Phytochemical screening and antioxidative property evaluation of lipid-producing fungi.

The increased demands for natural bioactive compounds have induced the search for unusual sources. Microorganisms, especially fungi are a potent source of secondary metabolites, which could act mainly as antioxidant compounds to prevent oxidative stress. In the present study three soil-isolated fungi Aspergillus niger, Aspergillus heteromorphus and Aspergillus fumigatus, were screened for their oleaginous property as well as their potential for the production of bioactive compounds. Fungal biomasses were freeze dried and extracted with methanol using a cold percolation process for the production of intracellular metabolites and the fungal culture media after fermentation were examined for extracellular metabolites. Intracellular and extracellular extracts of the isolated fungi along with the single-cell oils extracted from those fungi were screened for phytochemicals, which showed the presence of alkaloids, flavonoides, glycosides, phenols, saponins and terpenoids. All strains showed potent antioxidant activity, determined using 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2-azino-bis-3-ethylbenzthiazoline-6-sulfonic acid (ABTS) and ferric reducing antioxidant power (FRAP) activity. Extracellular extract and single-cell oil of A. heteromorphus showed the highest antioxidant activity with maximum ABTS radical scavenging activity and reducing potential. Highest content of phenolic and flavonoid compounds within the isolated fungi was found to be 37.58 mg gallic acid equivalent (GAE)/g and 62.07 mg catechine equivalent (CE)/g, respectively. Chromatographic analysis of the intracellular and extracellular extracts of the fungi showed the presence of gallic acid, di-hydroxy benzoic acid, ferulic acid, quercetin, epigerin, kampferol, trans cinnamic acid, chlorogenic acid and rutin, which made them biologically important and beneficial for human health.

Emulsions stabilized by soy protein nanoparticles as potential functional non-dairy yogurts.

BACKGROUND: Rice bran oil and soy protein nanoparticles (SPNs) may be considered as novel functional food ingredients for soy yogurt production. Formulation of soy yogurt with SPNs and rice bran oil, which has significant physiological functions, will convert them into functional food products. This study was conducted to develop rice bran oil-based soy protein nanoparticles emulsion (SPNE) and to evaluate physical properties, antioxidant activities, oxidative stability and microbiological load as well as textural attributes of SPNs incorporated yogurt (SPNY) during storage at 4 °C for 45 days. RESULTS: SPNs were prepared from soy protein isolate of defatted soy flour. Solubilization, crystallization and ultrasonication was carried out six times. After the sixth cycle of repeated solubilizing, crystallization and ultrasonication, the size of nano protein was reduced to 72.42 ± 0.22 nm from 586.72 ± 0.75 nm (after first cycle). Viscosity, penetration values and water-holding capacity of SPNs added to yogurt were decreased with increase in reduction size of SPNs. SPNs added to yogurt exhibited greater antiradical scavenging ability and ferric reducing antioxidant property than control yogurt. Fortified soy yogurt had significant higher oxidative stability and proteolytic activity. CONCLUSION: Fortification of non-dairy food products with SPNs, which has significant physiological functions, convert conventional soy yogurt into functional food products. © 2019 Society of Chemical Industry.

Effect of Fungal Fermentation on Enhancement of Nutritional Value and Antioxidant Activity of Defatted Oilseed Meals.

Agro-industrial residues contain high nutritive value. Nowadays, various advanced researches have been done for the production of various value-added products, using these wastes as substrates in the fermentation media. Flaxseed, mustard, and rice bran meal, residues of oil industry, were used as substrates for fermentation. Submerged fermentation with soil-isolated fungal species of the genus Aspergillus sp. was done for oil production by using these substrates in the fermentation media. Effect of fermentation by the oleaginous species of Aspergillus on the nutritive value and functional properties of flaxseed, mustard, and rice bran meal has been discussed for the first time in the present study. After fermentation, the seed meals showed substantial increase in the protein and ash content. The fungal strains utilized the carbohydrate present in the seed meals for the production of highly nutritional metabolites, which decrease the sugar contents of the meals. The fungi also showed extracellular amylase and cellulase activities which helped to hydrolyze the carbohydrates present in these meals, to utilize them for their metabolism. The enhancement was also observed in terms of antioxidant activity of the meals. Increase in the total phenolic and flavonoid contents was observed after fermentation along with radical scavenging activity of 1,1-diphenyl-2-picrylhydrazyl and 2,2-azino-bis-3-ethylbenzthiazoline-6-sulfonic acid reagents and ferric reduction potential. These effects of fermentation modify these cheap waste materials into nutrient dense substrates, which could be further used in the formulation of value-added products.

Evaluation of Prebiotic Properties of Galactooligosaccharides Produced by Transgalactosylation Using Partially Purified ß-Galactosidase from Enterobacter aerogenes KCTC2190.

Transgalactosylation reaction is the penultimate step in the production of galactooligosaccharides (GOSs) which has prominent applications in the treatment of disorders. In the present study, partially purified ß-galactosidase from Enterobacter aerogenes KCTC2190 was used for the synthesis of prebiotic GOSs. GOSs were produced using lactose as substrate. Structural elucidation of collected fractions of GOSs by liquid chromatography electrospray ionization mass spectrometry exhibited the appearance of major peaks of produced GOSs at m/z 241.20, 481.39, 365.11, 527.17, and 701.51 respectively. GOSs facilitated the growth of potential probiotic strains (Lactobacillus delbrueckii ssp. helveticus, Bifidobacterium bifidum, and Lactiplantibacillus plantarum) and liberated propionate and butyrate as principal short-chain fatty acids which established its prebiotic potency. Synbiotic combinations exhibited good antioxidant activities. Synbiotic combinations also exhibited antimicrobial activities against pathogenic microorganisms namely Staphylococcus aureus and Escherichia coli. Synbiotic combinations of GOSs and the respective probiotic microorganisms were able to decrease viable human bone cancer cells (MG-63).

Nutritional Evaluation of Oleogel Made from Micronutrient Rich Edible Oils.

The present study examined the nutritional properties of trans-free edible oleogels made from oil blends of rice bran and flaxseed in animal model. Oleogels were prepared by using mixture of palm stearin (PS) with cetyl laurate (CL) and palm stearin (PS) with cetyl caprylate (CC) as oleogelators. The oleogel samples were prepared with 15 weight % oleogelators (2:1 molar ratio of PS:CC or PS:CL) at 60°C with 1 hr constant stirring in blended oil. The prepared oleogel samples were subjected to DSC and XRD studies in order to evaluate their melting and crystal characteristics. Oleogel formed by using PS and CC showed the desired thermal characteristics. The peak melting temperature of the said sample was almost 44.5°C as determined by the DSC technique. The X-ray diffraction study clearly signified that the crystals were well developed. For nutritional evaluation, Male Wister rats were fed with prepared oleogel samples along with control diet for 4 weeks. Animals were divided into four groups. The control group was fed with normal stock diet containing blend of rice bran oil and flaxseed oil (4:1); one was fed with TFA rich vanaspati (TFA content is about 11.20%); experimental groups were fed with oleogel prepared by using PS:CC and oleogel prepared by using PS:CL respectively. Analysis of the blood lipid profile of the four groups was done. In vivo study established the cholesterol lowering properties of prepared oleogel samples which further enhanced the novelty of oleogel as healthy alternative of trans fat. The positive changes were more pronounced in case of rats fed with oleogel prepared with PS:CC as oleogelators. This study provides an elegant approach of producing trans-free edible quality oleogel with recognized cholesterol lowering property.

Antioxidative effect of rice bran oil and medium chain fatty acid rich rice bran oil in arsenite induced oxidative stress in rats.

The present study was adopted to evaluate the antioxidant efficacy of medium chain fatty acid (caprylic, capric and lauric) rich rice bran oils in comparison to rice bran oil in terms of altered biochemical parameters of oxidative stress following sodium arsenite treatment in rats. Animals were divided into ten groups; five normal groups and five arsenite treated groups. Results showed that activities of antioxidant enzymes in liver, brain and erythrocyte membrane increased with the administration of rice bran oil and MCFA rich rice bran oils both in normal and arsenite treated cases. Lipid peroxidation increased with the administration of sodium arsenite, but again administration of rice bran oil and MCFA rich rice bran oils decreased the lipid peroxidation. Caprylic acid rich rice bran oil showed the best ameliorative effects.

Analysis of sterol and other components present in unsaponifiable matters of mahua, sal and mango kernel oil.

The amount and characterization of phytosterol and other minor components present in three Indian minor seed oils, mahua (Madhuca latifolia), sal (Shorea robusta) and mango kernel (Mangifera indica), have been done. Theses oils have shown commercial importance as cocoa-butter substitutes because of their high symmetrical triglycerides content. The conventional thin layer chromatography (TLC), gas chromatography (GC) & gas chromatography-mass spectroscopy (GC-MS) techniques were used to characterize the components and the high performance thin layer chromatography (HPTLC) technique was used to quantify the each group of components. The experimental data showed that the all the three oils are rich in sterol content and among all the sterols, beta-sitosterol occupies the highest amount. Sal oil contains appreciable amount of cardenolides, gitoxigenin. Tocopherol is present only in mahua oil and oleyl alcohol is present in mango kernel oil. Hydrocarbon, squalene, is present in all the three oils. The characterization of these minor components will help to detect the presence of the particular oil in specific formulations and to assess its stability as well as nutritional quality of the specific oil.