100% and 60% of their original monophenolase and diphenolase activities at their optimum pH values, respectively. It was estimated from thermodynamic data that M. mastoidea had a thermostable monophenolase activity. Thiourea and ascorbic acid were highly potential inhibitors for monophenolase, and ascorbic acid and sodium metabisulphite for diphenolase activity. It is clear from the present results that the enzyme extracts prepared from M. mastoidea possess polyphenol oxidase activities with interesting properties.     

Partial purification and characterisation of endoglucanase from an edible mushroom, Lepista flaccida

A crude extract was prepared from the fruiting body of Lepista flaccida, an edible mushroom and endoglucanase activity of the extract was increased 14-fold with ammonium sulphate precipitation. Maximum enzyme activity was seen at pH 4.0 and 50 °C when carboxymethylcellulose was used as a substrate. K_0.5 and V_max values of the partially purified endoglucanase were 7.7 mg/ml and 25 ± 0.9 U/mg protein, respectively. The enzyme was quite stable over a broad range of pH (2.0–9.0) at 4 °C. When it was incubated at temperatures between 20 °C and 60 °C for 12 h, it conserved much of its original activity (over 40%). The activity of the enzyme increased by 234 ± 3.6% in the presence of 1 mM Mn²⁺. The endoglucanase was inhibited by EDTA, PMSF, β-ME and DDT. In conclusion, pH and thermal stability of the L. flaccida endoglucanase could make it useful for industrial purposes.     

Volatile components of mangaba fruit (Hancornia speciosa Gomes) at three stages of maturity

The effect of stage of maturity on the volatile components of mangaba fruit (Hancornia speciosa Gomes) growing at Sergipe State, Brazil, was investigated at three different stages. The volatile profile obtained by hydrodistillation, using a Clevenger-type apparatus, was analysed by GC–FID and GC–MS. It was possible to identify 33 compounds in the immature fruits, such as 1-octen-3-ol (2.8%), (Z)-linalool oxide (9.1%), (E)-linalool oxide (6.3%), linalool (16.1%), 2-phenylethanol (4.5%), α-terpineol (5.5%), geraniol (3.1%), hexadecanal (2.5%) and octadecanol (2.7%); 34 compounds in the fruits at the intermediate stage, such as ethyl propanoate (4.1%), n-propyl acetate (11.1%), 3-methyl-3-buten-1-ol (6.8%), 2-methyl propyl acetate (2.5%), furfural (18.6%), (Z)-3-hexenol (3.2%), 1-hexanol (2.4%), 3-methyl-3-buten-1-yl acetate (5.4%), (Z)-3-hexen-1-yl acetate (2.9%), n-hexyl acetate (3.3%), (Z)-linalool oxide (3.9%), (E)-linalool oxide (2.4%), linalool (3.8%), 2-phenylethanol (2.8%) and α-terpineol (2.5%); and 32 components in the mature fruits, such as 3-hydroxy-2-butanone (9.1%), 2,4,5-trimethyl-1,3-dioxolane (6.8%), 3-methyl-3-buten-1-ol (12.1%), 3-methyl-1-butanol (5.2%), furfural (8.3%), 3-methyl-1-butanyl acetate (8.8%) and 3-methyl-3-buten-1-yl acetate (28.2%).     

Nutrient and antinutrient distribution of edible mushroom, Pleurotus tuber-regium (fries) singer

Edible mushroom Pleurotus tuber-regium, separated into cap, stalk, and tuber, was analysed. The macronutrient profile (g/100 g) showed crude protein ranging from 4.1 to 13.8, with the highest concentration in the cap (13.8) than any of the other parts and total carbohydrates from 34.0 to 56.2, while the crude fat and ash contents were generally low. Potassium, the most abundant nutritive element was found to be the highest concentration (mg/g) in the stalk (3.3) while copper was found in trace amounts in all the parts. The total cyanide (mg/100 g), phytate (mg/100 g) and tannin (%TA) concentrations were all below levels considered harmful. Amino acids analysis show that the protein contained all essential amino acids while the calculated amino acids scores showed the sulphur containing amino acids to be most limiting. The foregoing highlights the high nutritive values of the major parts of the edible mushroom, Pleurotus tuber-regium.     

Biochemical intervention of ergothioneine-rich edible mushroom (Flammulina velutipes) extract inhibits melanosis in crab (Chionoecetes japonicus)

We investigated the effects of decreasing phenoloxidase (PO) activity and prophenoloxidase (proPO) gene expression on the inhibition of postharvest melanosis formation in the red queen crab, Chionoecetes japonicus. The cDNA of proPO from hemocytes of C. japonicus was partially cloned and sequenced. Immersion of live crabs in a 1.0% ergothioneine (ESH)-rich mushroom extract (Flammulina velutipes; ME) solution resulted in significant inhibition of haemolymph PO activity and a reduction of the proPO gene expression in hemocytes that consequently controlled melanosis in the crabs during ice storage. Treatments with a 0.05% w/v sodium sulphite solution or a 0.05% w/v 4-hexyl-1,3-benzenediol solution had similar positive effects as the treatment with a 1.0% ME solution in vivo. In vitro experiments showed that authentic l-(+)-ESH inhibited PO activity and decreased proPO gene expression in crab hemocytes. Thus, the application of ESH-rich ME can be a novel alternative to synthetic melanosis-inhibiting agents to control postharvest melanosis in crabs.     

Optimisation of the solvent extraction of bioactive compounds from Parkia speciosa pod using response surface methodology

Central composite design was employed to optimise the buffer-to-solids ratio (X₁: 20–50 ml/g), incubation temperature (X₂: 35–55 °C) and time (X₃: 100–200 min), obtaining extracts from Parkia speciosa pod with high total phenolic and flavonoid contents and high antioxidant activities. Analysis of variance showed that the contribution of a quadratic model was significant for the responses. An optimisation study using response surface methodology was performed and 3D response surfaces were plotted from the mathematical models. The optimal conditions based on combination responses were: X₁ = 20 ml/g, X₂ = 35–36 °C and X₃ = 100–102 min. These optimum conditions yielded total phenolic contents of 664–668 mg gallic acid equivalents/100 g, total flavonoid contents of 47.4–49.6 mg pyrocatechol equivalents/100 g, %DPPH_sc of 81.2–82.1%, %ABTS_sc of 78.2–79.8% and FRAP values of 3.2–3.3 mM. Close agreement between experimental and predicted values was found. This methodology could be applied in the extraction of bioactive compounds in the natural product industry.     

Nutritional and in vitro antioxidant properties of edible wild greens in Iberian Peninsula traditional diet

Wild greens are nutritionally well-balanced vegetables. Herein, nutritional and in vitro antioxidant properties of the sprouts of three commonly used species were determined. Wild asparagus revealed the highest levels of moisture (84.6 g/100 g fw), ash (12.3 g/100 g dw), proteins (22.4 g/100 g dw), total sugars (9.24 g/100 g dw), including sucrose (4.27 g/100 g dw), and of the essential n-6 fatty acid linoleic acid (44.5%); white bryony gave the highest contents of reducing sugars, including glucose (2.97 g/100 g dw), essential n-3 fatty acid α-linolenic acid (70.3%), and the best ratios of PUFA/SFA, and n-6/n-3 fatty acids (3.59 and 0.0907, respectively); black bryony showed the highest concentrations of carbohydrates (69.3 g/100 g dw), fructose and trehalose (3.83 and 1.34 g/100 g dw, respectively). Besides their culinary characteristics, their high content in vitamins (asparagus, 135 and 142 mg/100 g dw of total tocopherols and ascorbic acid, respectively), chlorophylls (white bryony, 50.9 mg/100 g dw), carotenoids (23.3 mg/100 g dw) and phenolics (black bryony, 759 mg GAE/g extract), together with the antioxidant properties (EC₅₀ values lower than 640 μg/ml) and potential health benefits increase their importance in traditional as well as in contemporary diets.     

Characterisation of esterolytic activity from two wild mushroom species, Amanita vaginata var. vaginata and Tricholoma terreum

Characterisation of esterase activities from the edible mushroom species, Amanita vaginata var. vaginata and Tricholoma terreum, were investigated. Native electrophoresis of the crude extracts prepared from both mushroom samples showed the presence of esterolytic activities. The extracts had the greatest activity in the presence of p-nitrophenyl butyrate (pNPB) as a substrate. pH and temperature optima were found to be 8.0 and 30 °C for both enzymes, respectively. V_max and K_m values were determined as 14.2 U/l and 71 μM for A. vaginata var. vaginata and 34.6 U/l and 9.6 μM for T. terreum, respectively. The pH-stability profile showed a stationary line between 3.0 and 10.0 for both enzymes. The esterolytic activities from the extracts were maintained between 10 and 40 °C for 4 h and started to decrease at 50 °C. The effects of EDTA, NaN₃, DTT and PMSF on the enzyme activity were also investigated.     

Antioxidant polyketide phenolic metabolites from the edible mushroom Cortinarius purpurascens

Phytochemical investigation of the ethyl acetate extract of the edible macrofungus, Cortinarius purpurascens, led to the isolation of nine anthraquinone-related pigments, citreorosein 6,8-dimethyl ether (1), physcione (2), rufoolivacin (3), rufoolivacin C (4), rufoolivacin D (5), leucorufoolivacin (6), verbindung cr11 (7), verbindung cr60 (8) and 1-Hydroxy-3-methyl-2-isopropanyl-6,8-dimethoxyanthraquinone (9). The structures of these isolated compounds were characterised by spectroscopic methods and comparison with published data. Among the tested compounds, 3–6 exhibited potent DPPH radical-scavenging activity with IC₅₀ values in the range of 3–8 μg/ml. The results indicated that the fungus is a possible source of natural products with potential antioxidant activity.     

Effect of physico-chemical factors and semi-synthetic media on vegetative growth of Lentinus subnudus (Berk.), an edible mushroom from Nigeria

Attempts were made to investigate the effect of different semi-synthetic growth media, pH, temperature, carbon and nitrogen compounds, as well as additives, on vegetative growth of L. subnudus (Berk.), an edible mushroom from Nigeria. The best mycelial extensions (92.7 and 92. mm) were obtained on potato dextrose agar (PDA) and yellow corn agar (YCA), respectively. Moderate growths (87.0, 85.0 and 80.0 mm) were observed on white corn agar (WCA), yeast extract agar (YEA) and malt extract agar (MEA), respectively, but least growth (38.6 mm) was recorded on ‘Ife brown’ beans agar (IBBA). This fungus grew within a temperature range of 15–40 °C (optimum 30 °C) and, pH range of 5.0–8.0 (optimum 5.5).     

Antioxidant Parkia speciosa pod powder as potential functional flour in food application: Physicochemical properties’ characterization

Chemical, physicochemical and functional properties of fibrous materials from freeze dried (FDPSP) and oven dried (ODPSP) Parkia speciosa pod (PSP) were evaluated in order to examine the potential applications in food. Preliminary screening of PSP using scanning electron microscope showed that PSP consisted of starches and fibres. Proximate analysis showed that both samples consisted of 4.3–5.2% of moisture, 9.5–10.7% of protein, 0.1–0.2% of fat, 0.01% of ash, 16.5–16.8% of crude fibre and 68.3–68.7% of carbohydrates. However, different functional properties were shown in these samples. FDPSP gave a lighter colour compared to ODPSP. Higher values of solubility (30.8%), water- and oil-holding capacities (3.72 and 1.55 g/g, respectively) were found in FDPSP. Conversely, higher emulsifying activity of 62.7% with high emulsion stability of 99.9% was shown in ODPSP. Higher antioxidative properties were also shown in FDPSP which consist TPC of 110.0 mg gallic acid equivalent/g sample and TFC of 8.5 mg pyrocatechol equivalents/g sample. These extracts (pre-diluted 50×) gave %DPPH_sc, %ABTS_sc and FRAP values of 65.3%, 77.4% and 1.9 mM FeSO₄, respectively. Therefore, it was suggested that PSP has the potential in producing functional fibres that could be imparted into the food system.     

Survival and reproduction of Tribolium castaneum (Herbst), Rhyzopertha dominica (F.) and Sitophilus oryzae (L.) following periods of starvation

This study determined the starvation tolerance of Tribolium castaneum (Herbst), Rhyzopertha dominica (F.) and Sitophilus oryzae (L.) in terms of both adult survival and reproduction, the impact of starvation on reproduction not having been studied before. Experiments were conducted at 30 °C and 55% or 70% r.h. using a laboratory strain and a field strain of each species. The number of progeny was a better indicator of the impact of starvation on a species than adult survival. Tribolium castaneum was the most tolerant species, requiring up to 35 d starvation before no progeny were produced. Rhyzopertha dominica and S. oryzae required up to 8 d starvation before no progeny were produced. The results suggest that hygiene will have a greater impact on populations of S. oryzae and R. dominica than T. castaneum.     

Nutritional quality and safety of cooked edible crab (Cancer pagurus)

Edible crab (Cancer pagurus) is one of the most important crustaceans consumed in Southern European countries, either as boiled or steamed cooked product. So far, the majority of studies assessing health benefits and risks associated to seafood consumption have been carried out in raw products, despite being generally cooked before consumption, and mostly in muscle tissue. Therefore, the aim of this study was to assess the effect of steaming and boiling on the chemical safety and nutritional value of C. pagurus caught in spring and summer. Generally, chemical and elemental composition of brown meat (tissue in the body cavity comprising mainly gonads and hepatopancreas) differed significantly from muscle (white meat in claws and legs). Additionally, the same tissue revealed differences in chemical and elemental composition of raw and cooked C. pagurus, likely due to water leaching. In contrast, few variations between seasons were observed. The results revealed that the consumption of cooked edible crab muscle should be promoted, whereas brown meat ingestion should be done parsimoniously.     

Antioxidant potentials and rosmarinic acid levels of the methanolic extracts of Salvia verticillata (L.) subsp. verticillata and S. verticillata (L.) subsp. amasiaca (Freyn & Bornm.) Bornm

This study was designed to examine the in vitro antioxidant activities and rosmarinic acid levels of the methanol extracts of Salvia verticillata subsp. verticillata and S. verticillata subsp. amasiaca. The extracts were screened for their possible antioxidant activity by two complementary test systems, namely DPPH free radical-scavenging and β-carotene/linoleic acid systems. In the first case, S. verticillata subsp. verticillata was superior to the subsp. amasiaca with an IC₅₀ value of 14.5 ± 1.21 μg mg⁻¹. In the β-carotene/linoleic acid test system, inhibition capacity of S. verticillata subsp. verticillata was 74.4 ± 1.29%. Antioxidant activities of BHT, ascorbic acid, curcumin and α-tocopherol were determined in parallel experiments. Activity of rosmarinic acid was also screened for better establishing the relationship between rosmarinic acid level and antioxidant activity for the plant extracts. S. verticillata subsp. verticillata had the highest rosmarinic acid level with a value of 28.7 ± 0.89 μg mg⁻¹. There is a strong correlation between the rosmarinic acid level and antioxidant activity potential. Our results showed that rosmarinic acid and its derivatives are more likely to be responsible for most of the observed antioxidant activities of Salvia species.