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

Abstract

In a single-stage process with the simultaneous addition of β -galactosidase and lactic culture, the lactose conversion, the processing time, viscosity and syneresis were evaluated. Fermentation was promoted by lactic culture containing two probiotic microorganisms, Bifidobacterium animalis and Lactobacillus acidophilus, associated with the typical microorganisms of yogurt.An enzymatic preparation containing β -galactosidases from Kluyveromyces lactis and Aspergillus niger was used. , enzyme concentration of 0.5 g L -1 and enzyme addition at the beginning of fermentation. In these conditions, a decrease in processing time (from 4.55 to 3.68 h) and an increase in lactose conversion (from 15.2 to 97.9%) were observed in relation to the fermentation without enzyme addition, and no detrimental changes in some physical properties of yogurt (viscosity, and syneresis).Index terms: Enzymatic catalysis, lactose hydrolysis, yogurt physical properties, β -galactosidase. RESUMONo processo em um único estágio com a adição simultânea de β -galactosidase e de cultura lática, foram avaliadas a conversão da lactose, o tempo de processamento, a viscosidade e a sinérese. A fermentação foi promovida por cultura láctica, contendo dois micro-organismos probióticos, Bifidobacterium animalis e Lactobacillus acidophilus, associados aos micro-organismos característicos do iogurte. Foi utilizado um preparado enzimático contendo β -galactosidases obtidas de Kluyveromyces lactis e de Aspergillus niger.Os efeitos da concentração inicial de lactose, concentração de enzima e tempo de adição da enzima foram avaliados por meio de um planejamento experimental (2 3 ensaios mais três pontos centrais). As seguintes condições foram estabelecidas: concentração inicial de lactose de 91 g L -1, concentração de enzima de 0.5 g L -1 e adição da enzima no início da fermentação. Nessas condições, um decréscimo no tempo de processamento (de 4,55 h para 3,68 h) e um incremento na conversão de lactose (de 15,2% para 97,9%) foram observados em relação à fermentação sem a adição da enzima, sem alterações prejudiciais em algumas propriedades físicas do iogurte (viscosidade, e sinérese). Termos para indexação:Catálise enzimática, hidrólise da lactose, propriedades físicas do iogurte, β -galactosidase.

Donkey Milk for Manufacture of Novel Functional Fermented Beverages

“…This could be due to greater activity of traditional yogurt cultures at typical yogurt pH value. Similar data were found by Batista and others () and Martins and others (). In general, there was a significant decrease in lactose content as a function of storage time linked to ability by starter bacteria to produce lactic acid.…”

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

“…On the other hand, some studies reported GOS synthesis in the preparation of traditional yogurts. The authors attributed this finding to the LAB and bifidobacteria cultures employed, reaching concentrations from 0.08 to 1.35 g L −1 . Likewise, Song et al detected β ‐galactosidase hydrolytic activities by LAB strains currently used in yogurt making ( L. acidophilus , Lactococcus lactis , Lactobacillus helveticus and Lactobacillus paracasei ); besides, they found that L. paracasei had the highest hydrolytic activity and good ability to synthesize GOS in reconstituted whey powder.…”

Organic acids profiles in lactose-hydrolyzed yogurt with different matrix composition

“…Damin et al (2009) also found increases in the time to reach pH 4.6 with increases in SMP and WPC levels for yogurts supplemented. Meanwhile, Martins et al (2012) reported processing time slightly higher for yogurts prepared from milk fortified with WPC.…”

“…After 8 h of incubation at 41°C, they achieved lactose values between 0.2 and 2.5 g.100 mL −1 , and values of glucose and galactose between 1.0-3.0 and 1.6-3.8 g.100 mL −1 , respectively. In turn, most recently, Martins et al (2012) obtained yogurts with 0.20 g.100 mL −1 of lactose using a milk base with 13.5% (w/w) of total solids and 9.1 g.100 mL −1 of lactose, prepared from whole milk powder and whey powder. The enzymatic catalysis was promoted by a mix of β-galactosidases from K. lactis and A. niger, and the lactic fermentation was carried out at 43°C for approximately 3.50 h using a commercial starter containing the typical yogurt cultures together with two probiotic bacteria (B. animalis and L. acidophilus).…”