The quality of quinoa flour is greatly determined by its non-starch components, mainly protein and lipids. Dry fractionation has an important impact on the composition and physicochemical properties of quinoa flour and grits. Quinoa cv. Titicaca, the most extensively grown in Europe and little studied so far, was used in this work. Hydration, techno-functional, rheological and thermal properties of three quinoa fractions obtained by dry fractionation (fine, medium and coarse) were evaluated and related to their particle size and composition. The medium fraction (~500 μm) was enriched in protein (50%) and lipids (80%) and depleted in starch (30%) with respect to the original grain; while the coarse fraction (~1000 μm) was enriched in starch (7%) and reduced in protein (15%). The fine fraction showed the most similar functional, pasting and rheological properties to the whole grain quinoa flour. The coarse fraction led to the most consistent gels, with the elastic (G') and viscous (G'') moduli being ten and twenty times higher than those found in the other quinoa fractions and the whole grain flour. The degree of retrogradation as well as the formation of the amylose-lipid complex were markedly affected by the particle size and not so by the composition of each fraction. This work allows to conclude that dry fractionation of quinoa grains is a feasible procedure to tailoring the nutritional profile of the flour and its techno-functional and rheological properties.

Cloudy apple juice has been treated by high pressure carbon dioxide (HPCD) as non-thermal technology to inactive polyphenoloxidase and pectinmethylesterase in batch mode. Stirring speed (from 200 to 600 rpm) induced an increase in the enzyme inactivation rate while a triple cycle of pressurization/depressurization led to the same enzyme inactivation efficiency. Enzyme inactivation kinetics were determined at different temperatures (from 35 to 45 ºC) and pressures (from 10 to 20 MPa). Data were described by the first order kinetic model and the Weibull model. For the first order kinetic model, decimal reduction time for HPCD treatment was found to be smaller than for mild heating, in the same temperature range. The same tendency was observed for the first decimal reduction time in the Weibull model. HPCD treatment resulted in a homogenization effect reflected in the shifting of the particle size distribution towards smaller diameters after treatment. HPCD treatment did not result in a change of water and oxalate soluble pectin content, total phenolic compounds and hidroxymethylfurfural content.

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Cloudy apple juice has been treated by thermosonication in batch mode as an alternative processing to thermal treatment. Thermosonication was found to be effective to inactivate polyphenol oxidase; however, pectinmethylesterase was found to be more resistant. An increase of the working ultrasound amplitude and the amount of energy supplied to the juice led to lower enzyme residual activities.Enzyme inactivation kinetics were determined at different temperatures (from 44 to 67 ºC).Inactivation data were described by the first order kinetic model and the Weibull model, both models yielding good fitting. Thermosonication treatment caused a homogenization effect reflected in the shifting of the particle size distribution towards smaller diameters. The effect of the nature of dissolved gases in the juice on enzyme inactivation was studied by displacing the air dissolved in the juice by bubbling nitrogen or carbon dioxide, previous to the thermosonication experiments. Higher inactivation rates were obtained by displacing the air with nitrogen.Industrial relevance: Consumers demand of natural and fresh-like products has driven the food industry to investigate alternative technologies to replace conventional food heat treatments that may affect food quality. Among these technologies, thermosonication treatment is an attractive technology that can inactivate microorganisms and enzymes. This work shows that some enzymes that cause deleterious effect on cloudy apple juice can be more effectively inactivated by thermosonication than by thermal treatment, in the same temperature range, reducing the damages caused by heating

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