In this work, production of inulinase was studied. Media formulation was optimized by experimental design and response surface techniques, as well as the pretreatment of the agro-industry residues used in the formulation of fermentation medium. Two agro-industry residues were investigated: sugarcane molasses (SCM) and corn steep liquor (CSL). Pretreatment with sulfuric acid was the most effective for clarification of SCM (pH 5.0, 24 h of resting time and final pH 4.0). Clarification of CSL was accomplished with phosphoric acid (pH 3.0, 24 h of resting time and final pH 5.5). A color reduction of approximately 70% was achieved for both substrates. The highest production of inulinase was obtained in a medium containing 100 g l −1 of pretreated SCM, 100 g l −1 of pretreated CSL and 6 g l −1 of Prodex Lac (yeast hydrolysate), yielding 1,139 U ml −1 .

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This work is focused on hybrid modeling of xanthan gum bioproduction process by Xanthomonas campestris pv. mangiferaeindicae. Experiments were carried out to evaluate the effects of stirred speed and superficial gas velocity on the kinetics of cell growth, lactose consumption and xanthan gum production in a batch bioreactor using cheese whey as substrate. A hybrid model was employed to simulate the bio-process making use of an artificial neural network (ANN) as a kinetic parameter estimator for the phenomenological model. The hybrid modeling of the process provided a satisfactory fitting quality of the experimental data, since this approach makes possible the incorporation of the effects of operational variables on model parameters. The applicability of the validated model was investigated, using the model as a process simulator to evaluate the effects of initial cell and lactose concentration in the xanthan gum production.

This study aimed to evaluate β-galactosidase immobilization. For this purpose, the ionic strength of the buffer, reaction time, amount of the immobilization support, and pH were evaluated by a central composite design. Assay 8, which consisted of 1.5 mol L −1 phosphate buffer (pH 7.5) and a reaction time of 2 h, produced the maximum yield. Eupergit ® C (400 mg) was subsequently used as an immobilization support. Immobilization kinetics wereinvestigated, and a significant increase in the yield was obtained after immobilization compared with that obtained from assay 8 (22.0 U mL −1 vs. 15.6 U mL −1). The enzyme efficiency of actuation was evaluated using o-nitrophenyl-β-d-galactopyranoside and lactose, with lactose providing better results. The reuse of β-galactosidase was evaluated, and more than 50% of the initial enzyme activity was maintained after five cycles of use. Enzyme characterization revealed that immobilization improved some aspects of the thermostability of β-galactosidase.

Dye and proteins recovered from broiler blood were used in the formulation of chicken sausages in substitution of soy proteins and synthetic dyes. Three formulations of chicken sausages were prepared: standard, liquid plasma, and freeze-dried plasma. The application of protein and blood dye in the formulation of sausages and sensory analysis followed the Brazilian legislation. Physicochemical, microbiological and sensory attributes of sausages were evaluated during 60. All the formulations met the physicochemical and microbiological requirements. Considering the sensory analysis, sausages prepared using freeze-dried plasma presented significant difference from the standard sausage. There was no significant difference in the acceptance between the standard and liquid plasma sausages. Therefore, the use of such byproducts can add value to meat products without any adverse effect consumers acceptability.