Lactose conversion and the synthesis of galactooligosaccharides in a simultaneous lagged bioprocess using β-galactosidases and probiotic microorganisms

Abstract

SummaryLactose conversion and the production of galactooligosaccharides (GOS) were evaluated in a simultaneous bioprocess using probiotic microorganisms and the addition of β-galactosidases, lagged or otherwise. The fermentation was carried out using normal yogurt cultures, Streptococcus thermophilus and Lactobacillus bulgaricus, associated with two probiotic microorganisms, Bifidobacterium animalis and Lactobacillus acidophilus. An enzymatic preparation containing β-galactosidases of distinct origins, obtained from Kluyveromyces lactis and Aspergillus niger was used. The simultaneous bioprocess was evaluated, varying the initial lactose and enzyme concentrations and also the time of addition of the enzymes, with a lag in the enzyme application in relation to the beginning of fermentation. The results indicated a positive impact on lactose conversion, reducing the disaccharide concentration by between 97.7 and 99.7%, as compared to 13.8 and 19.8% in fermentations without enzyme addition, obtaining between 2.7 and 4.2 g.L -1 GOS in the lagged processes carried out with the highest initial lactose concentration and the addition of the lowest enzyme concentration. Key words: Enzyme catalysis; Lactose conversion; Lactic fermentation; GOS. ResumoEm bioprocesso simultâneo conduzido por microrganismos probióticos e através da adição, defasada ou não, de β-galactosidases, foram avaliadas a redução da lactose e a obtenção de galacto-oligossacarídeos (GOS). A fermentação foi conduzida por culturas características de iogurte, Lactobacillus bulgaricus e Streptococcus thermophilus, associadas a dois microrganismos probióticos, Bifidobacterium animalis e Lactobacillus acidophilus. Foi utilizado um preparado enzimático contendo β-galactosidases de origens distintas, obtidas de Kluyveromyces lactis e de Aspergillus niger. O bioprocesso simultâneo foi avaliado variando as concentrações iniciais de lactose e de enzima, e o tempo de adição da enzima, caracterizando uma defasagem na aplicação da enzima em relação ao início da fermentação. Os resultados indicaram um impacto positivo na conversão da lactose, reduzindo entre 97,7 e 99,7% a concentração desse dissacarídeo, em comparação com 13,8 e 19,8% nas fermentações sem adição de enzima, bem como a obtenção de GOS entre 2,7 e 4,2 g.L -1 nos processos defasados realizados com concentração inicial máxima de lactose e com concentração mínima de enzima adicionada. Palavras-chave: Catálise enzimática; Conversão da lactose; Fermentação lática; GOS.Lactose conversion and the synthesis of galactooligosaccharides in a simultaneous lagged bioprocess using β-galactosidases and probiotic microorganisms Conversão da lactose e síntese de galacto-oligossacarídeos em bioprocesso simultâneo defasado com β-galactosidases e microrganismos probióticos Autores | Authors

Influence of lactose hydrolysis on galacto‐oligosaccharides, lactose, volatile profile and physicochemical parameters of different yogurt varieties

“…Scarce and variable information on GOS synthesis during reduced‐lactose yogurt manufacture employing the enzymatic process is reported. The most recent work has been carried out by Martins et al They reported GOS values between 0.9 and 4.9 g L −1 for fresh hydrolyzed yogurts. On the other hand, some studies reported GOS synthesis in the preparation of traditional yogurts.…”

“…and Table (b). Martins et al employed an approach similar to that used in this work (simultaneous enzymatic hydrolysis and fermentation) and the addition of enzyme before the start of fermentation. The lactose values obtained ranged from 0.2 to 68.1 g L −1 for hydrolyzed yogurts depending on the β ‐galactosidase dose, the initial lactose concentration in the milk and the time of enzyme addition.…”

Simultaneous enzymatic hydrolysis and lactic fermentation to obtain a yogurt with low lactose content

“…In the conventional process, enzymatic catalysis first occurs in a substrate at pH between 6.5 and 6.8 and temperatures between 4 and 6º C, for the purpose of minimizing microbiological contamination. This temperature takes the contact time to at least 30 h. In this conventional process, the substrate with low lactose content passes to the second stage of processing when the industrial application of lactic culture and early fermentation take place (MARTINS et al, 2011).…”

Optimization of agroindustrial medium for the production of carotenoids by wild yeast Sporidiobolus pararoseus

“…The composition of the production medium using S. salmonicolor (Valduga et al, 2009(Valduga et al, , 2014 and for S. pararoseus (Cabral et al, 2011). This methodology is also applied to obtain other bioproducts, such as biomass (Santos et al, 2012), galacto-oligosaccharides (Lisboa et al, 2012a;Lisboa et al, 2012b), dairy drinks (Martins et al, 2011;Martins et al, 2012;Burkert et al, 2012), enzymes (Maldonado et al, 2012;Campello et al, 2012;Alves et al, 2010), synthesis of natural flavors (Anschau et al, 2011;Aragão et al, 2011), phycocyanin (Moraes et al, 2010) and rhamnolipids (Rosa et al, 2010).…”