Preservation of Otolithus argenteus at low temperature

The studies provided data on the spoilage pattern of Otolithus argenteus during low temperature preservation. Changes in the total volatile bases, hypoxanthine, tyrosine, salt soluble nitrogen, non-protein nitrogen, pH, peroxide value, free fatty acids and thiobarbituric acid number along with organoleptic score have been reported. Organoleptically, fish stored at +20 degree C remained in acceptable condition upto 12 days while for those stored at 0 degree C in ice upto 19 days. Of the various indices tested Hypoxanthine, salt soluble nitrogen and total volatile bases nitrogen, in the order of merit can be used as freshness tests for refrigerated fish.

Preservation of prawns with chemicals

The preservation of prawns with boric acid, dipotassium hydrogen phosphate, sodium bisulphite, ascorbic acid, citric ascorbic acid mixture, acronise pd, foromycin and penicillin have been investigated. Acronise pd, foromycin and citric ascorbic acid mixture in the order named proved the most effective inhibitors of growth of the natural mixture flora at temperatures between -18°C and 28°C; while foromycin inhibited yeast growth and sodium bisulphite and boric acid retarded melanosis. Acronise pd caused marked inhibition of bacterial growth in 5 to 50 per ml concentration, when used as an immersion medium for 10 to 15 minutes. The other chemicals used exerted a less intense action or were without any effect.

Recent developments in fish processing and preservation

A review of the literature on fish processing will reveal that most of the important developments have taken place during the last twenty years. Sustained work by teams of scientists in different parts of the world, has not only contributed much to our knowledge of the chemistry and technology of fish but also resulted in revolutionary changes in the methods of preservation and processing of fishery products.

Experiments on preservation and weathering of net twines

Koura (1963) reporting the results of the comparative studies on different preservation methods of cotton twines stated that "by the difference of rotting in the different waters, not ever one method may be the most economical one". The observations were simultaneously made at Alexandria in Egypt in the sub-tropical region and Cuxhaven in the estuary of the River Elbe in the temperate zone. The course of weathering and effect of immersion in water of man-made fibres have also been mentioned in this communication. Subsequently work on similar lines were extended to Cochin in the tropical region with Cuxhaven and Hamburg as the other places of observation and the results of these studies are presented in this paper.

Preliminary studies on the effect of irradiation as a means of preservation of fish and shellfish

Preliminary investigations on the effect of irradiation on commercially important fish and shell fish like silver pomfret, Bombay duck and prawns were conducted. Irradiated samples had an extended storage life compared to their respective controls even though yellowish or brownish discoloration occurred earlier in irradiated fish. Irradiation enhanced the rate of drip formation. Brine treatment prior to irradiation retarded this rate. Pre-blanching was found to further extend the storage life of irradiated fish.

Preservation of fish by freezing and glazing. Pt. 1. Bacteriology of fresh, frozen and glazed fish

Microbiological investigation of fresh and frozen fishes such as pomfret, surmai and mackerel was carried out under various conditions of preservation. Glazing, block-freezing and preservation in gunny bag were affected. Determination of bacterial load and isolation, identification and classification of the resistant bacteria were made. Spore-formers of Subtilis mesentericus group were found to be resistant to freezing as well as glazing by ascorbic acid, citric acid and sodium nitrite except a mixture of sodium chloride and glucose. Bacterial load was reduced to a good extent and maintained low till the end of frozen storage period.

Preservation of fish by freezing and glazing. Pt. 2. Keeping quality of fish with particular reference to yellow discolouration and other allied organoleptic changes on prolonged storage

Organoleptic observations of quick, slow and block frozen, glazed and stored fish were recorded at regular intervals. Glazing was renewed at intervals of four weeks. Development of yellow discolouration in the case of white pomfret was followed. Keeping quality of glazed fish was better than unglazed frozen fish. Yellow discolouration could be controlled by ascorbic acid for 42 months and by a mixture of sodium chloride and glucose for 52 months.

Preservation of fish by freezing and glazing. Pt. 3. Effect of freezing, glazing and frozen storage on the B-vitamins and essential minerals present in the fish flesh

The changes occurring in moisture, thiamine, riboflavin niacin, phosphorus, iron and calcium in pomfret, surmai and frozen mackerel, glazed with ascorbic acid, citric acid, sodium chloride, glucose, sodium nitrite and kept under frozen storage were studied up to 6 months and results reported.

Bacteriology of chilled water during the preservation of fish

Except for the preliminary studies at Torry Research Station in Scotland, no results have been reported on the succession of the bacterial flora during the storage of fish in chilled water. The present work was undertaken to elucidate the dynamics of bacterial population changes in chilled fresh water under comparable conditions of storage in melting ice (+1° to +3°C.) which has been earlier studied by de Silva in 1960.

Promising practices in food security and nutrition assistance to vulnerable households in the Tonle Sap Region, Cambodia

The CGIAR Research Program on Aquatic Agricultural Systems (AAS) seeks to reduce poverty and improve food security for many small-scale fishers and farmers who are dependent on aquatic agriculture systems by partnering with local, national and international partners to achieve large-scale development impact. This study on promising practices in food security and nutrition assistance to vulnerable households in the Tonle Sap region forms part of the preliminary research that informs AAS work in the highly productive Mekong Delta and Tonle Sap Lake floodplain. The study aims to identify and learn from promising practices that have had a positive impact on the food security and nutrition of vulnerable households in the Tonle Sap region.

Impact of community-based fisheries management practices on production and species diversity in Turag-Bangshi basin floodplains in Kaliakoir, Gazipur, Bangladesh

The study was conducted to investigate the communities perception and compliance to community-based fisheries management (CBFM) in Turag-Bangshi floodplains under Kaliakoir, Gazipur District. Measures such as ban on use of the harmful fishing gears, seasonal fishing closure, halt of fry fishing, halt of dewatering of beels and the impact of establishment of sanctuaries on fish production and species diversity were introduced by MACH project. Almost all members of the communities in Turag-Bangshi MACH (Management of Aquatic Ecosystem through Community Husbandry) site welcomed the introduction and complied with the implementation of all management measures which helped stopped use of harmful fishing gears, ensured survival and breeding of brood fish in the rainy season, protected and allowed fry to grow big, restored lost and degraded fisheries and organized communities for sustainable development of the fisheries. A total of 51 species of fishes were found in Makosh beel (natural depression). Among these, small indigenous species (SIS) under Cyprinidae family (Puntius sophore) was the most dominant. Many species available in the past recorded disappeared from the Makosh beel due to loss of habitat and industrial pollution that damaged spawning and nursery grounds of fish. Introduction of some selective native endangered species (Nandus nandus, Notopterus notopterus, Ompok pabda and Labeo calbasu) by MACH in the Turag-Bangshi water bodies increased diversity of species from 82 to 95. Over a period of five years during MACH intervention, the average production remained nearly 200% higher than the baseline production of 57 kg/ha to present 207 kg/ha due to maintaining sanctuaries and the closed fishing seasons. Per capita daily fish consumption of the surrounding communities also increased by 78% (from 27 to 48 g/person/day) which is much higher than the national average fish consumption in Bangladesh. The implementation of community-based MACH project management measures substantially improved fish habitat, production, consumption and socio-economic conditions of the surrounding communities. The model can be used to improve the floodplains of Bangladesh.

Constraints in fish farming practices in Uttar Pradesh, India: an analysis

Aquaculture can be considered as a rapidly growing sector in many Indian states including Uttar Pradesh. The impressive overall upward trend in fish production is likely to continue in future years as there are plenty of unutilized or underutilized fishery resources in the state. In spite of the growing popularity of aquaculture in the state, fish farmers have been experiencing financial, social and technical constraints in fish farming practices. These constraints are adversely affecting farmers in obtaining expected fish yields and income. In this study, the most common problem areas were identified, analysed and ranked on the basis of farmers' perception.

Short-term preservation of Brachionus calyciflorus: effects of storage on protein, lipid and carbohydrate contents

The short-term preservation of Brachionus calyciflorus for 45 days at three different temperatures (4, -4 and -20°C) led to decrease in protein, lipid and carbohydrate contents in all the three cases. However, the rate of deterioration was much higher at 4C than at -4 and -20°C. At 4C, protein, lipid and carbohydrate contents reduced by 76.78, 81.11 and 62.83%, respectively, and at -4°C, these were 27.94, 37.46 and 18.42%, respectively, whereas at -20°C, the deterioration was limited to 9.28, 16.44 and 11.35%, respectively, when compared with the control values. Thus, preservation at -20°C is comparatively better as it exerts limited effect on the protein, lipid and carbohydrate contents of B. calycijlorus.