Response surface methodology study of the combined effects of temperature, pH, andawon the growth rate ofTrichoderma asperellum

2007 ◽  
Vol 103 (4) ◽  
pp. 845-854 ◽  
Author(s):  
B.A.D. Begoude ◽  
R. Lahlali ◽  
D. Friel ◽  
P.R. Tondje ◽  
M.H. Jijakli
Keyword(s):  
Growth Rate ◽  
Response Surface Methodology ◽  
Response Surface ◽  
Combined Effects ◽  
Effects Of Temperature

Response Surface Methodology towards Optimization of Calotropis Procera Essential oil Extraction by using Supercritical CO2.

2019 ◽  
Vol 09 ◽  
Author(s):  
Hossein Zaeri ◽  
Bahareh Kamyab Moghadas ◽  
Bijan Honarvar ◽  
Ali Shokuhi Rad
Keyword(s):  
Response Surface Methodology ◽  
Essential Oil ◽  
Response Surface ◽  
Extraction Time ◽  
Calotropis Procera ◽  
Retrieval Rate ◽  
The Family ◽  
Effects Of Temperature ◽  
Carbon Dioxide Co2 ◽  
Central Composite

: In this research, the extraction of essential oil from Calotropis Procera with the family name of Asclepiadaceae, by supercritical carbon dioxide (CO2) solvent has been investigated in detail, and the yield and chemical profile of the extracts achieved by this method were compared with those resulted by the conventional Hydro distillation method. To optimize the process parameters of CO2 supercritical extraction (SCE) of the Calotropis Procera, the Response Surface Methodology (RSM) with central composite design (CCD) was employed. The effects of temperature, pressure, and extraction time on the oil yield are considered for investigation. Results showed that the data were sufficiently fitted into the second-order polynomial model. The extraction conditions, including pressure, temperature, and extraction time, were studied between 150-200 bar, 40-50 ºC, and 50-100 min, respectively. The optimal conditions are achieved as the temperature of 47.19ºC, the pressure of 172.2 bar, and time of 86 minutes with the retrieval rate of 31.39%.

Growth Characteristics and Development of a Predictive Model for Bacillus cereus in Fresh Wet Noodles with Added Ethanol and Thiamine

2011 ◽  
Vol 74 (4) ◽  
pp. 658-664 ◽  
Author(s):  
BO-YEON KIM ◽  
JI-YOUNG LEE ◽  
SANG-DO HA
Keyword(s):  
Growth Rate ◽  
Response Surface Methodology ◽  
Bacillus Cereus ◽  
Predictive Model ◽  
Response Surface ◽  
Growth Rates ◽  
Vitamin B1 ◽  
Growth Characteristics ◽  
Quadratic Polynomial ◽  
Polynomial Model

Response surface methodology was used to determine growth characteristics and to develop a predictive model to describe specific growth rates of Bacillus cereus in wet noodles containing a combination of ethanol (0 to 2% [vol/wt]) and vitamin B1 (0 to 2 g/liter). B. cereus F4810/72, which produces an emetic toxin, was used in this study. The noodles containing B. cereus were incubated at 10°C. The growth curves were fitted to the modified Gompertz equation using nonlinear regression, and the growth rate values from the curves were used to establish the predictive model using a response surface methodology quadratic polynomial equation as a function of concentrations of ethanol and vitamin B1. The model was shown to fit the data very well (r2 = 0.9505 to 0.9991) and could be used to accurately predict growth rates. The quadratic polynomial model was validated, and the predicted growth rate values were in good agreement with the experimental values. The polynomial model was found to be an appropriate secondary model for growth rate (GR) and lag time (LT) based on the correlation of determination (r2 = 0.9899 for GR, 0.9782 for LT), bias factor (Bf = 1.006 for GR, 0.992 for LT), and accuracy factor (Af = 1.024 for GR, 1.011 for LT). Thus, this model holds great promise for use in predicting the growth of B. cereus in fresh wet noodles using only the bacterial concentration, an important contribution to the manufacturing of safe products.

scholarly journals Optimization of Storage Conditions of the Medicinal Herb Ilex asprella against the Sterigmatocystin Producer Aspergillus versicolor Using Response Surface Methodology

Toxins ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 499
Author(s):  
Xiaofang Lu ◽  
Chaoquan Luo ◽  
Jianyong Xing ◽  
Zhengzhou Han ◽  
Tong Li ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Southern China ◽  
Storage Conditions ◽  
Raw Material ◽  
Aspergillus Versicolor ◽  
Total Saponin ◽  
Different Temperatures ◽  
Effects Of Temperature ◽  
Central Composite

The root of Ilex asprella is a commonly used herb in Southern China, and also constitutes the main raw material of Canton herbal tea. I. asprella is readily contaminated by mildew because of rich nutrients. Aspergillus versicolor producing sterigmatocystin is one of the most common molds that contaminate foodstuffs and medicinal herbs. Previous study on the evaluation of fungal contamination on samples of I. asprella revealed that A. versicolor was the dominant contaminant. In this study, experiments based on response surface methodology combined with central composite design were carried out to determine the optimal storage conditions of I. asprella to minimize the contamination of sterigmatocystin. The herb, manually innoculated with A. versicolor, was stored under different temperatures (20–40 °C) and humidity (80–95%) for seven days. The effects of temperature and humidity were evaluated using total saponin, polysaccharide and the sterigmatocystin levels as quality indexes. The results showed that A. versicolor grew quickly and produced large amounts of sterigmatocystin on I. asprella, at humidity ranging from 85% to 90% and temperatures above 26 °C. Meanwhile, total saponin and polysaccharide amounts were reduced significantly. These findings suggested that I. asprella samples should be stored in an environment with humidity and temperature below 85% and 26 °C, respectively, to reduce A. versicolor growth and sterigmatocystin production.

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