Agricultural Research Management Information System

Home
Research Summary
Search
About Us
- ARMIS
- Brochure
Contact Us
Report
User Request
Data Input
Help
- Operation Manual
  - PDF
  - Video
- Program Area & Commodity
We have reached 37600 number of research entries at this moment.

- Logout

Research Detail

Home
Research
Detail

Postmortem Changes in Hilsa Fish-1. Studies on Rigormortis, Typical Yields and Protein Composition of Dark and White Muscle of Hilsa Fish (tenualosa Ilisha Ham.)

M.E. Haque
Bangladesh Fisheries Research Institute, Mymensingh

M.N.A. Khan
Department of Fisheries Technology, Bangladesh Agricultural University, Mymensingh-2202, Bangladesh

M.A.R. Faruk
Department of Fisheries Technology, Bangladesh Agricultural University, Mymensingh-2202, Bangladesh

K. Ahmed
Bangladesh Fisheries Research Institute, Mymensingh

M. Kamal
Department of Fisheries Technology, Bangladesh Agricultural University, Mymensingh-2202, Bangladesh

Abstract/ Executive Summary:

Hilsa (Hilsa ilisha) caught by gill net were immediately killed by cranial spiking. Three fish were kept in ice (0°C) and three other at room temperature (33 °C) to follow development of rigor mortis and changes in muscle pH. The rest were frozen stored at -20°C. Rigor started 15 minutes after death in all fish and reached full rigor (100%) state in 2 and 4 hours respectively in fish kept at 33 °( and (0°C). The fish at 33°C deteriorated 16 hours after while in full rigor but those at 0°C lasted 26 hours of death without deterioration. Freshly caught hilsa had a muscle pH around 7 which decreased with time rapidly at 33°C and slowly at 0°C. The relative proportion of protein fraction in white and dark muscle of fish stored at 0°C and -20 °C were also studied. The proportion of dark muscle was 30.34% of the white muscle. White muscle in fish at 0°C was found to contain 32.0% sarcoplasmic, 57.6% myofibrilla, 9.4% alkali-soluble and 1.1% stroma protein whereas these proteins in dark muscle were 29.9%, 58.4%, 9.8% and 1.9% respectively. The protein fractions of white muscle in frozen-fish were found 27.6% sarcoplasmic, 64.7% myofibrilla, 6.0% alkali-soluble and 1.7% of stroma protein whereas they were 30.6%, 58.6%, 8.9 and 1.9% for dark muscle. Some changes occurred in protein composition during frozen storage. The relative amounts of sarcoplasmic, alkali soluble and stroma protein fractions decreased while myofibrilla fraction increased in frozen condition. This may be attributed to drip loss of soluble protein during thawing.

Keywords: H. ilisha, Rigor-mortis, White and dark muscle, Protein composition

Location: Fisheries Technology Department, Bangladesh Agricultural University

Start Date: 00-00-1994

End Date: 00-00-1994

Program Area: Animal Health and Management

Commodity: Hilsa

Objectives:

The present study deals with the rigor-mortis, typical yields and protein composition of dark and white muscle of hilsa fish (Hilsa ilisha)

Methodology:

Fresh hilsa (Tenualosa ilisha), average body weight and length, 700-800g and 30-32cm respectively, were caught by gillnet from the river Meghna near Chandpur. Six live hilsa were killed by cranial spiking immediately after capture on board of a vessel. Three of those fish were kept in ice (0°C) in an insulated box and the other at room temperature (33 °C) to follow rigor-mortis development and changes in muscle pH. The remaining fishes were brought to the laboratory of Fisheries Technology Department, Bangladesh Agricultural University, Mymensingh in iced condition in an insulated box and frozen stored at-20°C for subsequent studies. Rigor index - "Rigor index" of the fish was measured essentially and used as a parameter of rigor tension. Briefly, the fish was placed on a horizontal table with half of its body (tail part) kept out of the table. At selected time intervals, rigor index was calculated by equation. Measurement of muscle pH - pH value of the muscle homogenate prepared by blending 10 g of fish muscle with 40 ml chilled water was measured by Corning pH meter. Typical yields and determination of protein fraction Fresh ice-stored and frozen-stored hilsa fishes were used for the study. Frozen fishes were partially thawed in ice. Transversal sections through the trunk representing the layout and relative distribution of the dark and ordinary muscles from fresh Hilsa ilisha. The fish were weighed individually and different body parts - head, edible flesh, scale, fin, intestine, egg, gills, skin and bone were separated with the help of a sharp knife, weighed and expressed in percentage of the total weight. For study of the protein composition, after removing the head and caudal fin, the specimen were filleted laterally into two parts. The white and dark muscles were carefully excised to minimize cross contamination of fibre type. The ordinary muscle was dissected from the dorsal part, while the dark myotomal muscle from the whole trunk under the lateral line. Twenty grams of each muscle were fractionated into various protein fraction following the procedure. All the operations were done at 3-4° The protein obtained after fractionation was determined by Biuret method and non-protein nitrogen of TCA extract by Kjeldahl method.

Source of Information: Bangladesh J. Fish. Res., 1 (1) : 91-99, 1996

Article Link (Online Journal):

Funding Source:

Total Budget (Tk.) :

Achievement/Findings:

1. The rigor-mortis of hilsa fish started within 15 min after capture irrespective of temperature. The progress of rigor was faster at 0°C than at 33°C.

2. The decline in muscle pH during rigor-mortis period was faster at 33 °C than at 0°C.

3. The proportion of dark to white muscle was 30.34%. The muscle protein of dark muscle are clearly distinct from those of white muscle in many respects such as dark muscle contained more sarcoplasmic and stroma protein than the white muscle. The percentage sarcoplasmic, alkali soluble and stroma protein fraction decreased, while myofibrillar fraction increased when the fish was kept frozen at -20°C.

Knowledge Management: Journal