scholarly journals Synergistic Effect of Enzyme Hydrolysis and Microwave Reactor Pretreatment as an Efficient Procedure for Gluten Content Reduction

Foods ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 2214
Author(s):  
Ivana Gazikalović ◽  
Jelena Mijalković ◽  
Nataša Šekuljica ◽  
Sonja Jakovetić Tanasković ◽  
Aleksandra Đukić Vuković ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Enzymatic Hydrolysis ◽  
Wheat Gluten ◽  
Control Process ◽  
Enzyme Hydrolysis ◽  
Hydrolysis Rate ◽  
Microwave Pretreatment ◽  
Microwave Reactor ◽  
Conventional Heat Treatment ◽  
Functional Features

In this study, we assessed the effects of microwave irradiation of wheat gluten proteins as a pretreatment performed in a microwave reactor that could accurately control process parameters as a function of power and temperature, as well as comparing it with conventional heat treatment. The aim was to identify suitable combinations of partial enzymatic hydrolysis and microwave pretreatment parameters to produce gluten hydrolysates with reduced allergenicity and conserved techno-functional features for food application. FTIR analysis, and total and reactive SH group contents confirmed that the microwave-controlled heating can significantly change the secondary structure and conformation of gluten protein. The microwave treatment had the largest effect at 200 W and 100 °C, at which the content of gluten has been reduced by about 2.5-fold. The microwave pretreatment also accelerated the enzymatic hydrolysis of gluten, changing the kinetic profile. The apparent hydrolysis rate constants (k2) were 1.00, 3.68, 3.48, 4.64 and 4.17 min−1 for untreated gluten, and those pretreated with microwave power of 200, 400, 600 and 800 W, respectively. Compared to the heat treatment, it appeared that microwave specific non-thermal effects had a significant influence on the gluten structure and allergenicity and, in combination with the enzymatic hydrolysis, ultimately yielded protein hydrolysates with enhanced antioxidant and functional properties.

Microwave Pre-Treatment of Corn Straw and its Enzymatic Hydrolysis

2013 ◽  
Vol 641-642 ◽  
pp. 971-974
Author(s):  
Mu Xin Han ◽  
Dong Mei Li ◽  
Yu Jie Feng ◽  
Yu Fei Tan ◽  
Yi Xing Yuan
Keyword(s):  
Response Surface Methodology ◽  
Enzymatic Hydrolysis ◽  
Response Surface ◽  
Microwave Power ◽  
Processing Time ◽  
Enzyme Hydrolysis ◽  
Corn Straw ◽  
Microwave Pretreatment ◽  
Optimum Parameters ◽  
Pre Treatment

To enhance enzymatic hydrolysis efficiency of the corn straw, a process microwave pretreatment of corn straw was optimized using response surface methodology (RSM). Estimated optimum parameters were as follows: water to corn straw ratio is 58:1, microwave power is 640w and processing time is 5 minutes. Under these conditions, a maximum enzyme hydrolysis ratio of corn straw (49.25%) after microwave pretreatment was reached.

Factors Limiting the Enzymatic Hydrolysis of Wheat Gluten

2014 ◽  
Vol 62 (20) ◽  
pp. 4762-4768 ◽  
Author(s):  
L. Giesler ◽  
D. Linke ◽  
R. G. Berger
Keyword(s):  
Enzymatic Hydrolysis ◽  
Wheat Gluten ◽  
Hydrolysis Of

scholarly journals No Major Differences Found between the Effects of Microwave-Based and Conventional Heat Treatment Methods on Two Different Liquid Foods

PLoS ONE ◽  
2013 ◽  
Vol 8 (1) ◽  
pp. e53720 ◽  
Author(s):  
Gábor Géczi ◽  
Márk Horváth ◽  
Tímea Kaszab ◽  
Gonzalo Garnacho Alemany
Keyword(s):  
Heat Treatment ◽  
Treatment Methods ◽  
Conventional Heat Treatment ◽  
Liquid Foods

Uphill Quenching of Aluminum Alloys

2019 ◽  
Author(s):  
Wellington da Silva Mattos ◽  
George Edward Totten ◽  
Lauralice de Campos Franceschini Canale
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Residual Stress ◽  
Aluminum Alloys ◽  
Temperature Gradient ◽  
Dimensional Stability ◽  
Steam Chamber ◽  
Conventional Heat Treatment ◽  
Quenching Process ◽  
Uphill Quenching

This article describes the concept of uphill quenching process applied in the heat treatment of aluminum alloys. Uphill quenching is interesting since residual stress reductions of up to 80% has been reported. In addition, substantial improvements in dimensional stability have been achieved for several types of aluminum parts. Often, uphill quenching is applied after quenching and before aging during the heat treatment of aluminum alloys. The uphill quenching process consists of the immersion of the part in a cryogenic environment, and after homogenization of the temperature, the part is transferred to the hot steam chamber to obtain a temperature gradient that will maintain the mechanical properties gained with this process. The results obtained are lower residual stress and better dimensional stability. The aim of this article is to provide a review of this process and to compare it with conventional heat treatment.

scholarly journals Kinetics of Enzymatic Hydrolysis of Southeast Sulawesi Sago Starch

2020 ◽  
pp. 53-61
Author(s):  
Ansharullah Ansharullah ◽  
Muhammad Natsir
Keyword(s):  
Enzymatic Hydrolysis ◽  
Maximum Velocity ◽  
Enzyme Concentration ◽  
Hydrolysis Rate ◽  
Sago Starch ◽  
Optimum Conditions ◽  
Kinetics Of ◽  
Hydrolysis Of ◽  
Substrate Concentrations ◽  
Menten Constant

The aims of this study were to characterize the kinetics of enzymatic hydrolysis of sago starch, obtained from Southeast Sulawesi Indonesia. The enzyme used for hydrolysis was bacterial ∝-amylase (Termamyl 120L from Bacillus licheniformis, E. C. 3.2.1.1).  The method to determine the initial velocity (Vo) of the hydrolysis was developed by differentiation a nonlinear equation (NLE).  The Vo of the hydrolysis was measured at various pH (6.0, 6.5,and 7.0), temperatures (40, 60, 75 and 95oC), enzyme concentrations (0.5, 1.0, 1.5 and 2.0 µg per mL) and in the presence of 70 ppm Ca++. The optimum conditions of this experiment were found to be at pH 6.5 – 7.0 and 75oC, and the Vo increased with increasing enzyme concentration. The Vo values at various substrate concentrations were also determined, which were then used to calculate the enzymes kinetics constant of the hydrolysis, including Michaelis-Menten constant (Km) and maximum velocity (Vmax) using a Hanes plot.  Km and Vmax values were found to be higher in the measurement at pH 7.0 and 75oC. The Km values  at four  different combinations of pH and temperatures (pH 6.5, 40oC; pH 6.5, 75oC; pH 7.0, 40oC; pH 7.0, 75oC) were found to be 0.86, 3.23, 0.77 and 3.83 mg/mL, respectively; and Vmax values were 17.5, 54.3, 20.3 and 57.1 µg/mL/min, respectively. The results obtained showed that hydrolysis rate of this starch was somewhat low.

scholarly journals Physical and Numerical Simulations of Closed Die Hot Forging and Heat Treatment of Forged Parts

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 15
Author(s):  
Łukasz Poloczek ◽  
Łukasz Rauch ◽  
Marek Wilkus ◽  
Daniel Bachniak ◽  
Władysław Zalecki ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Grain Size ◽  
Numerical Simulations ◽  
Phase Transformations ◽  
Hot Forging ◽  
Transformation Model ◽  
Controlled Cooling ◽  
Austenite Grain Size ◽  
Austenite Grain ◽  
Conventional Heat Treatment

The paper describes physical and numerical simulations of a manufacturing process composed of hot forging and controlled cooling, which replace the conventional heat treatment technology. The objective was to investigate possibilities and limitations of the heat treatment with the use of the heat of forging. Three steels used to manufacture automotive parts were investigated. Experiments were composed of two sets of tests. The first were isothermal (TTT) and constant cooling rate (CCT) dilatometric tests, which supplied data for the identification of the numerical phase transformation model. The second was a physical simulation of the sequence forging-cooling on Gleeble 3800, which supplied data for the validation of the models. In the numerical part, a finite element (FE) thermal-mechanical code was combined with metallurgical models describing recrystallization and grain growth during forging and phase transformations during cooling. The FE model predicted distributions of the temperature and the austenite grain size in the forging, which were input data for further simulations of phase transformations during cooling. A modified JMAK equation was used to calculate the kinetics of transformation and volume fraction of microstructural constituents after cooling. Since the dilatometric tests were performed for various austenitization temperatures before cooling, it was possible to include austenite grain size as a variable in the model. An inverse algorithm developed by the authors was applied in the identification procedure. The model with optimal material parameters was used for simulations of hot forging and controlled cooling in one of the forging shops in Poland. Distributions of microstructural constituents in the forging after cooling were calculated. As a consequence, various cooling sequences during heat treatment could be analyzed and compared.

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