Papers by Maria Fernanda Gayol
Manual for Christhin 0.1.36 Christhin (Chromatography Riser Thin) is software developed for the q... more Manual for Christhin 0.1.36 Christhin (Chromatography Riser Thin) is software developed for the quantitative analysis of data obtained from thin-layer chromatographic techniques (TLC). Once installed on your computer, the program is very easy to use, and provides data quickly and accurately. This manual describes the program, and reading should be enough to use it properly.
Industrial Crops and Products, 2009
This article appeared in a journal published by Elsevier. The attached copy is furnished to the a... more This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are encouraged to visit: http://www.elsevier.com/copyright Author's personal copy i n d u s t r i a l c r o p s a n d p r o d u c t s 2 9 (2 0 0 9) 177-181
Industrial Crops and Products, 2020
The objective of this study was to obtain concentrated α-linolenic acid ethyl esters from chia oi... more The objective of this study was to obtain concentrated α-linolenic acid ethyl esters from chia oil with values of chemical indicators permitted by current legislation for edible oils and its sensory quality was determined. In the transesterification reaction, sodium hydroxide catalyst concentration and alcohol: oil molar ratios were studied. The model of transesterification with artificial neural networks showed an optimum at a catalyst concentration of 0.387 g NaOH /100g oil and a 12.7:1 alcohol: oil molar ratio. The urea complexation was carried out at weight ratios urea: omega-3 fatty acid ethyl esters of 0.5:1, crystallisation at −10°C for 24 h. Molecular distillation was carried out in one and two stages, where the best results were provided by using one stage, a distillation temperature of 85°C and pressure of 1.579 × 10 −5 atm. The combination of transesterification, urea complexation and molecular distillation allowed obtaining an increase of 24.50 % of omega-3 fatty acids ethyl esters in the final product. This product contains 781.35 g/ kg omega-3, and values of free fatty acids and peroxide of 0.693 % and 1.052 meqO 2 /kg, respectively. Chia oil presents the higher values of nutty and cream flavour (positive attributes), and turbidity. In the final product these attributes diminishes considerably.
Journal of the Science of Food and Agriculture, 2019
BACKGROUND: The objective of this work was to reduce the acidity of acid corn oil for its subsequ... more BACKGROUND: The objective of this work was to reduce the acidity of acid corn oil for its subsequent use as edible oil. Also, its composition in tocopherols was determined. This oil is obtained as a by-product of corn alcohol production on an industrial scale and is currently used as a raw material in the biodiesel industry. RESULTS: The composition in tocopherols and fatty acids of acid corn oil was determined by gas chromatography and experiments of molecular distillation were carried out at different temperatures between 110 °C and 190 °C with a volumetric flow rate of 0.5 to 2 mL min-1 and a pressure of 5.10-5 atm. It was possible to reduce its acidity from 9.44% (as oleic acid) up to values less than 0.3% in the residue, with distillation temperatures higher than 180 °C; also, in the distillate the tocopherols were recovered, with concentrations up to 13360 ppm. CONCLUSION: It was possible to decrease the acidity and purify tocopherols from acid corn oil by molecular distillation, obtaining a residue with an acidity acceptable for human consumption and a distillate with a high tocopherols content. Therefore, using molecular distillation, added value was given to a by-product of the bioalcohol industry.
Journal of the science of food and agriculture, Jan 4, 2018
Anhydrous milk fat (AMF) is a valuable ingredient in several industries, but its cholesterol cont... more Anhydrous milk fat (AMF) is a valuable ingredient in several industries, but its cholesterol content is a disadvantage because it is associated with several diseases. The objective of this study was to remove the largest possible amount of cholesterol from AMF by molecular distillation and to analyze the sensory properties of the obtained product. AMF was subjected to various molecular distillation arrangements. The first set of experiments involved molecular distillations performed over a range of evaporation temperatures. Then, according to the outcome of the first set of experiments, a second set of experiments was carried out in order to study the effect of the feeding flow rate. Finally, the number of distillation stages was modified. The best results were obtained in a three-stage arrangement, in which ∼60% of cholesterol was removed with a 30.48% distillate yield. The sensory properties of this distillation cut were also the most similar to those of the untreated milk fat. © ...
Grasas y Aceites, 2017
A methodology for predicting the thermodynamic and transport properties of a multi-component oily... more A methodology for predicting the thermodynamic and transport properties of a multi-component oily mixture, in which the different mixture components are grouped into a small number of pseudo components is shown. This prediction of properties is used in the mathematical modeling of molecular distillation, which consists of a system of differential equations in partial derivatives, according to the principles of the Transport Phenomena and is solved by an implicit finite difference method using a computer code. The mathematical model was validated with experimental data, specifically the molecular distillation of a deodorizer distillate (DD) of sunflower oil. The results obtained were satisfactory, with errors less than 10% with respect to the experimental data in a temperature range in which it is possible to apply the proposed method.
Food Chemistry, 2018
The objective of this study was to evaluate the antioxidant activity of rosemary essential oil fr... more The objective of this study was to evaluate the antioxidant activity of rosemary essential oil fractions obtained by molecular distillation (MD) and investigate their effect on the oxidative stability of sunflower oil. MD fractions were prepared in a series of low-pressure stages where rosemary essential oil was the first feed. Subsequently, a distillate (D1) and residue (R1) were obtained and the residue fraction from the previous stage used as the feed for the next. The residue fractions had the largest capacity to capture free radicals, and the lowest peroxide values, conjugated dienes and conjugated trienes. The antioxidant activity of the fractions was due to oxygenated monoterpenes, specifically α-terpineol and cis-sabinene hydrate. Oxidative stability results showed the residues (R1 and R4) and butylated hydroxytoluene had greater antioxidant activity than either the distillate fractions or original rosemary essential oil. The residue fractions obtained by short path MD of rosemary essential oil could be used as a natural antioxidants by the food industry.
Separation and Purification Technology, 2015
The objectives of this study were to obtain fractions enriched in thymol by molecular distillatio... more The objectives of this study were to obtain fractions enriched in thymol by molecular distillation of oregano essential oil and to evaluate their antioxidant properties. In addition, this operation was modelled considering the effects of evaporation temperature and feeding flow on thymol concentration in the residue fractions by means of artificial neural networks (ANN). All residue fractions had a higher percentage of thymol than the distillates. The thymol composition in the residue fractions reached values up to 2.4 fold higher than in oregano essential oil. Higher concentrations of thymol produced lower values for IC 50 according to DPPH˙ technique, indicating an increase in antioxidant properties. During the storage test, all the residue fractions analysed showed better peroxide, conjugated dienes and conjugated trienes values than distillates and OEO when they were used in sunflower oil samples. The results of storage stability showed that residues and BHT are very good antioxidants. The ANN created demonstrated good predictive ability for the operation of molecular distillation of oregano essential oil.
Grasas y Aceites, 2013
Optimization of the protein concentration process from residual peanut oil-cake The objective of ... more Optimization of the protein concentration process from residual peanut oil-cake The objective of this study was to find the best process conditions for preparing protein concentrate from residual peanut oil-cake (POC). The study was carried out on POC from industrial peanut oil extraction. Different protein extraction and precipitation conditions were used: water/ flour ratio (10:1, 20:1 and 30:1), pH (8, 9 and 10), NaCl concentration (0 and 0.5 M), extraction time (30, 60 and 120 min), temperature (25, 40 and 60 °C), extraction stages (1, 2 and 3), and precipitation pH (4, 4.5 and 5). The extraction and precipitation conditions which showed the highest protein yield were 10:1 water/flour ratio, extraction at pH 9, no NaCl, 2 extraction stages of 30 min at 40 °C and precipitation at pH 4.5. Under these conditions, the peanut protein concentrate (PC) contained 86.22% protein, while the initial POC had 38.04%. POC is an alternative source of protein that can be used for human consumption or animal nutrition. Therefore, it adds value to an industry residue.
Grasas y Aceites, 2010
FSS4. The product with the highest consumer acceptance (7 = "like moderately" in a hedonic scale ... more FSS4. The product with the highest consumer acceptance (7 = "like moderately" in a hedonic scale of 9 points) was the one obtained by maceration at 100°C during 10 min and fried at 170°C for 5 min (FSS3). Proximate and fatty acid composition along with sensory attribute intensity ratings from descriptive analyses were determined on the fried-salted soybean with the highest consumer acceptance (FSS3). Proximate and fatty acid composition were also determined in raw soybeans. FSS3 had lower percentages of moisture and proteins, and higher lipids and carbohydrates than raw soybean. The use of sunflower oil in the frying process improved the fatty acid composition of the soybean product. Sensory attributes from descriptive analyses that were detected in high intensity ratings for the product were roasted, salty, crunchiness, hardness, brown color and gloss. This product is neither commonly consumed nor easily available in markets. It could be promoted to be consumed as a snack because of its high nutritional and sensory quality.
Journal of the Science of Food and Agriculture, 2009
BACKGROUND: The objective of this study was to evaluate the oxidative stability of roasted almond... more BACKGROUND: The objective of this study was to evaluate the oxidative stability of roasted almonds coated with prickly pear and 'algarrobo' pod syrups and the effect of these coatings on consumer acceptance. RESULTS: Prickly pear syrup had higher moisture, proteins, ashes and lipids, and lower carbohydrate content, than algarrobo pod syrup. Phenolics and antioxidant activity such as inhibition percentages of diphenyl picryl hydrazyl radical were higher in prickly pear syrup than algarrobo pod syrup. Roasted almonds had higher protein and lipid contents and lower total carbohydrates than coated almonds. Three main fatty acids detected in all almond products were palmitic (63.2 g kg −1), oleic (727.0 g kg −1) and linoleic (208.0 g kg −1) acids. The overall acceptance means in roasted almonds, roasted almonds coated with prickle pear syrup and roasted almonds coated with algarrobo pod syrup were 6.83, 6.65 and 6.70, respectively, on a 9-point hedonic scale. The peroxide and anisidine values increased in all products. The increase was higher in roasted almonds without coating. CONCLUSION: These results indicated that the syrup coatings provided protection against lipid oxidation in almond products. Prickly pear syrup showed better protection against lipid oxidation.
Journal of the Science of Food and Agriculture, 2010
Peanut paste and peanut butter have high oil contents and are thus susceptible to developing ranc... more Peanut paste and peanut butter have high oil contents and are thus susceptible to developing rancidity and off-flavours through lipid oxidation. Preservation of the chemical and sensory quality of these products is one of the main problems in the peanut industry. The purpose of this study was to compare the chemical and sensory stability of peanut paste prepared with high-oleic peanuts (cv. Granoleico, GO-P) with that of peanut paste prepared with normal peanuts (cv. Tegua, T-P) from Argentina. Chemical (peroxide and p-anisidine values and conjugated dienes) and sensory (roasted peanutty, oxidised and cardboard flavours) indicators of lipid oxidation were measured in peanut pastes stored at 4, 23 and 40 °C. Chemical indicator values and oxidised and cardboard flavours showed lower increments in GO-P than in T-P during storage. T-P had significantly higher peroxide value than GO-P. Roasted peanutty flavour showed a lower decrease in GO-P. Peanut paste prepared with high-oleic peanuts had four (at 4 °C), two (at 23 °C) and three (at 40 °C) times longer shelf-life than peanut paste prepared with normal peanuts. These results indicate that high-oleic Granoleico kernels provide peanut paste with higher protection against lipid oxidation.
Educación Física y Ciencia, 2007
Proyecto académico sin fines de lucro, desarrollado bajo la iniciativa de acceso abierto Palabras... more Proyecto académico sin fines de lucro, desarrollado bajo la iniciativa de acceso abierto Palabras clave: Opinión. Experiencia. Evaluación. Proceso evaluativo. Cultura evaluativa. Tradición. Política. Normativa.
Journal of the American Oil Chemists' Society, 2008
The objective of the research was to characterize the quality of damaged and undamaged jojoba see... more The objective of the research was to characterize the quality of damaged and undamaged jojoba seeds. The study was performed on jojoba seeds grown in La Rioja, Argentina. Proximal composition, fatty acid composition, acid value, peroxide value, conjugated dienes and trienes and protein electrophoresis profiles were determined in undamaged (JS) and damaged jojoba seeds (DJS). The fat content (wax) was lower in DJS (39.11%) than in JS (50.82%). The values of acid, peroxide, conjugated dienes and trienes were higher in DJS than in JS. No difference in fatty acid composition was observed between DJS and JS. The protein content was not significantly different between JS and DJS. However, DJS had lower soluble protein values. In the electrophoresis profiles, the band located at 50 kDa disappeared in DJS and the intensity of the band located at 25 kDa decreased. The deterioration process in jojoba kernels significantly affects the chemical quality of their proteins and waxes.
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Papers by Maria Fernanda Gayol