Green synthesis and characterization of Ag nanoparticles from Mangifera indica leaves for dental restoration and antibacterial applications.

Green synthesis has gained a wide recognition as clean synthesis technique in the recent years. In the present investigation, silver nanoparticles were prepared by a novel green synthesis technique using Mangifera indica (Mango leaves) and found to be successfully used in dental applications. The prepared samples were spectroscopically characterized by XRD, PSA, SEM with EDS, and UV-Vis spectroscopy. The crystalline size and lattice strain were analyzed from the XRD data which were counter-verified by W-H plots and particle size analyzer. The XRD peaks revealed that average crystalline size of the as-synthesized Ag nanoparticles was of 32.4 nm with face-centered cubic structure. This was counter-verified by particle size analyzer and Williamson-Hall plots and found to be 31.7 and 33.21 nm in the former and latter, and the crystalline size of Ag NPs could be concluded as 32 ± 2 nm. The morphological structure of the prepared sample was studied through SEM images and the chemical composition was analyzed by the EDS data. The band energy was calculated as 393 nm from UV-Vis, which confirmed the synthesized sample as Ag nanoparticles. To improve the mechanical bonding and hardness of the dentally used glass ionomer cement (GIC), the synthesized silver nanoparticles were incorporated into GIC in 2% weight ratio. The morphology of the prepared specimens was studied using optical microscope images. Vickers microhardness and Monsanto hardness tests were performed on GIC, GIC reinforced with microsilver particles and GIC reinforced with nanosilver particles and the latter derived a promising results. The results of the Monsanto tests confirmed the increase in hardness of the GIC reinforced with AgNps as 14.2 kg/cm2 compared to conventional GIC and GIC reinforced with silver microparticle as 11.7 and 9.5 kg/cm2. Similarly the Vickers hardness results exhibited the enhanced hardness of GIC-reinforced AgNps as 82 VHN compared to GIC as 54 and GIC-reinforced silver microparticles as 61 VHN. The antibacterial activity of AgNPs was tested by a well-diffusion method on Escherichia coli and Staphylococcus aureus bacteria, and the obtained results exhibited a promising antibacterial activity of the as-synthesized nanoparticles.

Physicochemical characteristics of phytonutrient retained red palm olein and butter-fat blends and its utilization for formulating chocolate spread.

Phytonutrients retained palm olein (PRPOL) was prepared and blended into butterfat at different ratios. The physicochemical characteristics and the phytonutrient composition of blends, as well as its utilization in the preparation of functional chocolate spread were evaluated. The results showed that the redness, yellowness, slip melting point, free fatty acids, peroxide value, iodine value, unsaponifiable matter, diacylglycerol and monoacylglycerol increased while lightness, saponification value, and triacylglycerol significantly decreased upon incorporation of increased quantities of PRPOL into butterfat. The incorporation affected short chain, medium chain and long chain fatty acids content along with variation in the palmitic, stearic, oleic acids content of the blends as compared to butterfat alone. Improvement in carotenoids (6-27 fold), phytotosterols (3-15 fold), tocopherols and tocotrienols (4-17 fold), and squalene (1-6 fold) in blends was observed upon incorporation of PRPOL. Cholesterol level in the blends was reduced (10-50 %) as compared to the butterfat. The blends showed an intermediate solid fat content of PRPOL and butterfat. Moreover, radical scavenging activity of the blends increased with increase in PRPOL quantity. Prepared chocolate spreads showed similar fat, moisture, colour components (L*, a* and b*) and better emulsion stability. The hardness of the spreads was increased upon increasing quantity of PRPOL. The sensory evaluation showed that chocolate prepared by replacing butterfat with 20 % PRPOL had acceptable sensory attributes.

Hypolipidemic mechanism of oryzanol components- ferulic acid and phytosterols.

UNLABELLED: The effect of oryzanol (well known hypolipidemic component in rice bran oil) and its chemical constituents- ferulic acid (FA) and phytosterols on hypolipidemia were investigated. METHODS AND RESULTS: Docking (in silico) studies showed that FA had a better binding ability with lipase while sterols bound well with HMG-CoA reductase. Further in vivo studies of feeding high fat (30%) to rats increased body weights, serum TC, TG, non-HDL-C and reduced HDL-C were observed, compared to normal diet fed group (ND). ORZ treated groups alleviated the lipid profile. Furthermore, increased organ weights, higher intestinal lipase activity, and liver lipid peroxidation was observed in the high-fat group (HF). These effects were ameliorated in oryzanol concentrate fed groups (ORZ). Higher fecal fat was found in ORZ groups, analysis of fecal matter by mass spectroscopy revealed the presence of FA. In vitro, a bile acid binding study supported the strong affinity of sterol towards bile acids. In conclusion, oryzanol in the intestine is cleaved into FA and sterol by intestinal lipase enzymes both lipase and HMG-CoA reductase activities were inhibited, respectively. These hydrolysates eliminated the bile acids, thus lowering lipid profiles.

Oryzanol as natural antioxidant for improving sunflower oil stability.

Sunflower oil is being made shelf stable by the incorporation of synthetic antioxidants such as tertiary butyl hydroquinone (TBHQ), while natural antioxidants like oryzanol and tocopherols can also be used. The aim of the current investigation was to evaluate the antioxidant effect of natural oryzanol (Oz) concentrate (15.5 % oryzanol) and purified Oz (80 % oryzanol) on oxidative and thermal stability of sunflower oil. Sunflower oil was incorporated with Oz concentrate to provide 0, 0.12, 0.25, 0.50, 0.84, 1.0, 1.60, 2.0, 2.5 and 3.20 % oryzanol in the oil, stored for 5 weeks at 37 °C and oxidative stability was evaluated. It was found that the oryzanol concentrate showed good antioxidant effect with increase in concentration of oryzanol. In another set of experiments, sunflower oil containing purified Oz at 1 % level individually and in combination with 0.1 % α- tocopherol (α-T) was heated at 120 °C for 24 h to evaluate thermal stability. Sunflower oil containing 1 % Oz (80 % purity) showed 98.40 % and sunflower oil containing 1 % Oz and 0.1 % α-T showed 108.75 % antioxidant effect compared to TBHQ taken as 100 %. The study indicated that sunflower oil containing 1 % Oz (80 % purity) and 0.1 % α-T combination provides a synergistic effect in inhibiting primary and secondary products and showed highest thermal stability. SFO containing 1 % Oz added as concentrate also showed good antioxidant effect during storage. Hence, instead of using synthetic antioxidants like TBHQ, we can add natural oryzanol (purified or as concentrate) to sunflower oil to increase its oxidative and thermal stability.

Preparation of food supplements from oilseed cakes.

Oilseed cakes have been in use for feed preparation. Being rich in proteins, antioxidants, fibers, vitamins and minerals, oilseed cakes have been considered ideal for food supplementation. These oilseed cakes can be processed and made more palatable and edible by suitable treatments and then incorporated as food supplements for human consumption. Rice bran pellets (RBP), stabilized rice bran (SRB), coconut cake (CC) and sesame cake (SC) were taken up for the study. These were mixed with distilled water and cooked in such a way to separate the cooked solid residue and liquid extract followed by freeze drying to get two products from each. The raw, cooked dried residue and extract were analyzed for various parameters such as moisture (0.9-27.4 %), fat (2.1-16.1 %), ash (3.3-9.0 %), minerals (2.6-633.2 mg/100 g), total dietary fiber (23.2-58.2 %), crude fiber (2.7-10.5 %), protein (3.2-34.0 %), and the fat further analyzed for fatty acid composition, oryzanol (138-258 mg/100 g) and lignan (99-113 mg/100 g) contents and also evaluated sensory evaluation. Nutritional composition of products as affected by cooking was studied. The cooked products (residue and extract) showed changes in nutrients content and composition from that of the starting cakes and raw materials, but retained more nutrients in cooked residue than in the extract. The sensory evaluation of cooked residue and extract showed overall higher acceptability by the panelists than the starting cakes and raw materials. On the basis of these findings it can be concluded that these cooked residue and extract products are highly valuable for food supplementation than the raw ones.

Stability of oryzanol fortified biscuits on storage.

Biscuit can be used as a functional food to deliver nutraceuticals to consumers. One such natural nutraceutical oryzanol is present in rice bran oil. Oryzanol possesses a variety of health benefits which include reduction of cholesterol in blood, improvement of capillary action of blood vessels, anti-aging effect and others. Biscuit is a well known cereal based processed food and the fortification of oryzanol into the biscuits will go a long way to provide antioxidant rich, highly stable and acceptable functional food to the consumers. Biscuits were prepared with commercially available fat (CF) and oryzanol fortified fat (OFF). The control biscuits (CB) and oryzanol fortified biscuits (OFB) were packed in 200 gauge polypropylene pouches, stored at 27 °C with different relative humidity (RH 11 %, 22 %, 32 %, 44 % and 56 %) and analysed for its stability during storage of 120 days. Critical moisture content of OFB (4.8 %) was slightly less than that of CB (5.3 %). The fat content of the CB (12.2 %) and OFB (12.5 %) did not change during storage while free fatty acid content (0.36 % and 0.60 %) and peroxide value (0.08 and 0.17 meq. O2/100 g biscuit) respectively for CB and OFFB was showed small but significant changes during storage. Oryzanol content (292 mg) and radical scavenging activity (81.1 %) of OFB did not change during storage. The biscuits had a shelf life of minimum 3 months at 27 °C. Oryzanol in OFB showed good stability during baking and storage of biscuits.

Quality characteristics and stability of Moringa oleifera seed oil of Indian origin.

Cold pressed and hexane extracted moringa seed oils (CPMSO and HEMSO) were evaluated for their physico-chemical and stability characteristics. The iodine value, saponification value and unsaponifiable matter of CPMSO and HEMSO were found to be 67.8 and 68.5 g I2 / 100 g oil, 190.4 and 191.2 mg KOH / g oil and 0.59 and 0.65%, respectively. The total tocopherols of CPMSO and HEMSO were found to be 95.5 and 90.2 mg/Kg. The fatty acid composition of CPMSO and HEMSO showed oleic acid as the major fatty acid (78-79%). The oxidative, thermal and frying stabilities of the CPMSO were compared with commercial raw and refined groundnut oil (GNO and RGNO). The CPMSO was of adequate thermal stability and better oxidative stability as it showed 79% lesser peroxide formation than GNO. The frying stability of CPMSO was better as it showed lower increase in free fatty acid (28%), peroxide value (10 meq O2/Kg) and color (25%) than RGNO (48%, 22 meq O2/kg and 52%, respectively) after frying.

Shelf-life study of Indian traditional food based nutraceutical (oryzanol) enriched instant mixes Bhath-OZ and Upma-OZ.

To provide nutraceutical such as oryzanol through food, two instant mixes based on the Indian traditional food cuisine Bisibele bhath and Upma(Bhath-OZ and Upma-OZ) were developed and evaluated for shelf-life. The formulations contained cereals, pulses, and spices along with oryzanol enriched oil and were packed in 200gauge/50 gauge metallized polyester packaging material and stored under ambient (27 °C 65%RH) and accelerated conditions (37 °C/92%RH). Samples were withdrawn periodically and peroxide value (PV), free fatty acid value (FFA), fatty acid composition, oryzanol, and total tocopherols content were estimated. Sensory evaluation of reconstituted products was also carried out. Oryzanol content (610 and 550 mg%) did not change appreciably in Bhath-OZ and Upma-OZ respectively. The peroxide value under ambient condition increased from 1.1 to 9.3 meq.O2/kg and 2.24 to 9.02 meq.O2/kg during the 6 month storage study at 27 °C and 65% RH, while under accelerated conditions at 37 °C and 92%RH, it increased from 1.12 to 8.54 meq. O2/kg and 2.24 to 6.96 meq. O2/kg during 2 month storage period. Bhath-OZ and Upma-OZ packed in metallized polyester pouches stored at 27 °C and 65% RH had a shelf-life of 4 months without affecting the oryzanol content and quality of instant mixes during the storage period.

Physico-chemical characteristics of defatted rice bran and its utilization in a bakery product.

Defatted rice bran (DRB), a byproduct of rice milling is a rich source of dietary fiber and minerals. In the present study, the physico-chemical characteristics, antioxidant potential of defatted rice bran (Laboratory-LDRB and Commercial -CDRB) and its utilization in preparation of bread were studied. The effect of incorporation of CDRB at varying levels (5, 10 & 15%) on the quality characteristics of bread including physical, rheological and sensory attributes were evaluated and the dietary fiber content and antioxidant activity were determined. The results indicated that LDRB had better nutrient profile, physical and antioxidant properties than CDRB. On the basis of physical characteristics, breads with 5% and 10% CDRB were found to be acceptable as such and those containing 15% were acceptable with addition of bread improvers. The dietary fiber content and total antioxidative activity of bread increased with increasing levels of CDRB, which also improved the shelf life. The results reveal that DRB can be incorporated in breads upto 10% and 15% as such or with bread improvers respectively, as source of fiber and natural antioxidant, as a functional ingredient.

Over-expression of recombinant human phospholipid scramblase 1 in E. coli and its purification from inclusion bodies.

Human phospholipid scramblase 1 (hPLSCR1) scrambles plasma membrane phospholipids during cell activation, blood coagulation and apoptosis. It was over-expressed in E. coli with a histidine tag and purified from the inclusion bodies (*30 mg/l culture broth) under denaturing conditions using 8 M urea. The denatured hPLSCR1 refolded into its native configuration when urea was removed as shown by a 10-fold increase in its intrinsic fluorescence. Active hPLSCR1 showed scrambling activity in vitro after reconstituting in proteoliposomes. hPLSCR1 showed higher rates of scrambling activity for phosphatidylethanolamine than phosphatidylcholine. Binding studies with the calcium analogue "Stains-all" dye showed a characteristic peak, termed as the J band, at 650 nm. This is the first report on high level expression of hPLSCR1 with histidine tag in E. coli.