Cibele Cristina Osawa

Titulação potenciométrica aplicada na determinação de ácidos graxos livres de óleos e gorduras comestíveis

Free fatty acids are a measure of evaluating fats and oils, submitted to abusive conditions, besides being a quality characteristic of edible vegetable oils. The official method of determination (AOCS Ca 5a-40, 2004) is based on titration, using phenolphthalein as an indicator. For crude and degummed oils, the titration end point is difficult to be observed due to the high level of pigments, resulting in dark solutions. In this case and others, such as self-life studies, in which sample quantities are limited, potentiometric titration may be a very good alternative.

Evaluation of the quality of pet foods using fast techniques and official methods

This paper was designed to evaluate the rancidity of 18 pet food samples using the Diamed FATS kits and official AOCS methods for the quantification of free fatty acids, peroxide value and concentrations of malonaldehyde and alkenal in the lipid extracted. Although expiration dates have passed, the samples presented good quality evidencing little oxidative rancidity. The results of this study suggest that the Brazilian pet food market is replete with products of excellent quality due to the competitiveness of this market sector.

Changes in breaded chicken and oil degradation during discontinuous frying with cottonseed oil

Discontinuous frying of breaded chicken in cottonseed oil was evaluated. Three 400 g batches of foodstuff were fried daily in a 28 L fryer at 182 °C for 4.5 minutes for 7-8 days, and the experiment was repeated three times. The total polar compounds in the oil were determined by the conventional method. Changes in the oil were determined by the quick tests Testo 265, Viscofrit and Fri-check based on physical constants, and the results were compared with those of total polar compounds obtained by the conventional method. The free fatty acids, conjugated dienes, Lovibond color, oxidative stability, fatty acid composition, and polymeric compounds were also determined. During frying, the oil samples presented 6.0-39.2% total polar compounds, 0.0-12.9% polymerized triacylglycerols, 1.3-14.5% oxidized triacylglycerols, 2.8-11.0% diacylglycerols, and 1.6-2.6% fatty acids and unsaponifiable polar compounds. The breaded chicken samples lost moisture, absorbed oil up to approximately 6%, and there were small changes in the fatty acid composition and low formation of trans-isomers. The best method for monitoring and discarding the oil was that used for the determination of total polar compounds.

Avaliação do perfil sensorial de chá light sabor pêssego

In this work, three different brands of light peach iced tea (A, B and C), purchased in a local market and packed in PET bottles were sensory analyzed. At first, Quantitative Descriptive Analysis (QDA) was conducted in order to obtain the sensorial profile, with eleven tasters, previously selected and trained. The product acceptance was evaluated by 33 consumers, representing the target public. The QDA results were submitted to ANOVA, Tukeys test and Principal Component Analysis (PCA). The sample A was mainly characterized by banana aroma and flavor; the sample B by artificial peach aroma and refreshment; while the sample C by sweetness and natural peach aroma. The acceptance test, analyzed by ANOVA and Tukeys test, showed a greater acceptance for the sample C. The colour of the samples was evaluated by the Cielab L*a*b* method and the sample C stood out by the red colour.

Deep-fat frying of meat products in palm olein

Este artigo estudou a fritura descontinua de alimentos carneos empanados em oleina de palma em uma fritadeira eletrica de 28 L, mantida a 182 oC durante 8 horas por dia. Diariamente, tres bateladas de 400-500 g de alimentos carneos foram fritos durante 4,5 minutos. Para comparacao, foram conduzidos testes de termoxidacao com a adicao de material inerte com umidade adicionada e sem a adicao de alimentos (apenas aquecimento). O teor de compostos polares totais nao atingiu o limite de 25% e a formacao de compostos polimerizados tambem nao ultrapassou 5%, refletindo a boa performance da oleina de palma para frituras. Outros parâmetros analiticos, assim como testes rapidos, foram avaliados. Os atributos sensoriais, tais como odor, cor e formacao de fumaca, determinaram quando o oleo de fritura deveria ser descartado. A adicao de agua ao material inerte contribuiu para um valor final de 1,00 ± 0,01% (em acido palmitico), enquanto que o oleo submetido apenas a aquecimento atingiu 0,26 ± 0,02% e os oleos usados na fritura de carne empanada e frango empanado, 0,38 ± 0,00% e 2,35 ± 0,01%, respectivamente. Isso sugere um efeito protetor da agua durante a fritura, pois o oleo submetido apenas a aquecimento foi mais susceptivel a degradacao.This study investigated the discontinuous frying of breaded meat products in palm olein in a 28 L-electric fryer maintained at 182 oC for 8 hours a day. Three 400-500 g batches of meat products were fried for 4.5 minutes daily. For comparison purpose, thermoxidation tests were performed using inert material with added moisture and without the addition of f ood (heating only). The total polar compound content did not reach the 25% limit, and nor did the formation of polymerized products exceed 5%, which indicates the good frying performance of palm olein for frying. Other analytical parameters and rapid tests were also evaluated. The sensory attributes, such as odor, colour, and foam formation determined when the frying oils should be discarded. The addition of water to the inert material contributed to the final value of 1.00 ± 0.01% (in palmitic acid), while the oil subjected only to heating reached respectively 0.26 ± 0.02%, and the oils used to fry breaded meat and breaded chicken reached 0.38 ± 0.00% and 2.35 ± 0.01%, respectively. This suggests a protective effect of the water during frying since the oil subjected only to heating was more prone to degradation.