Improving the textural and nutritional properties in restructured meat loaf by adding fibers and papain designed for elderly.

This study aimed to evaluate the effects of dietary fibers (apple, oat, pea, and inulin) in meat loaves treated with papain enzyme. In the first step, dietary fibers were added to the products at the level of 6%. All dietary fibers decreased the cooking loss and improved the water retention capacity throughout the shelf life of the meat loaves. Besides, the dietary fibers increased the compression force of meat loaves treated with papain, mainly oat fiber. The dietary fibers decreased the pH, especially the treatment with apple fiber. In the same way, the color was changed mainly by the apple fiber addition, resulting in a darker color in both raw and cooked samples. TBARS index increased in meat loaves added with both pea and apple fibers, mostly for the last one. In the next step, the combination of inulin, oat, and pea fibers was evaluated in the meat loaves treated with papain, combining fibers up to 6% total content likewise decreased cooking and cooling loss and increased the texture of the papain-treated meat loaf. The addition of fibers improved the acceptability of the texture-related samples, except for the three-fiber mixture (inulin, oat, and pea), which was related to a dry, hard-to-swallow texture. The mix of pea and oat fibers conferred the best descriptive attributes, possibly related to improved texture and water retention in the meat loaf, and comparing the use of isolated oat and pea, the perception of negative sensory attributes was not mentioned, such as soy and other off-flavors. Considering these results, this study showed that dietary fibers combined with papain improved the yielding and functional properties with potential technological use and consistent nutritional claims for elderly.

Evaluating different levels of papain as texture modifying agent in bovine meat loaf containing transglutaminase.

In this study, bovine meat loaves were produced with different levels of papain (0.00125%, 0.0025%, 0.00375%, and 0.005%) combined with transglutaminase (1%). The effect of this reformulation on pH, instrumental color, water activity, proximate composition, texture, yield, and scanning electron microscopy (SEM) of meat loaves was investigated. In addition, the enzymatic activity of papain was also analyzed. The papain addition increased the pH and the yield of the samples. The hardness was progressively reduced with the increase of papain level. Such changes could be seen through the images recorded by SEM, where an extremely fragmented structure was observed in treatments with higher papain concentration. Papain showed an optimum temperature of 80 °C. This study allowed to observe an intense proteolytic effect in all treatments, despite the papain concentration. Therefore, lower levels should be applied so that the product does not alter its sensory characteristics, such as soft and crumbly texture.

Incorporation and influence of natural gums in an alginate matrix for Serratia plymuthica immobilization and isomaltulose production.

Isomaltulose (IM) is a non-cariogenic sugar and substitute for sucrose that has been widely used in candies and soft drinks. This sugar is obtained from sucrose through enzymatic conversion, catalyzed by microbial glucosyltransferases. In this study, alternative gums, namely: gum Arabic (GA), algaroba gum (AG), and cashew gum (CG) were combined with alginate (ALG) for the immobilization of Serratia plymuthica, with the aim of improving its capability for conversion of sucrose into IM. Prior to the immobilization, the gums were characterized using FTIR spectroscopy, TGA, and XRD analysis. Then, they were combined with ALG and used to immobilize a cell mass of S. plymuthica by ionic gelation. The morphology of the produced beads was visualized using SEM, and the sucrose into IM conversion using the beads was performed in batch and continuous processes. CG showed the highest thermal stability and crystallinity. The use of CG (2.0 %, w/v) combined with ALG (2.0 %, w/v) showed the highest value for isomaltulose (236.46 g/L) produced in the first batch, and high stability in the continuous conversion process; resulting in an IM production of 199.24 g/L at 72 h of reaction. In addition, this combination produced less porous beads, able to maintain the entrapped cells longer. In conclusion, the production of IM by Serratia plymuthica cells immobilized in a matrix composed of ALG and CG is recommended, due to its high conversion capacity and high stability.

Isomaltulose: From origin to application and its beneficial properties - A bibliometric approach.

Consumers are concerned with the amount of sucrose added to foods and its effects on human health. One way to reduce this concern is through the consumption of sucrose substitutes, such as isomaltulose. Isomaltulose is an alternative sugar that should be regarded by the food industry as much healthier than sucrose, due to its beneficial properties; these include, low glycemic index and slow hydrolysis, prebiotic potential, and low cariogenic potential. In this work, a bibliometric analysis associated with a review of literature was conducted as a rigorous method for exploring and analyzing large volumes of scientific data, to understand the global scenario and identify the trends regarding isomaltulose. Important facts from its history and origin were discussed, as well the main research and countries that have contributed to its growing interest in the food industry. Over the years, from the discovery of new beneficial properties, more studies have been conducted, demonstrating that the interest in isomaltulose has been increasing. Finally, we concluded that isomaltulose is a promising sucrose substitute that could change the scenario of the sugar-rich foods market; and its use for the development of new products is highly encouraged.

Sequential optimization strategy for the immobilization of Erwinia sp. D12 cells and the production of isomaltulose with high stability and prebiotic potential.

Isomaltulose is a potential substitute for sucrose, with a high stability and prebiotic potential, for wide use in candies and soft drinks. This sugar is obtained from sucrose through enzymatic conversion using microbial glucosyltransferases. This work aimed to optimize a matrix to immobilize glucosyltransferase producing Erwinia sp. D12 cells using a sequential experimental strategy. The cell mass of Erwinia sp. D12 obtained in a bioreactor was immobilized in beads formed by ionic gelation. The conversion of sucrose into isomaltulose using the beads was performed in batch and continuous processes, and the isomaltulose was recovered through crystallization. The stability of isomaltulose was assessed in beverages of different pH values, and its prebiotic potential was verified with the growth of probiotic microorganisms. The optimized matrix composed of alginate (2.0% w/v), CaCl2 (2.0% w/v), gelatin (2.0% w/v), and transglutaminase (0.2% w/v) showed the highest mean of produced isomaltulose (199.82 g/L) after four batches. In addition, high stability during the continuous process resulted in an isomaltulose production above of 230 g/L for up to 72 h. The produced isomaltulose was more stable than sucrose in lemon soft drink and orange and grape energy drinks after 30 days of storage; and promoted the growth of Bifidobacterium animalis and Lactobacillus lactis. In conclusion, the production of isomaltulose by Erwinia sp. D12 cells immobilized using optimized conditions is recommended, due to its high conversion capacity, high stability, and prebiotic potential of crystals obtained.

L-asparaginase from Aspergillus oryzae spp.: effects of production process and biochemical parameters.

L-asparaginases prevent the formation of acrylamide, a substance commonly found in foods subjected to heat and that also contains reducing sugars and L-asparagine. This work aimed to select a strain of Aspergillus spp. able to produce L-asparaginase and to optimize the fermentation parameters, the partial purification and biochemical characterization were also performed. The Aspergillus oryzae IOC 3999 was selected due to its greater enzymatic activity: 1443.57 U/mL of L-asparaginase after 48 h of fermentation. The optimized conditions allowed for an increase of 223% on the L-asparaginase production: 2.9% lactose, 2.9% L-asparagine and 0.7% hydrolyzed casein, 0.152% KH2PO4, 0.052% KCl and MgSO4, 0.001% of CuNO3.3H2O, ZnSO4.7H2O and FeSO4.7H2O adjusted to pH 7.0; added a concentration of 5.05x106 spores/mL at 30 °C for 100 rpm. A purification factor of 2.11 was found and the molecular mass was estimated at 20.8 kDa. The enzyme showed optimum activity at 60 °C and pH 5 and stability at 50 °C for 1 h. The enzyme presented desirable biochemical characteristics, mainly the acid pH stability, indicating that the enzyme would work well in food matrices due to the closeness of pH, meaning that it could be a potential option for use in the food industry.

O-ATRP synthesized poly(ß-pinene) blended with chitosan for antimicrobial and antioxidant bio-based films production.

Antioxidant and antimicrobial activities are important characteristics of active film packaging designed to extend food preservation. In this study, functional bio-based films were produced using different concentrations of antioxidant poly(ß-pinene) bio-oligomer synthesized via organocatalyzed atom transfer radical polymerization (O-ATRP) and blended with chitosan of different molecular weights. The structural, mechanical, thermal, solubility, antioxidant, and antimicrobial properties of the films were investigated. The poly(ß-pinene)-chitosan blends presented significant pores and irregularities with the increase of poly(ß-pinene) concentration over 30%. Chitosan molecular weight did not show any important influence in the physical properties of the blends. Poly(ß-pinene) load decreased the materials' tensile strength and melting temperature, exhibiting a plasticizing effect on chitosan chains. The antioxidant and antimicrobial activities of the films were improved by poly(ß-pinene) incorporation and mainly depended on its concentration. Therefore, the incorporation of poly(ß-pinene) in chitosan films can be an alternative for active packaging production.

Lupin Protein Isolate Structure Diversity in Frozen-Cast Foams: Effects of Transglutaminases and Edible Fats.

This study addresses an innovative approach to generate aerated foods with appealing texture through the utilization of lupin protein isolate (LPI) in combination with edible fats. We show the impact of transglutaminases (TGs; SB6 and commercial), glycerol (Gly), soy lecithin (Lec) and linoleic acid (LA) on the micro- and nanostructure of health promoting solid foods created from LPI and fats blends. 3-D tomographic images of LPI with TG revealed that SB6 contributed to an exceptional bubble spatial organization. The inclusion of Gly and Lec decreased protein polymerization and also induced the formation of a porous layered material. LA promoted protein polymerization and formation of homogeneous thick layers in the LPI matrix. Thus, the LPI is a promising protein resource which when in blend with additives is able to create diverse food structures. Much focus has been placed on the great foamability of LPI and here we show the resulting microstructure of LPI foams, and how these were improved with addition of TGs. New food applications for LPI can arise with the addition of food grade dispersant Lec and essential fatty-acid LA, by improved puffiness, and their contributing as replacer of chemical leavening additives in gluten-free products.

Immobilization of Serratia plymuthica by ionic gelation and cross-linking with transglutaminase for the conversion of sucrose into isomaltulose.

Isomaltulose is an alternative sugar obtained from sucrose using some bacteria producing glycosyltransferase. This work aimed to optimize conditions for the immobilization of Serratia plymuthica through ionic gelation and cross-linking by transglutaminase using the sequential experimental strategy for the conversion of sucrose into isomaltulose. The effect of five variables (concentrations of cell mass, alginate, gelatin, transglutaminase, and calcium chloride) was studied, as well as the interactions between them on the matrix composition for the S. plymuthica immobilization. Three experimental designs were used to optimize the concentrations of each variable to obtain higher concentration of isomaltulose. A high conversion of sucrose into isomaltulose (71.04%) was obtained by the cells immobilized in a matrix composed of alginate (1.7%), CaCl2 (0.25 mol/L), gelatin (0.5%), transglutaminase (3.5%) and cell mass (33.5%). As a result, the transglutaminase application as a cross-linking agent improved the immobilization of Serratia plymuthica cells and the conversion of sucrose into isomaltulose.

Fungal L-asparaginase: Strategies for production and food applications.

L-asparaginase (L-asparagine amidohydrolase EC 3.5.1.1) is of great importance in pharmaceutical and food applications. This review aims to describe the production and use of fungal L-asparaginase focusing on its potential as an effective reducer of acrylamide in different food applications. Fungal asparaginases have been used as food additives and have gained importance due to some technical advantages, for example, fungi can grow using low-cost culture mediums, and the enzyme is extracellular, which facilitates purification steps. Research aimed at the discovery of new L-asparaginases, mainly those produced by fungi, have great potential to obtain cheaper enzymes with desirable properties for application in food aiming at the reduction of acrylamide.

l-Asparaginase from Aspergillus spp.: production based on kinetics, thermal stability and biochemical characterization.

This study describes the production of native l-asparaginases by submerged fermentation from Aspergillus strains and provides the biochemical characterization, kinetic and thermodynamic parameters of the three ones that stood out for high l-asparaginase production. For comparison, the commercial fungal l-asparaginase was also studied. Both commercial and l-asparaginase from Aspergillus oryzae CCT 3940 showed optimum activity and stability in the pH range from 5 to 8 and the asparaginase from Aspergillus niger LBA 02 was stable in a more alkaline pH range. About the kinetic parameters, the denaturation constant increased with the heating temperature for all l-asparaginases, indicating that the l-asparaginase activity decreased at higher temperatures, especially above 60 °C. Moreover, l-asparaginase from A. oryzae CCT 3940 remained stable after 60 min at 50 °C. None of the l-asparaginases were inhibited by high NaCl concentrations, which are highly desirable for food industry application. The catalytic activities of all the l-asparaginases were enhanced by the presence of Mn2+ and inhibited by p-chloromercuribenzoate and iodoacetamide. The l-asparaginase from the Aspergillus strains and the commercial enzyme had similar K m when l-asparagine was used as substrate. None of the l-asparaginases, except the l-asparaginase from A. niger LBA 02, could hydrolyze the substrate l-glutamine, which is of interest for medical proposes, since the glutaminase activity is usually related to adverse reaction during the leukemia treatment. This study showed that these new three non-recombinant l-asparaginases studied have potential application in the food and pharmaceutical industries, especially due to their good thermostability.

Optimization of the enzymatic hydrolysis of rice protein by different enzymes using the response surface methodology.

The optimization of the enzymatic hydrolysis of rice protein was determined using an experimental design tool. The semi-purified protease of Bacillus licheniformis LBA 46 and commercial protease Alcalase 2.4 L were used to produce rice hydrolysates using pH values ranging from 6 to 10 and enzyme concentrations varying from 50 to 150 U/mL. The optimized conditions were validated, and using the chosen conditions (pH 10 and 100 U/mL of protease), it was possible to confirm that the model was predictive for oxygen radical absorbance capacity (ORAC) and ferric reducing antioxidant power (FRAP) responses. The experimental values for the ORAC and FRAP responses were 940 and 18.78 TE µmol/g for the rice protein hydrolysates prepared with LBA protease and 1001.94 and 19.31 TE µmol/g for the rice protein hydrolysates prepared with Alcalase 2.4 L. After optimization of the enzymatic hydrolysis conditions, the antioxidant activity values increased when compared to the values for the intact rice protein: 324.97 TE µmol/g (ORAC) and 6.14 TE µmol/g (FRAP). It was also observed that the LBA protease had an action similar to the commercial protease, showing its potential for application in protein hydrolysis.

Modification of enzymes by use of high-pressure homogenization.

High-pressure is an emerging and relatively new technology that can modify various molecules. High-pressure homogenization (HPH) has been used in several studies on protein modification, especially in enzymes used or found in food, from animal, plant or microbial resources. According to the literature, the enzymatic activity can be modulated under pressure causing inactivation, stabilization or activation of the enzymes, which, depending on the point of view could be very useful. Homogenization can generate changes in the structure of the enzyme modifying various chemical bonds (mainly weak bonds) causing different denaturation levels and, consequently, affecting the catalytic activity. This review aims to describe the various alterations due to HPH treatment in enzymes, to show the influence of high-pressure on proteins and to report the HPH effects on the enzymatic activity of different enzymes employed in the food industry and research.

Microbial proteases: Production and application in obtaining protein hydrolysates.

The catalytic properties of the proteases have already allowed for their introduction into several industrial processes, such as food, chemical, pharmaceutical, etc. Recent advances in the biotechnology, particularly in the production of protein hydrolysates, have provided an important development of this area. The enzymatic hydrolysis allows for the use of different food protein sources that, after hydrolysis, can be used also as sources of bioactive peptides. Microbial proteases have interesting characteristics in the sense of low cost of production, good stability and specificity representing a powerful tool in the development and production of new protein hydrolysates with characteristics that can be explored industrially. This review aims to describe the production of proteases, the use of microbial proteases in enzymatic hydrolysis, in different industries and to explain the characteristics of such enzymes.

An overview of Bacillus proteases: from production to application.

Proteases have a broad range of applications in industrial processes and products and are representative of most worldwide enzyme sales. The genus Bacillus is probably the most important bacterial source of proteases and is capable of producing high yields of neutral and alkaline proteolytic enzymes with remarkable properties, such as high stability towards extreme temperatures, pH, organic solvents, detergents and oxidizing compounds. Therefore, several strategies have been developed for the cost-effective production of Bacillus proteases, including optimization of the fermentation parameters. Moreover, there are many studies on the use of low-cost substrates for submerged and solid state fermentation. Other alternatives include genetic tools such as protein engineering in order to obtain more active and stable proteases and strain engineering to better secrete recombinant proteases from Bacillus through homologous and heterologous protein expression. There has been extensive research on proteases because of the broad number of applications for these enzymes, such as in detergent formulations for the removal of blood stains from fabrics, production of bioactive peptides, food processing, enantioselective reactions, and dehairing of skins. Moreover, many commercial proteases have been characterized and purified from different Bacillus species. Therefore, this review highlights the production, purification, characterization, and application of proteases from a number of Bacillus species.

Draft genome sequence of Streptomyces sp. strain F1, a potential source for glycoside hydrolases isolated from Brazilian soil

ABSTRACT Here, we show the draft genome sequence of Streptomyces sp. F1, a strain isolated from soil with great potential for secretion of hydrolytic enzymes used to deconstruct cellulosic biomass. The draft genome assembly of Streptomyces sp. strain F1 has 69 contigs with a total genome size of 8,142,296 bp and G + C 72.65%. Preliminary genome analysis identified 175 proteins as Carbohydrate-Active Enzymes, being 85 glycoside hydrolases organized in 33 distinct families. This draft genome information provides new insights on the key genes encoding hydrolytic enzymes involved in biomass deconstruction employed by soil bacteria.

New Heterofunctional Supports Based on Glutaraldehyde-Activation: A Tool for Enzyme Immobilization at Neutral pH.

Immobilization is an exciting alternative to improve the stability of enzymatic processes. However, part of the applied covalent strategies for immobilization uses specific conditions, generally alkaline pH, where some enzymes are not stable. Here, a new generation of heterofunctional supports with application at neutral pH conditions was proposed. New supports were developed with different bifunctional groups (i.e., hydrophobic or carboxylic/metal) capable of adsorbing biocatalysts at different regions (hydrophobic or histidine richest place), together with a glutaraldehyde group that promotes an irreversible immobilization at neutral conditions. To verify these supports, a multi-protein model system (E. coli extract) and four enzymes (Candidarugosa lipase, metagenomic lipase, ß-galactosidase and ß-glucosidase) were used. The immobilization mechanism was tested and indicated that moderate ionic strength should be applied to avoid possible unspecific adsorption. The use of different supports allowed the immobilization of most of the proteins contained in a crude protein extract. In addition, different supports yielded catalysts of the tested enzymes with different catalytic properties. At neutral pH, the new supports were able to adsorb and covalently immobilize the four enzymes tested with different recovered activity values. Notably, the use of these supports proved to be an efficient alternative tool for enzyme immobilization at neutral pH.

Draft genome sequence of Streptomyces sp. strain F1, a potential source for glycoside hydrolases isolated from Brazilian soil.

Here, we show the draft genome sequence of Streptomyces sp. F1, a strain isolated from soil with great potential for secretion of hydrolytic enzymes used to deconstruct cellulosic biomass. The draft genome assembly of Streptomyces sp. strain F1 has 69 contigs with a total genome size of 8,142,296bp and G+C 72.65%. Preliminary genome analysis identified 175 proteins as Carbohydrate-Active Enzymes, being 85 glycoside hydrolases organized in 33 distinct families. This draft genome information provides new insights on the key genes encoding hydrolytic enzymes involved in biomass deconstruction employed by soil bacteria.

GH53 Endo-Beta-1,4-Galactanase from a Newly Isolated Bacillus licheniformis CBMAI 1609 as an Enzymatic Cocktail Supplement for Biomass Saccharification.

Galactanases (endo-ß-1,4-galactanases-EC 3.2.1.89) catalyze the hydrolysis of ß-1,4 galactosidic bonds in arabinogalactan and galactan side chains found in type I rhamnogalacturan. The aim of this work was to understand the catalytic function, biophysical properties, and use of a recombinant GH53 endo-beta-1,4-galactanase for commercial cocktail supplementation. The nucleotide sequence of the endo-ß-1,4-galactanase from Bacillus licheniformis CBMAI 1609 (Bl1609Gal) was cloned and expressed in Escherichia coli, and the biochemical and biophysical properties of the enzyme were characterized. The optimum pH range and temperature of Bl1609Gal activity were 6.5-8 and 40 °C, respectively. Furthermore, Bl1609Gal showed remarkable pH stability, retaining more than 75 % activity even after 24 h of incubation at pH 4-10. The enzyme was thermostable, retaining nearly 100 % activity after 1-h incubation at pH 7.0 at 25-45 °C. The enzymatic efficiency (K cat /K m ) against potato galactan under optimum conditions was 241.2 s(-1) mg(-1) mL. Capillary zone electrophoresis demonstrated that the pattern of galactan hydrolysis by Bl1609Gal was consistent with that of endogalactanases. Supplementation of the commercial cocktail ACCELLERASE(®)1500 with recombinant Bl1609Gal increased hydrolysis of pretreated sugarcane bagasse by 25 %.

Green Propolis: Thirteen Constituents of Polar Extract and Total Flavonoids Evaluated During Six Years through RP-HPLC.

In order to verify the chemical qualities of polar extract of Green Propolis produced in the State of Minas Gerais, Brazil, was analyzed by means of RP-HPLC, the concentration of eleven flavonoids, Artepillin C and p-coumaric acid were analyzed by means of RP-HPLC. Samples were collected in the months of February, March, May, July, September, and October, during a period of six years (2008 to 2013) and the results compared with purchased standards. Artepillin C was the main constituent (80-90%) found in all samples. Lower concentrations of p-coumaric acid, chrysin and kaempferide were observed in March, and of ricin and galangin in September. Respectively, these months correspond to the end of Summer and Spring period in Brazil. The variation in concentration of the analyzed constituents always occurred in the same month, during the entire six years of evaluation period. All thirteen constituents of Green Propolis were detected throughout the study period, and the average concentration of each one was similar in relation to the respective monthly collection period of each year. Due to similarities among chemical constituents of Green Propolis with those present in B. dracuncufolia, this plant was identified as being the principal source of Green Propolis.