Characterization of dietary fiber from residual cellulose sausage casings using a combination of enzymatic treatment and high-speed homogenization

The objective of this study was to characterize dietary fiber from residual cellulose sausage casings using a combination of enzymatic hydrolysis and high-speed homogenization. To modify structure and function of the cellulose, residual cellulose casings (40 or 50 mg mL(-1)) were subjected to enzymatic hydrolysis followed by high-speed homogenization to obtain dietary fiber at a targeted yield of 70%. Total dietary fiber of the sausage casing ingredient was 50% (w:w) on a dry basis, of which 45% was insoluble fiber and 5% soluble fiber when the treatment of 50 mg mL(-1) against total dietary fiber was used. The obtained fiber using 50 mg mL(-1) solids had the following characteristics: swelling capacity, 3.9 mL water.g sample(-1); water binding capacity, 2.5 g water.g sample(-1); and oil binding capacity, 2.7 g oil.g sample(-1). The particle size exhibited a bimodal distribution with the surface mean value of 65 mu m and volume mean of 377 mu m. The rheological behavior of the fiber dispersion was characterized as shear thinning, which could be described accurately with the Power Law model with equation of sigma = 0.82 gamma(0.3) , with at an apparent viscosity at 100 s(-1) of 27 mPa s. These results indicated that residual cellulose casings can be used as an inexpensive raw material to obtain an ingredient with adequate content and the inherent characteristics of dietary fiber.