CHAMPAGNE CRABS (Hypothalassia Acerba): YIELD and SENSORY CONSIDERATIONS
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CHAMPAGNE CRABS (Hypothalassia acerba): YIELD AND SENSORY CONSIDERATIONS Report prepared as part of Fisheries Research & Development Corporation Project 2013/711.30 New Opportunities for Underutilised Species Janet Howieson 2018 1 Contents 1. Background ..................................................................................................................................... 3 2. Project Development ..................................................................................................................... 3 3 Processing Methods, Results and Discussion ..................................................................................... 6 3.1 Trial 1 ............................................................................................................................................ 6 3.1.1 Methods ................................................................................................................................. 6 3.1.2 Results .................................................................................................................................... 7 3.1.3: Conclusions ......................................................................................................................... 11 3.2 Trial 2 .......................................................................................................................................... 11 3.2.1 Methods and Results ........................................................................................................... 11 3.2.2: Conclusions ......................................................................................................................... 14 3.3 Final Conclusions from Processing Trials .................................................................................... 14 4 High Pressure Pasteurisation (HPP) Trials ........................................................................................ 14 4.1 Methods and Results. ................................................................................................................. 14 4.2 Discussion .............................................................................................................................. 16 5 Conclusions ........................................................................................................................................ 17 2 1. Background Champagne Crab (Hypothalassia acerba) occur in the southern waters of Australia generally between 100 – 200m in water temps varying from 12 to 21 degrees Celcius. Champagne Crabs are distinguished by the numerous spines on the edges of the carapace (shell) and on the legs. A creamy orange colour they grow to around 15cm in carapace width. Trips may be 5 – 10 days in length and the species are taken in rock lobster or crab pots. The pots are baited with salmon or sardines or fish by product – including heads. Once on board, crabs are retrieved and main pincers are zip tied to prevent animals harming each other. They are put into a below deck live tank, full of fresh seawater that is kept aerated. When vessels reach the wharf the water is drained from tanks and the produce is transferred as quickly as possible to onshore live tanks. This practice ensures animals stabilise and acclimatise before being shipped within a few days or up to 2 weeks to domestic and overseas buyers. For shipment, crabs are placed very briefly in near freezing salt water or in an ice slurry to reduce their body temp and send them into a torpor. They are then packed in Styrofoam boxes with chill packs ready for live transport. The main market is into China via live export. They are sold in small quantities on the local market, either live or cooked and as a whole animal. However Champagne Crabs are undervalued because the meat is difficult to extract and the spikes make them difficult to handle. They also destroy each other if not treated properly on board. Further, Champagne Crabs are not as highly prized on the export markets as deep sea crab species because of their smaller size and less favourable colour. Locally, these crabs are not a species well known for eating and of little demand. Again this is generally because it is time consuming to extract meat after cooking. 2. Project Development Dr Janet Howieson was approached in 2015 by Neil Dorrington in regard to investigating some quality and other aspects of Champagne Crabs. It was considered that such an investigation would fall under the project CRC/FRDC 2013/711.30: Developing new opportunities for underutilised species. Subsequently an introductory meeting was held and a preliminary research plan was developed (see Table 1). 3 Table 1: Research Plan: Champagne Crab Product Development Stage Parameters to Measure Research Activities Comments 1. Harvest Crabs will be harvested by best practice and transported live to processing facility. Harvest strategy discussion: all at once or through the year (may influence product development options). Cost to harvest (seasonal or all during the year) to assist with understanding economic feasibility. Freeze on board with dedicated vessels if short harvest season. 2. Humane Killing Flesh quality* (texture, odour) Impact of humane killing Crab claw may be separated and sold as (chef panel to advise/assess??). techniques (freezing to put to separate product. Work out optimum Claw appearance (??) sleep, drowning, spike) on flesh time to remove crab claw (and method) quality etc. 3. Hair Removal Coverage of hair on crabs (eg are Map hair on crab Carapace. Hairs are reported to taint flavour and they on the claws) Conduct literature survey on hair get stuck in throats. Proportion of hairs removed by the removal strategies on other species different techniques. Test options to remove hairs: burn, Impact of hair removal strategy on scald (steam), other?? (as perhaps outer shell/claw appearance and identified by literature review). flesh quality. Assess impact of hair presence on Does hair presence during cooking palatability after cooking. actually decease palatability 4. Processing strategies Flesh quality Assess quality of frozen flesh from Is crab claw to be separated initially? a. Freeze whole and Meat Yield raw and cooked product. Frozen product preferred?? raw (for later Shell hardness Shelf-life considerations. Is there differences in yield/quality defrost and Assess best methods of cooking associated with males/females. 4 Stage Parameters to Measure Research Activities Comments extraction) (steam/boil) Is there differences in yield/quality b. Cook and freeze Assess yields from raw and cooked associated with stage of moult. whole (for later crabs. Is there dfferences in yield/quality defrost and Is there a way to recognise associated with cookng method extraction) moulting stage (in other species c. Extract meat from associated with yield). raw crab and freeze d. Extract meat from cooked crab and freeze 5. Meat extraction Yield Assess yield and cost and feasibility If extracted meat is the preferred strategies Flesh quality from the various extraction product, off shore processing may be an a. Hand picked in Aust Economic feasibility based on techniques option due to Aust labour costs. (raw or cooked??) extraction price, yield and price to Techniques to break the armour Also can investigate mechanical b. Hand picked off shore sell. plate initially. extraction in association with Peter (raw or cooked??) Part pre-processing to reduce Jecks and Curtin Uni CRC project c. Machine extraction transport costs??? 2014/704. (Peter Jecks??) (raw or May need to address issues associated cooked??) with extremely hard shell. 6. Market preference Preferred product options as Crab claws as separate product or Consultation with chefs required dictated by market ?? not (size preferred??) Frozen extracted meat as preferred product (raw or cooked??) Whole product (but very hard shell and hairs). *Need to benchmark optimum flesh quality parameters at beginning of study. May be best met by development of expert chef panel to provide comment. 5 3 Processing Methods, Results and Discussion 3.1 Trial 1 Four parts to the initial trial 1were planned. Part A: Map extent of hairs Part B: Understand Recovery Yields Part C: Trial different processing/storage options. Part D: Check if hairs are causing taint in meals containing the crabs. Three live Champagne Crabs were therefore sourced from Southern Trading Pty Ltd for the preliminary trials. All crabs were male. 3.1.1 Methods Part A: Map Extent of Hairs. Detailed photos were taken of raw crabs to enable mapping of the extent of the hairs and spikes. Part B: Understand Recovery Yields Crabs were cooked by boiling and the individual parts (legs, large claw, small claw and body) weighed. Following crab meat was hand-picked from the individual parts and the extracted meat weighed. Meat recoveries were calculated. Part C: Trial different processing/storage options Informal meat quality assessments for leg meat, claw meat and body meat were undertaken after the following different processing/storage options. a. Cooked whole, meat extracted fresh, assessed. b. Cooked whole, meat extracted, vac packed, frozen for 4 weeks, thawed, assessed. c. Cooked whole, placed in plastic bag, frozen for 4 weeks, thawed, meat extracted, assessed. It was decided not to look extraction of meat from raw crab as this was considered too difficult. It was not possible to vac pack the whole crab due to spikes/claws breaking the plastic bag. Meat was informally assessed for colour, taste,