Raul A. P. A. Cruz

This study investigated whether heat treatments (raw, 63 °C for 30 min, and 85 °C for 5 min) affect protein hydrolysis by endogenous enzymes in the milk of ruminants (bovine, ovine, and caprine) using a self-digestion model. Self-digestion consisted of the incubation for six hours at 37 °C of the ruminants’ milk. Free amino group concentration was measured by the o-phthaldialdehyde method, and peptide sequences were identified by chromatography-mass spectrometry. Results showed that heat treatments prior to self-digestion decreased the free NH₂ by 59% in bovine milk heated at 85 °C/5 min, and by 44 and 53% in caprine milk heated at 63 °C/30 min and 85 °C/5 min, respectively. However, after self-digestion, only new free amino groups were observed for the raw and heated at 63 °C/30 min milk. β-Casein was the most cleaved protein in the raw and heated at 63 °C/30 min bovine milk. A similar trend was observed in raw ovine and caprine milk. Self-digestion increased 6.8-fold the potential antithrombin peptides in the bovine milk heated at 63 °C/30 min. Enhancing bioactive peptide abundance through self-digestion has potential applications in the industry for functional products. Overall, heat treatments affected the free amino groups according to the species and heat treatment applied, which was reflected in the varying degrees of cleaved peptide bonds and peptides released during self-digestion.

Production of active rice husk silica (ARHS) in bubbling fluidized bed boiler of a thermoelectric unit (TEU) and its addition to high performance concrete (HPC) with a compression resistance of 90 MPa was developed in the last 10 years. A first factory in Brazil was established at Alegrete town, RS, and other factories are under planning. Data of ARHS production, specification and HPC trace are presented. Design of parabolic solar collector coverage (PSCC) for air heating for biomass drying in a special silo of the TEU is presented as well. Cost of HPC/ARHS is 10 times less than steel (USD 200/ton vs. USD 2000/ton, specific mass 2.5 vs. 7.6 g/cm³, respectively). Those characteristics allow simultaneous solution of four ecological problems: large span coverage, rain water collection, daily solar energy collection and storage, and drying of biomass. The integration of those characteristics results in decrease of biomass consumption maintaining the same UTE efficiency. Tracking parabolic solar collector can be avoided between Cancer and Capricorn Tropics, and it is sufficient its eastern-western orientation with inclination to the Equator by the latitude angle. Coverage of the area occupied by TEU is sufficient to dry its biomass consumption. Preheating of boiler water with solar energy is possible decreasing biomass consumption in sunny days; biomass is partially consummed at night and cloudy days. Coupling the above technologies with high pressure steam TEU and fast-growing short-rotation forest gives to the biomass electrical energy generation a competitive economical position with hydraulic, coal, natural gas, and aeolic energy generation.