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 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.

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.

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The present study evaluated the purification of inulinase by changing the ionic strength of the medium by addition of NaCl and CaCl 2 followed by precipitation with n-propyl alcohol or iso-propyl alcohol. The effects of the concentration of alcohols and the rate of addition of alcohols in the crude extract on the purification yield and purification factor were evaluated. Precipitation caused an activation of enzyme and allowed purification factors up to 2.4-fold for both alcohols. The purification factor was affected positively by the modification of the ionic strength of the medium to 0.5 mol.L -1 NaCl before precipitation with the alcohol (n-propyl or iso-propyl). A purification factor of 4.8-fold and an enzyme yield of 78.1 % could be achieved by the addition of 0.5 mol.L -1 of NaCl to the crude extract, followed by the precipitation with 50 % (v/v) of n-propyl alcohol, added at a flow rate of 19.9 mL/min.

This work investigates the separation of soybean oil/compressed n‐butane and soybean oil/liquefied petroleum gas (LPG) mixtures, using ultra‐ and nanofiltration membranes. For this purpose, soybean oil/n‐butane and soybean oil/LPG in the mass ratio of 1:3 were continuously fed into a flat sheet module without the recycle. The effects of the feed pressure (10, 20, and 30 bar), the pressure difference (1, 5, and 10 bar) and the pre‐treatment with ethanol and n‐propanol on the oil permeate flux and oil retention were investigated. The membranes with best performance (higher oil retention combined with high solvent permeate flux) were Sepa GM (4 kDa) and Sepa HL (98 % MgSO4), previously conditioned in ethanol. The Sepa GM membrane showed oil retention between 95 to 99 %. The Sepa HL membrane showed oil retention between 83 to 97 %. The pre‐treatment with ethanol improved the permeate flux. In most of the experimental conditions severe membrane fouling was observed. A change in the permeate flux and oil retention behaviour was observed in the assays with LPG as solvent due to the different gas composition when compared with n‐butane.