Protection of polyphenols in blueberry juice by vacuum-assisted block freeze concentration.
Food Chem Toxicol
; 109(Pt 2): 1093-1102, 2017 Nov.
Article
em En
| MEDLINE
| ID: mdl-28344085
ABSTRACT
Block freeze concentration allows produces high-quality cryoconcentrates with important protection of valuable components from fresh fruit juices. The aim of this study was to investigate the use of vacuum-assisted block freeze concentration under different experimental conditions to protect polyphenols in the elaboration of concentrated blueberry juice. Fresh blueberry juice was radial or unidirectional frozen at -20 and -80 °C for 12 h and vacuum process was performed at 80 kPa during 120 min. Results showed a significant solute increased in the concentrated fraction in all treatments, and the best treatment was - 20 °C/unidirectional with a value of ≈63 °Brix, equivalent to an increase of 3.8 times in the total polyphenol content (76% of retention). The color of concentrated samples was darker than the initial sample, with ΔE* values of >25 CIELab units in all treatments. The vacuum-assisted block freeze concentrations was an effective technology for protecting polyphenols and obtain a concentrated with a higher concentration of solids from blueberry juice, as well as interesting values of process parameters.
Palavras-chave
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Mirtilos Azuis (Planta)
/
Polifenóis
/
Sucos de Frutas e Vegetais
/
Conservação de Alimentos
Idioma:
En
Ano de publicação:
2017
Tipo de documento:
Article