Response surface methodology was applied to determine the optimum processing conditions that lead to maximum water loss, weight reduction and minimum solid gain as well as water activity during osmotic dehydration of carrots. Temperature (30-50oC), processing time (120-240 min), glucose syrup DE=42 (30-50% w/w) and salt (5-15%) concentrations were the factors investigated with respect to water loss (WL), Weight Reduction (WR), Solid Gain (SG), and water activity (aw). Experiments were arranged according to Central Composite Rotatable Design with these four factors each at three different levels, including central and axial points. Experiments were conducted with constant agitation rate of 200 rpm and solution to sample ratio of 10:1 (w/w). With respect to water loss, solid gain, weight reduction and water activity, both linear and quadratic effects of variables were found to be significant (p<0.001). For each response, second order polynomial models were developed using Multiple Linear Regression Analysis. Analysis of Variance (ANOVA) was performed to check the adequacy and accuracy of the fitted models. The optimal conditions for maximum water loss and weight reduction as well as minimum solid gain and water activity correspond to temperature of 30oC, glucose syrup concentration of 43.315%, salt concentration of 5%, time of 227.19 min to obtain water loss of 66.97 (g/100 g fresh sample), weight reduction of 62.52 (g/100 g fresh sample), solid gain of 4.475 (g/100 g fresh sample) and water activity of 0.789.

Ultrasonic distillation has been implemented as a green technology for desalination of saltwater due to its low energy consumption. It has also been proposed as an alternative to conventional distillation for separating water-ethanol mixtures, offering easy operating conditions and significant reduction in energy consumption (up to 80%). The Response Surface Methodology (RSM) was employed to optimize key parameters that influence ethanol enrichment, which includes initial ethanol concentration, solution height, and the quantity of ultrasonic modules. A central composite design (CCD) was utilized to reduce the number of experimental trials while formulating a predictive mathematical model. The findings suggest that elevated initial ethanol concentrations and an augmented number of modules significantly improved the ethanol concentration in the collected mist. Under optimal conditions—65% ethanol concentration, 2.5 cm solution height, and three modules—the purity of ethanol attained was akin to that achieved through conventional distillation techniques, accompanied by markedly diminished energy consumption. This research illustrates the potential of ultrasonic distillation for ethanol separation, offering operational efficiency and reduced energy demands.

Inulin is widely used in functional foods throughout the world for its health-promoting and technological properties. Helianthus tuberosus is cultivated widely in the northern part of Iran. Helianthus tuberosus can be a valuable source of Inulin. To optimize conventional extraction of Inulin, various combinations of time, temperature, and solvent: solid ratio, were used. In this research, a series of statistically designed studies were performed to investigate the effect of each of the independent variables (temperature and pH of extraction medium, extraction time, and solvent: solid ratio). The following variables: solvent: solid ratio (5-12 v/w), temperature (40-90oC) and time (5-40 min) were studied. The central composite design (CCD) and response surface methodology (RSM) were employed as experimental design and statistical analysis. Based on canonical analysis, the optimal conditions for maximizing Inulin extraction yield (42.2%) were 76.64oC for 23.90 min and solvent: solid ratios of 12:1 (v/w).

The bioconversion of sweet sorghum bagasse as lignocellulosic biomass into bioethanol is a complex and challenging process. The present study focuses on optimizing the pretreatment, enzymatic hydrolysis, and fermentation processes during bioethanol production from the bagasse of a drought-tolerant and high-yield sweet sorghum genotype (ISCV 25264). A comparison of acid and alkali pretreatment methods on enhanced enzymatic saccharification of sweet sorghum bagasse indicated that alkali pretreatment with NaOH was more effective. Three independent variables including the NaOH concentration (2-4%), pretreatment time (10-40 min), and pretreatment temperature (80-120°C) were optimized using Response Surface Methodology (RSM) based on central composite design. Pretreatment optimization resulted in a glucose concentration of about 84 g/L during the enzymatic hydrolysis. Afterward, the key variables affecting the hydrolysis process, which included the substrate concentration (5-10%), time (20-70 h), and the temperature (38-50°C) of the hydrolysis reaction were optimized by RSM. Glucose concentration was increased to 93 g/L by using the optimized enzymatic hydrolysis parameters (substrate concentration of 10%, incubation time of 60 h, and incubation temperature of 50°C). Subsequently, Simultaneous Saccharification and Fermentation (SSF) and separate hydrolysis and fermentation (SHF) methods were performed for bioethanol production using Saccharomyces cerevisiae. The results indicated that the ethanol concentration after 48 h was higher under the SHF method (48.714 g/L), compared to SSF (29.582 g/L); however, this method was not commercially attractive due to the much longer total time for bioethanol production. Finally, optimization of the parameters during the SSF process (substrate and yeast concentrations of 30% and 4%, respectively) led to an ethanol concentration of 33 g/L. The optimization of the bioethanol production process in this research has created a platform for pilot-scale studies to investigate the feasibility of bioethanol production from sweet sorghum bagasse at the industrial level.

Background: Inulin is widely used in functional foods throughout the world for its health-promoting and technological properties. Burdock tuber can be a valuable source of inulin. It is cultivated widely in the northern & western parts of Iran. But scarce studies about its extraction exist. It has been increasingly used in functional foods due to its texture improvement, sugar and fat replacer characteristics and beneficial nutritional attributes, as prebiotic ingredient.Objective: Optimize conventional extraction of inulin, by using central composite design (CCD) and response surface methodology (RSM).Methods: In this Research, a series of statistically designed studies such as central composite design and response surface methodology were performed to investigate the effect of each of the independent variables, solvent: solid ratio (5-15 v/w), temperature (40-90°C) and time (5-40 min) on yield of inulin extraction from burdock tubers. Response surface methodology was employed to optimize multiple variables to predict the best performance conditions with a minimum number of experiments. According to determination of inulin content of extraction liquid, firstly total carbohydrate was determined by the phenolsulphuric acid method, then reducing sugar was determined by the dinitrosalicylic acid method and finally the inulin content was measured with the difference between total carbohydrate and reducing sugars. Inulin extraction yield (%) was calculated using the following relationship= (inulin content × volume of extraction liquid/mass of Burdock tuber powder) ×100.Results: Based on canonical analysis, the optimal conditions for maximizing inulin extraction yield (12%) were at 66.14°C for 37.6 min and solvent: solid ratios of 14: 98 (v/w).Conclusion: Using the response surface methodology, the optimum set of the independent variables was obtained graphically in order to obtain the desired levels of inulin extraction.

Saccharomyces cerevisiae has many different uses such as baker's yeast and bioethanol production. Response surface methodology (RSM) is a complex of statistical techniques for experimental model creation. In this study was done to determination of optimal condition of bioethanol production from starch by yeast using RSM. Initially saccharomyces cerevisiae was proliferated on agar then by α-amylase, dextranase and amyloglucosidase respectively, then starch 5% was hydrolyzed to glucose. 250 ml glucose was put at 30 º C and velocity of 150 rpm for 36 h. Bioethanol quantity was evaluated by dichromate oxidation and ethanol measurement methods and temperature, time and pH variables were considered at 25-98 º C, 1 to 6 weeks and 3 to7, respectively. The highest bioethanol production was 12. 5 ml at 30 º C, pH 4 also at 80 º C, and pH 7 for 5 weeks. The lowest bioethanol production was 3 ml at 98 º C, pH 7 for 1 week which was practically compatible. Regarding the results, RSM method has many benefits such as increase in efficiency of chemical reactions, prevention of wasting raw material, time, money and energy which could use in different biological reactions.

Laboratory runs can be minimized via experimental design which yields the optimum and best data regarding the independent parameters. In this research work, response surface methodology (RSM) based on a threelevel central composite design (CCD) was utilized to optimize and evaluate the interactive effects of processing conditions for polymerization of 1, 3-butadiene (Bd) diene monomer using Ziegler-Natta catalyst. The polybutadiene rubber (PBR) having different cis content and molecular weight was obtained. The catalyst components included neodymium versatate (NdV3) as catalyst, triethyl aluminum (TEAL) as cocatalyst or activator, and ethylaluminum sesquichloride (EASC) as chloride donor. For the modeling, three independent variables, namely monomer concentration (8-28 wt%), reaction time (1. 5-2. 5 h), and reaction temperature (45-75º, C) at three levels were selected to optimize the dependent variables or responses including monomer conversion, viscosity-average molecular weight and the cis isomer content of the obtained polymer. The interaction between three crucial parameters was studied and modeled. Quadratic models were obtained to relate process conditions to dependent variables. It was observed that the optimal conditions predicted by RSM were consistent with the experimental data. Statistical analysis demonstrated that concentration of the monomer and the time of reaction significantly affected cis content. Moreover, processing conditions to achieve the desired response variables were predicted and experimentally approved. The optimal reaction conditions derived from RSM are monomer concentration = 19 wt%, polymerization time = 2 hours, and polymerization temperature = 50º, C. Polymerization was carried out at optimum conditions. The appropriate level of dependent variables including 94. 2% monomer conversion, 151812 g/mol viscosity-average molecular weight and 98. 8% cis content was acquired.

Recently, the synthesis of biolubricants has been the focus of researchers because of their good lubricating properties and environmentally friendly products. This study was performed to optimize reaction parameters for the enzymatic transesterification reaction between waste edible oil methyl ester (biodiesel, FAME) and trimethylolpropane (TMP) by using Response Surface Methodology (RSM). The parameters that affect the enzymatic transesterification reaction were chosen as temperature (35–55°C), amount of catalyst (0–10 %wt. of mixture), TMP-to-FAME molar ratio (0.17-0.33), and reaction time (0–96 h), to produce TMP triester (biolubricant). Response surface methodology (RSM) and three-level–four-factor Central Composite Design (CCD) were employed to evaluate the effects of these synthesis parameters on the percentage conversion of FAME by transesterification. Enzyme amount and reaction time were the most important variables. The optimum reaction conditions were determined to be the temperature at 50°C; the amount of catalyst, 5%wt; molar ratio, 0.25 and 48 h of reaction time, under these conditions 91% TMP ester's yield was obtained. The interaction parameter of the lipase quantity with the FAME to TMP molar ratio was found to be the most important among all of the other parameters.

The objective of this study was to investigate the production of natural-cement composite fiber using poplar, wheat straw and three types of additives. In this study, variables in making the boards were: usage percent of wheat straw (0, 15 and 30%) and fibers of poplar (70, 85 and 100%), and levels and types of additives (three levels and three types of additives, i. e. calcium chloride, magnesium chloride and calcium hydroxide, respectively). After producing test specimens, compressive strength (1, 3, 7 and 28 days), thickness swelling (TS), the modulus of rupture (MOR), and internal bond (IB), were evaluated. The highest and the lowest compressive strength (32. 5 and 7. 1 MPa) after 28 days were respectively for samples containing 7% calcium hydroxide and 3% magnesium chloride. Also, the boards with 30 percent wheat straw and 70 percent poplar wood fiber with the amount of 3% calcium chloride had a higher MOR compared to other boards. In general, the results suggest that calcium chloride additives with amount of 5% and the average value of 15% straw to 85% poplar is the appropriate amount for achieving acceptable values of IB and MOR. Due to its significance in the statistical analysis, the model presented by Response Surface Methodology provided a suitable and significant estimate to determine the application of the variables.

In this study the effect of grape fiber and chitosan on Lactobacillus Fermentum viability, physicochemical and sensorial properties in yoghurt containing kiwi was investigated during storage, using response surface methodology (RSM). Amounts of grape fiber, chitosan and storage time were in the range of 0-1.2 %, 0-1 % and 3-21 day, respectively. The results indicated that with increasing the amount of chitosan, Lactobacillus Fermentum viability decreased, but it was increased by increasing grape fiber during storage significantly (P<0.05). Moisture and syneresis of samples reduced significantly by increasing the amounts of chitosan and fiber (P<0.05). According to sensory evaluation, increasing the amounts of chitosan caused decrease in color scores. Flavor scores decreased as grape fiber increased significantly (P<0.05). In conclusion, using 0.9% grape fiber, 0.1% chitosan, and 12 day storage were found as optimum conditions for producing probiotic kiwi fruit yogurt.