Su-il Park

Preparation of regular sized Ca-alginate microspheres using membrane emulsification method

J.-O. YOU{, S.-B. PARK{, H.-Y. PARK{, S. HAAM{*, C.-H. CHUNG} and W.-S. KIM{ { Department of Chemical Engineering, College of Engineering and Bioproducts Research Center, Yonsei University, Seoul 120-749, Korea { DDS Team, Pharmaceutical & Health Research Institute, Paci®c R & D Center, 314-1 Bora-ri Kiheung-eup Yongin-si Kyounggi-do, 449-900, Korea } Department of Chemical Engineering, School of Chemical, Polymer and Textile Engineering, SUNGKYUNKWAN University, Kyounggi-do, 440746, KoreaMonodisperse Ca-alginate microspheres were prepared using the membrane emulsification method. Three ionic types of drugs (anionic, cationic and non-ionic) were incorporated into the microspheres, and the effects of sodium alginate concentration and the pressure applied during the dispersing process on the properties of the microspheres were examined. Monodisperse microspheres were obtained when the concentration of alginate solution was 2 wt% and the pressure applied was 0.4 x 10(5) Pa. The mean size of microspheres was approximately 4 microm. Lidocaine x HCl (cationic), sodium salicylate (anionic) and 4-acetamidophenol (non-ionic) were selected as ionic model drugs and included in the alginate microspheres. Lidocaine x HCl (cationic drug) release was more retarded than that of the anionic drug, because of the electrostatic attraction between the negative charge of the ionized carboxyl group in the alginate chain and the positive charge of the cationic drug. In acidic release medium, a slow release was observed due to the low swelling characteristic and the increased viscosity of alginate, regardless of ionic type of drug.

Application of chitosan-incorporated LDPE film to sliced fresh red meats for shelf life extension

Chitosan lactate was impregnated as an antimicrobial additive into low density polyethylene (LDPE) with different concentrations. The antimicrobial effectiveness was tested with three pathogenic bacteria, specifically Listeria monocytogenes, Escherichia coli and Salmonella enteritidis. Also, these chitosan incorporated films were applied on red meat surfaces to determine the effectiveness of chitosan on color shelf life extension and microbial growth inhibition. Chitosan was exposed to 0.1% peptone water containing the three pathogens in separate tests and inhibited microbial growth a higher levels with increasing concentration of chitosan in the film matrix. Oxygen permeability was not affected by the incorporation of chitosan, while the water vapor permeability increased with the addition of chitosan. Film elongation decreased with the addition of chitosan. When chitosan incorporated films were applied on fresh red meat, microorganisms on the meat surface were not inhibited but significant extension of red color shelf life were observed in refrigerated, sliced red meats.

Ca-alginate microspheres encapsulated in chitosan beads

Chitosan beads (CBs) incorporating Ca-alginate microspheres (CAMs), containing a drug, were prepared as an oral sustained delivery system. Stable and monodisperse Ca-alginate microspheres loaded with drug were obtained by a membrane emulsification method. The Ca-alginate microspheres were encapsulated in chitosan beads by the ionotropic gelation method with a polyelectrolyte complex reaction between two oppositely charged polyions. The surface and internal characteristics of the beads were improved by ionic cross-linking in tripolyphosphate (TPP) solution adjusted to pH 5.0. The release experiments were performed using lidocaine·HCl (cationic drug) and sodium salicylate (anionic drug) as model drugs. Initial release of drugs depended on the degree of swelling. Ca-alginate microspheres encapsulated in chitosan beads were superior to both drug-loaded CBs and CAMs beads for sustained release because they had a three-layer composition; a calcium alginate core bounded by an inter-phasic chitosan-alginate membrane, which itself was surrounded by a layer of chitosan-TPP.

Utilization of Monolinolein as a Substrate for Conjugated Linoleic Acid Production by Bifidobacterium breve LMC 520 of Human Neonatal Origin

This study was designed to isolate bifidobacteria from human intestines that efficiently converts monolinolein, a monoglyceride form of linoleic acid, into conjugated linoleic acid (CLA), as well as to optimize culture conditions for improving CLA production during milk fermentation. Among 150 screened neonatal bifidobacteria, Bifidobacterium breve LMC 520 showed the highest CLA-producing ability and was tested with different types of fat substrates at various concentrations to determine the optimal conditions for CLA production. Monolinolein was tested as a substrate for CLA production. The incubation time optimized for CLA production was 24 h, and CLA production was proportionally increased with monolinolein concentration. The incubation of LMC 520 with commercial starter strains caused minimal reduction in CLA production. Our results demonstrate that the CLA-producing ability of B. breve LMC 520 could offer beneficial effects when utilized as a starter culture for the development of functional dairy products.

Eco-Design for Food Packaging Innovations

Sustainability has emerged as a core design concept in packaging development to minimize environmental impacts, maximize cost saving, and avoid excessive or deceptive packaging. Environmental improvement through eco-design can only be achieved on the basis of holistic approaches integrating environmental, economic, and social considerations. Source reduction, recycling and reuse are the ways to implement practically the eco-design of packaging without sacrificing product safety. The sustainable packaging design principles of effective, efficient, cyclic, and safe should be kept in mind in developing the package. Eco-design software tools such as PIQET and SavvyPack are helpful to evaluate and compare several packaging options. It is possible to decrease the environmental impact of food packaging systems and increase customer satisfaction at the same time by establishing a strategy, prioritizing all efforts involved, and utilizing proper assessment methods or software. Optimum packaging design must balance potential reductions in food loss, the ratio of the impact of the food to the impact of the packaging, the handling of food waste, and the handling of packaging waste, which depend on the logistics of food supply. Interactions between packaging systems and logistic processes need to be looked into thoroughly for the helpful packaging solution that is workable in the food supply chain.

Leakage analysis of LLDPE/Nylon flexible packaging by mass extraction leakage test and bioaerosol challenge test

F and fruit juices represent an important part of the human diet because they shows a significant economic value on the market, remain among the products subject to counterfeiting practices, inducing a negative impact on the consumer and food industry. Sugars and organic acids are important components of fruits chemical composition, providing powerful tools for authenticity of fruit products. They also have an effect on the sensory properties and nutritional value of fruit products. The present study was undertaken to determine the concentration of several sugars and organic acids in different fresh fruit juices by using HPLC-ELSD and HPLC-PDA methods in order to establish the variance range of this compounds for each type of fruit juices and to create a referential database. Linear discriminant analysis (LDA) models were constructed to classify juices according to the type of fruit, different sample locations and to distinguish between authentic, blended or adulterated juices. The developed methodology based on fingerprinting of sugars and organic acids in conjunction with a comprehensive database and chemometric methods reveals a high potential for certification of fruit juices authenticity.