Development of Biodegradable Composites Using Polycaprolactone and Bamboo Powder.

The use of biodegradable polymers in daily life is increasing to reduce environmental hazards. In line with this, the present study aimed to develop a fully biodegradable polymer composite that was environmentally friendly and exhibited promising mechanical and thermal properties. Bamboo powder (BP)-reinforced polycaprolactone (PCL) composites were prepared using the solvent casting method. The influence of BP content on the morphology, wettability, and mechanical and thermal properties of the neat matrix was evaluated. In addition, the degradation properties of the composites were analysed through soil burial and acidic degradation tests. It was revealed that BP contents had an evident influence on the properties of the composites. The increase in the BP content has significantly improved the tensile strength of the PCL matrix. A similar trend is observed for thermal stability. Scanning electron micrographs demonstrated uniform dispersion of the BP in the PCL matrix. The degradation tests revealed that the biocomposites with 40 wt·% of BP degraded by more than 20% within 4 weeks in the acidic degradation test and more than 5% in the soil burial degradation test. It was noticed that there was a considerable difference in the degradation between the PCL matrix and the biocomposites of PCL and BP. These results suggest that biodegradable composites could be a promising alternative material to the existing synthetic polymer composites.

Application of the rat liver lysosome assay to determining the reduction of toxic gliadin content during breadmaking.

Enriched caricain was able to detoxify a major proportion of the gliadin in wholemeal wheat dough by allowing it to react for 5h at 37 °C during the fermentation stage. A reduction of 82% in toxicity, as determined by the rat-liver lysosome assay, was achieved using 0.03% enzyme on weight of dough. Without enzyme, only 26% reduction occurred. The difference in reduction of toxicity achieved is statistically significant (p < 0.01). The results are very similar to those obtained in our previous work using an immuno assay and the same enzyme preparation. They confirm the value of caricain as a means of reducing the toxicity of gliadin and open the way for enzyme therapy as an adjunct to the gluten free diet. This approach should lead to better control over the elimination of dietary gluten intake in conditions such as coeliac disease and dermatitis herpetiformis.

The effect of fermentation and addition of vegetable oil on resistant starch formation in wholegrain breads.

Resistant starch has potential health benefits but the factors affecting its formation in bread and baked products are not well studied. Here, the formation of resistant starch in wholemeal bread products was evaluated in relation to the processing conditions including fermentation time, temperature and the inclusion of palm oil as a vitamin source. The effects of each the factor were assessed using a full factorial design. The impact on final starch content of traditional sourdough fermentation of wholemeal rye bread, as well as the bulk fermentation process of wheat and wheat/oat blends of wholemeal bread, was also assessed by enzyme assay. Palm oil content was found to have a significant effect on the formation of resistant starch in all of the breads while fermentation time and temperature had no significant impact. Sourdough fermentation of rye bread was found to have a greater impact on resistant starch formation than bulk fermentation of wheat and wheat blend breads, most likely due the increased organic acid content of the sourdough process.

Reduction of toxic gliadin content of wholegrain bread by the enzyme caricain.

Increasingly the number of individuals being diagnosed with some form of sensitivity to the proteins in wheat grains represents a cause for concern. Currently, the treatment is dietary withdrawal of gluten, but commercial gluten-free bread presents some undesirable properties. The objective of this study has been to assess the ability of the enzyme caricain (from papaya latex) to detoxify gliadin in whole wheat flour and develop bread suitable for coeliacs and gluten intolerant individuals. Ion exchange chromatography was used to enrich the caricain in papaya latex and an enzyme-linked immunosorbent assay test kit was used for the analysis of gliadin residues in the baked bread. The partially purified enzyme was found to be more effective in reducing gliadin content than the crude papain and the resultant loaves had acceptable crumb and crust characteristics. Caricain appears to be capable of detoxifying gliadin and has the potential to mitigate the problems confronting coeliacs.