763 Journal of Food Protection, Vol. 63, No. 6, 2000, Pages 763±767 Copyright Q, International Association for Food Protection Chlordane and Toxaphene Residues following Cooking of Treated Channel Cat®sh Fillets C. R. SANTERRE,1* R. INGRAM,2 D. H. XU,3 G. W. LEWIS,4 AND L. G. LANE2 1Department of Foods and Nutrition, Purdue University, West Lafayette, Indiana 47907-1264; 2Mississippi State Chemical Laboratory, Mississippi State, Mississippi 39762; 3Department of Fisheries and Allied Aquacultures, Auburn University, Auburn, Alabama 36849; and 4Warnell School of Forest Resources, University of Georgia, Athens, Georgia 30602, USA MS 99-215: Received 28 July 1999/Accepted 17 December 1999 Downloaded from http://meridian.allenpress.com/jfp/article-pdf/63/6/763/1673844/0362-028x-63_6_763.pdf by guest on 27 September 2021 ABSTRACT The reduction in residues of chlordane and toxaphene following cooking (frying, baking, and smoking) of ®llets obtained from treated Channel cat®sh (Ictalurus punctatus) was determined. On average, cooking reduced moisture content by 17% and increased fat content by 28 to 274%. Frying reduced chlordane residues by 56 to 86% on a dry basis (db) or 84 to 92% on a percent fat basis (fb) when raw ®llets were compared to cooked ®llets. Baking and smoking reduced chlordane signi®cantly less (P , 0.05) than frying with reductions in residues of 12% and 9% (db) or 30% and 33% (fb), respectively. Frying reduced toxaphene residues by 40 to 49% (db) or 65 to 77% (fb), while baking and smoking reduced toxaphene by 35% and 24% (db) or 51% and 59% (fb), respectively. Numerous reports (12, 27) have documented the pres- studies previously discussed, that residues in wild ®sh may ence of organochlorine residues in wild ®sh including frequently exceed the FDA guidelines. chlordane (5±8, 15) and toxaphene (19). Average total The reduction in food contaminants during preparation chlordane residues in wild ®sh have been reported as high and cooking have been reported (17, 22, 23, 34). More as 6.69 ppm wet basis for wild ®sh collected in a national speci®cally, the reduction in ®sh contaminants during food survey during 1978 to 1979 (25) and less than 0.07 ppm preparation has been investigated for the past 30 years (1± in a 1987 sampling (8); however, typical average levels are 4, 13, 14, 16, 20, 21, 24, 28±33, 35, 36). Even though demonstrated by other reports that indicate levels in ®n®sh researchers have reported mixed results, it is clear from from Maryland waters at 0.12 ppm (7); carp from the Upper these studies, that preparation and cooking signi®cantly re- Steele Bayou, Mississippi at 0.15 ppm (12); carp and bass duce pesticide residues in ®sh. from Tuttle Creek Lake, Kansas at 0.1 and 0.092 ppm (5), The objective of this study was to determine the in¯u- respectively; Channel cat®sh from the lower Mississippi ence of frying, smoking, and baking on residues of chlor- River at 0.17 ppm (15); and Channel cat®sh from the Mis- dane and toxaphene in ®llets from treated Channel cat®sh. souri River at 0.116 ppm (6). Other researchers have re- MATERIALS AND METHODS ported average chlordane residues in farm-raised Channel cat®sh of less than 0.045 ppm (26) and 0.10 ppm (18). Channel cat®sh were raised at a density of 18 ®sh (15 kg) Recently, toxaphene residues have been reported by the in each tank (tank volume was 10.22 m3; water was exchanged Food and Drug Administration (FDA) (11) in the Total Diet ®ve times during the study) with two tanks for each residue. Fish Study and in infant foods sampled during 1998. Average were fed a 32% protein, ¯oating cat®sh feed (Alabama Farmers toxaphene residues in wild ®sh have been reported as high Cooperative IMC, Decatur, Ala.) for a period of 25 days at the as 21 ppm for wild ®sh collected in a national survey dur- rate of 1% body weight and then at a rate of 0.5% for next 13 ing 1980 to 1981 (27); however, typical levels are dem- days in order to maintain water quality. Feed composition was 32% protein, 2.5% fat, 6.0% ®ber, and 12% moisture. Chlordane onstrated by other reports that indicate average levels in (technical grade, Ultra Scienti®c, Inc., No. Kingstown, R.I.) and Largemouth bass and Channel cat®sh from Lake Provi- toxaphene (technical grade, Ultra Scienti®c, Inc.) were incorpo- dence, Louisiana at 8.96 and 2.27 ppm (19), respectively; rated into feed at 2 mg kg21. Thoroughly ground feed was mixed in Largemouth bass from Lake Bruin, Louisiana at 3.58 with chlordane or toxaphene and made into pellets using 3% car- ppm; and carp from the Upper Steele Bayou, Mississippi boxymethyl cellulose as a feed binder. The total amount of treated at 3.06 ppm (12). feed consumed by the ®sh during 38 days was 5.4 kg. A group The FDA (10) has established action limits for total of ®sh (control) were fed commercial feed with no added residues. chlordane and toxaphene residues in the raw edible portion At harvest, 24 ®sh for each organochlorine treatment were of ®sh at 0.3 and 0 ppm, respectively. It is evident from collected and divided into four groups of six ®sh to be processed using one of four preparation methods. Fish were physically stunned using a heavy hammer, beheaded using a band saw (mod- * Author for correspondence. Tel: 765-496-3443; Fax: 765-494-0674; el 22, Biro Manufacturing Co., Marblehead, Ohio), then skinned E-mail: [email protected]. (Techo, Townsend Engineering Co., Des Moines, Iowa), and hand 764 SANTERRE ET AL. J. Food Prot., Vol. 63, No. 6 TABLE 1. Average chlordane residues in six raw and cooked ®sh ®llets from chlordane-fed cat®sh prepared by frying, baking, or smoking or analyzed raw Chlordane (ppb) mean concentration 6 SD (n 5 6) Moisture content Lipid content Wet basis Cooka Raw Cook % diff. Raw Cook % diff. Raw Cook FR 76.9 6 1.6 60.5 6 3.2 221.2 6 5.2 3.7 6 1.6 10.6 6 1.6 274 6 242 30 6 13 22 6 9 IF 75.8 6 1.2 67.6 6 1.5 210.8 6 0.8 5.3 6 1.1 8.6 6 1.3 73 6 55 30 6 8 5 6 0 BK 75.1 6 2.5 61.9 6 4.1 217.6 6 3.0 4.8 6 1.8 6.1 6 2.3 28 6 17 36 6 12 48 6 16 SM 75.6 6 1.3 65.6 6 1.8 213.2 6 1.7 6.2 6 1.4 8.4 6 2.3 36 6 20 43 6 13 54 6 14 Downloaded from http://meridian.allenpress.com/jfp/article-pdf/63/6/763/1673844/0362-028x-63_6_763.pdf by guest on 27 September 2021 a Cooking method: FR, deep fried; IF, polyphosphate injected and fried; BK, baked; SM, smoked. b Values in each column followed by different letters are signi®cantly different (P 5 0.05). ®lleted into two mirror-image ®llets keeping the belly ¯aps intact. Individual ®llets were ground twice using a meat grinder Matched ®llets were subsequently analyzed for the chlorinated (model 31FG10 Waring Products Div., New Hartford, Conn.). The residues with one ®llet being maintained raw while the other ®llet samples were placed in glass jars and stored at 2238C. Between was cooked using one of the four preparation methods. Corre- each sample, all utensils were cleaned thoroughly with detergent sponding ®llets from each ®sh were wrapped in aluminum foil (Alconox Inc., New York, N.Y.) rinsed with water, dried, and (Reynold Metals Co., Richmond, Va.) and placed in zip-lock plas- rinsed with 2-propanol (Baker Analyzed, J. T. Baker Inc., Phil- tic bags (Glad-Lock, First Brand Corp., Danbury, Conn.). The lipsburg, N.J.). bags were stored for 1 to 3 months at 2238C prior to further A 5-g ground sample of ®sh was weighed for moisture anal- processing at which time they were thawed at 48C overnight. ysis. The sample was placed in an air oven at 1058C for 24 h and Frying (FR) of samples was done using a 10-liter deep fryer then weighed for weight loss. Extraction of fat and pesticide res- (Colinco Fish Cooker CC-10, Damark International, Minneapolis, idues from ®sh was performed using a modi®ed FDA method (9). Minn.) with canola oil (Crisco, Proctor & Gamble, Cincinnati, A 5-g sample was placed into a glass beaker and mixed with 75 Ohio). Breaded (House Autry, House Autry Mills Inc., Newton g of anhydrous sodium sulfate (Fisher Scienti®c), then placed in Grove, N.C.) ®llets were fried at 1908C for about 7 to 10 min a desiccator at room temperature for at least 12 h. The mixture until golden brown. An internal temperature of 718C was obtained was transferred into a prerinsed 35-mm inner diameter by 90-mm and measured by a thermocouple. For a variation on the previous glass thimble (extra coarse, size 22) and extracted with a Soxhlet frying method, ®sh were injected (IF) with a 6% polyphosphate apparatus for at least 7 h using 300 ml hexane (Burdick and Jack- solution (Lem-O-fos, Rhone-Poulenc Basic Chemical Co., Shel- son, Muskegon, Mich.) at a turnover rate of between four and ®ve ton, Conn.) to add not more than 10% of ®llet weight. This is a times per hour.