FSFB, 3rd International Congress, 14-17 October, 2008, Querétaro
FP-01 Production of crystallized pear (var. D´anju) using osmotic dehydration Manivel, R. A; Yahuaca, J. B. Laboratorio de Análisis de Alimentos, Laboratorio de Biotecnología Facultad de Quimicofarmacobiología, Universidad Michoacana de San Nicolás de Hidalgo Calle Tzintzuntzan #173 Col. Matamoros, Morelia Mich. México E-mail: ramch03hotmail.com
Osmotic dehydration represents a technological alternative to reduce post-harvest losses of fruits. The objective of this work was to study the influence of the concentration of the osmotic agent (sucrose) and the temperature on the osmotic dehydration of pear fruits. For the study pears var. "D´anju" were obtained from the local market, selected, peeled, sliced quarters and immersed in osmotic solution (sucrose syrup of 50° and 60° Brix) at 70°, 80°and 90°C. The pieces were removed after 30, 60, 120, 180, 240, 300, 360, 420 y 480 min. The variables studied were solute gain (GS), water loss (PA) in fruits and °Brix reduction in the syrup. For all treatments, water loss and solids gain increased at significant level in the high concentration solution (60°Brix) and high temperature (90° C). The highest PA, and GS were obtained in shorter time when the pear immersed was at 60°Brix at 80° and 90°C than with 50°Brix at all temperatures. The observations of the present work about GS and PA allow concluding that the concentration of the syrup and the temperature influences the process of osmotic dehydration of pear. In all cases the water loss was more important than the solids gain.
(keywords: Osmotic dehydration; water loss; solids gain; temperature; concentration)
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FSFB, 3rd International Congress, 14-17 October, 2008, Querétaro
FP-02 Effect of Osmotic Dehydration on the Quality of a Banana Snack Product Tapia-Molina, A. R., Calderón-Santoyo, M. Luna-Solano, G. and Ragazzo-Sánchez, J. A. 1
Instituto Tecnológico de Tepic. Laboratorio Integral de Investigación en Alimentos. Av. Tecnológico No. 2595 C.P. 63175. Tepic, Nayarit, MÉXICO, Tel. (311) 213 15 43. 2 Instituto Tecnologico de Orizaba, Division de Estudios de Posgrado e Investigacion, Av. Oriente 9 no. 852, Orizaba, Veracruz, 94320
[email protected]
Osmotic dehydration was examined as a pretreatment before frying in order to produce a fried banana snack with a low fat content. A relationship between dehydration kinetics as well as frying kinetics and the type of solution used for osmotic dehydration before frying of banana snacks has been developed to demonstrate that oil uptake during frying is a direct function of water content. The effect of osmotic dehydration on sensory properties (flavor and texture) and microbiological quality (aerobic bacterial, fungal, and yeast counts) of the banana snack was also investigated. Sugar solutions at two concentrations (40° and 60 °Bx) and 3 soaking times (2, 4, and 6 h) were used. Results showed that osmotic drying pretreatment significantly reduced oil uptake in banana snacks during frying and sensory properties were improved. The osmotic treatment also maintained the good microbiological status of the product.
(keywords: Osmotic dehydration, frying, banana snack)
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FSFB, 3rd International Congress, 14-17 October, 2008, Querétaro
FP-03 Evaluation of Ohmic Heating Processing Parameters on Nixtamalized Corn Flour Quality Gaytán-Martínez, M., Figueroa-Cárdenas, JD., Vázquez-Landaverde, P., Morales-Sánchez, E. Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional. Libramiento Norponiente No. 2000. Real de Juriquilla. C.P. 76230. Querétaro, Qro. México. *
[email protected]
Nixtamalization (alkaline cooking) is the primary step in the production of products such as corn chips, corn tortillas and tortilla chips. The process involves cooking and steeping of corn in excess water with lime added to produce nixtamal. Commercial nixtamalization results in 5–14% corn solids loss in the liquid effluent generated during cooking-steeping and washing. Loss of corn solids not only causes economic loss to corn processors but also creates costly waste and wastewater disposal problems. Ohmic heating works by passing an electric current through the food causing internal heat generation. The objective of this work was to assess which ohmic heating process parameters had a greater impact on the quality of nixtamalized corn products. The independent variables analyzed were particle size (0.5 and 0.8 mm), moisture content (50 - 70%), lime concentration (0-0.4%), voltage (80 - 110 V) and the final cooking temperature (90 – 110 °C). Three main products were obtained: flour, dough and tortillas. For flour and dough, water-absorption capacity and viscosity were measured; while yield, texture and moisture content were measured for tortillas. Results showed that moisture, final cooking temperature and voltage were the most significant factors ( =0.05) influencing product quality. The response variables more affected by the process were viscosity, moisture and yield. It was concluded that ohmic heating is able to produce nixtamalized corn products with good quality, having great potential to be used in the corn processing industry.
(key words: nixtamalization, ohmic heating, corn products.)
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FSFB, 3rd International Congress, 14-17 October, 2008, Querétaro
FP-04 Determination of Reducing Sugars in Selected Variants of Agave mezcalero (Agave duranguensis) from the Southeast of Durango Cifuentes, D. L. A.; Gómez, O. S; Hernández, V. V. Biotecnología y alimentos, CIIDIR-IPN, Unidad Dgo. Sigma s/n Fracc. 20 de Noviembre II C. P. 34220 Durango, Dgo. México. e-mail:
[email protected].
The production of mezcal is made from Agave at southeast of Durango. Frequently, Agave has strong variation in total reducing sugars, weight of head and time of maturation, these differences make to vary the volume and quality of mezcal from lot to lot. To determine the variation of weight of heads and their total of reducing sugars, three localities were selected: Ejidos El Caliche, Los Olagues y Los Ojitos from Nombre de Dios, Durango. The sample was obtained from 513 agaves (heads) from Ejido El Caliche, to determine the variation of weight (kg) of agaves used to produce mezcal. The determination of total reducing sugars was conducted on samples from 17 selected agaves in Ejidos El Caliche, Los Olagues y Los Ojitos. It was found that 66.1% of the agaves used to produce mezcal, oscillate between 6.9 and 18.8 kg, whereas agaves with weights of 30.7 to 54.6 kg only constitutes 28% and finally, agaves of 66.4 to 233 kg only represent the 5.9%. Statistical differences were found related to reducing sugars, in the heads sampled from different selected sites. The total reducing sugars concentration presented a variation 8 to 26%. The greatest reducing sugars concentration for the head harvested was in Ejido Los Olagues with 22.5% and Ejido Ojitos de Moreno with 22.3%. The average of total reducing sugars from three ejidos was 17.6%. In conclusion, the relation found between weight and total reducing sugars was, agaves with weight of 70 to 233 kg, had total reducing sugars from 13 to 16%, whereas agaves of 25 to 60 kg had a concentration from 8 to 26%.
(keywords: cenizo, mezcal, Agave duranguensis)
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FSFB, 3rd International Congress, 14-17 October, 2008, Querétaro
FP-05 Evaluation of stability and production of carbon dioxide in mother doughs and direct doughs from strong flours Gómez, O. S.; Orea, L. G.; Hernández, V. V. a
Biotecnología y alimentos, CIIDIR-IPN, Unidad Dgo. Sigma s/n Fracc. 20 de Noviembre II C. P. 34220 Durango, Dgo. México.Correo-e:
[email protected].
The study of rheology of baking doughs is important for wheat trading, flour quality and its transformation into bread. Bakers can standardize the phases of baking process, but it is necessary to have the knowledge about stability of doughs, CO2 retention capacity and volume that doughs can develop, because these properties are directly related to the quality of bread. In this work the stability and production of CO2 from baking doughs were evaluated using different percentages of mother dough and direct dough. The flour used in this work was Turbo remix 40 of good baking quality. The fermentation time of mother dough was 3 h, 6 h and 9 h. The mother dough percentages used were 100, 75, 50, 25 and zero, the complement was direct dough; the developing dough and its CO2 production were evaluated to each sample. The rheofermentograms were obtained in the Rheofermentometer F2 showed important parameters such as maximum height (Hm), height of second fermentation (h), time, maximum volume, height of bread (T1), time to end of the test (T2), maximum height of gaseous detachment (H‟m), maximum time of gaseous detachment (T‟1), time where the curves are separeted ((Tx), total volume of CO2 (Vt), lost volume (Vp), retained volume (Vr), and retention coefficient (Cr). A completely randomized design with a factorial arrangement was used. The data obtained were analyzed by means of analysis of variance, with p≤0.05 and comparison of means by the Tukey test. The best rheological treatment of dough was obtained when 25% of mother dough, fermented during 6 h, at 25°C, 70% relative humidity and 75% direct dough were utilized. With a CO2 retention coefficient of 96.8%, volume of dough was considered as very good, showing good stability.
(keywords: flour, rheofermentograms, rheology).
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FSFB, 3rd International Congress, 14-17 October, 2008, Querétaro
FP-06 Effect of Hot Air Drying on Quality Parameters of Pulp of Lychee (Litchi chinensis Sonn) Fruit Castro-Ahumada, J. O., Carrillo-López, A., Caro-Corrales, J. J., and Zazueta-Morales, J. J. Maestría en Ciencia y Tecnología de Alimentos, Universidad Autónoma de Sinaloa, Apdo. Postal 1354, CP 80000, Culiacán, Sinaloa, México. Corresponding:
[email protected].
Ninety eight percent of Mexican Lychee (Litchi chinensis Sonn.) fruit is commercialized as fresh fruit, but the highly perishable nature of the fruit produces very high postharvest losses (about 50%). It is very important to study new alternatives to process this fruit. The objective of this work was to study the effect of drying temperature (60, 70, and 80°C) on the dried pulp quality (bulk density (BD), shrinkage, water adsorption (WA), water activity (aw), and total color difference (E)) and engineering parameters (mass transfer coefficient (kY) and effective diffusivity (Deff)). The whole fruit was blanched, peeled, cutted and dried, the experiment was carried out at a constant air velocity (1.45 m/s) using a laboratory convective tray drier, the air was heated using liquified petroleum gas (LPG). Effective moisture diffusivity was estimated using the finite element method (FEM) because the shape of the fruit was irregular, and the results were analyzed as mean values with standard deviations. Differences between mean values were established using Fisher‟s test Values were considered at 95% level of significance (p
