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1.
Effects of natural and synthetic antioxidants on changes in refined, bleached, and deodorized palm olein during deep-fat frying of potato chips 总被引:2,自引:0,他引:2
The effects of antioxidants on the changes in quality characteristics of refined, bleached, and deodorized (RBD) palm olein
during deep-fat frying (at 180°C) of potato chips for 3.5 h/d for seven consecutive days in five systems were compared in
this study. The systems were RBD palm olein without antioxidant (control), with 200 ppm butylated hydroxytoluene (BHT), 200
ppm butylated hydroxyanisole (BHA), 200 ppm oleoresin rosemary, and 200 ppm sage extract. Fried oil samples were analyzed
for peroxide value (PV), thiobarbituric acid (TBA) value, iodine value (IV), free fatty acid (FFA) content, polymer content,
viscosity, E1%
1 cm at 232 and 268 nm, color, fatty acid composition, and C18:2/C16:0 ratio. Sensory quality of the potato chips fried in these systems prior to storage was also evaluated. The storage stability
of fried potato chips for 14 wk at ambient temperature was also determined by means of the TBA values and sensory evaluation
for rancid odor. Generally, in the oil, oleoresin rosemary gave the lowest rate of increase of TBA value, polymer content,
viscosity, E1%
1 cm at 232 and 268 nm compared to control and three other antioxidants. The order of effectiveness (P<0.05) in inhibiting oil oxidation in RBD palm olein was oleoresin rosemary > BHA > sage extract > BHT > control. Prior to
storage, the sensory evaluation of fried potato chips for each system showed that there was no significant (P>0.05) difference in terms of flavor, odor, texture, and overall acceptability. The same order of effectiveness (P<0.05) of antioxidants was observed for storage stability study of fried potato chips by TBA values. However, there was no
significant (P > 0.05) difference in sensory evaluation for rancid odor during storage periods. 相似文献
2.
Synergistic effects of rosemary, sage, and citric acid on fatty acid retention of palm olein during deep-fat frying 总被引:1,自引:0,他引:1
Irwandi Jaswir Yaakob B. Che Man David D. Kitts 《Journal of the American Oil Chemists' Society》2000,77(5):527-533
A study to optimize the use of oleoresin rosemary extract, sage extract, and citric acid in refined, bleached, and deodorized
(RBD) palm olein during deep-fat frying of potato chips was performed using response surface methodology. Results showed that
the natural antioxidants used in this study retarded oil deterioration, as evidenced by retention of fatty acid profiles.
The linoleic to palmitic (C18∶2/C16∶0) ratio was chosen as the parameter for optimizing the use of natural antioxidants in
RBD palm olein during deep-fat frying. Linoleic (R
2=0.946) and palmitic (R
2=0.825) acids were found to be the most important dependent variables, giving highest R
2 values to various antioxidant treatments after 25 h of frying. All three antioxidants had independent significant (P<0.05) effects on the C18∶2/C16∶0 ratio. In fact, significant effects on the C18∶2/C16∶0 ratio of RBD palm olein were also
given by a second-order form. A combination of 0.076% oleoresin rosemary extract, 0.066% sage extract, and 0.037% citric acid
produced the optimal retention of the essential fatty acid C18∶2. In addition, a synergistic effect among these antioxidants
on the fatty acid ratio of RBD palm olein was found. 相似文献
3.
Irwandi Jaswir Yaakob B. Che Man David D. Kitts 《Journal of the American Oil Chemists' Society》2000,77(11):1161-1168
Response surface methodology (RSM) was used to optimize the amounts of rosemary and sage extracts together with citric acid as synergist antioxidants in stabilizing refined, bleached, and deodorized palm olein during repeated deep-fat frying of potato chips. For all physicochemical properties studied, these phytochemical antioxidant treatments significantly (P<0.05) reduced the oxidation rate of the oil. During 5 d of frying, anisidine value, peroxide value, free fatty acid, polymer content, color units, viscosity, and absorbances at 232 and 268 nm gradually increased, whereas iodine value and ratio of 18∶2/16∶0 decreased. Further statistical analyses, including coefficient of determination (R 2) and probability of F values, indicated that mathematical models for each physicochemical parameter could be developed confidently in this study, with R 2 for all parameters greater than 0.90. These results suggested that an optimal mixture of phytochemical antioxidants derived from rosemary and sage together with citric acid could be produced using RSM for stabilizing thermally processed oil. For many physicochemical parameters examined, the use of moderate levels of antioxidants could result in optimal responses. 相似文献
4.
Response surface methodology was used to model the incorporation of stearic acid into a blend of palm olein and palm kernel
oil in hexane using the sn-1,3-regiospecific lipase Lipozyme RM IM. The factors investigated were incubation time, temperature, and substrate molar
ratio. A second-order model with interaction was used to fit the experimental data. The coefficients of determination, R
2 and Q
2, were 0.96 and 0.90, respectively. The adjusted R
2 was 0.95. The regression probability was less than 0.001, and the model showed no lack of fit. Also, a linear relationship
was observed between the predicted and observed values. All parameters studied had positive effects on incorporation of stearic
acid, with substrate molar ratio having the greatest effect. The interaction terms of substrate molar ratio with temperature
and time also had positive effects on incorporation, whereas the effect of the squared term of substrate molar ratio was negative.
The quadratic terms of temperature and time, as well as their interaction term, had no significant effect on incorporation
at α0.05. Model verification was done by performing a chi-square test, which showed that there was no significant difference between
predicted values and a new set of observed responses. 相似文献
5.
In this study, response surface methodology was utilized to determine the optimal conditions for the extraction of carotenes (α- and β-carotene) and tocols (α-tocopherol, α-, γ-, and δ-tocotrienol) from crude palm olein using ethyl lactate (EL) and ethanol (EtoL) in a temperature-controlled mixer-settler system. Central composite design with four factors including temperature (X1), mixing time (X2), volume fraction (VF) of olein (X3), and VF of EtOL (X4) was used to investigate the multivariate relationship with the five responses including enrichment factor and recovery of both carotenes and tocols. The optimum extraction conditions were determined at 20°C, 10?min of mixing, 48% of crude palm olein, 31.2% of EL and 20.8% of EtoL (corresponding to 0.5 VF of olein and 0.4 VF of EtoL). The enrichment factors of carotenes and tocols were 0.88 and 2.56, respectively while 11.3% of carotenes and 31.2% of tocols were recovered. 相似文献
6.
Ittipon Worapun Kulachate Pianthong Prachasanti Thaiyasuit 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2012,87(2):189-197
BACKGROUND: Production of biodiesel from crude palm oil (CPO) with 6 wt% of free fatty acid (FFA) using a low‐frequency ultrasonic irradiation (40 kHz) technique was investigated in the present work. The objective of this study was to determine the relationship between various important parameters of the alkaline catalyzed transesterification process to obtain a high conversion to biodiesel. Response surface methodology (RSM) was used to statistically analyze and optimize the operating parameters of the process. A central composite design (CCD) was adopted to study the effects of the methanol to oil molar ratio, the catalyst concentration, reaction temperature, and irradiation time on conversion to biodiesel. RESULTS: The result from the RSM analysis indicated that the methanol to oil molar ratio, catalyst concentration and irradiation time have the most significant effects on the conversion to biodiesel. Moreover, a coefficient of determination (R2) value of 0.93 shows the fitness of a second‐order model for the present study. Based on this second‐order model, the optimum conditions for alkaline catalyzed transesterification of CPO were found to be a methanol to oil molar ratio of 6.44:1, catalyst concentration 1.25 wt%, reaction temperature 38.44 °C and irradiation time 25.96 min. At the calculated optimum condition, the conversion to biodiesel reached 97.85%. Under these same conditions, the experimental value was 98.02 ± 0.6%. CONCLUSIONS: The mathematical model developed has been proven to adequately describe the range of the experimental parameters studied and provide a statistically accurate prediction of the optimum conversion to biodiesel. Copyright © 2011 Society of Chemical Industry 相似文献
7.
Ta Yeong Wu Abdul Wahab Mohammad Jamaliah Md. Jahim Nurina Anuar 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2009,84(9):1390-1396
BACKGROUND: The membrane filtration process enables the treatment of wastewater, producing permeate which is less polluted. However, disposal is usually required for the retentate, which is produced as a concentrated constituent along with the permeate. In this study, the authors explored the possibility of reusing, rather than disposing of, the retentate of pre‐filtered palm oil mill effluent (POME) as a fermentation substrate in protease production by a wild type strain of Aspergillus terreus IMI 282743. In addition, the quantitative and interactive effects of the concentration factor for retentate, temperature, inoculum concentration, and fermentation time on the optimization of protease production were investigated using response surface methodology (RSM). RESULTS: Using RSM, the optimum conditions were found to be a concentration factor of 7.27, temperature of 37.95 °C, inoculum concentration of 1.30% (v/v) and fermentation time of 3.83 days. The protease production was increased 4.37‐fold in comparison with the results obtained under non‐optimized conditions. CONCLUSION: To a certain extent, protease production could be enhanced with an increase in concentration factor and temperature, and a decrease of inoculum concentration and fermentation time. Also, POME retentate was found to be a good substrate for protease production with high product activity and without nutrient supplementation. Copyright © 2009 Society of Chemical Industry 相似文献
8.
A. L. Ahmad C. Y. Chan S. R. Abd Shukor M. D. Mashitah 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2009,84(7):1063-1069
BACKGROUND: Palm oil mill effluent (POME) is a liquid waste that is highly polluting and has a significant impact on the environment if not dealt with properly. POME contains oil and carotenes that needs to be treated before discharge. In this work solvent extraction was used to recover oil‐containing carotenes from POME. Optimum conditions for the extraction of oil and carotenes from POME were determined using response surface methodology. RESULTS: A central composite design was used to investigate the effects of three independent factors, namely solvent:POME ratio, mixing rate (rpm) and mixing time (min) on the responses, extracted oil and carotenes recovery. The optimal conditions for extraction of oil and carotenes from POME were 8:10 solvent:POME ratio; 500 rpm mixing rate and 25 min mixing time. Under these conditions, the amount of oil extracted from POME was 7885 mg L?1, and carotenes recovery was 87.1%. CONCLUSION: The experimental values agreed with those predicted, thus indicating the suitability of the model employed in optimizing the extraction parameters. A high yield of carotenes was obtained under the optimized conditions, with relatively low solvent levels. Copyright © 2009 Society of Chemical Industry 相似文献
9.
10.
A statistical Box–Behnken design of experiments was performed to evaluate the effects of individual operating variables and their interactions on the acrylonitrile (AN) removal of C0 = 100 mg/L as fixed input parameter. The variables examined in this study included activated carbon‐granular (AC) dosage, w, temperature, T, and time of contact, t. The significant variables and optimum conditions were identified (w = 4 g/L, T = 30°C, and t = 120 min with AN uptake of 23.97 mg/g of AC) from statistical analysis of the experimental results using response surface methodology (RSM). 相似文献
11.
12.
Maria Antonopoulou Vassilios Papadopoulos Ioannis Konstantinou 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2012,87(10):1385-1395
BACKGROUND: TiO2 heterogeneous photocatalysis should be optimized before application for the removal of pollutants in treated wastewaters. The response surface methodology (RSM) and artificial neural networks (ANNs) were applied to model and optimize the photocatalytic degradation of total phenolic (TPh) compounds in real secondary and tertiary treated municipal wastewaters. RESULTS: RSM was developed by considering a central composite design (CCD) with three input variables, i.e. TiO2 mass, initial concentration of TPh and irradiation intensity. At the same time a feed‐forward multilayered perceptron ANN trained using back propagation algorithms was used and compared with RSM. Under the optimum conditions established in experiments ([TPh]0 = 3 mg L?1; [TiO2] = 300 mg L?1; I = 600 W m?2) the degradation for both TPh and total organic carbon (TOC) followed pseudo‐first‐order kinetic model. Complete degradation of TPh took place in 180 min and reduction of TOC reached 80%. A significant abatement of the overall toxicity was accomplished as revealed by Microtox bioassay. CONCLUSIONS: It was found that the variables considered have important effects on TPh removal efficiency. The results demonstrated that the use of experimental design strategy is indispensable for successful investigation and adequate modeling of the process and that ANNs gave better modelling capability than RSM. Copyright © 2012 Society of Chemical Industry 相似文献
13.
《Ceramics International》2016,42(10):11666-11673
To enhance the quality of alkali-activated slag (AAS) materials, scientific and efficient mix design method is preferred. This paper presents an optimization of AAS materials using Response Surface Methodology (RSM). Three factors related to early strength such as modulus (n), concentration of alkali activator (CAA) and liquid–solid ratio (LSR) were investigated. Specimens with different mix ratios were prepared based on RSM design. The early mechanical performance was assessed, after 2 or 3 h of curing. Then response surface models were established and the effect law of each factor was systemically analyzed. The result shows that both n and CAA have a significant effect on the early strength, while LSR affects slightly. By adjusting the mix design parameters, the early performance of AAS can be effectively improved. This study verifies that RSM is efficient in the preparation of AAS and it can control the early strength of AAS accurately. 相似文献
14.
Torben H. Rnne Charlotte Jacobsen Xuebing Xu 《European Journal of Lipid Science and Technology》2006,108(3):182-192
A mixture of butterfat and rapeseed oil (7 : 3, wt/wt) was interesterified using immobilized lipase from Thermomyces lanuginosus at 50 °C. The interesterified mixture was then deodorized at five temperatures (60–180 °C) and three samples were withdrawn at 1, 2, and 3 h. The operation was monitored by free fatty acid (FFA) content, peroxide value (PV), volatiles, and the sensory evaluation of the samples with respect to flavor and odor (most importantly the butter flavor and odor and the off‐flavor and odor from butyric acid). ANOVA partial least squares regression analysis showed that deodorization time, and especially deodorization temperature, significantly affected the sensory properties and levels of volatiles, FFA and peroxides in the samples. The best compromise between removing undesirable off‐flavors while maintaining the desirable butter flavor seemed to be obtained by using a deodorization temperature of 120 °C for 2 h. Response surface methodology analysis showed a significant effect of deodorization temperature and, to a lesser extent, deodorization time. The butter flavor and odor had an optimum at a deodorization temperature of approximately 100–120 °C for 1–2 h. These conditions are therefore recommended in order to remove the off‐flavor and odor, while maintaining as much as possible of the attractive butter flavor and odor. 相似文献
15.
AbstractIn this study, formic acid removal from its aqueous solutions through bulk ionic liquid membrane (BILM) was investigated. Tributyl phosphate (TBP) as a carrier in imidazolium-based ionic liquids was used. D-optimal design based on response surface methodology has been applied to investigate the effect of various operating factors. Initial formic acid concentration, TBP concentration, and NaOH concentration were selected as numerical factors, and ionic liquid type was chosen as a categorical factor. The model equations were obtained to determine BILM process behavior. The removal efficiencies, represented by the extraction and stripping efficiencies, were calculated from the experimental data. The highest removal efficiencies were determined at higher concentration values of TBP and NaOH. All ionic liquids studied in this study had good transport selectivity for the removal of formic acid. The design study showed that BILM is an effective method for the removal of formic acid from the water. 相似文献
16.
Optimized purification of mono‐PEGylated lysozyme by heparin affinity chromatography using response surface methodology
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Luis Alberto Mejía‐Manzano M Elena Lienqueo Edgardo J Escalante‐Vázquez Marco Rito‐Palomares Juan A Asenjo 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2017,92(10):2554-2562
17.
M. L. Damstrup T. Jensen F. V. Sparsø S. Z. Kiil A. D. Jensen X. Xu 《Journal of the American Oil Chemists' Society》2006,83(1):27-33
The aim of this study was to optimize production of MAG by lipase-catalyzed glycerolysis in a tert-pentanol system. Twenty-nine batch reactions consisting of glycerol, sunflower oil, tert-pentanol, and commercially available lipase (Novozym®435) were carried out, with four process parameters being varied: Enzyme load, reaction time, substrate ratio of glycerol to oil, and solvent amount. Response surface methodology was applied to optimize the reaction system based on the experimental data achieved. MAG, DAG, and TAG contents, measured after a selected reaction time, were used as model responses. Well-fitting quadratic models were obtained for MAG, DAG, and TAG contents as a function of the process parameters with determination coefficients (R2) of 0.89, 0.88, and 0.92, respectively. Of the main effects examined, only enzyme load and reaction time significantly influenced MAG, DAG, and TAG contents. Both enzyme amount and reaction time showed a surprisingly nonlinear relationship between factors (process parameters) and responses, indicating a local maximum. The substrate ratio of glycerol to oil did not significantly affect the MAG and TAG contents; however, it had a significant influence on DAG content. Contour plots were used to evaluate the optimal conditions for the complex interactions between the reaction parameters and responses. The optimal conditions established for MAG yield were: enzyme load, 18% (w/w of oil); glycerol/oil ratio, 7∶1 (mol/mol); solvent amount, 500% (vol/wt of oil); and reaction time, 115 min. Under these conditions, a MAG content of 76% (w/w of lipid phase) was predicted. Verification experiments under optimized reaction conditions were conducted, and the results agreed well with the range of predictions. 相似文献
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19.
Hojjat Dadkhah 《Chemical Engineering Communications》2019,206(3):398-408
In this article, response surface methodology (RSM) was used to obtain optimum conditions for removal of p-nitrophenol (PNP) by UV/H2O2 process using spinning disk photoreactor (SDP). For this purpose, the effect of five independent variables, the initial concentration of PNP, the initial concentration of H2O2, pH, solution volume, and irradiation time on the PNP removal percent, was investigated. Central composite design, one of the response surface techniques used for process optimization. The results showed a good agreement between the RSM predicted and experimental data with “R2” and “Adjusted R2” of 0.9692 and 0.9480, respectively. In addition, “Predicted R2” of 0.8909 is in reasonable agreement with “Adjusted R2” of 0.9488. At optimal conditions, that is, PNP concentration of 20.78?mg L?1, H2O2 concentration of 1355.83?mg L?1, solution volume of 566.08?mL, irradiation time of 12.30?min, and pH of 4.59 the removal percent predicted by RSM is 100% which has good correspondence with its experimental value (98.67%). 相似文献