RESUMO: Neste estudo, o efeito da aplicação de alta pressão hidrostática (HHP) sobre o concentrado proteico de soro de leite foi avaliado antes (pré-tratamento - PT) e durante os processos de hidrólise (assistida por hidrólise - HA). Utilizou-se o delineamento fatorial 22 com três pontos centrais, onde as variáveis independentes foram pressão (100, 250, 400 MPa) e tempo (5, 20 e 35 minutos). A hidrólise foi avaliada pelo conteúdo de proteínas solúveis e aminoácidos aromáticos, além do perfil peptídico por RP-HPLC. As análises de ABTS e ORAC foram utilizadas para avaliar a capacidade antioxidante in vitro. A redução do teor de proteína solúvel foi de aproximadamente 20% para a hidrólise convencional e para todos os pontos de PT até 4h de reação, enquanto a hidrólise assistida por HHP a 100 MPa mostrou uma redução de 35% de proteína em 35 minutos de reação. Além disso, a pressurização favoreceu a hidrólise péptica da β-lactoglobulina em até 98% e também melhorou a capacidade antioxidante in vitro dos hidrolisados, que aumentaram de 34,25 para 60,89 μmoles de TE g-1 de proteína no melhor tratamento. Os resultados sugerem que o uso da hidrólise assistida por HHP favoreceu a hidrólise péptica, com redução no tempo de hidrólise e aumento da atividade antioxidante.

ABSTRACT: The effect of high hydrostatic pressure (HHP) application on whey protein concentrate was evaluated both before (pre-treatment - PT) and during (hydrolysis assisted - HA) hydrolysis processes. A factorial design 22 with 3 central points was used with pressure (100, 250, 400 MPa) and time (5, 20 and 35 minutes) as independent variables. The hydrolysis was evaluated and monitored by soluble protein, aromatic amino acid contents and RP-HPLC. ABTS and ORAC tests were used to evaluate the in vitro antioxidant capacity. The reduction of soluble protein content was approximately 20% for conventional hydrolysis and for all PT treatments up to 4 h of reaction, while HHP assisted hydrolysis at 100 MPa showed a 35% protein reduction after 35 minutes of reaction. In addition, pressurization favored peptic hydrolysis of β-lactoglobulin by up to 98% and also improved the in vitro antioxidant capacity of the hydrolysates, which increased from 34.25 to 60.89 μmoles TE g-1 of protein in the best treatment. The results suggest that the use of HHP assisted hydrolysis favored the peptic hydrolysis, with a reduction in hydrolysis time and increased antioxidant activity.

Abstract The pericarp of passion fruit can be processed to be used as a new ingredient in the food industry, or as source of pectin. Pericarp samples were taken with a 5 mm cylindrical metal probe to measure the apparent density. Pericarp fractions of eighty fruits at three maturation stages were dried and their flours were quantified and evaluated by instrumental color. The pectin was extracted and its degree of esterification (DE) was quantified. The yield of flour of epicarp and mesocarp reached 3.4% and 4.6% (dry basis) at different maturation stages of passion fruit, respectively. The content of pectin was higher in mesocarp flour, also, its DE increased deeply with the fruit maturation. The mesocarp with the lower density can be separated from the epicarp in a water flow system, which allows the production of clearer flour with the highest content of pectin and the highest DE in ripe fruits.

Abstract Whey is well-known for the functional and bioactive properties of its proteins and peptides, which are of great interest to food and nutraceutical industries. The aim of this study was to investigate the effect of four different commercial proteases (Novo ProD® (NPD), Alcalase® (ALC), Pancreas Trypsin® (TRY), and Flavourzyme® (FLA)) in the generation of hydrolysates with emulsifying and antioxidant activities. Hydrolysis processes were carried out for 5 h, reaching maximum degrees of 18.5, 15.5, 9.2, and 8.7% for NPD, ALC, TRY, and FLA, respectively. All tested enzymes generated very diverse, but conservative peptide profiles when comparing the treatments along the time, with the main enzymatic actions up to 120 min-reaction. An increase in the in vitro antioxidant activity was found for all treatments, achieving 46%, 40%, 40% and 22% for ALC, TRY, NDP and FLA, respectively. TRY hydrolysate maintained or slightly increased its emulsifying capacity along the time, however, a decrease in emulsifying capacity was found for ALC and NPD hydrolysates when compared to the non-hydrolyzed whey protein concentrate (WPC). All tested enzymes generated hydrolysates with enhanced antioxidant and/or emulsifying activities, which may be used as food ingredients and the choice of the enzyme will depend on the need.