Proximate Chemical Composition and Fatty Acids of Three Small Coastal Pelagic

MALCOLM B. HALE

Introduction Small pelagic species, primarily the petfood canning plant, did not include herrings, the smaller jacks, and an­ the Spanish sardine or round scad. Sea­ Information on the proximate chem­ chovies, make up the greatest un­ sonal proximate compositions were re­ ical composition and fatty acid profiles derutilized finfish resource in the Gulf ported for whole thread herring, but of a number of pelagic species has been of Mexico (Reintjes, 1979). Based on fatty acids were not determined. Sid­ developed at the Charleston Laboratory egg and larval survey data reported by well (1981) listed proximate analyses of the NMFS Southeast Fisheries Houde (1976) and Leak (1977), the for several flesh and whole samples Center. The data reported here are for combined potential yield for thread her­ of thread herring and for several sam­ Spanish sardine, Sardinella aurita; At­ ring, Spanish sardine, and round scad ples ofsardine from the eastern Atlantic lantic thread herring, Opisthonema og­ was estimated at 190,000-325,000 met­ (S. aurita, but referred to as golden !inurn; and round scad, ric tons in the eastern Gulf of Mexico. sardine). Round scad was not reported. punctatus. These species are placed in a Although menhaden are fully exploited Proximate and fatty acid compositions common grouping referred to as for meal and oil production, and there of raw and canned thread herring and "coastal herrings," for utilization pur­ are bait fisheries for other coastal her­ Spanish sardine were included in a poses, although the round scad is actu­ rings, there has been no significant di­ study of the effects of canning on fatty ally a member of the jack family, rect food use of coastal herrings in the acids (Hale and Brown, 1983), which . Gulf of Mexico. demonstrated that heat processing did Coastal herrings are generally small, not significantly alter the fatty acid pro­ dark fleshed, and bony. They contain files. moderate to high levels of oil, which is This paper includes some of those subject to oxidation during frozen stor­ data along with other analyses for a ABSTRACT- The coastal herrings com­ age. They are not suitable for tradi­ range of seasonal samples. We also pre­ plex comprises the largest underutilized tional fresh or frozen products in devel­ sent information, not previously avail­ fisheries resource in the Gulf of Mexico. oped countries but they have potential able, on the chemical composition of Several species have good potentialforfood for use as canned products. Consider­ edible forms of the three small pelagic use as canned products, but the lack of chemical composition data inhibits their able interest has developed in recent species with potential for much greater development. In this paper, proximate chem­ years in the canning ofcoastal herrings, use. ical compositions andfatty acid profiles are but very little information on the chem­ Materials and Methods reported for seasonal samples of Spanish ical composition of these species has sardine, Sardinella aurita; thread herring, been published to encourage such a de­ Round scad and Spanish sardine were Opisthonema oglinum; and round scad, Decapterus punctatus, from both the Atlan­ velopment. obtained from both the South Atlantic tic Ocean and the Gulf of Mexico. Mean Thompson (1966) reported seasonal Bight and the Gulf of Mexico. The At­ protein contents ranged from 20.6 percent compositions of various species ofGulf lantic samples were collected during for thread herring to 22.6 percent for round of Mexico industrial fish. The fish, resource survey cruises, sealed in scad from the Gulf. Mean fat contents ranged from 1.8 percent for Spanish sar­ caught by commercial trawlers for a heavy polyethylene bags, and frozen dines from the Atlantic to 3.2 percent for onboard the vessel. Thread herring, as thread herringfrom the Gulf. Fat contents of well as scad and Spanish sardine, were Malcolm B. Hale is with the Charleston Labo­ sardines and scad decreased over the period obtained from the Gulf of Mexico. of spring to late summer. Spanish sardines ratory, Southeast Fisheries Center, National Marine Fisheries Service, NOAA, PO. Box Samples were obtained from baitfish have a particularly high level of 22 :6w3, 12607, Charleston, SC 29412-0607. This paper harvesters, primarily in Port St. Joe, but in general the fatty acid profiles of the is Contribution No. SEFC 83-41C from the three species were similar and did not Southeast Fisheries Center's Charleston Fla. (Raffields Fisheries), or in the change seasonally. Laboratory. Panama City, Fla., area. The samples

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O'--~-_-~- -~- - o'-~---~----_-_-~-~-__- Jan. Feb. March Apr. May June July Aug. Sept. Oct. Nov. Jon. Feb. March Apr. Moy June July Aug. Sept. Oct. Nov.

Figure I.-Fat content of headed and gutted Spanish Figure 2.-Fat content of headed and gutted round sardine, Sardinella aurita , versus month of harvest. scad, Decapturus punctatus, versus month of harvest.

were frozen before being transported to Table 1.-Proximate chemical analyses of the raw, headed, and gUlled form of round scad, Charleston, S.c., for processing. Spanish sardine, and thread herring. Analyses were generally made after Number Average Percent less than 2 months of frozen storage. of weight Species Source samples (g) Protein Fat Moisture Ash All samples were homogenized in a Round scad Atlantic 11 35.1 21.64 252 74.06 3.12 food processor, placed in poly­ Gult 3 36.8 22.60 2.60 73.95 260 propylene sample cups, frozen, and Spanish Aliantic 6 33.4 2083 1.79 76.05 2.68 stored until analyzed. Samples were sardine Gulf 6 60.9 20.90 2.42 74.73 269 analyzed for crude protein by the Kjel­ Thread dahl method (AOAC, 1965). Samples herring Gulf 4 78.9 20.65 3.22 73.23 3.68 were dried to constant weight overnight at WO°C for moisture determination, and were heated overnight at 600°C for ash determination. Total fat was de­ termined by a chloroform-methanol with electronic integrator. Identifica­ The chemical compositions of samples extraction (Smith et aI., 1964). Dupli­ tion of fatty acid esters was as described from the Atlantic did not differ signifi­ cate analyses were performed on all by Ackman and Burgher (1965). cantly from those of Gulf samples. Al­ samples. though Spanish sardines from the Gulf Fatty acids were determined by gas­ Results and Discussion were larger, and had a slightly higher liquid chromatography of methyl esters. The coastal herring species de­ mean fat content, correlations between The esters were prepared from ex­ scribed have high protein contents and fish size and fat content were generally tracted oils by a boron trifluoride­ moderate fat contents. Overall average low. The fat content did vary with the methanol procedure (Metcalfe and values of the proximate chemical com­ season, however, apparently as a func­ Schmitz, 1961). A column packed with positions determined for the raw, tion of the reproductive cycle. diethylene glycol succinate polyester headed and gutted (H&G) forms of Fat content decreased in both (DEGS) was employed in a Hewlett­ round scad, Spanish sardine, and thread Spanish sardine and round scad during Packard l Model 5831A chromatograph herring are listed in Table I. The sam­ the summer (Fig. 1 and 2). Samples ples referred to in Table I are compos­ were not available to describe the fat ites of 8-20 fish each, depending on fish increase that must occur during the fall .. 1Mention of trade names or commercial firms does not imply endorsement by the National size. The H&G form is that most likely The data available for thread herring Marine Fisheries Service, NOAA. to be utilized in canned food products. indicate an increase in fat content dur-

20 Marine Fisheries Review ing the early fall. A September H&G Table 2.-Proxlmate chemical composition of three Table 3.-Major fatty acids of Spanish sardine, product forms of round scad, Spanish sardine, and thread herring, and round scad. sample approached 4 percent fat and an thread herring. October skinless fillet sample exceeded Percent of total fatty acids Percent 5 percent fat. Thompson (1966) re­ Species Product Spanish Thread Round ported for whole thread herring an in­ and source form Protein Fat Moisture Ash Faltyacid' sardine herring scad crease from 4.3 percent fat in late Sep­ Round Fillet 22.22 1.90 75.71 1.42 14:0 2.8 4.7 3.9 scad H&G 21.64 2.52 74.06 3.12 16:0 232 23.8 20.5 tember to 15.6 percent fat about I month (Atl.) Whole 20.03 296 74.18 3.89 18:0 7.7 7.8 93 later. The lowest and highest oil con­ Spanish Fillet 22.40 1.31 75.86 1.77 16:1 4.8 5.6 6.0 tents measured for thread herring by sardines H&G 20.83 1.79 76.05 268 18:1 8.6 10.6 11.7 (Atl.) Whole 18.59 1.64 76.99 4.08 20:1 0.9 1.3 1.1 Thompson were similar to those mea­ 22:1 0.3 0.3 0.3 sured for menhaden, but the median of Thread Fillet 20.63 2.58 75.68 1.36 herring H&G 20.65 322 73.23 3.68 18:2w6 1.4 1.5 2.0 all seasonal samples was much lower in (Gulf) 18:3w3 0.5 0.9 0.9 thread herring (5.1 vs. 13.3 percent). 18:4w3 0.6 1.0 1.0 Proximate analyses of three product 20:4w6 2.6 3.3 2.7 forms (skinless fillets, headed and gut­ 20:5w3 63 6.4 6.6 22:5w6 1.7 1.5 1.6 ted, and whole fish) are listed in Table 22:5w3 1.2 1.6 1.8 2. These are average values of the At­ terns are similar, with high concentra­ 22:6w3 27.0 18.8 20.0 lantic samples of scad and sardine and tions of long-chained polyunsaturates. Total saturates 37.7 42.1 36.2 of the Gulf samples of thread herring. Additional data are needed to better de­ Total monoenes 16.7 20.1 20.5 Samples of whole thread herring were scribe fat content in the fall and winter, not analyzed. but the reported data should be of value Total PUFA' 45.6 37.8 43.3 The major fatty acids determined for for greater utilization of the abundant ,For polyunsaturated falty acids. the first number to the ri9ht of the colon indicates the number of double the three species are listed in Table 3. coastal herring resources. bonds and the last number is the number of carbon The species exhibit a similar pattern, atoms separating the first double bond from the Acknowledgments methyl end of the molecule. with high concentrations of 16:0 and 'PUFA = Polyunsaturated falty acids. 22:6w3. Spanish sardines are particu­ Jim Bonnet performed the proximate larly rich in the 22:6 fatty acid. The chemical analyses and Tom Brown per­ totals of the highly unsaturated fatty formed the fatty acid analyses. Charles acids, containing 5 and 6 double bonds, Barans and Charles Wenner ofthe South in the eastern Gulf of Mexico. Proc. range from 28.3 percent in the thread Carolina Marine Resources Research Gulf Caribb. Fish. Inst. 28:73-82. Leak, J. C. 1977. Distribution and abundance of herring to 36.2 percent in the Spanish Institute, and Rick Dufresne of the Na­ Carangidae (Pisces, perciformes) larvae in the sardine. Recent research indicates that tional Marine Fisheries Service, eastern Gulf of Mexico, 1971-1974. Univ. these fatty acids may help to prevent Panama City, Fla. , are thanked for their Miami, Master's Thesis, 83 p. Metcalfe, L. D., and A. A. Schmitz. 1961. The coronary attacks by reducing blood assistance in sample collection. rapid preparation of fatty acid esters for gas clotting rates as well as reducing chromatographic analysis. Anal. Chern. cholesterol levels in the blood (Rawls, Literature Cited 33:363-364. Rawls, R. 1981. Fatty acid sQurce a factor in heart 1981). Erucic acid (22: Iw9), which has Ackman, R. G., and R. D. Burgher. 1965. Cod disease. Chern. Eng. News 59(6):24 (Feb. 9). adverse effects on certain laboratory liver oil fatty acids as secondary reference Reintjes, J. W. 1979. Pelagic clupeoid and caran­ standards in the GLC of polyunsaturated fatty gid resources for fishery development in the (e.g., heart lesions in male acids of origin: Analysis ofa dermal oil Gulf of Mexico and Caribbean Sea. Proc. Gulf weanling rats) when fed at high levels, of the Atlantic leatherback turtle. J. Am. Oil Caribb. Fish. Inst. 31:38-49. is quite low in these species. The total Chern. Soc. 42:38-42. Sidwell, Y. D. 1981. Chemical and nutritional AOAC. 1975. Official methods of analysis of the comparison offinfishes, whales, crustaceans, of all 22:1 isomers is only about 0.3 Association of Official Analytical Chemists. mollusks, and their products. NOAA Tech. percent of total fatty acids. 12th ed. Assoc. Off. Anal. Chern., Wash., Memo. NMFS F/SEC-1I, 432 p. The results of this study indicate that D.C. Smith, P., Jr., M. E. Ambrose, andG. M. Knobl, Hale, M. B., and T. Brown. 1983. Fatty acids and Jr. 1964. Improved rapid method for determin­ Spanish sardine, thread herring, and lipid classes of three underutilized species ing total lipids in fish meal. Commer. Fish. round scad have high protein and mod­ and changes due to canning. Mar. Fish. Rev. Rev. 26(7):1-5. 45(4-6):45-48. Thompson, M. H. 1966. Proximate composition erate fat contents during the normal Houde, E. D. 1976. Abundance and potential for of Gulf of Mexico industrial fish. U.S. Fish period of availability. Fatty acid pat- fisheries development of some sardine-like Wildl. Serv., Fish. Ind. Res. 3(2):29-67.

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