AROMA AND FLAVOR

Author: JURADO GARCÍA-POSADA ÁNGELA.
Year: 2004.
University: EXTREMADURA [www.unex.es].
Place of defense: FACULTAD DE VETERINARIA.
Place of preparation: FACULTAD DE VETERINARIA.

Summary: That argument was raised with the aim of contributing to the understanding of how changes in the raw material can affect the flavor of Iberian ham and how it related parameters flavor evolve during maturation. That left 80 perniles coming pure Iberian pigs belonging to two different batches depending on the food received in its infancy bait (the batch included mountain hams from pigs regime exploited in mountain and the lot to think hams from pigs pilot and samples were taken at different times of trial: end-postsalado (day 120), end of a dryer (day 230), bodego (day 361 and day 516) and the final product (day 722). Developments in both batch was very similar both in physical and chemical parameters in the various fractions microgenadas, in the lipid fraction and the volatile compounds, with the key stage of a dryer in the process of development, especially for the development of flavor, and that favors the beginning of Maillard reactions and Strecker. Study of volatile compounds could allow monitoring of the maturation of Iberian ham: hams with a greater degree of maturation were characterized by fewer compounds from oxidation and more compounds Strecker and Maillard. Specifically, the volatile compounds bencenometanol, 2-metilpropanal, 2 + -metibutanal, 2-metil-1-butanol, dimetildisulfuro and coelución consisting of the compounds 2,6-dimetilpiracina and dihidro-2 (3 H) -furanona would be good indicators of the duration of the trial. addition, it has been shown that the free amino acids are closely linked to the flavor, including glutamic acid, whose concentration was higher in the mountain hams also include free amino acids precursors of volatile compounds, a fact that is reflected in the evolution experienced by free amino acids and compounds Strecker and Maillard during maturation of Iberian ham. Moreover, the administration of feed rich in oleic acid has managed to imitate the profile fatty acids majority of intramuscular fat pigs fed mountain. Nevertheless, among hams from pigs fed with this feed and fed mountain are still differences that mainly affect the flavor and odor characteristics of which confirms that it is not only intramuscular major fatty acids which influence the formation of compounds involved in these features.

Author: SENTANDREU VICENTE ENRIQUE.
Year: 2005.
University: VALENCIA [www.uv.es].
Place of defense: I.DE AGROQUÍMICA TECN.DE LOS ALIMENTOS.
Place of preparation: INSTITUTO DE AGROQUÍMICA Y TECNOLOGÍA DE LOS ALIMENTOS.

Summary: The cultivation of citrus in the area of Valencia is a basic pillar of the economy of the region, sharing the bulk of the production of citrus orange (Citrus sinensis) and the mandarin (Citrus reticulata). Traditionally, the orange production has been higher than in mandarin but, in response to developments in recent years, the cultivation and production of mandarin in Spain has increased to reach or even exceed that of orange, as in the Valencia. Under this new situation, the surplus mandarins for fresh consumption increase year after year, creating a new problem that must be resolved urgently. One of the possible solutions to this new situation is the proposal by the Ministry of Agriculture, Fisheries and Food of the Generalitat Valenciana, which suggests devoting 20% of the production of mandarin Valencian towards obtaining industrial high quality juice . This situation coupled with that Spain is the leading exporter of fresh mandarins in the world, makes the Spanish tangerine juice can be an interesting product from the commercial point of view. On the other hand, there are numerous references on the beneficial properties that have juice from citrus varieties. Some of these properties are provided by its content type flavonoid compounds, which have been the subject of numerous studies, showing his activities as antimicrobial agents, agents that prevent diseases caridovasculares, agents and even antiallergics have been reported activities anticancerígenas. In addition to these individual actions of the flavonoids, citrus juices are going to be characterized by a high capacity antiradical, thus preventing the emergence of many degenerative diseases. Despite extensive awareness about the flavonoids in citrus juices, it has not been proposed so far, any methodology oriented characterization and classification of different varieties of mandarin through the flavonoid content of their juice. Therefore, the objectives it seeks to achieve, in this regard, this thesis can be summarized as follows: 1 .- To develop a method of analysis that allows the simultaneous determination of the main comupuestos type flavonoid present in juice mandarin (glycosides of flavanona and flavones polimetoxiladas). This methodology is based on measurements obtained by high performance liquid chromatography. 2 .- Characterization juices based on the profiles obtained from the flavonoid content. From these profiles, it is necessary to define those parameters that are characteristic for each variety, in order to be used as a useful tool for characterization. 3 .- Determination of the adequacy of the characterization parameters defined, even when the juices have been subjected to various processes of collection, processing and storage. Moreover, as in the case of flavonoids, the ability of antiradical citrus juices has also been extensively studied, mainly through the tracking of the process of reducing a stable free radical measures through commercial espectrofotométricas. One of this methodologies employed by the free radical 2,2-difenil-1-picrilhidracil (DPPH). However, as is right now, this methodology can be described as unsatisfactory for the following reasons: 1 .- Because it is not published any approximation theory about 8 of the ci 135c nética reduction by DPPH bioactive species present in the juice, there is no standard definition of such activity. As a result, empirical studies are kind of different authors have defined a parameter "ad hoc" to quantify the antiradical activity, in accordance with their needs. 2 .- The parameters defined, so far, to quantify activity antiradical (EC50, 1 / EC50, 1 / EC50 * TEC50) are, moreover, very difficult to determine experimentally because they require the determination of the value of asíntota of reaction. It must be remembered that for a citric juice, for example, duration of the reaction may exceed 3 hours, with the problems of instability instruments and reagents that this entails. In addition, no time can be shorter, because it does not have a kinetic equation to fit the experimental data, if we want to measure the value of asíntota accurately. 3 .- The parameters for quantifying published antiradical activity provide no information about the speed of kinetics. However, the biggest problem lies in providing a value of the overall antiradical activity of the sample being tested. In a citric juice, for example, coexisting with different components antiradical activity. The most abundant is the ascorbic acid, which exhibits a very fast kinetics, but also are flavonoids, carotenoids and derivatives = cinnamic acid, which, despite having some kinetic slower and are much lower concentration, are also very antiradicals powerful. We know, moreover, that the properties of the latter bioactive compounds are different from those of ascorbic acid. What is needed, therefore, is a methodology that provides not only the antiradical activity of a citric juice, but also the relative contributions of the principal bioactive agents present. Taking into account the foregoing so far and to the theoretical limits raised, the aims of this doctoral thesis in this regard can be summed up as: 1 .- To conduct a theoretical approach on the kinetics of reduction by DPPH part of tangerine juice and its components. As a result of this study, it has to obtain a single parameter that defines the antiradical activity, both in complex biological matrices of single species, which can be used regardless of the type of objectives to be achieved. 2 .- Once known kinetics reduction DPPH, this can be defined through a kinetic equation, which must conform perfectly to the experimental results obtained. This expression has to be able to predict the value of asíntota reaction necessary for the determination of antiradical activity, using for this purpose, reasonable response times. This will be achieved avoid any deviations analytical caused by the lack of stability instrumentation and reagents over time. 3 .- The kinetic equation obtained in addition to providing the calculation of the total activity antiradical juice, it should indicate what the partial contributions of different bioactive components present in this complex biological matrix, and indicate in particular, speed the kinetics of each of these components. It will explore further the possible connection that may exist between the contribution antiradical particular components present in the juices and its contents in them. Thus, although the proposed methodology is geared towards determining the activity of antiradical citrus juices, this in turn can be used as a tool for quantitative analysis. 4 .- It will assess whether the characteristics antiradicals of tangerine juice, can be useful in carrying out studies for the characterization and classification varietal. 5 .- Finally, consider the changes suffered by the ability of antiradical tangerine juice when they have been subjected to various processes of collection, processing and storage

Author: GARCÍA GONZÁLEZ DIEGO LUIS.
Year: 2005.
University: SEVILLA [www.us.es].
Place of defense: INSTITUTO DE LA GRASA - CSIC.
Place of preparation: FACULTAD DE FARMACIA.

Summary: The aroma is property that sensory further characterizes the food and determines the acceptability of consumers. Because of its importance and the information it provides enormous, the food industry has always tried to get an objective measure of smell. Traditionally, evaluation of the flavor is carried out via a panel of tasters or experts or consumers. However, the tasting panel, has the disadvantages of being an expensive method, can not be applied on a routine basis, and in some cases, have a subjective component that is difficult to remove. An alternative is the identification and quantification of volatile compounds by gas chromatography, this method offers a wealth of information about the flavor of food, but has the disadvantages of being a technical expensive reagents consuming and can not be applied online. A second panel cta alternative is the use of gas sensors that generate a rapid response when exposed to the aroma of food. Methodologies based sensor systems do not use any sample pretreatment, are non-destructive techniques and information is easy to interpret. The main objective of this thesis was to evaluate all the potential of sensor systems or electronic nose in the evaluation of the sensory quality of fatty foods, in particular its flavor, developing new methods of analysis that could serve as a method of analysis routine complementary to the sensory analysis by tasters. It has carried out the development of a sensor system for the analysis of the flavor of fatty foods. In order to establish relations between the responses of sensors metallic oxides and the presence of volatile compounds responsible for flavor, it has developed a procedure based on coupling GC-nariz electronics. Compounds scent of virgin olive oil producing high responses sensors are ethanol, hexanal (E) -2-hexenal, 1-pentanol, 6-metil-5-hepten-2-ona, acetate hexilo and acetate (Z) -3-hexenilo, 1-hexanol, (Z) -3-hexen-1-ol, (E) -2-hexen-1-ol and acetic acid. In analyzing the scent of cured ham, sensors showed greater sensitivity to 3-metilbutanal, hexanal, 2,3-butanodiona, 3-metil-1-butanol, hexanol, limonene and acid isobutírico. There has been a rapid detection of defects sensory virgin olive oil with an array of sensors MOS, besides obtaining a correct classification of each attribute negative (98% classification). There have been two models of classification based on the response of MOS sensors to distinguish virgin olive oils and non lampante lampante; being the percentages of correct classification of 89% (using discriminant analysis) and 94% (using neural networks). The sensors used in the model showed sensitivity to the volatile compounds responsible for the sensory defects. Similar results were obtained (= 90%) when the time of the study with a SAW sensor system and a system of olfacción artificial based on the direct coupling of head space and dynamic mass spectrometry (DHS-MS). Moreover, it has obtained a grading scale of pasta and olive flight soil classification percentages of 100% in the samples training and 95% in the validation sample. It has extended the implementation of the MOS sensor system based on the differentiation of hams cured depending on the type of pork (Iberian vs.blancos), not obtaining errors in the classification. Lastly has designed a prototype electronic nose based on MOS sensor low cost for the analysis of the flavor of fatty foods, which has been the subject of a patent industry. This prototype incorporates novelty include a prerequisite for separation of volatile compounds, a profile Breeders response sensors which offers more information than conventional systems.

Author: DOS ANJOS PIMENTA MARQUES MAIA FERRO PALMA SILVINA.
Year: 2005.
University: EXTREMADURA [www.unex.es].
Place of defense: VETERINARIA.
Place of preparation: VETERINARIA.

Summary: The work of this Doctoral Thesis have approached objectively assess the influence on the quality chemical and sensory loins produced using two different processes, smoking greatly appreciated in Portugal in this type of product and drying tradition in Spain. Moreover, it has made the study of the processes degradativos of proteins and lipids and changes in the physical properties that occur during maturation. The differences between the two technologies do not affect the main features of spine healed, appreciate slight differences in color, aroma and flavor in the sensory evaluation that do not translate into a higher level of acceptance by consumers in either rates of loins. They are notable effects of smoke on the increase in nitrates and protective agent against oxidation and microbial growth. The results of individual determinations in the two types of processing were similar along the accused however we found some significant differences as the CRA that presents different developments in the loins and dried in the loins ahumanos. Also ash, the percentage of clorudos and salt nitrifying higher values in the loins smoked in the game. The spine smoking, physico-chemical and sensory characteristics very similar to the spine healed but drying are remarkable pieces delas hardness greater and greater smell smoke which coincides with a lesser degree of protein degradation and increased formation of volatile compounds. The loins processed by the two technologies presented only traces of PAHs, not found in higher amounts in their loins smoked, as you might expect. These may be due to the manner of implementation of smoke that is not conducive to the deposit of these compounds in trace amounts with the technique used, but if the deposit of other volatile compounds. The other group of compounds of potential risk to the consumer as are the nitrifying salts are significantly increased in the case of smoked loins but completely satisfied with safety standards.

Author: VENTANAS CANILLAS SONIA.
Year: 2005.
University: EXTREMADURA [www.unex.es].
Place of defense: VETERINARIA.
Place of preparation: VETERINARIA.

Summary: The objectives of this Doctoral Thesis were: 1, - Knowing the influence of genetics (Race Iberian versus Crusaders with Duroc and Crusaders mother Duroc versus Crusaders mother Iberian), and food during the bait (commercial feed, feed fortified with high oleic sunflower and supplemented with alfa-tocoferol and mountain) in areas related to the quality of the raw material (longuissimus dorsi) and the spine healed, mostly those determined by the content and features of the intramuscular fat. 2-To assess the usefulness of different alternatives and / or complementary to the formal method established by the Quality Standard for the classification of raw materials in terms of food received by the animals during the bait. 3-Establish the influence of genetics and nutrition act protein and lipid oxidation longissimus dorsi muscle and spine healed. 4, - Knowing the effect of genetics and nutrition, and the intramuscular fat content, have on the characteristics of cured pork loin Iberian and on the consumer preference for this product. 5-To assess the formation of volatile compounds derived from the degradation of strecker in model systems that include phospholipids longissimus muscle doris Iberian pork in a position similar to the maturation of a meat product and in the absence of microorganisms. 6-Know the content GIM influence on the formation and dynamics of the release of volatile compounds during the period of maturation of cured pork loin Iberian. 7, - Knowing the effect of genetics and feed in the profile of volatile compounds of loins cured Iberian pigs without adobo.

Author: CARBONELL ADROVER LEIRE.
Year: 2006.
University: VALENCIA [www.uv.es].
Place of defense: INSTITUTO DE AGROQUIMICA Y TECNOLOGIA DE ALIMENTOS.
Place of preparation: FACULTAD DE FARMACIA / INSTITUTO DE AGROQUÍMICA Y TECNOLOGÍA DE ALIMENTOS.

Summary: The fundamental objective of this thesis is to study the conditions of the raw material and the process of development to get juice chilled Mandarin high quality. The main conclusions were obtained are as follows: I.