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Previous issue date: 2007-12-01 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / In this work deals with the quality of vegetable oils. Thus, refined oils from soybean
(Glycine max L), both conventional and transgenic, and the crude and refined oils of
nhandiroba (Fevillea trilobata L) were investigated. All the oil samples were studied
before, during and after the frying process. The oxidative process of these oils was
also quantified. With this purpose, the vegetable oils were submitted to the
temperature (180 ± 50 oC) in recipients of glass, aluminum, iron and stainless steel.
The oil samples were collected in aliquots of 10 ml each, at time intervals of 0, 8, 24,
48 and 72 hours. The analyses of acid value, iodine value, peroxide value, panisidine
content and color were carried out. The quantification of the iron and
aluminum ions was undertaken by atomic absorption. The quantification of a-
tocopherol in crude nhandiroba oil was determined by HPLC. The thermal stability of
the oils was assessed using the thermogravimetric curves and the chromatograms of
the studied oil samples. The toxicological properties were evaluated; as well
organoleptic tests were performed. In vivo laboratorial tests studied the icthyotoxicity
in Poecilia reticulata L. alevins and the cytotoxicity in Artemia saline L. larvae. In the
sensorial analysis hedonic tests were applied and the following attributes were
appraised: aspect, flavor, scent and texture of chicken and fish croquettes. The
croquettes were fried in recipients of glass, utilizing refined conventional soybean and
nhandiroba oils. The results showed that all the oils investigated during the 72 hours
of frying, in the four types of recipients, displayed increasing figures of peroxide
value, p-anisidine content and color. The acid value varied, whereas the iodine value
decreased. The vegetable oil made from conventional soybean presented important
oxidative alterations, when submitted to a heating time of 72 consecutive hours in the
four different types of frying recipients. In the recipients of iron and stainless steel,
such differences were larger than in the aluminum and glass recipients. The results
of the transgenic soybean oil, crude and refined nhandiroba oils showed mild
oxidative modifications in all the four types of recipients tested. In the frying process,
the physico-chemical properties of the vegetable oils influenced the sensorial profile
of the victuals. It was observed for the sensorial property aspect that there was no
meaningful difference between the two oil types, in other words, the aspects of the
fried croquettes in the two oils were considered to be the same. In the evaluation of
the attributes scent, texture and flavor, it was noticed, for the chicken croquettes, a
difference between the two oil types. The conventional soybean oil was better
accepted, obtaining the best notes. In the frying of the fish croquette, the nhandiroba
oil displayed the best sensorial characteristics. Therefore, in the frying process the
cooking recipients of glass, aluminum, iron and stainless steal exert a deleterious
influence on soybean oils, as well as on nhandiroba oils. The iron recipient is the one
that provokes the largest oxidative effect and the glass recipient the one with the
smallest oxidation damage. These alterations, which took place in the investigated
oils, influence their quality. / Nesta pesquisa foi analisada a qualidade dos óleos refinados de soja (Glycine max
L.) convencional e transgênico (MSOY 8866RR) e do óleo bruto e refinado de
nhandiroba (Fevillea trilobata L.) antes, durante e após os processos de frituras e
também foram quantificados seus processos oxidativos. Os óleos foram submetidos
à temperatura (180 ± 50C) em recipientes de vidro, alumínio, ferro e inox. As
amostras de óleos foram coletadas em volumes de 10 mL cada, nos intervalos de
tempo de 0, 8, 24, 48 e 72 horas. Nas amostras dos óleos foram realizadas análises
de índice de acidez (IA), índice de Iodo (II), índice de peróxido (IP), valor de panisidina
(VA) e cor. A quantificação dos íons ferro e alumínio foi realizada através
de absorção atômica. A quantificação de a-tocoferol foi realizada no óleo de
nhandiroba bruto por HPLC. O estudo da estabilidade térmica foi verificado através
das curvas termogravimétricas e dos perfis cromatográficos dos óleos. Ainda, foram
realizados estudos das propriedades toxicológicas e avaliações organolépticas dos
óleos. Os testes laboratoriais in vivo de ictiotoxicidade sobre alevinos Poecília
reticulata L. e citotoxicidade sobre larvas de Artemia salina L. foram realizados nos
óleos. Na análise sensorial foram aplicados testes hedônicos para os atributos:
aspecto, sabor, odor e textura em croquete de frango e de peixe, em recipiente de
vidro nos óleos refinados de soja convencional e de nhandiroba. As análises dos
resultados mostraram que, os óleos pesquisados durante as 72 horas de fritura nos
quatro tipos de recipientes utilizados apresentaram taxas de IP, VA e cor crescentes,
variação no IA e valores decrescentes de II. No óleo de soja convencional foram
ocorridas alterações oxidativas relevantes, quando submetido ao tempo de
aquecimento de 72 horas consecutivas nos quatro diferentes tipos de recipientes de
fritura, sendo que em recipiente de ferro e inox essas alterações foram maiores do
que em recipientes de alumínio e vidro. Nas análises dos óleos de soja transgênico,
nhandiroba bruto e refinado foram verificadas modificações oxidativas brandas nos
quatro tipos de recipientes testados. No processo de fritura, também, foi observado
para a propriedade sensorial aspecto, que não houve diferença entre os croquetes
de frango e peixe. Na avaliação dos atributos odor, textura e sabor, foi constatado
que na fritura do croquete de frango foi registrado diferença entre os tratamentos, o
óleo de soja convencional foi mais aceito, obtendo as melhores notas. O croquete de
peixe frito no óleo de nhandiroba apresentou as melhores características sensoriais.
Portanto, no processo de fritura os recipientes de vidro, alumínio, ferro e inox
exercem diferentes efeitos deletérios nos óleos de soja e nhandiroba, sendo o
recipiente de ferro o que provoca maior efeito oxidativo no óleo e o de vidro, o menor
dano de oxidação. Estas alterações ocorridas nos óleos pesquisados influenciam na
sua qualidade.
| Identifer | oai:union.ndltd.org:IBICT/oai:tede.biblioteca.ufpb.br:tede/4020 |
| Date | 01 December 2007 |
| Creators | Freitas, Lindeberg Rocha |
| Contributors | Paulo, Marçal de Queiroz |
| Publisher | Universidade Federal da Paraíba, Programa de Pós-Graduação em Ciência e Tecnologia de Alimentos, UFPB, Brasil, Química e Bioquímica de Alimentos |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/doctoralThesis |
| Format | application/pdf |
| Source | reponame:Biblioteca Digital de Teses e Dissertações da UFPB, instname:Universidade Federal da Paraíba, instacron:UFPB |
| Rights | info:eu-repo/semantics/openAccess |
| Relation | -3168359563433608541, 600, 600, 600, 600, -6862012265378275791, -7636512811479495338, 2075167498588264571 |
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