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1.
Carbohydr Polym ; 291: 119483, 2022 Sep 01.
Article in English | MEDLINE | ID: mdl-35698322

ABSTRACT

In this work, we studied the development of a biocomposite formulated with alginate and gelatin, crosslinked with genipin for application as support for ß-galactosidase immobilization. Also, the biocomposites with the immobilized enzyme were characterized by thermal analyses and SAXS (size, density, and interconnectivity of alginate rods) for a detailed analysis of the microstructure, as well as the thermal and operational stabilities of the enzyme. The structural modifications of the biocomposite determined by SAXS demonstrate that the addition of both genipin and enzyme produced a significant reduction in size and density of the Ca(II)-alginate rods. Immobilized ß-galactosidase could be stored for 175 days under refrigeration maintaining 80% of its initial activity. Moreover, 90% of its relative activity was kept after 11 reuses in a batch process of lactose hydrolysis. Thus, the biocomposite proved to be effective as support for enzyme immobilization.


Subject(s)
Alginates , Aspergillus oryzae , Aspergillus oryzae/metabolism , Enzyme Stability , Enzymes, Immobilized/chemistry , Gelatin , Hydrolysis , Iridoids , Lactose/chemistry , Scattering, Small Angle , X-Ray Diffraction , beta-Galactosidase/metabolism
2.
Acta sci., Biol. sci ; 44: e60336, mar. 2022. tab, graf
Article in English | VETINDEX | ID: biblio-1370235

ABSTRACT

Yeast's beta-galactosidase is an intracellular enzyme, through which it is possible to determine in vivo its activity as a biocatalyst in the lactose hydrolysis. Permeabilization process was used for transforming the microorganisms cells into biocatalysts with an enhanced enzyme activity. The potential application of this enzyme technology in industrial process depends mainly on the enzyme activity. Beta-galactosidase enzyme that hydrolyzes lactose, for instance, is largely dependent on the reaction time and its stability under different physical conditions, such as pH, temperature and enzyme concentration. The objective of this study was to optimize the cellular permeabilization process of Kluyveromyces marxianusCCT 3172 and Saccharomyces fragilisCCT 7586 cultured in cheese whey for lactose hydrolysis. Box-Behnken design was carried out for cell permeabilization with three independent variables, ethanol concentration, permeabilization time and temperature. The best permeability conditions for K. marxianusCCT 3172 were 27% (v v-1) ethanol, 3 min at 20ºC, with specific enzymatic activity of 0.98 U mg-1.For S. fragilisCCT 7586, a specific enzymatic activity of 1.31 U mg-1was achieved using 45% (v v-1) of ethanol, 17 min. of reaction under 17ºC. Thus, it was concluded that cellular permeabilization with ethanolis an efficient process to determine beta-galactosidase activity.(AU)


Subject(s)
Permeability , Kluyveromyces , beta-Galactosidase , Whey , Lactose , Yeasts , Cheese , Enzymes/biosynthesis
3.
Int J Biol Macromol ; 199: 307-317, 2022 Feb 28.
Article in English | MEDLINE | ID: mdl-35007635

ABSTRACT

This study aimed to develop single-step purification and immobilization processes on cellulosic supports of ß-galactosidase from Kluyveromyces sp. combined with the Cellulose-Binding Domain (CBD) tag. After 15 min of immobilization, with an enzymatic load of 150 U/gsupport, expressed activity values reached 106.88 (microcrystalline cellulose), 115.03 (alkaline nanocellulose), and 108.47 IU/g (acid nanocellulose). The derivatives produced were less sensitive to the presence of galactose in comparison with the soluble purified enzyme. Among the cations assessed (Na+, K+, Mg2+, and Ca2+), magnesium provided the highest increase in the enzymatic activity of ß-galactosidases immobilized on cellulosic supports. Supports and derivatives showed no cytotoxic effect on the investigated cell cultures (HepG2 and Vero). Derivatives showed high operational stability in the hydrolysis of milk lactose and retained from 53 to 64% of their hydrolysis capacity after 40 reuse cycles. This study obtained biocatalyzers with promising characteristics for application in the food industry. Biocatalyzers were obtained through a low-cost one-step sustainable bioprocess of purification and immobilization of a ß-galactosidase on cellulose via CBD.


Subject(s)
Enzymes, Immobilized , Lactose , Cellulose , Enzyme Stability , Enzymes, Immobilized/chemistry , Hydrolysis , Lactose/chemistry , beta-Galactosidase/chemistry
4.
Bioresour Technol ; 345: 126497, 2022 Feb.
Article in English | MEDLINE | ID: mdl-34883192

ABSTRACT

For the first time, this work reported the one-step purification and targeted immobilization process of a ß-galactosidase (Gal) with the Cellulose Binding Domain (CBD) tag, by binding it to different magnetic cellulose supports. The process efficiency after ß-galactosidase-CBD immobilization on magnetic cellulose-based supports showed values of approximately 90% for all evaluated enzymatic loads. Compared with free Gal, derivatives showed affinity values between ß-galactosidase and the substrate 1.2 × higher in the lactose hydrolysis of milk. ß-Galactosidase-CBD's oriented immobilization process on supports increased the thermal stability of the immobilized enzyme by up to 7 × . After 15 cycles of reuse, both enzyme preparations showed a relative hydrolysis percentage of 50% of lactose in milk. The oriented immobilization process developed for purifying recombinant proteins containing the CBD tag enabled the execution of both steps simultaneously and quickly and the obtention of ß-galactosidases with promising catalytic characteristics for application in the food and pharmaceutical industries.


Subject(s)
Cellulose , Lactose , Enzyme Stability , Enzymes, Immobilized/metabolism , Hydrolysis , Magnetic Phenomena , beta-Galactosidase/metabolism
5.
Int J Biol Macromol ; 191: 881-898, 2021 Nov 30.
Article in English | MEDLINE | ID: mdl-34571129

ABSTRACT

A review on the enzyme ß-galactosidase from Kluyveromyces lactis is presented, from the perspective of its structure and mechanisms of action, the main catalyzed reactions, the key factors influencing its activity, and selectivity, as well as the main techniques used for improving the biocatalyst functionality. Particular attention was given to the discussion of hydrolysis, transglycosylation, and galactosylation reactions, which are commonly mediated by this enzyme. In addition, the products generated from these processes were highlighted. Finally, biocatalyst improvement techniques are also discussed, such as enzyme immobilization and protein engineering. On these topics, the most recent immobilization strategies are presented, emphasizing processes that not only allow the recovery of the biocatalyst but also deliver enzymes that show better resistance to high temperatures, chemicals, and inhibitors. In addition, genetic engineering techniques to improve the catalytic properties of the ß-galactosidases were reported. This review gathers information to allow the development of biocatalysts based on the ß-galactosidase enzyme from K. lactis, aiming to improve existing bioprocesses or develop new ones.


Subject(s)
Enzymes, Immobilized/chemistry , Fungal Proteins/chemistry , Kluyveromyces/enzymology , beta-Galactosidase/chemistry , Enzymes, Immobilized/metabolism , Fungal Proteins/metabolism , beta-Galactosidase/metabolism
6.
Food Chem ; 359: 129890, 2021 Oct 15.
Article in English | MEDLINE | ID: mdl-33934029

ABSTRACT

A new support for the immobilization of ß-d-galactosidase from Kluyveromyces lactis was developed, consisting of mesoporous silica/titania with a chitosan coating. This support presents a high available surface area and adequate pore size for optimizing the immobilization efficiency of the enzyme and, furthermore, maintaining its activity. The obtained supported biocatalyst was applied in enzyme hydrolytic activity tests with o-NPG, showing high activity 1223 Ug-1, excellent efficiency (74%), and activity recovery (54%). Tests of lactose hydrolysis in a continuous flow reactor showed that during 14 days operation, the biocatalyst maintained full enzymatic activity. In a batch system, after 15 cycles, it retained approximately 90% of its initial catalytic activity and attained full conversion of the lactose 100% (±12%). Additionally, with the use of the mesoporous silica/titania support, the biocatalyst presented no deformation and fragmentation, in both systems, demonstrating high operational stability and appropriate properties for applications in food manufacturing.


Subject(s)
Chitosan , Enzymes, Immobilized/metabolism , Kluyveromyces/enzymology , Silicon Dioxide , Titanium , beta-Galactosidase/metabolism , Bacterial Proteins/metabolism , Enzyme Stability , Hydrolysis , Lactose/metabolism
7.
Prep Biochem Biotechnol ; 51(7): 714-722, 2021.
Article in English | MEDLINE | ID: mdl-33287624

ABSTRACT

The present study aimed to evaluate the lactose hydrolysis conditions from "coalho" cheese whey using ß-galactosidase (ß-gal) produced by Kluyveromyces lactis immobilized with sodium alginate. Three sodium alginate-based immobilization systems were evaluated (0.5, 0.7, and 1% w/v) for maximizing the immobilization yield (Y), efficiency (EM), and recovered activity (ar). The lactose hydrolysis capacity of the immobilized form of ß-gal was determined, and simulated environments were used to assess the preservation of the immobilized enzyme in the gastrointestinal tract. The results showed that ß-gal immobilization with 1% (w/v) sodium alginate presented the best results (EM of 66%, Y of 41%, and ar of 65%). The immobilization system maintained the highest pH stability in the range between 5.0 and 7.0, with the highest relative activity obtained under pH 5 conditions. The temperature stability was also favored by immobilization at 50 °C for 30 min was obtained a relative activity of 180.0 ± 1.37%. In 6 h, the immobilized ß-gal was able to hydrolyze 46% of the initial lactose content. For the gastrointestinal simulations, around 40% of the activity was preserved after 2 h. Overall, the results described here are promising for the industrial applications of ß-galactosidase from K. lactis.


Subject(s)
Alginates/chemistry , Enzymes, Immobilized/chemistry , Fungal Proteins/chemistry , Kluyveromyces/enzymology , Lactose/chemistry , beta-Galactosidase/chemistry , Enzyme Stability , Hot Temperature , Hydrogen-Ion Concentration , Hydrolysis
8.
J Dairy Sci ; 102(11): 9763-9766, 2019 Nov.
Article in English | MEDLINE | ID: mdl-31447143

ABSTRACT

The effects of unfavorable conditions responsible for the viability loss of Lactococcus cells during spray drying can be minimized by the application of dairy matrices as encapsulating materials. This study aimed to evaluate the use of dairy matrices with different lactose contents on the survival of Lactococcus lactis during drying and storage. The use of hydrolyzed-lactose milk resulted in notable loss of cell viability (3.90 log cycles). However, milk enriched with lactose or without fat showed better protection (viability loss between 0.26 and 1.41 log cfu/g) and greater cell survival during storage at room temperature. The enrichment of milk with lactose seems to be ideal for the drying of heat-sensitive bacteria.


Subject(s)
Desiccation/methods , Lactococcus lactis/metabolism , Lactose/metabolism , Milk/metabolism , Analysis of Variance , Animals , Hot Temperature , Hydrolysis , Milk/chemistry
9.
Food Chem ; 246: 343-350, 2018 Apr 25.
Article in English | MEDLINE | ID: mdl-29291859

ABSTRACT

ß-d-Galactosidase is an important enzyme in the dairy industry, and the enzyme from the yeast Kluyveromyces lactis is most widely used. Here, we report immobilization of the enzyme on a silica/chitosan composite support, devised to have 10% and 20% chitosan (SiQT10 and SiQT20, respectively). Morphological and textural characterizations showed that chitosan is dispersed in micrometric regions in silica. For comparison, a silica organofunctionalized with 3-aminopropyltrimethoxysilane (SiO2aptms) was prepared. Performance of the biocatalysts was tested for lactose hydrolysis, and the enzyme immobilized in SiQT10 and SiQT20 composites showed higher efficiency (62% and 47%, respectively) compared with the enzyme in SiO2aptms. Operational stability in this system was evaluated for the first time. After 200 h of continuous use in a fixed-bed reactor, SiQT10 remained with approximately 90% activity. Thus, in addition to demonstrating compatibility for food processing, these results align the enzyme stabilization properties of chitosan with the mechanical resistance of silica.


Subject(s)
Chitosan/chemistry , Enzymes, Immobilized/chemistry , Silicon Dioxide/chemistry , beta-Galactosidase/chemistry , beta-Galactosidase/metabolism , Enzyme Stability , Enzymes, Immobilized/metabolism , Food Handling , Hydrolysis , Kluyveromyces/enzymology , Lactose/metabolism
10.
Semina Ci. agr. ; 38(2): 749-758, mar-abr. 2017. tab, graf
Article in English | VETINDEX | ID: vti-16268

ABSTRACT

Ice cream is a food product that pleases the palate of consumers worldwide. Whey powder (WP) has various technological and functional properties. However, WP increases the lactose content of the final products in which it is incorporated and causes grittiness and intolerance in lactose-sensitive individuals. This study aimed to produce ice cream with milk powder (MP) replaced by WP (MP/WP), decrease the lactose content by enzymatic hydrolysis and verify the physicochemical and microbiological parameters of the final product. Initially, the variables ?-galactosidase concentration and reaction time were studied for the response of the percentage of lactose hydrolysis in a milk ice cream base, using a full 22 factorial design(FFD).With the reaction conditions defined (0.5 g L-1 of ?-galactosidase at 37 C for 4 h)the sucrose concentration and MP/WP replacement variables were then studied in the ice cream formulation for the percentage of lactose hydrolysis and overrun responses using a 22 FFD. The lactose hydrolysis, which ranged between 86.59-97.97%, was not affected by the MP/WP replacement in the ice cream, whilst the overrun was increased by the MP/WP replacement. The physicochemical and microbiological parameters of the ice cream were either not influenced or positively influenced by lactose hydrolysis and MP/WP replacement.(AU)


O sorvete é um alimento que agrada o paladar dos consumidores mundialmente. O soro em pó (WP) tem várias propriedades tecnológicas e funcionais. No entanto, sua adição em alimentos contribui para aumentar o teor de lactose no produto final, trazendo como consequências a arenosidade e a impossibilidade de consumo por pessoas intolerantes à lactose. O objetivo deste trabalho foi elaborar sorvetes com substituição do leite em pó (MP) por WP (MP/WP), reduzir o teor de lactose por hidrólise enzimática e determinar os parâmetros físico-químicos e microbiológicos do produto final. Inicialmente, as variáveis concentração de ?-galactosidase e tempo de reação foram estudadas tendo como resposta o percentual de lactose hidrolisada na base láctea, aplicando um planejamento fatorial completo (FFD) 22. Com as condições de reação definidas (0,5 g L-1 de ?-galactosidase a 37 C por 4 h), as variáveis concentração de sacarose e substituição de MP/WP foram estudadas na formulação de sorvete tendo como resposta o percentual de lactose hidrolisada e overrun, pela aplicação de um FFD 22. O percentual de hidrólise da lactose variou entre 86,59 e 97,97% e a substituição MP/WP não afetou a hidrólise da lactose no sorvete, enquanto o overrun aumentou com a substituição MP/WP. Os parâmetros físico-químicos e microbiológicos dos sorvetes não foram influenciados ou foram influenciados positivamente pelas variáveis hidrólise da lactose e substituição MP/WP.(AU)


Subject(s)
Ice Cream/analysis , Lactose/chemistry , Hydrolysis , beta-Galactosidase , Whey , Lactose Intolerance , Food, Fortified
11.
Ci. Anim. bras. ; 18: 1-9, 2017. ilus, tab
Article in English | VETINDEX | ID: vti-16900

ABSTRACT

The purpose of this study was to evaluate the behavior of E. coli O157:H7 during lactose hydrolysis and fermentation of traditional and low lactose yogurt. It also aimed to verify E. coli O157:H7 survival after 12 h of storage at 4 °C ±1 °C. Two different types of yogurts were prepared, two with whole milk and two with pre-hydrolyzed whole milk; in both groups one yogurt was inoculated with E. coli O157:H7 and the other one was not inoculated. The survival of E. coli and pH of yogurt were determined during fermentation and after 12-h refrigeration. The results showed that E. coli O157:H7 was able to grow during the fermentation period (from 4.34 log CFU.mL-1 to 6.13 log CFU.mL-1 in traditional yogurt and 4.34 log CFU.mL-1 to 6.16 log CFU.mL-1 in low lactose yogurt). The samples with E. coli O157:H7 showed gas formation and syneresis. Thus, E. coli O157:H7 was able to survive and grow during fermentation of traditional and low lactose yogurts affecting the manufacture technology. Moreover, milk contamination by E. coli before LAB addition reduces the growth of L. bulgaricus and S. thermophilus especially when associated with reduction of lactose content.(AU)


Objetivou-se no presente estudo avaliar o comportamento da E. coli O157:H7 durante o processo de hidrólise da lactose e fermentação de iogurte tradicional e com teor reduzido de lactose. Além disso, objetivou-se verificar a viabilidade da E. coli O157:H7 e a viabilidade das bactérias ácido láticas após 12 h de estocagem a 4 °C ±1 °C. Dois diferentes tipos de iogurte com amostras controle e amostras inoculadas foram preparados, sendo dois com leite integral e dois com leite integral pré-hidrolisado; em ambos os grupos um foi inoculado com E. coliO157:H7 e um não foi inoculado. A sobrevivência da E. coli e o pH dos iogurtes foram determinados durante a fermentação e após 12h de refrigeração. A partir dos resultados observou-se que a E. coli O157:H7 foi capaz de se multiplicar ou manter-se viável durante a fermentação (4,34 UFC.mL-1 para 6,13 UFC.mL-1 no iogurte tradicional e 4,34 UFC.mL-1 para 6,16 log UFC.mL-1em iogurte com lactose reduzida). Nas amostras inoculadas com E. coli O157:H7 houve formação de gás e sinérese. Dessa forma, concluiu-se que a E. coli O157:H7 foi capaz de sobreviver e de se multiplicar durante a fermentação afetando a tecnologia de fabricação. Além disso, a contaminação do leite antes da adição das BAL reduziu o crescimento de L. bulgaricus e S. thermophilus, especialmente quando associado à redução da lactose.(AU)


Subject(s)
Escherichia coli O157 , beta-Galactosidase , Lactose , Streptococcus thermophilus , Yogurt/microbiology , Lactobacillus delbrueckii , Cultured Milk Products/microbiology
12.
Article in English | VETINDEX | ID: vti-745249

ABSTRACT

Abstract The purpose of this study was to evaluate the behavior of E. coli O157:H7 during lactose hydrolysis and fermentation of traditional and low lactose yogurt. It also aimed to verify E. coli O157:H7 survival after 12 h of storage at 4 ºC ±1 ºC. Two different types of yogurts were prepared, two with whole milk and two with pre-hydrolyzed whole milk; in both groups one yogurt was inoculated with E. coli O157:H7 and the other one was not inoculated. The survival of E. coli and pH of yogurt were determined during fermentation and after 12-h refrigeration. The results showed that E. coli O157:H7 was able to grow during the fermentation period (from 4.34 log CFU.mL-1 to 6.13 log CFU.mL-1 in traditional yogurt and 4.34 log CFU.mL-1 to 6.16 log CFU.mL-1 in low lactose yogurt). The samples with E. coli O157:H7 showed gas formation and syneresis. Thus, E. coli O157:H7 was able to survive and grow during fermentation of traditional and low lactose yogurts affecting the manufacture technology. Moreover, milk contamination by E. coli before LAB addition reduces the growth of L. bulgaricus and S. thermophilus especially when associated with reduction of lactose content.


Resumo Objetivou-se no presente estudo avaliar o comportamento da E. coli O157:H7 durante o processo de hidrólise da lactose e fermentação de iogurte tradicional e com teor reduzido de lactose. Além disso, objetivou-se verificar a viabilidade da E. coli O157:H7 e a viabilidade das bactérias ácido láticas após 12 h de estocagem a 4 ºC ±1 ºC. Dois diferentes tipos de iogurte com amostras controle e amostras inoculadas foram preparados, sendo dois com leite integral e dois com leite integral pré-hidrolisado; em ambos os grupos um foi inoculado com E. coli O157:H7 e um não foi inoculado. A sobrevivência da E. coli e o pH dos iogurtes foram determinados durante a fermentação e após 12h de refrigeração. A partir dos resultados observou-se que a E. coli O157:H7 foi capaz de se multiplicar ou manter-se viável durante a fermentação (4,34 UFC.mL-1 para 6,13 UFC.mL-1 no iogurte tradicional e 4,34 UFC.mL-1 para 6,16 log UFC.mL-1em iogurte com lactose reduzida). Nas amostras inoculadas com E. coli O157:H7 houve formação de gás e sinérese. Dessa forma, concluiu-se que a E. coli O157:H7 foi capaz de sobreviver e de se multiplicar durante a fermentação afetando a tecnologia de fabricação. Além disso, a contaminação do leite antes da adição das BAL reduziu o crescimento de L. bulgaricus e S. thermophilus, especialmente quando associado à redução da lactose.

13.
Ciênc. anim. bras. (Impr.) ; 18: 1-9, 2017. ilus, tab
Article in English | VETINDEX | ID: biblio-1473558

ABSTRACT

The purpose of this study was to evaluate the behavior of E. coli O157:H7 during lactose hydrolysis and fermentation of traditional and low lactose yogurt. It also aimed to verify E. coli O157:H7 survival after 12 h of storage at 4 °C ±1 °C. Two different types of yogurts were prepared, two with whole milk and two with pre-hydrolyzed whole milk; in both groups one yogurt was inoculated with E. coli O157:H7 and the other one was not inoculated. The survival of E. coli and pH of yogurt were determined during fermentation and after 12-h refrigeration. The results showed that E. coli O157:H7 was able to grow during the fermentation period (from 4.34 log CFU.mL-1 to 6.13 log CFU.mL-1 in traditional yogurt and 4.34 log CFU.mL-1 to 6.16 log CFU.mL-1 in low lactose yogurt). The samples with E. coli O157:H7 showed gas formation and syneresis. Thus, E. coli O157:H7 was able to survive and grow during fermentation of traditional and low lactose yogurts affecting the manufacture technology. Moreover, milk contamination by E. coli before LAB addition reduces the growth of L. bulgaricus and S. thermophilus especially when associated with reduction of lactose content.


Objetivou-se no presente estudo avaliar o comportamento da E. coli O157:H7 durante o processo de hidrólise da lactose e fermentação de iogurte tradicional e com teor reduzido de lactose. Além disso, objetivou-se verificar a viabilidade da E. coli O157:H7 e a viabilidade das bactérias ácido láticas após 12 h de estocagem a 4 °C ±1 °C. Dois diferentes tipos de iogurte com amostras controle e amostras inoculadas foram preparados, sendo dois com leite integral e dois com leite integral pré-hidrolisado; em ambos os grupos um foi inoculado com E. coliO157:H7 e um não foi inoculado. A sobrevivência da E. coli e o pH dos iogurtes foram determinados durante a fermentação e após 12h de refrigeração. A partir dos resultados observou-se que a E. coli O157:H7 foi capaz de se multiplicar ou manter-se viável durante a fermentação (4,34 UFC.mL-1 para 6,13 UFC.mL-1 no iogurte tradicional e 4,34 UFC.mL-1 para 6,16 log UFC.mL-1em iogurte com lactose reduzida). Nas amostras inoculadas com E. coli O157:H7 houve formação de gás e sinérese. Dessa forma, concluiu-se que a E. coli O157:H7 foi capaz de sobreviver e de se multiplicar durante a fermentação afetando a tecnologia de fabricação. Além disso, a contaminação do leite antes da adição das BAL reduziu o crescimento de L. bulgaricus e S. thermophilus, especialmente quando associado à redução da lactose.


Subject(s)
Yogurt/microbiology , Lactose , Streptococcus thermophilus , beta-Galactosidase , Lactobacillus delbrueckii , Cultured Milk Products/microbiology
14.
Semina ciênc. agrar ; 38(2): 749-758, 2017. tab, graf
Article in English | VETINDEX | ID: biblio-1500713

ABSTRACT

Ice cream is a food product that pleases the palate of consumers worldwide. Whey powder (WP) has various technological and functional properties. However, WP increases the lactose content of the final products in which it is incorporated and causes grittiness and intolerance in lactose-sensitive individuals. This study aimed to produce ice cream with milk powder (MP) replaced by WP (MP/WP), decrease the lactose content by enzymatic hydrolysis and verify the physicochemical and microbiological parameters of the final product. Initially, the variables ?-galactosidase concentration and reaction time were studied for the response of the percentage of lactose hydrolysis in a milk ice cream base, using a full 22 factorial design(FFD).With the reaction conditions defined (0.5 g L-1 of ?-galactosidase at 37 C for 4 h)the sucrose concentration and MP/WP replacement variables were then studied in the ice cream formulation for the percentage of lactose hydrolysis and overrun responses using a 22 FFD. The lactose hydrolysis, which ranged between 86.59-97.97%, was not affected by the MP/WP replacement in the ice cream, whilst the overrun was increased by the MP/WP replacement. The physicochemical and microbiological parameters of the ice cream were either not influenced or positively influenced by lactose hydrolysis and MP/WP replacement.


O sorvete é um alimento que agrada o paladar dos consumidores mundialmente. O soro em pó (WP) tem várias propriedades tecnológicas e funcionais. No entanto, sua adição em alimentos contribui para aumentar o teor de lactose no produto final, trazendo como consequências a arenosidade e a impossibilidade de consumo por pessoas intolerantes à lactose. O objetivo deste trabalho foi elaborar sorvetes com substituição do leite em pó (MP) por WP (MP/WP), reduzir o teor de lactose por hidrólise enzimática e determinar os parâmetros físico-químicos e microbiológicos do produto final. Inicialmente, as variáveis concentração de ?-galactosidase e tempo de reação foram estudadas tendo como resposta o percentual de lactose hidrolisada na base láctea, aplicando um planejamento fatorial completo (FFD) 22. Com as condições de reação definidas (0,5 g L-1 de ?-galactosidase a 37 C por 4 h), as variáveis concentração de sacarose e substituição de MP/WP foram estudadas na formulação de sorvete tendo como resposta o percentual de lactose hidrolisada e overrun, pela aplicação de um FFD 22. O percentual de hidrólise da lactose variou entre 86,59 e 97,97% e a substituição MP/WP não afetou a hidrólise da lactose no sorvete, enquanto o overrun aumentou com a substituição MP/WP. Os parâmetros físico-químicos e microbiológicos dos sorvetes não foram influenciados ou foram influenciados positivamente pelas variáveis hidrólise da lactose e substituição MP/WP.


Subject(s)
Hydrolysis , Lactose/chemistry , Whey , Ice Cream/analysis , beta-Galactosidase , Food, Fortified , Lactose Intolerance
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