Andra - Ionela Ghizdareanu | University Politehnica of Bucharest (original) (raw)
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Papers by Andra - Ionela Ghizdareanu
Polymers
The objective of this study was to investigate the effects of enzymatic hydrolysis using α-amylas... more The objective of this study was to investigate the effects of enzymatic hydrolysis using α-amylase from Bacillus amyloliquefaciens on the mechanical properties of starch-based films. The process parameters of enzymatic hydrolysis and the degree of hydrolysis (DH) were optimized using a Box–Behnken design (BBD) and response surface methodology (RSM). The mechanical properties of the resulting hydrolyzed corn starch films (tensile strain at break, tensile stress at break, and Young’s modulus) were evaluated. The results showed that the optimum DH for hydrolyzed corn starch films to achieve improved mechanical properties of the film-forming solutions was achieved at a corn starch to water ratio of 1:2.8, an enzyme to substrate ratio of 357 U/g, and an incubation temperature of 48 °C. Under the optimized conditions, the hydrolyzed corn starch film had a higher water absorption index of 2.32 ± 0.112% compared to the native corn starch film (control) of 0.81 ± 0.352%. The hydrolyzed corn ...
The aim of the research was to compare the shelf life of fruit smoothies, obtained by two differe... more The aim of the research was to compare the shelf life of fruit smoothies, obtained by two different accelerated aging methods. An accelerated shelf life test (ASLT) was conducted, and various quality indicators were measured during this time, such as: pH, titratable acidity, colour, total aerobic count (TAC) and sensory analysis. The test was performed on smoothie beverages purchased from Romanian market for 24 days, the samples being stored at three different temperatures: 5°C, 10°C and 15°C. The analysis of the quality parameters showed that the pH, titratable acidity and the measurement of colour suffered a minor value modification, while the TAC number increased as the storage temperature increased. The results of the research were analysed using Arrhenius equation and Q10 Rule. The TAC changes followed an apparent first-order kinetics, their rates and activation energies were estimated from the experimental data (as a plot of temperature vs time). The fruit smoothies had an est...
Polymers
The objective of this study was to investigate the effects of enzymatic hydrolysis using α-amylas... more The objective of this study was to investigate the effects of enzymatic hydrolysis using α-amylase from Bacillus amyloliquefaciens on the mechanical properties of starch-based films. The process parameters of enzymatic hydrolysis and the degree of hydrolysis (DH) were optimized using a Box–Behnken design (BBD) and response surface methodology (RSM). The mechanical properties of the resulting hydrolyzed corn starch films (tensile strain at break, tensile stress at break, and Young’s modulus) were evaluated. The results showed that the optimum DH for hydrolyzed corn starch films to achieve improved mechanical properties of the film-forming solutions was achieved at a corn starch to water ratio of 1:2.8, an enzyme to substrate ratio of 357 U/g, and an incubation temperature of 48 °C. Under the optimized conditions, the hydrolyzed corn starch film had a higher water absorption index of 2.32 ± 0.112% compared to the native corn starch film (control) of 0.81 ± 0.352%. The hydrolyzed corn ...
The aim of the research was to compare the shelf life of fruit smoothies, obtained by two differe... more The aim of the research was to compare the shelf life of fruit smoothies, obtained by two different accelerated aging methods. An accelerated shelf life test (ASLT) was conducted, and various quality indicators were measured during this time, such as: pH, titratable acidity, colour, total aerobic count (TAC) and sensory analysis. The test was performed on smoothie beverages purchased from Romanian market for 24 days, the samples being stored at three different temperatures: 5°C, 10°C and 15°C. The analysis of the quality parameters showed that the pH, titratable acidity and the measurement of colour suffered a minor value modification, while the TAC number increased as the storage temperature increased. The results of the research were analysed using Arrhenius equation and Q10 Rule. The TAC changes followed an apparent first-order kinetics, their rates and activation energies were estimated from the experimental data (as a plot of temperature vs time). The fruit smoothies had an est...