Recipient Organization
NORTH CAROLINA STATE UNIV
(N/A)
RALEIGH,NC 27695
Performing Department
Food, Bioprocessing, and Nutrition Sciences
Non Technical Summary
North Carolina's blue crab industry has drastically declined, primarily due to the high labor cost associated with processing. Traditionally, blue crabmeat is recovered commercially by hand-picking after cooking whole crabs under pressure and subsequent cooling. This process is both labor and time consuming with significant loss in yield and flavor due to liquid loss during pressure cooking and by evaporation loss during chilling of cooked crabs. Mechanical extraction of crabmeat from raw results in 3 times higher yield at substantially less labor input than the current industry process of cooking, cooling and hand-picking crabmeat. The product is obtained shell fragment-free, an advantage over hand picked body meat, but has an unappealing paste texture. Restructuring of raw crabmeat, based on its heat-induced gelation properties, holds the key to competitive marketing of this product. The market for blue crabmeat remains strong and the high prices for traditional hand-picked meat including imported crabmeat present a unique marketing opportunity for mechanically recovered raw crabmeat, which can be extracted from crabs now being underutilized in North Carolina because of foreign competition based on cheap labor. The proposed research will provide the technical data base necessary to insure that restructured crab products of consistent quality can be produced from raw crab meat that likely varies considerably in properties due to many source variables. Baseline data on raw crab composition and performance (functionality) in restructuring will be collected as affected by normal variability in crab physiology and composition across variations in sex, size, harvest location, season, etc. with sampling continuing throughout two harvest seasons.
Animal Health Component
60%
Research Effort Categories
Basic
10%
Applied
60%
Developmental
30%
Goals / Objectives
Establish quality measurement parameters for raw Atlantic blue crabmeat to monitor meat produced by both feasible methods and from all likely sources. The metric of success will be a set of well defined test methods that concisely measure compositional and chemical/physical properties important to formulation and processing of raw crabmeat into restructured food products of consistent and high quality and safety. Sample over a two year period across the likely population of crabmeat that can be commercially produced: all seasons and locales of harvest, sizes of crabs, sex of crabs, molting cycles, etc.. The metric of success will be development of a baseline database which can assure that supplies of raw crabmeat of sufficient quality/properties can be procured adequate to the needs for successful commercial production of restructured crab meat Develop strategies for effective cryoprotection of crabmeat to enable freezing so as to extend processing timeline and expand geographical market opportunities. The metric of success will be achieving a frozen product which when thawed up to one year from production will be sufficiently functional and acceptable to produce restructured food products of consistent and high quality. Optimize binding parameters (time/temperature, +/- added TGase, possible endogenous protease effects) produced by heat-induced gelation and/or fiber spinning to restructure raw crabmeat into a product of equal acceptability as traditional hand-picked crab. The metric of success will be to proscribe the acceptable limits of process parameters used for restructuring of raw crabmeat, with respect to measured variance in the properties of available raw crabmeat (measured in objective 2), which produce a restructured crabmeat of consistent high acceptability, as judged by comparative sensory testing when evaluated in traditional applications, such as crab cakes.
Project Methods
Objective 1 (Establishing Quality Parameters): Methods to monitor the following attributes of raw crabmeat will be developed to establish baseline data essential for insuring uniform performance in the reforming process to be developed for mechanically extracted raw crabmeat: a. Lanier et al. 2005). Thus ionic strength (salts concentration and composition) and pH are parameters which must be optimized for each meat source with respect to heat gelation properties, and these must in turn be adjusted relative to time/temperature parameters of heating in the formation of the gel. Proteolytic and crosslinking enzymes also must be monitored. The procedure for evaluating gelling properties of a myofibrillar-based material like raw crabmeat have been well developed for surimi derived from fish (Baker 2000; Lanier et al. 2005; Kim et al. 2005) and therefore should be applicable. d. Water content and water-holding properties. Purge/drip can also shorten shelflife by promoting bacterial growth in the packaged product. A timed purge/drip, and/or accelerated (by centrifugal force) purge/drip, test(s) will be used (Stevenson et al. 2013). Objective 2 (Baseline Database Development) Live crabs of commercial size will be processed by mechanical extraction. Harvest location, crab size, sex and condition (molting cycle, etc.) will be monitored, with sufficient sampling from lots representing each of these variables to constitute a statistically significant sampling of meat representing that variable. Objective 3 (Cryoprotection Strategies): The same quality parameters developed as measurements under objective (1) will be evaluated before and after varied holding times at these different temperatures. Additionally Ca-ATPase activity will be monitored as it is a well accepted measure of myofibrillar protein denaturation (Carvajal et al. 2005), and sodium dodecyl polyacrylamide electrophoresis (SDS-PAGE) of component proteins will be carried out to detect any cross-linking (aggregation) or proteolysis of proteins which may (have) occur(red) prior to or during storage (Stagg et al. 2012). Samples cryoprotected by will be similarly evaluated as untreated meat samples, comparing several feasible cryoprotectant additives of each approach at reasonable, acceptable levels. Objective 4 (Optimize Binding Parameters and Product Restructuring): Using the rheological methodology developed under objective 1 (c) (for evaluating heat gelation properties during restructuring of crabmeat), we will further optimize effects of the meat binding process: mainly time, temperature of heat processing and added ingredient parameters (salts, phosphates, TGase, etc).