Increasing fungi amyloglucosidase activity by high pressure homogenization

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)High pressure homogenization (HPH) was recently described as a process able to improve the activity of some enzymes; therefore, the HPH effects on amyloglucosidase (AMG) were investigated. Enzyme solution at pH 2.9, 4.3 and 6.5 were processed at pressures of 0 (just sample circulation on the equipment), 500, 1000, 1500 and 2000 bar and the HPH effects were determined through the enzyme residual activity measured at 35, 65 and 80 degrees C. Results at 35 degrees C showed no relative changes on AMG activity after HPH up to 2000 bar for the three evaluated pH. Similarly, at 65 degrees C (optimum temperature), native and homogenized enzyme at pH 2.9 and 6.5 showed no significant activity changes. On contrary, when enzyme was homogenized at pH 4.3 and its activity evaluated at optimum temperature, a significant activity increase (5-8%) was observed after homogenization at pressures of 1000 bar and above. At 80 degrees C, it was observed an AMG relative activity increase after HPH for the three evaluated pH. Sample homogenized at pH 2.9 showed a gradual and significant activity increase, reaching a maximum increment of 100% after homogenization at 2000 bar with reference to the native enzyme. At pH 4.3 and 6.5, homogenization up to 1000 bar resulted on a significant AMG activity increase of around 20 and 30%, respectively. Therefore, the results highlighted that HPH can increase AMG activity, being dependent on the pH of enzyme solution and the applied pressure. Also, it was observed that process can change the AMG activity at different temperatures, being especially interesting when AMG activity at high temperature is required. Industrial relevance: Two important application of amyloglucosidase are the starch saccharification to obtain corn syrup and the use in juice processing aiming to prevent turbidity and viscosity enhancement caused by unripe fruit. The HPH is suggested to process the enzyme prior to application, to increase its activity at high temperature with consequent time and energy economy during saccharification process. Also HPH is a promising non thermal methodology applied to stabilize juices microbiologically and physically, through particle size reduction and the high stability of amyloglucosidase during HPH process can be important to guarantee the effectiveness of amyloglucosidase during and after HPH. (c) 2012 Elsevier Ltd. All rights reserved.162125Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FAPESP [2010/02540-1

High pressure homogenization of a fungi alpha-amylase

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The activity and stability of alpha-amylase after high pressure homogenization were investigated. The enzyme buffer solution was processed at homogenization pressures up to 1500 bar. No changes in the enzymatic activity at 15, 45 and 75 degrees C were observed after the homogenization process. The evaluation of calcium requirement to preserve the et-amylase stability during homogenization was carried out and the results indicated that the enzyme was stable even with no calcium available. The stability during storage (4 days), at pH from 4.0 to 6.7 and at a temperature from 15 to 75 degrees C was also unaltered after homogenization. Additionally, the homogenization at elevated temperature (65 degrees C) was not able to change the alpha-amylase activity. Therefore, it was concluded that this enzyme is resistant to the high pressure homogenization process. Industrial relevance: The application of alpha-amylase in juice processing is growing, mainly on juice from fruits with high starch content (i.e. banana and apple) and, also to prevent turbidity and viscosity enhancement caused by unripe fruit. The HPH is a promising non thermal methodology applied to stabilize juices microbiologically and physically, through particle size reduction and the high stability of alpha-amylase during HPH process can be important to guarantee the effectiveness of alpha-amylase during and after HPH. (C) 2011 Elsevier Ltd. All rights reserved.13107111Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FAPESP [2010/02540-1

INNOVATIONS IN PACKAGE SYSTEMS FOR HEAT PROCESSED FOOD

This literature review aimed to evaluate the different package systems available to heat processed food and how they may affect the kind of process used and the final quality of the products. Were approached the main heat processes and their requirements concerning thermal and mechanical resistance of the package, as well as the advantages and limitations of the main used materials. It were also described the recent developments in order to minimize the restrictions of each type of material, improving its resistance and reducing costs, beyond barrier proprieties required to prevent undesirable physical-chemical changes in food during its storage caused by humidity, oxidation and material migration from package. It was concluded that there are many package options to heat treated food and that while traditional packages are being studied for weight reduction in order to be competitive, flexible or plastic packages are being formulated to be compatible to heat processing at low cost.28225527

Changes in commercial glucose oxidase activity by high pressure homogenization

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)High pressure homogenization (HPH) has been described as a process able to change enzyme activity and stability of enzymes. This study investigated the HPH effects on commercial glucose oxidase (GO) activity. Enzyme solutions at pH 5.0, 5.7 and 6.5 were processed at pressures 50, 100, and 150 MPa. The HPH effects were determined by the enzyme residual activity measured at 15, 50 and 75 degrees C immediately after homogenization and after 1 day of storage. Results showed that low pressures (50 MPa) reduced the GO relative activity at all temperatures evaluated when samples were homogenized at pH 5.0. However, a relative recovery of enzyme activity was observed when homogenization was carried out at pressures of >= 100 MPa. For samples processed at pH 5.7, the homogenization at 100 MPa reduced the relative enzyme activity at 15 and 50 degrees C. On the contrary, a 25% improvement on GO relative activity at 75 degrees C was observed after homogenization at 150 MPa. For samples homogenized at pH 6.5, the process continuously reduced the GO relative activity at 15 degrees C and almost no changes were observed when activity was evaluated at 50 and 75 degrees C. After 1 day, the GO relative activity of homogenized samples could increase up to 400%, as compared to the native one stored under the same condition. The results confirmed that HPH changes the GO activity, being able to increase or decrease it. This activity change may be associated to continuous modifications in enzyme structure due to homogenization pressure and pH of solution. Additionally, the GO relative stability increase in aqueous solution highlights HPH as an interesting tool to improve GO performance, expanding the potential application range of glucose oxidase in food industry. Industrial relevance: GO is an important enzyme in food industry due to its ability to consume oxygen and glucose. However its high instability on food matrix limits GO application. Therefore, the application of high pressure homogenization as an emerging technology to keep enzyme activity in aqueous solution is interesting to improve GO applications. (C) 2012 Elsevier Ltd. All rights reserved.16355360Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FAPESP [2010/02540-1

High Pressure Processing Of Cocoyam, Peruvian Carrot And Sweet Potato: Effect On Oxidative Enzymes And Impact In The Tuber Color

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)High pressure processing (HPP) is a non-thermal technology used to activate or inactivate enzymes. This study investigated the effects of HPP (600 MPa for 5 or 30 min at 25 degrees C) on cocoyam, Peruvian carrot and sweet potato color, and the polyphenoloxidase (PPO) and peroxidase (POD) activities in tuber cubes, puree, and enzyme extract subjected to HPP. The results showed enzyme inactivation by HPP in cocoyam (up to 55% PPO inactivation in puree and 81% POD inactivation in extract) and Peruvian carrot (up to 100% PPO and 57% POD inactivation the extract). In contrast, enzyme activation was observed in sweet potato (up to 368% PPO and 27% POD activation in puree). The color results were compatible to enzyme activity: the color parameters remained unchanged in cocoyam and Peruvian carrot, which showed high PPO and POD inactivation after HPP. Furthermore, the impact of HPP on the enzymes was influenced by the matrix in which HPP was carried out, evidencing that the enzyme structure can be protected in the presence of other food constituents. Industrial relevance: The enzymes PPO and POD are an important concern for vegetable processing, due its ability to induce browning after vegetables are cut. The HPP at 600 MPa for 5 or 30 min can be used to inactivate these enzymes in cocoyam and Peruvian carrot, guaranteeing the color and freshness of the tubers similar to the fresh cut vegetable. (C) 2016 Elsevier Ltd. All rights reserved.34302309Sao Paulo Research Foundation (FAPESP) [2012/13509-6]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

THERMAL INACTIVATION OF LACTOBACILLUS PLANTARUM IN A MODEL LIQUID FOOD

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Thermal process is one of the safest and most frequently used methods for food preservation. The use of model food in thermal treatment studies has several experimental advantages and enables reproducibility. Correct physical characterization of the model food and determination of thermal resistance of microorganisms are essential requirements in thermal treatments experiments. The present work determined the rheological characteristics of a 0.3% (w/w) carboxymethylcellulose (CMC) suspension, used as model liquid food, and the thermal resistance of Lactobacillus plantarum, a target microorganism in pasteurization processes. The rheological characterization was conducted using a double wall concentric-cylinder rheometer with controlled stress, at various temperatures ranging from 25 to 80C. The L. plantarum thermal resistance was evaluated using the three-neck flask method, at 52, 55, 58 and 61C. The rheological behavior of the model food was adjusted to the power law, with pseudoplastic behavior, consistency index (k) of 0.09Pa.s(n) and behavior index (n) of 0.80 at 25C. The parameters A(k) and the activation energy (Ea(k)) of the Arrhenius model were 0.0003Pa.s(n) and 14,140.7 J/mol/K, respectively. The values of D(52C), D(55C), D(58C) and D(61C) of L. plantarum were 76.3, 36.7, 16.4 and 7.3 s, respectively, with a z of 8.9C. The results showed that the model food system evaluated in this work represents several types of fruit juices. The use of well-characterized model food systems could greatly improve experimental consistency and reproducibility of thermal process studies, which are characteristics highly desirable but still scarce in the literature.34410131027Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPESP [2007/04121-6

Inactivation of Lactobacillus brevis in Beer Utilizing a Combination of High-Pressure Homogenization and Lysozyme Treatment

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)J. Inst. Brew. 117(4), 634-638, 2011 Inactivation of Lactobacillus brevis in beer by high-pressure homogenization (HPH) and lysozyme addition was evaluated. The minimum inhibitory concentration of lysozyme against L. brevis was determined and found to be 100 mg.L-1. The effects of the homogenization process on lysozyme antimicrobial activity and muramidase activity, and the microbial reduction promoted by HPH, and by HPH associated with lysozyme, were evaluated. A significant reduction in lysozyme muramidase activity was observed under 250 MPa, however, no reduction in antimicrobial activity was observed after homogenization up to 300 MPa. The HPH at 100, 140 and 150 MPa promoted 1, 3 and 6 decimal reductions in L. brevis microbial counts, respectively. The HPH and lysozyme association had an additive effect on microbial inactivation, immediately after homogenization, and the lysozyme remained active during 10 days of storage, increasing the inactivation of L. brevis up to a 6 decimal reduction. Therefore, the application of lysozyme with HPH has the potential to reduce the level of pressure required for beer processing, improving the economic costs when utilizing HPH.1174634638Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FAPESP [2001/06872-2

Effects of High Pressure Homogenization on Beer Quality Attributes

The aim of the present study was to evaluate the use of high pressure homogenization (HPH) as an alternative to thermal pasteurization for beer stabilization and to evaluate the effect of processing on colour, haze and redox potential immediately after the process and during the product shelf-life (100 days). The results obtained showed good colour retention, changes in the redox potential and greater values for turbidity, presenting a higher value for the product treated by HPH than for the thermally treated samples reported in literature. The evaluation of the results indicated that the HPH process is a promising process for beer treatment in terms of guaranteeing better colour retention. However to make this product stable, it would be necessary to perform stabilization treatments to minimize the negative effects of processing on the haze of the final product.117219519