ABSTRACT
The aim of this study was to concentrate whey protein by ultrafiltration process, evaluating the pressure at 1-3 bar and temperature of 10-20â. In the conditions that show the more protein concentration were evaluated the interfacial and emulsifying properties at pH 5.7 and 7.0. The whey concentrate at 10â and 1.5 bar showed the higher protein value 36% (w/w), with soluble protein of 33.82% (solubility of 93.94%) for pH 5.7 and 34% (solubility of 94.4%) for pH 7.0, respectively. The whey concentrate powder present particle size distribution between 0.4-110 um. The whey at pH 5.7 and 7.0 was not observed significant differences in the resistance parameters of the oil/water layer interface. The interfacial film formed by the proteins presented an essentially elastic behavior in both pH, and in pH 5.7 the emulsion was more stable with lower diameter droplets. The concentrate whey showed techno-functional properties (emulsification and solubility), which allow the use as ingredients in products of industrial interest in food products such as mayonnaise, ice cream, sauces, and others.
Subject(s)
Ultrafiltration , Whey Proteins , Emulsions/chemistry , Hydrogen-Ion Concentration , Solubility , Whey Proteins/chemistryABSTRACT
ABSTRACT: This study aimed to evaluate the effects of adding probiotic culture (Bifidobacterium animalis subsp. Lactis Bb-12) and prebiotics (fructooligosaccharide - FOS) to yoghurt formulations stored at 4°C for 28 days, using an experimental design (independent variables: (0-3% of FOS and probiotic starter cultures 0-3%). The pH, acidity, fat, syneresis, protein, ºBrix, sugars, FOS and probiotic bacteria count were analyzed. The probiotic- and prebiotic-added yoghurt formulations showed lower acidity, syneresis and glucose than the control yoghurt and compared to formulations containing probiotic and prebiotic separately. The 3% probiotic and prebiotic formulation showed a lower loss of concentration of FOS, and after 28 days presented 1.5g of FOS per 100g (0.3% kestose, 0.7% nystose, 0.5% fructosyl-nystose). Furthermore, the addition of prebiotics exerted a protective effect on probiotic bacteria, enhancing their survival.
RESUMO: Este estudo teve como objetivo avaliar os efeitos da adição de cultura probiótica (Bifidobacterium animalis subsp. Lactis Bb-12) e prebióticos (fructooligosacarídeo - FOS) a formulações de iogurte armazenadas a 4°C por 28 dias, utilizando um planejamento experimental (variáveis independentes: (0-3% de FOS e cultura probiótica starter 0-3%). Foram analisados pH, acidez, gordura, sinérese, proteína, ºBrix, açúcares, FOS e contagem de bactérias probióticas. As formulações de iogurte adicionado de probiótico e prebiótico apresentaram menor acidez, sinérese e glicose quando comparados ao iogurte controle e também em comparação com as formulações contendo probiótico e prebiótico sozinhas. A formulação com 3% de probiótico e prebiótico apresentou menor perda de concentração de FOS e, após 28 dias, apresentou 1,5g de FOS por 100g (0,3% de kestose, 0,7% de nystose , 0,5% de fructosil-nistose). Além disso, a adição de prebióticos exerceu um efeito protetor sobre as bactérias probióticas e aumentou a sua sobrevivência.