Keeping Quality of Fresh and Frozen Sand Lance, Ammodytes sp.

J. J. L1CCIARDELLO, E. M. RAVESI, and M. G. ALLSUP

Introduction et aI., 1979). It has been suggested them for available food (Hen­ that this phenomenon may be drickson, 1979). Sand lance, Ammodytes sp., also associated with the decline in the There is no directed commercial commonly referred to as sand eels, Atlantic mackerel, Scomber scom­ fishery for sand lance on the U.S. east are elongated, slender, round-bodied brus, and Atlantic herring Clupea coast. There is a small limited fish which resemble small eels (Fig. I), harengus, stocks (Morse, 1982). It domestic market for the bait industry swim with an undulating motion in was also proposed that the increased and an even smaller ethnic market for large schools, and grow to a max­ abundance on the Grand Banks human consumption (Smith, 1978). imum length of about 6 inches resulted from the depletion of Atlan­ In Europe, particularly Denmark and (Bigelow and Schroeder, 1953). In the tic cod, Gadus morhua, (Winters, West Germany, sand lance from the western Atlantic Ocean their range ex­ 1983). In 1974, the percentage of sand North Sea form the basis of an impor­ tends from about Cape Hatteras to lance larvae comprising the total tant industrial fishery where they are Labrador. These fish are usually winter larval fish population in the reduced to fish meal and oil found in shoal waters either along the Mid-Atlantic Bight, Southern New (Borgstrom, 1962; Kietzmann, 1969). immediate coast or on offshore banks England area, and Georges Bank was In 1978, the New England Fishery having a sandy bottom. With the aid about 50 percent, whereas by 1979 Development Program sponsored a of their long pointed snout, they occa­ this figure had reached close to 90 study to determine the feasibility of sionally burrow in the sand, hence the percent. During that period, the catching sand lance off southern New name sand eel. abundance estimates increased by a England (Stellwagen Bank) and the Within recent years there has been factor of 20 times (Sherman et aI., results were reported by Smith and l an explosion in the numbers of sand 1981). These sand lances purportedly Testaverde • The NMFS Northeast represent a threat to important com­ lance in the northwest Atlantic (Meyer 'Smith. R. M., and S. Testaverde. 1978. mercial species such as Atlantic cod, Development of a day-trawler fishery for sand haddock, Melanogrammus aegle­ launce (Arnmodytidae) off the coast of New The authors are with the Gloucester jinus; herring, etc., in that not only England: Technical and biological considera­ LaboralOry, Northeast Fisheries Center. Na­ tions. Speech presented at the 23rd Annual tional Marine Fisheries Service. NOAA. are they preying on their young larval Atlamic Fisheries Technological Conference. Gloucester. MA 01930. forms, but are also competing with Williamsburg, Va.

c. I 1 3 4 S , 1 I • .. II 12 IJ 14 IS Ii 17 II I' 21 11 Ii 11111111111111t 11111111111111111111111" 11111111111111111111111" 1IllllllllllllllllillUIll"I" Illuul.lllllllllllllllllllllllllm1111,11,111" t11/11111111111111111111111 d1111/111111' 1,1111111111111' II, 1II111III

Figure I. -Sand lance, Ammodyles sp., from Slellwagen Bank.

78 Marine Fisheries Review Fisheries Center's Gloucester Labora­ (9 = excel1ent, 5 = marginal) by 12 (1974) reported a lipid content of 1.5 tory participated in that study by laboratory personnel with experience percent for Ammodytes lancedatus, comparing methods of holding the in tasting fish of variable quality. and whether this lower value sand lance on board the fishing vessel, Shelf life was considered to have ex­ represents a species or seasonal dif­ and also by determining the species' pired when the sensory score value ferences is not known. fresh and frozen storage character­ reached 6. istics with regard to its potential as a For the frozen storage study, the Fresh Study human food. This paper reports the 2-day post-mortem fish, either iced or Sand lance held in CSW generally results of that investigation. held in CSW, were headed and gut­ remained in rigor longer compared ted, batter-breaded, frozen and then with the fish stowed in ice. This may either air-packed in 2 mil polyethylene have been due to the more rapid Materials and Methods bags or vacuum-packed in bags made lowering of the body temperature by The sand lance were caught on from Curlon S-6602 (nylon-PVDC­ the CSW. Duration of rigor in fish is Stel1wagen Bank in July by a com­ surlyn) and then stored at O°F. a function of both the storage mercial trawler using a small-mesh net Samples from the four different temperature and the time required to in the cod end. One portion of the treatments (ice-air, ice vacuum, CSW­ equilibrate to that temperature. The catch was immediately iced on board air, CSW-vacuum) were periodically appearance of the CSW fish was also ship in standard wood fish boxes examined for organoleptic quality and slightly better because there was less (125-pound capacity) and another peroxide value, and for extractable crushing and the CSW had washed portion was placed in an insulated protein nitrogen (EPN) by the pro­ the surface slime off the fish. At the tank containing chil1ed seawater cedure of Ravesi and Anderson end of the initial 2-day holding (CSW) prepared by mixing one part (1969). period, the chilled seawater had ac­ seawater with one part ice. The fish For the proximate analysis, quired an off odor, probably the were received at the laboratory the moisture content was determined by result of bacterial growth. During same day they were caught. The iced drying to constant weight in an air subsequent storage in ice there was and boxed fish were placed in a walk­ oven at 212°F (100°C). Ash was not much of an apparent difference in refrigerator at 34-36°F. The CSW assayed by incineration in a muffle between the two treatments except for tank was relocated in the pilot plant furnace at I,022°F (550°C). Lipid frequency of burst or blown bellies and connected to a recirculating content was determined by a which was greater among fish initially refrigeration unit set to maintain a methanol-chloroform extraction pro­ held in CSW. This condition occurs in water temperature of 32-34°F. After 2 cedure (Bligh and Dyer, 1959). fish caught when they have been days post-mortem, the fish were Nitrogen content obtained by micro­ heavily feeding and their digestive removed, iced in conventional boxes, Kjeldahl method was multiplied by tract contains a high content of pro­ and also stored in the refrigerator. 6.25 to obtain protein value. All teolytic enzymes which dissolve the Periodical1y, samples from both statistical analyses were performed on belly tissues. In Figure 2, percent treatments were assayed for: Aerobic a programmed HP-97 calculator. burst bellies for the two treatments, plate count (68°F) using the agar determined on randomly selected medium of Lee and Pfeifer (1974); samples of 40 fish per testing, has peroxide value by an iodine titration Results and Discussion been plotted as a function of storage time. procedure (Riemenschneider et al. , Composition 1943) on either a chloroform­ Based upon the appearances of the anhydrous sodium sulfate extract of Sand lance chemical composition is eyes and odor of the flesh, fish from the tlesh (Dyer and Morton, 1956) or presented in Table 1. With a fat con­ both treatments were considered to be a chloroform-methanol extract (Bligh tent greater than 5 percent, these fish in very good condition after 5 days and Dyer, 1959); trimethylamine would have to be classified as fatty. and in good condition after 8 days. (TMA) content by a modification of However, the fat content of pelagic After 12 days the eyes were slightly the Dyer picrate method (Tozawa et fish usually varies seasonally and it is cloudy and the flesh had developed an aI., 1971). For a Torrymeter reading not known whether the fat content (Jason and Richards, 1975), six meas­ determined in this study was minimal, urements were made on the lateral maximal, or average. The species of line along the entire length and the sand lance we studied was most prob­ results averaged. For sensory evalua­ ably American sand lance, Am­ Table1.-Chemlcel composition 01 ssnd Isnce. tion, the fish were headed and modytes americanus. Sidwell et al. Composition (%) eviscerated, batter-breaded, and deep Form Water Protein Lipid Ash fried in corn oil. The cooked product 2Mention of trade names or commercial fmns Whole 73.2 17.1 6.9 2.6 with breading removed was rated for does not imply endorsement by the National Edible flavor and texture on a scale of 1 to 9 Marine Fisheries Service, NOAA. portion 75.4 18.3 5.1 2.0

47(1),1985 79 oily, fishy odor which had intensified day of testing. End of iced shelf life 15 random fish which constituted the by the 15th day. for both treatments occurred at 14 sample. At the onset of spoilage the The average flavor scores for the days. It is believed that the slight meter reading was estimated from fish prestored in CSW were slightly downgrading of the flavor scores of regression analysis as 11-12. With lower throughout a IS-day storage the CSW samples was due to an in­ gadoid species we have usually period compared with the all-iced creased degree of rancidity in these observed a meter reading of 5-7 at in­ samples (Fig. 3). A significant flavor fish. The more rapid rate of peroxide cipient spoilage. There was very good difference (5 percent level) based on a accumulation in these samples com­ correlation (r = 0.93) between log t test was only observed at the eighth pared with the all-iced samples sup­ meter reading and flavor score. Thus, ported this opinion (Fig. 4). The CSW if used judiciously, this instrument fish probably absorbed some salt might be employed to assess quality which is known to accelerate the rate of even small fish such as sand lance. of lipid oxidation. Frozen Study The texture of the CSW fish was 100 scored slightly lower throughout Throughout a 50-week storage 90 storage compared to all-iced fish, period at OaF the ice-vacuum samples / / because of a softening. However, tex­ showed the best flavor stability (Fig. 80 / / tural deterioration was not the 7). Frozen storage lives were / limiting quality factor governing estimated from regression lines to be: U) 70 w /1 --' ;t storage life. 40 weeks for the ice-vacuum fish; 25 w--' 60 /

20

16 ,,' / w w 7 12 o 0 / a:: :3 " o §! /0,-----_/ u / (j) w o "'~ a:: o § 8 7 a:: / ~ w 6 0.. 0/ ",<:> -J ,~ LL /: ICED-+--- ICED 4 " 0 CSw I ICED / " " 5 , 00~---"'=-.!,....-"---!-4--'--!:-6" ---Io.----!8~"'---.J,10,....-~J,.12---'-14l-.... 0 2 4 6 8 10 12 14 If' STORAGE TIME (DAYS) STORAGE TIME (DAYS)

Figure 3. - Effect of shipboard stowage method Figure 4. - Effect of stowage method aboard ship on on flavor score of sand lance held in ice. peroxide value of sand lance held in ice.

80 Marine Fisheries Review extract and a Bligh-Dyer chloroform­ The texture of the sand lance dur­ rate than indicated by taste tests. It is methanol extract. There was essential­ ing frozen storage was remarkably possible that products of lipid ly no difference in the result and for stable. Over a 60-week period the degradation caused denaturation of future work the chloroform-sodium average organoleptic texture score the sarcoplasmic proteins and this sulfate method would be recom­ had only decreased by 1 point on a would account for the change in mended because of its simplicity. 9-point scale and the final rating was EPN. The ice-vacuum treatment, Takama et al. (1978) also reported the "good." Yet, during storage, there which showed the least rancidity, also problem of rancidity in frozen sand was a sharp steady decrease in extract­ had the lowest loss of EPN. Correla­ lance and they were able to suppress able protein nitrogen (Fig. 9) which tion between sensory texture score the reaction by treatment with a water would seem to indicate that the pro­ and EPN was only fair (r = 0.64); dispersible tocopherol mixture. teins were being denatured at a greater however, the EPN value signalling

36 16 '" 15 to z 14 30 is e;, <[ 0 w 13 0 0:: '- 24 12 a- a:: w II S f- w 18 ::> 10 ';: >- <[ a:: 9 ::> 0:: 0 f- 12 f- 8 7 6 6

0 2 4 6 8 10 12 14 16 18 0 0 2 4 6 8 10 12 14 16 18 STORAGE TIME (DAYS) STORAGE TIME (DAYS)

Figure 6. - Effect of shipboard stowage method of Tor­ Figure 5. - Effect of shipboard stowage method on rymeter readings of sand lance held in ice. trimethylamine content of sand lance held in ice.

60

50

W w 40 0:: ::::J o -.J ~ 6 g 30 w 0:: 0 o x 0 i!l a:: 20 w 0:: 5 0-

10

4 0 0 10 20 30 40 50 o 10 20 30 40 50 STORAGE TIME (WEEKS) STORAGE TIME (WEEKS)

Figure 8. - Peroxide value of sand lance treated in Figure 7. - Flavor score of sand lance treated in various manners and stored at O°F. various manners and stored at O°F.

47(1),1985 81 fried smelt. Since sand lance are prone Langton. 1979. Relative abundance, behavior and food habits of the American sand lance, to the development of oxidative ran­ Ammodytes americanus, from the Gulf of cidity, appropriate protective meas­ Maine. Fish. Bull. 77:243-252. ures should be taken when long-term Morse, W. 1982. Spawning stock biomass estimates of sand lance, Ammodytes sp., off storage is anticipated. Although the northeastern United States, determined from transport of whole fish in CSW has MARMAP plankton surveys, 1974-1980. 80 several advantages, it is not advocated ICES C. M. 1982/G:59 Demersal Fish Com­ mittee. that sand lance be held in this medium Ravesi, E. M., and M. L. Anderson. 1969. z 70 beyond 48 hours because of the Effect of varying the extraction procedure on 0- the protein extractability of frozen-stored fish UJ potential adverse effects on flavor Fishes of the Gulf of Maine. Fish. Bull. 74, P. Berrien, and L. Ejsymont. 1981. Con­ 577 p. U.S. Gov. Print. Off., Wash., D.C. gruent shifts in sand eel abundance in western Bligh, E. G., and W. J. Dyer. 1959. A rapid and eastern North Atlantic ecosystems. 40 method of total lipid extraction and purifica­ Nature 291 :486-489. tion. Can. J. Biochem. Physiol. 37:911-917. Sidwell, V. D., P. R. Foncannon, N. S. Moore, 0 10 20 30 40 50 60 Borgstrom, G. 1962. Trends in utilization of and J. C. Bonnet. 1974. Composition of the STORAGE TIME (WEEKS) fish and shellfish. In G. Borgstrom (editor), edible portion of raw (fresh or frozen) crusta­ Fish as Food, Vol. 2, p. 638-722. Acad. ceans, finfish and mollusks. I. Protein, fat, Press, Inc., N.Y. moisture, ash, carbohydrate, energy value, Figure 9. - Extractable protein Dyer, W. J., and M. L. Morton. 1956. Storage and cholesterol. Mar. Fish. Rev. 36(3):21-35. nitrogen content of sand lance of frozen plaice fillets. J. Fish. Res. Board Smith, F. 0., Jr. 1978. Test runs show hope treated in various manners and Can. 13:129-134. for sand eel fishery. Natl. Fisherman stored at OaF. Hendrickson, R. 1979. Prolific sand eel seen 59(8): 15. interrupting the northeast Atlantic's food Takama, K., S. Andou, K. Zama, S. chain. Natl. Fisherman 58(6): 14. Nakamura, and S. Akatsuka. 1978. The Jason, A. c., and J. C. S. Richards. 1975. quality of frozen sand lance treated with a The development of an electronic fish water dispersible tocopherol mixture. Bull. unacceptable texture was estimated freshness meter. J. Phys. E. Sci. Instr. Fac. Fish., Hokkaido Univ. 29:56-64. from the regression line as 24. For 8:826-830. Tozawa, H., K. Enokihara, and K. Amano. Kietzmann, U. 1969. Evaluation of quality of 1971. Proposed modification of Dyer's gadoid species we have usually frozen fish and shellfish. In R. Kreuzer method for trimethylamine determination in observed a value of about 30. (editor), Freezing and irradiation of fish, p. cod fish. In R. Kreuzer (editor), Fish inspec­ 358-360. Fish. News (Books) Ltd., Lond. tion and quality control, p. 187-190. Fish. Summary Lee, J. S., and D. K. Pfeifer. 1974. Innuences News (Books) Ltd., Lond. of recovery media and incubation Winters, G. H. 1983. Analysis of the biological Sand lance have good potential as a temperatures on the types of microorganisms and demographic parameters of northern isolated from seafoods. J. Milk Food sand lance, Ammodytes dubius, from the food fish. Breaded and fried, their Technol. 37:553-556. Newfoundland Grand Bank. Can. J. Fish. gustatory characteristics are akin to Meyer, T. L., R. A. Cooper, and R. W. Aquat. Sci. 40:409-419.

82 Marine Fisheries Review