Chemical and functional properties of the native banana (Musaacuminata × balbisiana Colla cv. Awak) pseudo-stem and pseudo-stem tender core flours

This research was conducted to evaluate the differences in chemical composition and functional profiles of native banana pseudo-stem flour (NBPF) and boiled tender core of the banana pseudo-stem flour (TCBPF). Chemical analyses indicated that the proximate contents (moisture, fat, protein and ash), were significantly higher in TCBPF than in NBPF. The levels of total dietary fibre, insoluble dietary fibre, lignin, hemicellulose and cellulose were all higher in NBPF than TCBPF, while there was no significant difference in soluble dietary fibre. NBPF also had higher contents of polyphenols and flavonoids than TCBPF. Both the antioxidant capacity and the free radical-scavenging capacity were higher in NBPF than in TCBPF. On the other hand, the TCBPF showed significantly higher swelling power, water holding capacity and solubility, although its oil holding capacity was lower than NBPF. We conclude that banana pseudo-stem flour is a potential functional food ingredient for products containing high dietary fibre.     

Antioxidant activities of phenolic rich fractions (PRFs) obtained from black mahlab (Monechma ciliatum) and white mahlab (Prunus mahaleb) seedcakes

The antioxidant activities of phenolic rich fractions (PRFs) from crude methanolic extract (CME), and its fractions using ethyl acetate (EAF), hexane (HF) and water (WF) of black mahlab (Monechma ciliatum) and white mahlab (Prunus mahaleb) seedcakes were investigated. The total phenolic compounds were found to be higher in white mahlab than black mahlab seedcakes. The antioxidant activity determined by the DPPH method revealed that black mahlab PRFs had the highest antioxidant activity, compared to white mahlab fractions. The presence of antioxidants in the two mahlab PRFs reduced the oxidation of β-carotene by hydroperoxides from these extracts/fractions. The effect of the two mahlab PRFs on the oxidative stability of corn oil at 70 °C was tested in the dark and compared with butylated hydroxyanisole (BHA). The CME performed better antioxidant activity in inhibiting the formation of both primary and secondary oxidation products. The qualitative and quantitative characterisation of phenolic compounds was carried out by HPLC/DAD.     

Purification and characterisation of two enzymes related to endogenous formaldehyde in Lentinula edodes

In this study, γ-glutamyl transpeptidase (GGT) and l-cysteine sulphoxide lyase (C-S lyase) were purified from the fruiting body of Lentinula edodes in three steps and then characterised. We found that GGT together with C-S lyase caused the generation of endogenous formaldehyde in L. edodes. GGT was composed of a large subunit of 41 kDa and a small subunit of 25 kDa, and C-S lyase was composed of two identical subunits of 46 kDa, as determined by SDS–PAGE. GGT was stable at pH 8.0–10.0 with an optimum pH of 8.8, and was stable at 20–50 °C with an optimum activity at 37 °C. C-S lyase was stable at pH 8.0–9.0 with an optimum pH of 8.5, and was stable at 20–60 °C with an optimum activity at 40 °C. The present work supports the study of the mechanism of endogenous formaldehyde in L. edodes.     

Eco-friendly modification and antibacterial functionalization of viscose fabric

Pretreatment of viscose fabric with monochlorotraizinyl β-cyclodextrin (MCT-βCD), as an eco-friendly modifying agent, is accompanied by creation of hosting nanocavities onto the cellulose structure thereby enabling inclusion of certain antibacterial agents namely triclosan, as a classic agent, and AgNO₃, as well as bioactive agents like green tea extract and Aloe vera gel. The efficiency of hosting the nominated antibacterial agents to confer antibacterial functionality is governed by the type of modification method and follows the decreasing order: exhaustion > pad-steam fixation > pad-dry-cure. The imparted antibacterial functionality of MCT-βCD-loaded fabric samples is determined by type of the hosted antibacterial agent into cavities of βCD and follows the decreasing order: AgNO₃ > green tea extract > triclosan > Aloe vera gel. Nitrogen content analysis, FTIR spectra, SEM image and EDX spectrum of Ag-loaded fabric sample confirmed the impact of suggested treatment sequence on the chemical and surface properties of the functionalized viscose fabric. The results also demonstrate that the imparted antibacterial activity against S. aureus (G+ve) and E. coli (G?ve) bacteria slightly decreased after 15 washing cycles.     

Survival of bifidobacteria in the presence of bile salt

The ability of Bifidobacterium species to survive in the presence of sodium glycocholate, at concentrations ranging from 0 to 3 g liter^?1, was tested. Bacterial growth was monitored by measuring the optical density for up to 48 h. All the Bifidobacterium strains tested showed growth limitation in the presence of sodium glycocholate. However, after a series of propagations in fresh trypticase-peptone-yeast extract medium devoid of bile salt all bacterial strains retained their activity. It was concluded that Bifidobacterium species are able to survive physiological and higher bile salt levels and that bifidobacteria can be considered for use as dietary adjuncts.     

Quality improvement of kenaf-based tofu: effects of kenaf seed substitution,and coagulant types and concentrations on the physicochemical quality,texture profile and microstructure of the tofu

Tofu was made by substituting kenaf seed (K) with soybean (S) at 100 (positive control), 50%, 40%, 30%, 20%, 10% and 0% (negative control). The results indicated that kenaf seed substitution at all ratios significantly increased the soluble solids and protein content of the milky extracts. The yield, moisture and protein content of the tofu were significantly increased with the increase in kenaf seed substitution, while the lipid content was significantly decreased. The tofu made with kenaf seed substitution of 50%, 40% and 30% had the same protein content (43.76–45.36 g/100 g) with the positive control (45.36 g/100 g), but a significantly higher lipid content (32.00–35.75 g/100 g) than that of the positive control (27.50 g/100 g). The microstructure of the tofu revealed that only the positive control had a honey-comb structure, whilst the tofu made from kenaf seed-soybean blends had a pseudo-honey like structure. Up to 30% of soybean can be added into the kenaf-based tofu, without any negative effect on the textural and colour properties and, protein content, but significantly improved the essential amino acids content of the kenaf-based tofu. Therefore, the blend of 70K:30S ratio using 0.5 g% glucono delta-lactone as a coagulant is recommended to produce kenaf seed-soybean tofu.     

Mixed Metal Mordant Dyeing of Wool using Root Extract of Rheum emodi (Indian Rhubarb/Dolu)

In the present study, the root extract of Rheum emodi (Indian Rhubarb/Dolu/Revandchini) has been used as a natural dye to develop a variety of harmonizing natural shades on woolen yarn using combination of ecofriendly mixed metal mordants. Dyeings were carried out in neutral acidic, and alkaline medium using 0.5%–5% dye concentrations pre-treated with (4.5% iron + 0.1% tin), (2.5% iron + 0.5% tin), and (0.5% iron + 0.9% tin) mordant combinations. A total of 54 shades have been developed by varying the amount of dye and percentage combination of mordants. The hue of color ranged from reddish-brown, greenish-yellow to dark yellow. The color of dyed woolen yarns was investigated in terms of color strength (K/S), CIELab, CIELch values. Fastness properties (light, washing, and rub/crocking) of dyed woolen yarn samples were also assessed.