Study on shelf life of fish cake prepared from surimi of silver carp (Hypophthalmichthys molitrix) during frozen storage

Surimi was prepared from silver carp with an aim to put this underutilized fish for profitable use. The mince prepared was washed twice with chilled water (5°C) using mince to water ratio (w/v) of 1:2 for 5-6 minutes each. After final dewatering to moisture content to about 80%; half the quantity of washed minced meat was mixed with cryoprotectants (4% sorbitol, 4% sucrose and 0.3% sodium tripolyphosphate) to produce surimi. The prepared surimi and the dewatered minced meat were packed in LDPE bags, frozen using a plate freezer and stored at -20°C. Surimi and dewatered minced meat from frozen storage were used as base material for production of fish cakes. These were fried at 160°C for 3 to 4 minutes before serving for organoleptic test. Changes in salt soluble nitrogen, total volatile base nitrogen, non-protein nitrogen, peroxide value and free fatty acid of surimi and dewatered mince were estimated at every ten days interval during the storage period of 3 months. The study has indicated that frozen storage of surimi could be a potential method for effective utilization of silver carp. This surimi when incorporated in fish cakes yielded products which retained the shelf life even up to 90 days of storage.

The nature of small-scale farmer managed irrigation systems in North West Province, Sri Lanka and potential for aquaculture

RRAs were carried out in two Small Tank Cascade systems (STCs) of North West Province, Sri Lanka (less than 1000 ha total watershed area). A total of 21 tanks and 7 villages were investigated with primary emphasis on two upper watershed communities. The two systems differ primarily in their resource base; namely rainfall, natural forests and proximity to large scale perennial irrigation resources. [PDF contains 86 pages]

Effects of landscape gradients on wetland vegetation communities: information for large-scale restoration

Projects of the scope of the restoration of the Florida Everglades require substantial information regarding ecological mechanisms, and these are often poorly understood. We provide critical base knowledge for Everglades restoration by characterizing the existing vegetation communities of an Everglades remnant, describing how present and historic hydrology affect wetland vegetation community composition, and documenting change from communities described in previous studies. Vegetation biomass samples were collected along transects across Water Conservation Area 3A South (3AS).

Littoral vegetation of Lake Tohopekaliga: community descriptions prior to a large-scale fisheries habitat-enhancement project

An extreme dry-down and muck-removal project was conducted at Lake Tohopekaliga, Florida, in 2003-2004, to remove dense vegetation from inshore areas and improve habitat degraded by stabilized water levels. Vegetation was monitored from June 2002 to December 2003, to describe the pre-existing communities in terms of composition and distribution along the environmental gradients. Three study areas (Treatment-Selection Sites) were designed to test the efficacy of different treatments in enhancing inshore habitat, and five other study areas (Whole-Lake Monitoring Sites) were designed to monitor the responses of the emergent littoral vegetation as a whole. Five general community types were identified within the study areas by recording aboveground biomasses and stem densities of each species. These communities were distributed along water and soils gradients, with water depth and bulk density explaining most of the variation. The shallowest depths were dominated by a combination of Eleocharis spp., Luziola fluitans, and Panicum repens; while the deeper areas had communities of Nymphaea odorata and Nuphar luteum; Typha spp.; or Paspalidium geminatum and Hydrilla verticillata. Mineralized soils were common in both the shallow and deep-water communities, while the intermediate depths had high percentages of organic material in the soil. These intermediate depths (occurring just above and just below low pool stage) were dominated by Pontederia cordata, the main species targeted by the habitat enhancement project. This emergent community occurred in nearly monocultural bands around the lake (from roughly 60–120 cm in depth at high pool stage) often having more diverse floating mats along the deep-water edge. The organic barrier these mats create is believed to impede access of sport fish to shallow-water spawning areas, while the overall low diversity of the community is evidence of its competitive nature in stabilized waters. With continued monitoring of these study areas long-term effects of the restoration project can be assessed and predictive models may be created to determine the efficacy and legitimacy of such projects in the future.

Evidence for changes in large-scale upwelling in the California Current over the past 700 years [abstract]

EXTRACT (SEE PDF FOR FULL ABSTRACT): Bidecadal radiocarbon measurements on tree rings provide a detailed series of carbon-14 activities at isotopic equilibrium with atmospheric carbon dioxide. ... Most marine environments do not permit development of a comparable series of carbon-14 ages with which to compare the terrestrial tree ring series. However, we have recently begun work on such a series using material from the varved sediments of the Santa Barbara Basin off southern California. ... We now have a nearly continuous record of carbon-14 dates representing the age of the water over the upper 100 meters. ... The ocean reservoir ages show an increase prior to 1450 and a progressive decrease with time after 1450. Although there may be other explanations, we believe this trend is principally the result of changes in large-scale upwelling of water from below 500 meters. These changes were probably also associated with changes in the intensity of the California Current.

A small scale fish meal dryer

A batch type rotary drum dryer for the production of fish meal suitable for operation in the fishing villages of India has been designed, fabricated and operated successfully. The dyer can be used for production of fish meal from whole lean fish or press-cake from fish body oil extraction plants. The time taken to reach a moisture level below 10% is 5-8 hours depending upon the type of material fed into the dryer.

A pilot scale set up for the manufacture of fish hydrolysate

This paper describes a set up for a pilot plant with a capacity of 50 kg raw material per batch for the production of fish hydrolysate by enzymatic hydrolysis. Process flow sheet and complete specifications and functions of individual equipment have been described. Multifunctional equipment designed for this pilot plant set up has reduced the number of equipment considerably.

Identification and determination of muscle's fatty acids and amino acids in Cobia and Indian squid

The present study aims to find the effect of freezing Time on the quality of Cobia (Rastrelliger kanagurta) and Indian Squid in commercial scale during freezing and subsequent frozen storage (−18◦C). Total time for freezing was significantly different (P<0.05) between the Cobia and Indian squid samples. The difference in the freezing time could be attributed to the varied quality of the 2 samples. Upon freezing, the moisture content decreased in Indian Squide samples compared to Cobia freezer where protein content decreased in both the samples. Upon freezing and during frozen storage, lipid oxidation products (peroxide value, and free fatty acid value) and volatile bases (total volatile base nitrogen) showed an increasing trend in both the samples with values slightly higher in Indian squid samples compared to cobia frozen samples. The total plate counts showed a significantly (P<0.05) decreasing trend in both the samples. K value did not show any significant (P<0.05) difference between the samples whereas the histamine formation was significantly (P<0.05) increased in Indian squid frozen samples compared to cobia samples. The taste and overall acceptability was significantly different (P<0.05) in cobia samples compared to Indian squid frozen samples on 5th month. Both samples were in acceptable condition up to 5 month but the Cobia frozen samples quality was slightly better than the air blast frozen samples.