ทดลองการแช่เย็นและเก็บรักษาปลาโอ
แสงไทย พจน์สมพงส์ สุเมธ สุพิชญางกูร และ ศิโรจน์ คุละลัมพะ
รายงานวิชาการและการทดลองประจำปี 2525-2526 กองพัฒนาอุตสาหกรรมสัตว์น้ำ กรมประมง หน้า 11-25
2525
บทคัดย่อ
Experiments on the handling of longtail tuna (Thunnus tonggol) were made by using fish caught by pole and line fishing vessel. Fish of 5 minutes after catch were divided into 3 lots. First lot of fish was chilled in a mixture of ice and sea water and agitated manually in an insulated box and called ‘treatment I’ second lot of fish was chilled in a mixture of ice and sea water and agitated for 15 minutes and sea water was drain out; fish was mixed with ice in the second insulated box and called ‘treatmentII’. Third lot of fish was directly mixed with ice in another insulated box and called ‘treatment III’. The proportion of fish and ice used was 10:18 by weight. The amount of ice used could reduce the temperature of fish to 0°c and maintain that temperature for more than 24 hours in atmospheric condition. on reaching the shore, three boxes of fish were stored at0°c in the chilled room for laboratory studies. The results obtained were as follows:
1) Fish sample from treatment I, II and III were rated as very good for 3 days, good up to 7 days and acceptable to fair up to 12 days.From panel scores, it was seen that fish sample from treatment I was slightly much better than that of the others for 7 days to 12 days storage. However, the panel scores of the three treatments were not significantly different.
2) Panelists rated the cooked flavour and texture of fish sample from treatment I to be better than that of treatment II and treatment III respectively. on the other hand, the external appearance of raw from treatment I, especially skin colour on the cheeks and head changed into pink and the original colour of the body were washed away while keeping for several days. It was seen that skin colour of fish from treatment III seemed to be better than that of treatment II and I respectively. only texture of raw fish, preserved in the mixture of ice and sea water was better than that of the others and the external texture was related to the cooked flavour and odour.
3) In accordance with fishing method, catching time and market system at present, chilling and stowing of fish on board are suggested to use all treatments as previously mentioned. Chilling and stowing of fish with the mixture of ice and sea water in the fish hold are suggested to do in purse seine fishing vessels.Chilling fish with the mixture of ice and sea water prior to keeping fish in boxes with ice should be done in little tuna drift gill nets fishing vessel. Chilling and keeping fish with ice in boxes can be still used in trawl fishing boat. However, instead of using the latter suggestion, chilling fish in the mixture of ice and seawater prior to bowing the fish is more effective.