Enzymatic Solubilisation and Degradation of Soybean Fibre Demonstrated by Viscosity, Fibre Analysis and Microscopy

The effect of a commercial multienzyme product obtained by fermentation from Aspergillus aculeatus on soybean and soybean meal was investigated using viscosity measurements, dietary fibre component analysis and different microscopy techniques utilizing histochemical dyes and antibody labelling. The results obtained demonstrated a strong viscosity reducing effect of the enzyme preparation on soluble galactomannan and xyloglucan polysaccharides and in addition non-starch polysaccharide analysis demonstrated a notable solubilisation of all polysaccharide constituents. The degradation of these components as native integral parts of cell walls upon exposure to the enzyme was visualized with microscopy. Two histochemical dyes, coriphosphine O and alcian blue were successfully used to follow pectin solubilisation after enzyme treatment. Commercial antibodies recognizing specific components of pectin and hemicellulose components of soybean cell wall were also used to visualize several enzyme activities in the commercial enzyme preparation The challenges of using commercial antibodies elicited from a given plant source to detect similar epitiopes on another plant source are also discussed. Non-starch polysaccharide analysis of the insoluble dietary fibre constituents before and after enzyme treatment corroborated the visualized mode of action demonstrated by microscopy. The combination of techniques provided visual and quantitative measurements of the solubilisation and degradation of hemicellulose pectic soybean cell wall components as part of the undesirable antinutrients in animal feed.