Flavour Components and the Effects of Organic Acids Washing on the Earthy Flavour and Physical Attributes of the Black Tilapia (O. Mossambica) Fillets

The selection and training of panelists for identification of earthy attributes in wild black tilapia was carried out using triangle test and Quantitative Descriptive Analysis procedures. Training was carried out in three stages. The first stage was the introduction to fish flavour characteristic...

Full description

Saved in:
Bibliographic Details
Main Author: Ahmad, Nurul Izzah
Format: Thesis
Language:English
English
Published: 2000
Subjects:
Online Access:http://psasir.upm.edu.my/id/eprint/8417/1/FSMB_2000_5_IR.pdf
Tags: Add Tag
No Tags, Be the first to tag this record!
id my-upm-ir.8417
record_format uketd_dc
spelling my-upm-ir.84172024-01-15T03:23:31Z Flavour Components and the Effects of Organic Acids Washing on the Earthy Flavour and Physical Attributes of the Black Tilapia (O. Mossambica) Fillets 2000-04 Ahmad, Nurul Izzah The selection and training of panelists for identification of earthy attributes in wild black tilapia was carried out using triangle test and Quantitative Descriptive Analysis procedures. Training was carried out in three stages. The first stage was the introduction to fish flavour characteristics while the second and third stages were the familiarization and discrimination stages, respectively. Earthy was the main characteristic for odour and flavour in freshwater fish, while shellfish, briny and sour characteristics were described for marine fish. The threshold level for geosmin was 0.lµgml-1. Earthy flavour attribute was more easily detected as compared to aroma or aftertaste attributes. The volatile flavour compounds identified in black tilapia from three different water environments (cultured pond, lake and channel) were aldehydes, ketones, alcohols, acids and esters, aromatic compounds, furans, cyclic- and hydrocarbons, Ncontaining compounds and S-containing compounds. 62 compounds were detected in cultured black tilapia, 139 in black tilapia taken from lake and 89 in black tilapia taken from channel. The major compound identified in all samples was 2,6-bis(tert-butyl)-4-methylphenol. Other abundant compounds were 1 , 1-( 6-hydroxy- 2,5-benzofurandiyl)bis-ethanone, butyl 2-methylpropyl 1 ,2-benzenedicarboxylate, hexadecanal, heptadecane and benzothiazole. The earthy flavoured compounds, geosmin and isobomeol were found in trace amount in all samples. Acetic, citric and tartaric acids washings at 0.125, 0.25, 0.5, 1 and 2% respectively, were carried out to determine their effects on the removal of the earthy odour and the physical attributes (hardness and colour) of black tilapia fillets. Washing with 0.5% citric acid resulted in fillets with acceptable hardness and colour characteristics and showed a minimum denatured muscle zone. Washing with 0.5% tartaric acid decreased (P<0.01) the hardness, while washing with 0. 5 % acetic acid increased the whiteness (P<0.05) and imparted acetic acid smell. The sensory scores showed that washing with 0.5% acetic, citric and tartaric acid respectively decreased 75, 65 and 48% of earthy odour from uncooked black tilapia fillets. Tilapia. Freshwater fishes. 2000-04 Thesis http://psasir.upm.edu.my/id/eprint/8417/ http://psasir.upm.edu.my/id/eprint/8417/1/FSMB_2000_5_IR.pdf text en public masters Universiti Putra Malaysia Tilapia. Freshwater fishes. Food Science and Technology Bakar, Jamilah English
institution Universiti Putra Malaysia
collection PSAS Institutional Repository
language English
English
advisor Bakar, Jamilah
topic Tilapia.
Freshwater fishes.

spellingShingle Tilapia.
Freshwater fishes.

Ahmad, Nurul Izzah
Flavour Components and the Effects of Organic Acids Washing on the Earthy Flavour and Physical Attributes of the Black Tilapia (O. Mossambica) Fillets
description The selection and training of panelists for identification of earthy attributes in wild black tilapia was carried out using triangle test and Quantitative Descriptive Analysis procedures. Training was carried out in three stages. The first stage was the introduction to fish flavour characteristics while the second and third stages were the familiarization and discrimination stages, respectively. Earthy was the main characteristic for odour and flavour in freshwater fish, while shellfish, briny and sour characteristics were described for marine fish. The threshold level for geosmin was 0.lµgml-1. Earthy flavour attribute was more easily detected as compared to aroma or aftertaste attributes. The volatile flavour compounds identified in black tilapia from three different water environments (cultured pond, lake and channel) were aldehydes, ketones, alcohols, acids and esters, aromatic compounds, furans, cyclic- and hydrocarbons, Ncontaining compounds and S-containing compounds. 62 compounds were detected in cultured black tilapia, 139 in black tilapia taken from lake and 89 in black tilapia taken from channel. The major compound identified in all samples was 2,6-bis(tert-butyl)-4-methylphenol. Other abundant compounds were 1 , 1-( 6-hydroxy- 2,5-benzofurandiyl)bis-ethanone, butyl 2-methylpropyl 1 ,2-benzenedicarboxylate, hexadecanal, heptadecane and benzothiazole. The earthy flavoured compounds, geosmin and isobomeol were found in trace amount in all samples. Acetic, citric and tartaric acids washings at 0.125, 0.25, 0.5, 1 and 2% respectively, were carried out to determine their effects on the removal of the earthy odour and the physical attributes (hardness and colour) of black tilapia fillets. Washing with 0.5% citric acid resulted in fillets with acceptable hardness and colour characteristics and showed a minimum denatured muscle zone. Washing with 0.5% tartaric acid decreased (P<0.01) the hardness, while washing with 0. 5 % acetic acid increased the whiteness (P<0.05) and imparted acetic acid smell. The sensory scores showed that washing with 0.5% acetic, citric and tartaric acid respectively decreased 75, 65 and 48% of earthy odour from uncooked black tilapia fillets.
format Thesis
qualification_level Master's degree
author Ahmad, Nurul Izzah
author_facet Ahmad, Nurul Izzah
author_sort Ahmad, Nurul Izzah
title Flavour Components and the Effects of Organic Acids Washing on the Earthy Flavour and Physical Attributes of the Black Tilapia (O. Mossambica) Fillets
title_short Flavour Components and the Effects of Organic Acids Washing on the Earthy Flavour and Physical Attributes of the Black Tilapia (O. Mossambica) Fillets
title_full Flavour Components and the Effects of Organic Acids Washing on the Earthy Flavour and Physical Attributes of the Black Tilapia (O. Mossambica) Fillets
title_fullStr Flavour Components and the Effects of Organic Acids Washing on the Earthy Flavour and Physical Attributes of the Black Tilapia (O. Mossambica) Fillets
title_full_unstemmed Flavour Components and the Effects of Organic Acids Washing on the Earthy Flavour and Physical Attributes of the Black Tilapia (O. Mossambica) Fillets
title_sort flavour components and the effects of organic acids washing on the earthy flavour and physical attributes of the black tilapia (o. mossambica) fillets
granting_institution Universiti Putra Malaysia
granting_department Food Science and Technology
publishDate 2000
url http://psasir.upm.edu.my/id/eprint/8417/1/FSMB_2000_5_IR.pdf
_version_ 1794018744949800960