This article reviews recent advances in polymer blends and composites from renewable resources, and introduces a number of potential applications for this material class. In order to overcome disadvantages such as poor mechanical properties of polymers from renewable resources, or to offset the high price of synthetic biodegradable polymers, various blends and composites have been developed over the last decade. The progress of blends from three kinds of polymers from renewable resources-(1) natural polymers, such as starch, protein and cellulose; (2) synthetic polymers from natural monomers, such as polylactic acid; and (3) polymers from microbial fermentation, such as polyhydroxybutyrate-are described with an emphasis on potential applications. The hydrophilic character of natural polymers has contributed to the successful development of environmentally friendly composites, as most natural fibers and nanoclays are also hydrophilic in nature. Compatibilizers and the technology of reactive extrusion are used to improve the interfacial adhesion between natural and synthetic polymers.

Microbial transglutaminase (MTGase) has been shown to effectively induce soymilk with a certain level of solid content to form filled tofu. The gel formation of this kind of tofu and the influence of reaction parameters on the properties of formed tofu were investigated by dynamic oscillatory and/or large-strain rheological measurements. The gelation process and the development of the mechanical moduli (especially the storage modulus, G0) of this kind of tofu were highly dependent upon the incubation temperature. Textural property analysis (TPA) results showed that many TPA parameters of this kind of tofu, including gel hardness, gumminess, springiness and cohesiveness, were also affected by the applied enzyme amount, the pH of soymilk and the presence of NaCl, especially for gel hardness. In addition, the additional heating and cooling treatment could significantly improve the gel strength of tofu, induced by MTGase at lower temperatures (e.g. 25 and 37 1C). These results suggested that a new kind of tofu with good quality could be produced using the enzymatic cross-linking technique, by the combination with the thermal treatment.

In this study, the effects of acetylation on the swelling and enzymatic degradation of maize starch as well as the release rate of drug from tablets coated with starch-based polymer were examined. Maize starch acetates (SA) were prepared by acetyl esterification with a degree of substitution from 1.31 to 2.40, and bovine serum albumin was used as a model drug. For in-vitro drug release assays, the starch based polymer was incubated in simulated gastric fluid, simulated intestinal fluid and simulated colonic fluid, respectively. The resistant starch content and swelling property of maize starch were increased by acetylation, which retarded its enzymatic degradation. Drug release studies have shown that SA-coated tablets could deliver the drug to the colon. These results suggest that the SA can be used for a potential drug delivery carrier for colon-targeting biomacromolecule drugs.

Spirulina platensis was batch cultivated in a novel 3.5 l magnetic air-lift photobioreactor with external-loop on which 0–0.55 T electromagnetic field (EMF) was imposed to investigate the EMF effects on the algal growth and nutrition composition. At the same time, the correlative mechanism was discussed mainly based on C, N, P uptake. It was found that, EMF has double-side effects on S. Platens is cultivation depend on EMF intensity. 0.25 T EMF stress was found to be suitable for the algal cultivation enhancement increasing the maximum cell dry weight by 22% in a time period two days less than that of the control at 35 C and 2521mol photons m2 S1. In addition, the nutritional composition of S. platens is was improved in both essential amino acids such as histidine and trace elements Ni, Sr, Cu, Mg, Fe, Mn, Ca, Co and V. It was suggested it was possible to optimize the cultivation process of S. platens is by imposing suitable weak EMF which may enhance the nutrition assimilation e.g. C, N, P and minerals by S. platens is.