Isolation and antioxidative properties of phenolics-saponins rich fraction from defatted rice bran

The study presents a protocol for the preparation of phenolics-saponins rich fraction (PSRF), a new active nutraceutical from defatted rice bran followed by the determination of its antioxidant properties. PSRF was prepared by employing a simple alcoholic fractionation procedure on the crude alcoholic extract (CAE) of defatted rice bran. PSRF was found to be significantly higher in the contents of total phenolic, saponin, and steroidal saponin than CAE and its counterpart, aqueous fraction (AqF) (p < 0.05). Except for iron chelating activity, PSRF exhibited notably higher activity than CAE and AqF in all antioxidant activity assays performed (p < 0.05). HPLC-DAD analysis revealed that PSRF contained substantially higher amounts of gallic acid, 4-hydroxybenzoic acid, caffeic acid, p-coumaric acid, and ferulic acid than CAE and AqF (p < 0.05). In conclusion, alcoholic fractionation of CAE simultaneously concentrated the phenolic compounds and saponins into PSRF, thus contributed to its higher antioxidant activity. Due to its elevated antioxidant properties, PSRF may be recommended for investigation as an active ingredient in the nutraceutical, functional food, and natural food preservative formulations. This is also the first report suggesting defatted rice bran as a potential and sustainable source of saponins

Nutritional quality of tropical black long-spined urchin, Diadema setosum gonads: a comparative analysis between male and female gonads

Sea urchin gonads or roes are luxurious culinary and medicinal ingredient of which quality is greatly influenced by their biochemical compositions. This study aimed to assess and compare nutritional compositions between roe of male and female black long-spined urchin (Diadema setosum) inhabiting a tropical coastal area of Malaysia. The proximate nutritional composition of both male and female roe exhibited an order of protein > carbohydrate > lipid, which is contradictory to that of temperate D. setosum. Major amino acids in D. setosum roe were glycine, glutamate, aspartate, leucine and lysine whereas dominant fatty acids were C14:0, C16:0, C16:1, C18:1 n-9; C20:4 n-6 and C20:5 n-3. The ratio of essential amino acids to non-essential amino acids; unsaturated fatty acids (UFA) to saturated fatty acids (SFA); as well as PUFA to saturated fatty acids of roe from either gender were found to be similar i.e. 0.6, 1.2 and 0.5 respectively. Prominent protein as well as AHA and EPA content suggest D. setosum roe as an interesting subject recommended for investigation as active ingredient in nutraceutical, functional food and pro-health formulations. This study is also the first to illustrate some variations between tropical and temperate species of D. setosum

Defatted kenaf seed meal (DKSM) : prospective edible flour from agricultural waste with high antioxidant activity

The present study reports nutritional composition, phenolic content and antioxidant activity of defatted kenaf seed meal (DKSM) in comparison to wheat, rice and sweet potato flours. Proximate analysis revealed that DKSM was high in protein (26.19 g/100 g DKSM) and carbohydrate (57.09 g/100 g DKSM). Magnesium, potassium and phosphorus were the major minerals (>1 g/100 g DKSM) found in DKSM through Energy Dispersive X-ray Spectrometric analysis. DKSM also exhibited appreciably higher total phenolic (3399.37 μg gallic acid equivalent (GAE)/g defatted material) and flavonoid contents (251.00 μg rutin equivalent (RE)/g defatted material) as well as antioxidant activity as compared to all selected edible flours (p < 0.05). Gallic acid, (+)-catechin, 4-hydroxybenzoic acid, vanillic acid and syringic acid were determined as the predominant phenolics in DKSM through HPLC–DAD analysis. On the basis of this study, DKSM may be declared and commercialized as a highly antioxidative and nutritive edible flour, which can be prospectively used in the development of natural food preservative, nutraceuticals and functional foods

Antioxidant activity of phenolics-saponins rich fraction prepared from defatted kenaf seed meal

The current study is aimed to determine the antioxidant properties of crude ethanolic extract (CEE) of defatted kenaf seed meal (DKSM) and its derived n-butanol (BF) and aqueous (AqF) fractions. Spectrophotometric assays showed that BF contained the highest amount of phenolic compounds and saponins, followed by CEE and AqF (p < 0.05). Similarly, HPLC-DAD analysis revealed that level of all the detected predominant phenolic compounds was significantly higher in BF (p < 0.05). Through multiple antioxidant assays, BF exhibited higher antioxidant activity than CEE and AqF, except for iron chelating activity (p < 0.05). Antioxidant activity of CEE and fractions were strongly correlated to their phenolic and saponin contents. This study showed that phenolic compounds and saponins could be extracted and partially purified simultaneously from DKSM by employing a simple alcoholic extraction–fractionation procedure. High antioxidative phenolics–saponins rich fraction from DKSM is a potential active ingredient that could be applied in nutraceuticals, functional foods as well as natural food preservatives

Improved pre-treatment protocol for scanning electron microscopy coupled with energy dispersive X-ray spectroscopy analysis of selected tropical microalgae

Suitable protocol for identification and classification of microalgae using scanning electron microscopy, coupled with energy dispersive X-ray spectroscopy (SEM-EDX), is important to obtain accurate information of their ultrastructure description. The objective of this study was to modify microalgae pre-treatments for reliable SEM-EDX analysis. Sixteen cultured tropical microalgae were subjected to two-step chemical fixation of glutaraldehyde and osmium tetroxide, sample washing in sodium cacodylate, ethanol and acetone dehydration, critical point-drying, mounting and gold sputter-coating prior to SEM visualisation and elemental characterisation. In this study, short period of chemical fixation and optimum separation forces, at 3213 x g for 3 min during every chemical solution change, were successfully established with high quality SEM images. Ultrastructure, particularly clear and useful images of cell wall ornamentation in Scenedesmus spp. and Desmodesmus sp.; areola patterns in Biddulphia sinensis and Thalassiosira sp. and morphological appearances such as interconnecting structures in Coelastrum sp. and Crucigenia sp., were obtained. Twelve elements of Y, Nb, Fe, Ca, Cl, K, Cu, F, Ir, P, Mg and Si were detected within the 16 investigated microalgae species. This study illustrated that microalgae identification and classification, as well as their elemental characterisation, could be simultaneously and effectively analysed by SEM-EDX using a modified pre-treatment protocol

Characterization of the physical properties of the ancient nanostructured biomaterials (nacre layer) retrieved using ethylenediaminetetraacetic acid (EDTA)

Nacre can be found in many seashells species made up of about 95% of volume of multilayer structure of crystalline aragonite and consists of both inorganic and organic biomaterial. Nacre is one of the natural structural materials which constructed at ambient temperature having hard and soft phases arranged in multifaceted hierarchical architectures, thus spanning the characteristic dimensions from the nanoscale to the macroscale. The physical characteristics of the retrieved nacre powder from the nacre layer by using ethylenediaminetetraacetic acid (EDTA) method were analyzed by means of X-ray fluorescence (XRF), X-ray diffraction (XRD), Fourier Transform Infrared (FTIR) Spectroscopy, and thermal analyzer Differential Scanning Calorimetry (DSC)/Thermagravimetric (TGA). XRF analysis revealed the high content of calcium carbonate in comparison to the untreated nacre. The XRD confirmed the aragonite properties of the retrieved nacre while FTIR spectroscopy identified the calcium carbonate phases due to the differences in carbonate ions, CO2-/3. Simultaneous thermal analyzer (DSC/TGA) was used for analysis of the thermal decomposition of the retrieved nacre powder. Here, we successfully evaluated the properties of the ancient nanostructured biomaterial; nacre retrieved using EDTA for future application in bone tissue engineering

Production of fucoxanthin-rich fraction (FxRF) from a diatom, Chaetoceros calcitrans (Paulsen) Takano 1968

Fucoxanthin is the major carotenoid produced by diatoms and shown to exhibit potent anti-obesity and anti-cancer activities. This study presents a simple protocol for the preparation of fucoxanthin-rich fraction (FxRF) with high antioxidative properties from a selected marine diatom, Chaetoceros calcitrans. Fucoxanthin concentrates were prepared from crude methanolic extract (CME) with liquid–liquid partitioning of three types of solvent systems (i.e. diethyl ether–water, dichloromethane–water and ethyl acetate–water), followed by comparative antioxidant evaluation. Dichloromethane fraction (DCMF) was found to contain significantly higher (p < 0.05) level of carotenoid (7.13 ± 0.01 mg·g− 1 DW) and fucoxanthin (5.25 ± 0.03 mg FX·g− 1 DW) contents accompanied with elevated (p < 0.05) antioxidant activities (DPPHradical dot and ABTSradical dot+ radical scavenging, and beta carotene bleaching assays) as compared to other tested fractions. This study showed that FxRF with enhanced antioxidant properties could be effectively produced and concentrated through the DCM–H2O partition of CME

Antioxidant capacities of fucoxanthin-producing algae as influenced by their carotenoid and phenolic contents

Natural antioxidants from sustainable sources are favoured to accommodate worldwide antioxidant demand. In addition to bioprospecting for natural and sustainable antioxidant sources, this study aimed to investigate the relationship between the bioactives (i.e. carotenoid and phenolic acids) and the antioxidant capacities in fucoxanthin‐producing algae. Total carotenoid, phenolic acid, fucoxanthin contents and fatty acid profile of six species of algae (five microalgae and one macroalga) were quantified followed by bioactivity evaluation using four antioxidant assays. Chaetoceros calcitrans and Isochrysis galbana displayed the highest antioxidant activity, followed by Odontella sinensis and Skeletonema costatum which showed moderate bioactivities. Phaeodactylum tricornutum and Saccharina japonica exhibited the least antioxidant activities amongst the algae species examined. Pearson correlation and multiple linear regression showed that both carotenoids and phenolic acids were significantly correlated (p < 0.05) with the antioxidant activities, indicating the influence of these bioactives on the algal antioxidant capacities

A review: modified agricultural by-products for the development and fortification of food products and nutraceuticals

Producing more food for a growing population in the coming decades, while at the same time combating environmental issues, is a huge challenge faced by the worldwide population. The risks that come with climate change make the mission more daunting. Billion tons of agriculture by-products are produced each year along the agricultural and food processing processes. There is a need to take further actions on exploring the inner potential of agro-waste to stand out as food ingredient to partially or fully substitute the foods in orthodox list. Some of the agro-waste contains the most valuable nutrients in the plant and it is truly a “waste” to dispose any of them. Furthermore, the paper aims at discussing the possible methods of modification to improve the safety and feasibility of the agro-waste either through physical, chemical or microbiological ways. The safety issues and bioactivity contains in the agro-waste also been discussed to present the better overall ideas about the employing of agro-waste in food applications

Production and characterization of collagen and gelatin from edible jellyfish (Acromitus hardenbergi Stiasny, 1934) for fabrication of biofunctional scaffold

Jellyfish have always been an important fishery commodity and a multi-million business widely practised in China, Japan, Malaysia, Indonesia, Thailand, Vietnam and the Philippines. This study aimed to explore food and nutritional properties of indigenous jellyfishes; which contributes to the development of simple and efficient extraction procedures of jellyfish collagen and gelatin that would be practical in the production of biomedical-significant matrices for potential tissue engineering applications. It was found that edible jellyfishes were food of low calorific value (ranged from 1.0 to 4.9 kcal/g dry weight) and high protein (ranged from 20.0 to 53.9 g/ 100g dry weight) and minerals (total ash ranged from 15.9 to 57.2 g/ 100g dry weight) components. Collagen was estimated to comprise approximately half the total protein content of edible jellyfishes, hence the major protein component of edible jellyfishes. Among the jellyfishes, A. hardenbergi exhibited significantly (p 0.05) to those extracted using the pepsinassisted extraction. However, the collagen produced by the improved process retained high molecular weight distributions and polypeptide profiles similar to the conventional acid-assisted extraction. They possessed better appearance,instrumental colour and were found to be non-toxic in vitro and free of heavy metal contaminations. Findings from comparisons between the novel and the conventional procedures illustrated that different treatments of collagen extraction process imparts significant impacts to the quality, quantity and cost of the collagen produced. The study also managed to extract gelatin successfully from jellyfish tissues with satisfactory yield, gelling (Bloom) and sensory properties. Jellyfish gelatin has high protein content (>80%) with low moisture (<2.5%), ash (<2.0%) and negligible fat contents. All gelatins had very mild to undetectable fishy odour and were all whitish in appearance. Jellyfish collagen and gelatin were then used to fabricate porous scaffolds suitable for tissue engineering application by freeze-drying the mixture with different proportions of chitosan solutions. The addition of jellyfish gelatin into the scaffold formulation, to partially substitute collagen, was able to reduce the production cost while improving functional characteristics of the scaffolds. The combinations of different jellyfish collagen and gelatin concentrations were observed to have significant effects on the cross-section morphology and the molecular integrity of the cross-linked scaffolds. Proportional combination of jellyfish collagen into the ternary scaffolds was found to significantly (p < 0.05) increase mean pore size and porosity. All ternary scaffolds exhibited mean pore size in the range of 200-300 μm and porosity above 90%. These results suggested that the chitosan: jellyfishderived collagen and gelatin tripolymer matrix is a potential candidate for soft tissues equivalent with enhanced biostability and good biocompatibility. Overall, the findings of this study supported that jellyfish is potentially practical as a sustainable source of high quality collagen and gelatin. Jellyfish-derived biomaterials were also found to exhibits good biophysicofunctionality in the fabrication of scaffolds for tissue engineering. Scaffolds, fabricated in the current study is but a beginning for more forms of functional matrices such as hydrogel, sol, liquid, concentrate and powder