Potential Application of High Hydrostatic Pressure on the Production of Hydrolyzed Proteins with Antioxidant and Antihypertensive Properties and Low Allergenicity: A Review.

The high hydrostatic pressure (HHP) process has been studied for several applications in food technology and has been commercially implemented in several countries, mainly for non-thermal pasteurization and shelf-life extension of food products. HHP processing has been demonstrated to accelerate proteolytic hydrolysis at a specific combination of pressure and pressure-holding time for a given protein source and enzyme. The enzymatic hydrolysis of proteins is a well-known alternative to producing biologically active peptides, with antioxidant and antihypertensive capacity, from different food protein sources. However, some of these protein sources contain allergenic epitopes which are often not degraded by traditional hydrolysis. Moreover, the peptide profile and related biological activity of a hydrolysate depend on the protein source, the enzymes used, the parameters of the proteolysis process (pH, temperature, time of hydrolysis), and the use of other technologies such as HHP. The present review aims to provide an update on the use of HHP for improving enzymatic hydrolysis, with a particular focus on studies which evaluated hydrolysate antihypertensive and antioxidant capacity, as well as residual allergenicity. Overall, HHP has been shown to improve the biological properties of hydrolysates. While protein allergenicity can be reduced with traditional hydrolysis, HHP can further reduce the allergenicity. Compared with traditional hydrolysis methods, HHP-assisted protein hydrolysis offers a greater opportunity to add value to protein-rich products through conversion into high-end hydrolysate products with enhanced nutritional and functional properties.

Effect of high hydrostatic pressure on the antioxidant capacity and peptic hydrolysis of whey proteins / Efeito da alta pressão hidrostática na hidrólise péptica das proteínas do soro de leite e na capacidade 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.

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.

Influence of osmotic dehydration on bioactive compounds, antioxidant capacity, color and texture of fruits and vegetables: a review / Influência da desidratação osmótica sobre os compostos bioativos, capacidade antioxidante, cor e textura de frutas e olerícolas: uma revisão

ABSTRACT: Osmotic dehydration (OD) is a conservation technique applied to foodstuffs, which promotes partial reduction of water, extends their shelf life and reduces both post-harvest losses and changes in product characteristics. Currently, it has been given emphasis on trying to understand how the process affects the quality of processed vegetables, because process variables can interfere in their antioxidant capacity, color and texture. Moreover, the antioxidant capacity can be affected by chemical changes, leaching losses, reduced moisture and solid gain as well as the present bioactive in the profile of the performed analysis method. In color, the overall changes are caused by temperature increase, which can cause enzymatic and/or non-enzymatic browning, decomposition or entrainment of pigments present in the tissue. Conversely, the osmotic agent has a greater impact on texture, which causes changes in the sensory attributes such as gumminess, even crispness and flavor of the product. Although there is a large number of studies on the OD, the current scenario in terms of effect on the quality of osmodehydrated products are still incipient, especially in relation to antioxidant capacity. Despite the fact that there is a large number of studies on the OD, current efforts are focused on understanding the process effect on the product quality, notably in relation to antioxidant capacity. Thus, further studies on the internal changes in osmodehydrated foods are needed, since there is a variation of process factors, which may have an impact on the different tissues of the fruit and vegetable crops submitted to OD.

RESUMO: A desidratação osmótica (DO) é uma técnica de conservação de alimentos que promove a redução parcial de água, estende a validade comercial, diminui as perdas pós-colheita e as alterações nas características dos produtos. Atualmente, tem sido dada ênfase à busca do entendimento de como o processo afeta a qualidade dos vegetais desidratados, pois as variáveis do processo podem interferir em sua capacidade antioxidante, cor e textura. Além disso, a capacidade antioxidante pode ser afetada por transformações químicas, perdas por lixiviação, redução da umidade e ganho de sólidos, bem como pelo perfil dos compostos bioativos presentes e método de análise realizado. Quanto à cor, as alterações em geral são provocadas pelo aumento da temperatura, que pode ocasionar escurecimento enzimático e/ou não enzimático, decomposição ou carreamento dos pigmentos presentes no tecido. Por outro lado, o agente osmótico apresenta maior impacto na textura, provocando alterações nos atributos sensoriais como gomosidade, crocância e sabor do produto. Embora exista um grande número de trabalhos abordando a DO, os esforços atuais estão concentrados no entendimento sobre o efeito do processo sobre a qualidade dos produtos, sobretudo em relação à capacidade antioxidante. Dessa forma, há a necessidade de mais estudos sobre as alterações geradas pela DO nos alimentos, uma vez que há uma variação de fatores do processo, capaz de impactar de diversas formas os diferentes tecidos vegetais das frutas e olerícolas submetidas à DO.