Nanoparticle sensor for label free detection of swine DNA in mixed biological samples

We used 40 ± 5 nm gold nanoparticles (GNPs) as colorimetric sensor to visually detect swine-specific conserved sequence and nucleotide mismatch in PCR-amplified and non-amplified mitochondrial DNA mixtures to authenticate species. Colloidal GNPs changed color from pinkish-red to gray-purple in 2 mM PBS. Visually observed results were clearly reflected by the dramatic reduction of surface plasmon resonance peak at 530 nm and the appearance of new features in the 620–800 nm regions in their absorption spectra. The particles were stabilized against salt-induced aggregation upon the adsorption of single-stranded DNA. The PCR products, without any additional processing, were hybridized with a 17-base probe prior to exposure to GNPs. At a critical annealing temperature (55 °C) that differentiated matched and mismatched base pairing, the probe was hybridized to pig PCR product and dehybridized from the deer product. The dehybridized probe stuck to GNPs to prevent them from salt-induced aggregation and retained their characteristic red color. Hybridization of a 27-nucleotide probe to swine mitochondrial DNA identified them in pork–venison, pork–shad and venison–shad binary admixtures, eliminating the need of PCR amplification. Thus the assay was applied to authenticate species both in PCR-amplified and non-amplified heterogeneous biological samples. The results were determined visually and validated by absorption spectroscopy. The entire assay (hybridization plus visual detection) was performed in less than 10 min. The LOD (for genomic DNA) of the assay was 6 µg ml − 1 swine DNA in mixed meat samples. We believe the assay can be applied for species assignment in food analysis, mismatch detection in genetic screening and homology studies between closely related species

Targeting double genes in multiplex PCR for discriminating bovine, buffalo and porcine materials in food chain

Beef, buffalo and pork are the major meat of economic, religious and health concern. Current methods to authenticate these materials in food chain are based on mainly single gene targets which are susceptible to break down by food processing treatments. We, for the first time, described here a double gene targeting short-amplicon length multiplex polymerase chain reaction assay for discriminating bovine, buffalo and porcine materials in a single assay platform. The advantage of the assay is evidenced in terms of fidelity, cost and time since it is highly unlikely that two different targets would be missing even in a decomposed specimen. Detection of multiple targets in a single assay definitely saves analytical cost and time. Mitochondrial cytochrome b (cytb) and ND5 genes were targeted and six different targets (length: 90–146 bp), two for each of cow (120 and 106bp), buffalo (90 and 138bp) and pig (73 and 146bp), were amplified from raw, boiled, autoclaved and microwaved cooked meat under pure and mixed matrices. The detection limit was 0.02 ng DNA under pure states and 0.1% meat in binary mixtures and meatball products. Screening of Malaysian meatball products revealed all beef products were buffalo positive in which 35% were totally replaced. In contrast, all pork products were found uncontaminated from beef and buffalo

α-glucosidase inhibitors isolated from Mimosa pudica L.

The aim of the study was to isolate digestive enzymes inhibitors from Mimosa pudica through a bioassay-guided fractionation approach. Repeated silica gel and sephadex LH 20 column chromatographies of bioactive fractions afforded stigmasterol, quercetin and avicularin as digestive enzymes inhibitors whose IC50 values as compared to acarbose (351.02 ± 1.46 μg mL−1) were found to be as 91.08 ± 1.54, 75.16 ± 0.92 and 481.7 ± 0.703 μg mL−1, respectively. In conclusion, M. pudica could be a good and safe source of digestive enzymes inhibitors for the management of diabetes in future

Effect of accelerated storage on chemical compositions of mango seed fat and palm oil mid-fraction blends as cocoa butter replacers

In this study, mango seed fat (MSF) and its recommended blends were stored under accelerated condition. During the accelerated storage, the changes of fatty acids, total phenolic, tocopherol, and phytosterol contents, iodine, free fatty acid (FFA), and peroxide values were examined every six days. Results upon storage, palmitic and stearic acids increased from 18.0 to 22.5% and from 33.3 to 36.7%, while oleic and linoleic acids decreased from 40.5 to 34.3% and from 5.4 to 2.1% in blend containing 85 g MSF/100 g fat. The iodine values of MSF and its recommended blends decreased (48.2 ± 1.2 to 32.0 ± 0.8 g iodine/100 g fat), while the peroxide (1.1e4.2 ± 0.0 milliequivalent O2/kg fat) and FFA (1.8-3.9 ± 0.0 g/100 g of fat) values increased after accelerated storage. The results obtained from this study provide an indication about the storage stability of MSF and its blends as cocoa butter replacers to food industry, in particular chocolate industry

Physicochemical properties of cocoa butter replacers from supercritical carbon dioxide extracted mango seed fat and palm oil mid-fraction blends

Supercritical carbon dioxide (scCO2) extracted mango seed fat (MSF) was blended with palm oil mid-fraction (POMF) to obtain cocoa butter replacers (CBRs). The fatty acid constituents and physicochemical properties of the formulated blends were analysed by gas chromatography (GC). In this study, the fatty acid constituents and other physicochemical properties such as iodine value (43.2 to 43.4 g I2 /100 g fat), saponification value (195.7 to 195.9 mg KOH/g fat), acid value (2.1 to 2.7%), and slip melting point (33.8 to 34.9°C) of blends MSF/POMF at ratios 85/15, 80/20, 75/25, and 70/30 were found similar to the physicochemical properties of commercial cocoa butter. Thus, it could be concluded that the MSF/POMF blends that are blends 85/15, 80/20, 75/25, and 70/30 (3 to 6) could be suggested as CBRs in terms of the physicochemical properties like fatty acid constituents, iodine, saponification and acid values and slip melting point

Identification of bioactive compounds with GC Q-TOF MS in the extracts from Clinacanthus nutans using subcritical carbon dioxide extraction

Subcritical carbon dioxide Soxhlet extraction of biologically active compounds from Clincanthus nutans was investigated by full factorial design to identify and optimize the factors (particle size and co-solvent) affecting extract yield, antioxidant activity, total phenolic content, total flavonoid content, and α-glucosidase inhibitory activity. An average of 3.103% yield, 98.90% antioxidant activity, 49.40 mg/g (GAE) TPC, 43.76 mg/g (RE), and 88.58% AGI activity can be achieved using the optimum levels of independent variables. The GC-Q-TOF MS identification of optimized extract shown that different classes of phytoconstituents were successfully separated by CO2-Soxhlet to produce potential antioxidant and α-glucosidase inhibitory activity

Techniques for the extraction of phytosterols and their benefits in human health: a review

This review summarizes the information on the health-promoting effects of phytosterols and the techniques for their extraction. The extraction and analysis processes of phytosterols are complex and have not been fully established. Phytosterols have significant roles in the areas of foods, nutrition, pharmaceuticals, and cosmetics. Free phytosterols extracted from plant sources are widely used in fortified foods and dietary supplements. Most phytosterols are extracted from plant matrices using organic solvents which are health and environmental hazards. However, the application of supercritical fluid in the extraction of phytosterols has offered a promising green technology in overcoming the limitations of conventional extraction

Preparation of Mesoporous Silica-Supported Chiral Amino Alcohols for the Enantioselective Addition of Diethylzinc to Aldehyde and Asymmetric Transfer Hydrogenation to Ketones

Optically active (−)-ephedrine, (−)-norephedrine, and (−)-prolinol were immobilized onto cubicmesoporousMCM-48 silica. The immobilized amino alcohols served as a heterogeneous chiral catalyst for the asymmetric addition of diethylzinc to aldehydes and transfer hydrogenation to ketones. The developed catalytic process yielded optically enriches secondary aromatic alcohols with 92–99% conversion and 70–82% enantioselectivity

Some formulas of L. Carlitz on Hermite polynomials

We have used the idea of ‘quasi inner product’ introduced by L. R. Bragg in 1986 to consider generating series ∑n=0∞Hn2(x)Hn2(y)tn22n(n!)2 studied by L. Carlitz in 1963. The pecularity of the series is that there is (n!)2 in the denominator, which has a striking deviation from the usuaI generating series containing n! in the denominator. Our generating function for the said generating series is quite different from that of Carlitz, but somewhat analogous to generating integrals derived by G. N. Watson (Higher Transcendental function Vol.III, P 271-272 for the case of Legendre, Gegenbauer and Jacobi polynomials