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Hard tofu was developed from kenaf seed, and the effects of coagulant types and concentrations on the physicochemical, textural, and microstructural properties of the tofu were studied. Glucono delta-lactone (GDL), CH3COOH, MgCl2, and CaSO4 were the coagulants used at concentrations of 0.25, 0.5, 0.75, and 1.0 g% (w/v). Kenaf seed milky extract was obtained from the seed soaked at 65°C for 2 h 40 min, and ground using 1:6 seed-to-water ratio. The extracted milky extract was cooked to 95°C for 3 min, cooled to 80°C, and then coagulated with appropriate coagulant concentration. The yield, physicochemical, texture, and microstructure of the tofu were examined. The results indicated that the yield and moisture content of the tofu were not significantly affected by coagulant types and concentrations. Coagulant types affected the crude protein, crude fat, and surface colour of the tofu. GDL-coagulated tofu had significantly higher crude protein (35.09 - 39.07 g/100 g), while MgCl2-coagulated tofu had significantly higher crude fat (59.64 - 63.15 g/100 g). The hardness, chewiness, and springiness of the tofu were affected by the coagulant types and concentrations. CH3COOH-coagulated tofu had significantly higher hardness (2490.1 - 4005.8 g), while MgCl2-coagulated tofu had significantly lower hardness (814.45 - 2009.9 g). Scanning electron microscopy of all the tofu showed a rough-like structure of denser aggregated proteins with large pores, except for the tofu made with 0.25 g% (w/v) which exhibited a pseudo-honey-like structure of compacted network strands. It was concluded that all the coagulants at 0.25 g% (w/v) were suitable to produce kenaf seed tofu. [ABSTRACT FROM AUTHOR]

Kenaf is a multipurpose herbaceous plant of economic significance. This study analysed the effects of different soaking temperatures of kenaf seed on the physicochemical qualities of the extracts. Kenaf seed extracts were extracted separately from kenaf seed soaked at temperatures of 25, 35, 45, 55 and 65 oC at their respective optimum soaking time of 10.27, 7.00, 5.00, 3.50 and 2.67 h. The extraction yield, proximate composition, anti-nutritional factors, colour profile and thermal stability of the extracts obtained at the different soaking temperatures and time were analysed and compared. Also, the fatty acids and amino acids compositions of kenaf seed meal and the extract were determined and compared. The extraction yield of the extracts significantly increased as the soaking temperatures of the seed increase from 25-65 oC. The different soaking temperatures had no significant effects on the proximate composition of the extracts except for the ash content which decreased as the soaking temperature of the seed increases. However, the soaking temperatures significantly affected the colour profile of the extracts. Soaking of kenaf seed significantly reduced the trypsin inhibitor activity, tannic and phytic acid of the extracts. This study also found that both the kenaf seed oil and kenaf seed extract oil were rich source of hexadecenoic acid (26.71 and 26.11 %), 9-octadecenoic acid (33.80 and 40.41 %) and 9,12-octadecadienic acid (30.59 and 28.62 %), respectively. Additionally, the total essential amino acids of the kenaf seed (462.80 mg/g) and freeze-dried kenaf seed extract (487.44 mg/g) were not significantly different. Soaking of kenaf seed at 25, 45 and 65 oC and their respective optimum soaking time of 10.27, 5.00 and 2.67 h are recommended for the extraction of kenaf seed extract. [ABSTRACT FROM AUTHOR]

Kenaf (Hibiscus cannabinus L.) seed is a valuable protein source that could be used to prepare protein hydrolysates with antihypertensive properties. However, the potential of using kenaf seeds for health food and pharmaceutical applications has not been fully exploited. Thus, the aim of this study was to identify and characterise the Angiotensin-I-Converting Enzyme (ACE) inhibitory peptides derived from the optimized hydrolysis conditions of kenaf seed protein hydrolysates (KSPH). The optimum hydrolysis conditions determined by response surface methodology (RSM) were as follows: temperature 65 °C, pH 6.5, hydrolysis time 2.25 h, and enzyme/substrate (E/S) ratio of 0.03 (w/w). Under these conditions, the degree of hydrolysis (DH) was 55.28 % and ACE inhibitory activity was 75.51 %. Also, the low molecular weight peptide fractions, <2 kilodalton (kDa) and 2–5 kDa showed the highest ACE-inhibitory activity (82.27 % and 83.69 %, respectively). The 2–5 kDa fraction by Quadrupole-Time-of-Flight Liquid Chromatography-Mass Spectrometry (QTOF LC − MS) revealed the abundance of six peptides, LYWSYLYN, ALFYWVS, LLLHAL, AKSCVVFP, INPPSTTN, and WTIPTPS. Kinetic studies showed that peptide LYWSYLYN possessed the highest Michaelis constant (Km), maximum velocity (Vmax) values and the lowest inhibitor constant (Ki) values, suggesting of its superior ACE inhibitory activity compared to other peptides. [ABSTRACT FROM AUTHOR]

Kenaf (Hibiscus cannabinus L.) seed is an underutilized protein-rich resource considered as a by-product of the kenaf fiber processing industry. Its high protein content (34%) makes it a promising candidate as a source of bioactive protein hydrolysates. In this study, the potential of enzymatically hydrolyzed kenaf seed protein to generate multifunctional bioactive peptides was evaluated. Kenaf seed protein concentrate was hydrolyzed using four different proteolytic enzymes (papain, alcalase, bromelain, and flavourzyme) at their respective optimum pH and temperature. The choice of enzyme affected the bioactivities to a certain degree as KSPH were shown to possess high ACE inhibitory activity and low-to-moderate DPP-IV and antioxidant activity. Papain KSPH showed the highest ACE inhibitory activity with 95% inhibition compared to other enzymatic hydrolysates, and therefore was chosen for further investigation of its antihypertensive activity. Papain KSPH was profiled for its hydrophobicity by RP-HPLC and revealed that the majority of late-eluting fractions exerted the highest ACE inhibitory activity. Spontaneously hypertensive rats showed a decrease of approximately 18–46 mmHg in their systolic blood pressure (BP) from 0 to 24 h after oral administration of papain KSPH at dosages of 100 mg/kg, 300 mg/kg, and 500 mg/kg. However, the effect was not dose-dependent. As a novel protein source, future research should aim to demonstrate the safety of kenaf seed protein and its hydrolysates, and validate its bioactivity through human intervention trials. Overall, kenaf seed protein has the potential to generate antihypertensive hydrolysates with multifunctional bioactivities as part of a functional food ingredient. [ABSTRACT FROM AUTHOR]

Kenaf belongs to the family Malvaceae noted for their economic and horticultural importance. Kenaf seed is a valuable component of kenaf plant. For several years, it has been primarily used as a cordage crop and secondarily as a livestock feed. The potential for using kenaf seeds as a source of food‐based products has not been fully exploited. Consumers are becoming more interested in naturally healthy plant‐based food products. Kenaf seed, the future crop with a rich source of essential nutrients and an excellent source of phytocompounds, might serve suitable roles in the production of value‐added plant‐based foods. At present kenaf seed and its value‐added components have not been effectively utilized for both their nutritional and functional properties as either ingredient or major constituent of food products. This review focuses on the possible food applications of kenaf seed and its value‐added components based on their nutritional composition and functional properties available in literature, with the purpose of providing an overview on the possible food applications of this underutilized seed. The review focuses on a brief introduction on kenaf plant, nutritional function, lipids and proteins composition and food applications of the seed. The review elaborately discusses the seed in terms of; bioactive components, antioxidants enrichment of wheat bread, antimicrobial agents, as edible flour, as edible oil and a source of protein in food system. The review closes with discussion on other possible food applications of kenaf seed. The need for food scientists and technologists to exploit this natural agricultural product as a value‐added food ingredient is of great significance and is emphasized. [ABSTRACT FROM AUTHOR]

This study investigated the preservation efficacy of kenaf seed peptides mixture (KSPM) in extending the shelf-life of cream cheese matrix and the effect on its physicochemical properties. Also, the safety of KSPM towards mammalian cells and the underlying fungicidal mode of action in-vitro and in-silico were assessed. The KSPM at 500 and 1000 mg/kg effectively prolonged the shelf-life of cream cheese for up to 11–21 days when stored at 25 °C and 4 °C, and significantly reduced the inoculated conidia counts by ∼3 log 10 conidia/g. The safety assessment showed that KSPM maintained the proliferation of normal cell lines up to 30 mg/mL. The cell surface potential energy and hydrophobicity of fungi were altered due to the potent interactions between the peptides and the cell envelope, with KSPM causing significant fungal cell wall permeability and subsequent disruption of the cytoplasmic membrane integrity. KSPM treatment induced morphological destruction of conidia and mycelium and caused a significant loss of fungal cellular materials including K+, sugar, protein and nucleic acids (DNA and RNA), indicating irreversible damage to the fungal cytoplasmic membrane. The in-silico molecular docking study revealed that the peptides mixture efficiently interacted with fungal mannoprotein via the formation of hydrogen bonding, electrostatic interactions and hydrophobic forces. The molecular dynamics simulation showed that the peptide KPTGMR was tightly embedded into the fungal phospholipid bilayer membrane and inserted into the phosphate head groups which led to the formation of gaps, suggesting a transmembrane pore or channel action mechanism. [Display omitted] • KSPM preserved the shelf-life of cheese for 11 days at 25 °C and 21 days at 4 °C. • KSPM maintained the physicochemical properties of cheese matrix. • KSPM did not induce cytotoxic effect up to a very high concentration of 30 mg/mL. • The main KSPM mechanism was through altered membrane permeability and integrity. • The peptide interacted with fungal phospholipid bilayer via pore/channel formation. [ABSTRACT FROM AUTHOR]

The combination of green-nanotechnology and biology may contribute to anticancer therapy. In this regard, using gold nanoparticles (GNPs) as therapeutic molecules can be a promising strategy. Herein, we proposed a novel biocompatible nanogold constructed by simply microwave-heating (MWI) Au3+ ions and kenaf seed (KS) extract within a minute. The phytoconstituents of KS extract have been utilized for safe synthesis of gold nanoparticles (KS@GNPs). The biogenic KS@GNPs were characterized by UV-vis Spectra, TEM, HR-TEM, XRD, FTIR, DLS, EDX, and SEAD techniques. The legitimacy and toxicity concern of KS@GNPs were tested against RAW 264.7 and NIH3T3 cell lines. The anticancer efficacy was verified using LN-229 cells. The pathways of KS@GNPs synthesis were optimized by varying the KS concentration (λmax 528 nm), gold salt amount (λmax 524 nm), and MWI times (λmax 522 nm). TEM displayed spherical shape and narrow size distribution (5–19.5 nm) of KS@GNPs, whereas DLS recorded Z-average size of 121.7 d·nm with a zeta potential of −33.7 mV. XRD and SAED ring patterns confirmed the high crystallinity and crystalline face centered cubic structure of gold. FTIR explored OH functional group involved in Au3+ ions reduction followed by GNPs stabilization. KS@GNPs exposure to RAW 264.7 and NIH3T3 cell lines did not induce toxicity while dose-dependent overt cell toxicity and reduced cell viability (26.6%) was observed in LN-229 cells. Moreover, the IC50 (18.79 µg/mL) treatment to cancer cell triggered cellular damages, excessive ROS generation, and apoptosis. Overall, this research exploits a sustainable method of KS@GNPs synthesis and their anticancer therapy. [ABSTRACT FROM AUTHOR]

Abstract: Kenaf (Hibiscus cannabinus) a plant of the family Malvaceae, is a valuable fiber plant native to India and Africa. Kenaf seeds contain alpha-linolenic acid, phytosterol such as β-sitosterol, vitamin E and other antioxidants with chemopreventive properties. In the present study we examined the hypothesis that kenaf seed ‘supercritical fluid extract’ (SFE) extract could suppress the early colon carcinogenesis in vivo by virtue of its bioactive compounds. To accomplish this goal, 60 male rats were randomly assigned to 5 groups which were (1) negative control group [not induced with azoxymethane (AOM)]; (2) positive control group (induced with AOM but received no treatment); (3) group treated with 500mg/kg kenaf seed SFE extract; (4) group treated with 1000mg/kg kenaf seed SFE extract; (5) group treated with 1500mg/kg kenaf seed SFE extract. At 7 weeks of age, all rats except the negative control group received 15mg/kg of AOM injection subcutaneously once a week for 2 weeks. Rats were euthanized at 13 weeks of the experiment. Number of ACF (mean±SD) ranged from 84.4±4.43 to 179.5±12.78 in group 2, 3, 4, 5. ACF reductions compared with the untreated group were 45.3, 51.4 and 53.1% in rats fed with 500, 1000 and 1500mg/kg body weight, respectively. There were no significant differences in weight gain among groups. Our finding indicates that kenaf seed SFE extract reduced AOM-induced ACF in Sprague–Dawley male rats. [Copyright &y& Elsevier]

The objective of this study was to investigate and compare fatty acids, tocopherols and sterols of kenaf seed oil extracted by supercritical carbon dioxide and traditional solvent methods. Fatty acids, tocopherols and sterols were determined in the extracted oils as functions of the pressure (400 bar, 600 bar), temperature (40 °C, 80 °C) and CO flow rate (25 g/min) using a 1-L extraction vessel. Gas chromatography was used to characterize fatty acids and sterols of the obtained oils while tocopherols were quantified by HPLC. No differences were found in the fatty acid compositions of the various oil extracts and the main components were found to be linoleic (38%), oleic (35%), palmitic (20%) and stearic acid (3%). Extraction of tocopherols using high pressure (600 bar/40 °C, 600 bar/80 °C) gave higher total tocopherols (88.20 and 85.57 mg/100 g oil, respectively) when compared with hexane extraction which gave yield of 62.38 mg/100 g oil. Extraction of kenaf seed oil using supercritical fluid extraction at high temperature (80 °C) gave higher amounts of sterols when compared with hexane extraction. [ABSTRACT FROM AUTHOR]

Kenaf seed meal protein concentrate (KSPC) and lyophilized kenaf seed milky extract protein concentrate (KSMEPC) were obtained via alkaline extraction. The proximate compositions, amino acids and functional properties of both concentrates were compared. KSPC was found to be significantly higher in protein, essential and non-essential amino acids but, lower in lipid and carbohydrate contents than KSMEPC. The solubility, water absorption capacity and denaturation temperature of KSPC and KSMEPC were similar. However, KSMEPC had significantly higher oil absorption capacity, foam capacity and stability, and a significantly lower emulsion property than KSPC. The heat coagulability and coagulation capacity of the protein concentrates were not significantly different. But, the heat coagulability was significantly increased as the concentration of the protein concentrates increased from 4 to 20%. This study showed that kenaf seed may be considered as a potential ingredient in food products like tofu, meat extender, butter and mayonnaise. Image 1 • Extraction steps affected the amino acids profile of kenaf seed milky extract. • Protein concentrate from kenaf seed meal had better emulsion capacity and stability. • The heat coagulability and coagulation capacity of the concentrates were concentration-dependent. • On the bases of the thermal stability of the concentrates, they are potential ingredients in meat extenders. • Based on their heat coagulability they are potential ingredients in tofu making. [ABSTRACT FROM AUTHOR]