Physicochemical and functional properties of gelatin extracted from Yak skin.

Different molecular weight distribution (MWD) gelatin was extracted from Yak skin after enzymatic pretreatments and their physicochemical and functional properties (SDS-PAGE, UV-vis absorption spectra, DSC, FT-IR, Amino acid analysis, AFM, emulsibility and foamability) were analyzed. The gelatin was extracted by pepsin and got different MWD of Yak skin gelatin by controlling the enzymolysis time. The SDS-PAGE showed the MWD of the Yak skin gelatin. The UV-vis absorption turned out that the broad MWD of Yak skin gelatin had a higher maximum absorption peaks. The FT-IR and AFM indicated that the gelatin structures and microstructures changed with the change of the MWD. The broad MWD of the Yak skin gelatin had a higher denaturation temperature (TD), and it was higher than most of the other mammals and marine biological gelatin. The broad MWD gelatin also had higher imino acids (proline and hydroxyproline) contents and lower foamability and emulsibility compared to the narrow MWD gelatin. These findings, obtained for the first time for Yak skin gelatin, showed that it has great potential for application as an alternative to commercial gelatin due to its good thermotolerance, particularly in the applications of the biological materials, stabilizer of thermo-tolerant and so on.

Enzyme immunoassay for the detection of porcine gelatine in edible bird's nests.

Porcine gelatine is a common adulterant found in edible bird's nests (EBNs) used to increase the net weight prior to sale. This study aimed to develop indirect enzyme-linked immunosorbent assays (ELISAs) for porcine gelatine adulteration using anti-peptide polyclonal antibodies. Three indirect ELISAs were developed (PAB1, 2 and 3), which had limits of detection (LODs) of 0.12, 0.10 and 0.11 µg g(-1), respectively. When applied to standard solutions of porcine gelatine, the inter- and intra-assays showed coefficients of variation (CVs) less than 20% and were able to detect at least 0.5 ng µg(-1) (0.05%) porcine gelatine in spiked samples. The proposed ELISA offers attractions for quality control in the EBN industry.

Analytical methods for gelatin differentiation from bovine and porcine origins and food products.

Usage of gelatin in food products has been widely debated for several years, which is about the source of gelatin that has been used, religion, and health. As an impact, various analytical methods have been introduced and developed to differentiate gelatin whether it is made from porcine or bovine sources. The analytical methods comprise a diverse range of equipment and techniques including spectroscopy, chemical precipitation, chromatography, and immunochemical. Each technique can differentiate gelatins for certain extent with advantages and limitations. This review is focused on overview of the analytical methods available for differentiation of bovine and porcine gelatin and gelatin in food products so that new method development can be established.

Surface selective binding of nanoclay particles to polyampholyte protein chains.

Binding of nanoclay (Laponite) to gelatin-A and gelatin-B (both polyampholytes) molecules was investigated at room temperature (25 degrees C) both experimentally and theoretically. The stoichiometric binding ratio between gelatin and Laponite was found to be strongly dependent on the solution ionic strength. Large soluble complexes were formed at higher ionic strengths of the solution, a result supported by data obtained from light scattering, viscosity, and zeta potential measurements. The binding problem was theoretically modeled by choosing a suitable two-body screened Coulomb potential, U(R(+)) = (q(-)/2epsilon)[(Q(-)/R(-))e(-kR(-))-(Q(+)/R(+))e(-kR(+))], where the protein dipole has charges Q(+) and Q(-) that are located at distances R(+) and R(-) from the point Laponite charge q(-) and the dispersion liquid has dielectric constant (epsilon). U(R(+)) accounted for electrostatic interactions between a dipole (protein molecule) and an effective charge (Laponite particle) located at an angular position theta. Gelatin-A and Laponite association was facilitated by a strong attractive interaction potential that led to preferential binding of the biopolymer chains to negatively charged face of Laponite particles. In the case of gelatin-B selective surf ace patch binding dominated the process where the positively charged rim and negatively charged face of the particles were selectively bound to the oppositely charged segments of the biopolymer. The equilibrium separation (R(e)) between the protein and nanoclay particle revealed monovalent salt concentration dependence given by R(e) approximately [NaCl](alpha) where alpha = 0.6+/-0.2 for gelatin-A and alpha = 0.4+/-0.2 for gelatin-B systems. The equilibrium separations were approximately 30% less compared to the gelatin-A system implying preferential short-range ordering of the gelatin-B-nanoclay pair in the solvent.

Evaluation of electrospun PCL/gelatin nanofibrous scaffold for wound healing and layered dermal reconstitution.

The current design requirement for a tissue engineering skin substitute is that of a biodegradable scaffold through which fibroblasts can migrate and populate. This artificial "dermal layer" needs to adhere to and integrate with the wound, which is not always successful for the current artificial dermal analogues available. The high cost of these artificial dermal analogues also makes their application prohibitive both to surgeons and patients. We propose a cost-effective composite consisting of a nanofibrous scaffold directly electrospun onto a polyurethane dressing (Tegaderm, 3M Medical) - which we call the Tegaderm-nanofiber (TG-NF) construct - for dermal wound healing. Cell culture is performed on both sides of the nanofibrous scaffold and tested for fibroblast adhesion and proliferation. It is hoped that these studies will result in a fibroblast-populated three-dimensional dermal analogue that is feasible for layered applications to build up thickness of dermis prior to re-epithelialization. Results obtained in this study suggest that both the TG-NF construct and dual-sided fibroblast-populated nanofiber construct achieved significant cell adhesion, growth and proliferation. This is a successful first step for the nanofiber construct in establishing itself as a suitable three-dimensional scaffold for autogenous fibroblast populations, and providing great potential in the treatment of dermal wounds through layered application.

Food allergy to gelatin in children with systemic immediate-type reactions, including anaphylaxis, to vaccines.

BACKGROUND: Anaphylaxis to measles-mumps-rubella vaccines has been reported. We have suspected that most such reactions are caused by gelatin contained in the vaccines. OBJECTIVE: To confirm the relation between systemic allergic reactions to vaccines and the presence of anti-gelatin IgE, we measured anti-gelatin IgE in children who demonstrated allergy to gelatin-containing vaccines. Furthermore, to clarify the relation between allergic reactions to gelatin in vaccines and foods, we surveyed the occurrence of allergic reactions to gelatin-containing foods in the same children. METHODS: Serum samples were taken from 26 children who had systemic immediate-type reactions, including anaphylactic shock, to vaccines and the same number of children without allergic reactions. Specific IgE to gelatin in these samples was measured. We then surveyed whether these children had allergic reactions to gelatin-containing foods before and after vaccination. RESULTS: Twenty-four of the 26 children with allergic reactions to vaccines had anti-gelatin IgE ranging from 1.2 to 250 Ua/ml. Seven had allergic reactions on ingestion of gelatin-containing foods. Of these, two had reactions before vaccination, and five had reactions after vaccination. All the control children without allergic reactions to vaccines had no anti-gelatin IgE. CONCLUSION: We reconfirmed a strong relationship between systemic immediate-type allergic reactions, including anaphylaxis, to vaccines and the presence of specific IgE to gelatin. Moreover, some of the children also had allergic reactions to food gelatin before or after vaccination.