1、Designation: E 1810 96 (Reapproved 2004)Standard Practice forEvaluating Effects of Contaminants on Odor and Taste ofExposed Fish1This standard is issued under the fixed designation E 1810; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revi
2、sion, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 The flavor quality of fish and shellfish (hereinaftercollectively termed “fish”) is related to thei
3、r exposure tocompounds that might be present in the food chain and thewater in which they live. High-quality fresh fish have apleasant, low-intensity flavor impact. Certain compoundsmight cause deterioration of, or change to, the flavor of thefishs flesh. Examples of sources of contaminants include
4、woodprocessing effluent, odorants of detergents, microbial genesis,accidents during the transportation of petroleum products,industrial sewage, farm runoff, and feedstuffs. Although knowncontaminant compounds can be detected by instrumentalmeans, the presence of many unknown contaminants is firstdet
5、ected through odor and flavor evaluation. This practicedescribes methodology for determination of the effects ofwater-related contaminants on the odor and taste of exposedlive fish, where flavor impairment is a suspected issue. Thispractice supersedes the sensory evaluation procedures detailedin Pra
6、ctice D 3696.1.2 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to
7、establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. Specific hazardsstatements are given in Section 7.2. Referenced Documents2.1 ASTM Standards:2D 3696 Practice for Evaluating an Effluent for Flavor Im-pairment to Fish FleshE 25
8、3 Terminology Relating to Sensory Evaluation of Ma-terials and Products2.2 Federal Documents:3CFR Regulations 21, Part 50Protection of Human Sub-jects, April 1994.3. Terminology3.1 DefinitionsSee Terminology E 253.4. Summary of Practice4.1 Fish that are suspected of having been exposed tocontaminati
9、on are to be processed and maintained for sensoryanalysis in accordance with appropriate manufacturing prac-tices. After cleaning and evisceration, fish are wrapped inprotective covering such as aluminum foil (which will notimpact flavor), placed in labeled plastic bags, and maintained atlow tempera
10、ture, necessary for preservation of the product.Samples must be frozen if sensory testing cannot be conductedwithin 24 h. Immediately prior to sensory testing, the fish arethawed under refrigeration, if frozen, and homogeneous com-posite samples are prepared by blending. Individually foil-wrapped al
11、iquots of 20-g fish (sufficient to provide all panelistswith identical samples for testing) are steamed and presented totrained sensory panelists for odor or flavor evaluation, or both.5. Significance and Use5.1 This procedure is used to determine the effects ofwater-related contaminants on the odor
12、 and taste of exposedfish. This procedure may be used as evidence in showingcompliance with regulatory procedures.5.2 This practice is designed for use by fish processors orresearch laboratories for evaluations by a trained and moni-tored sensory panel under the supervision of a sensory profes-siona
13、l.6. Apparatus6.1 Aluminum Foil, heavy-duty, approximately 0.5-mmthickness, or1This practice is under the jurisdiction of ASTM Committee E18 on SensoryEvaluation of Materials and Products and is the direct responsibility of Subcom-mittee E18.06 on Food and Beverage Evaluation.Current edition approve
14、d Oct. 1, 2004. Published October 2004. Originallyapproved in 1996. Last previous edition approved in 1996 as E 1810 96.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer
15、 to the standards Document Summary page onthe ASTM website.3Code of Federal Regulations, available from the U.S. Government PrintingOffice, Washington, DC 20402.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6.2 Polyethylene Bags, h
16、eat-sealable, as an alternative toaluminum foil.6.3 Steam Bath, with rack and lid.6.4 Thermometer, with a range from 20 to 100C.6.5 Electrical Warming Tray.7. Precautions and Safety Hazards7.1 Fish that are being cleaned in the field should be washedwith a source of clean, fresh water, and not with
17、effluent or thedilution water (river, lake, etc.). In the event that no clean wateris available, the fish should be transported to a source of cleanwater for cleansing, eviscerating, and freezing. Use papertowels to wipe the fish clean.7.2 Do not taste fish that have died or are suspected ofhaving d
18、ied as a result of exposure to contaminants, or thatshow any signs of toxic effects, because they might be toxic tothe taster or possible tissue deterioration might influence thetest results.7.3 Where possible, if fish are to be frozen, they should havebeen eviscerated prior to freezing because the
19、contents of theviscera may lead to subsequent flavor effects.7.4 Minimize personal contact with the effluent or dilutionsof the effluent because it is always possible that some hazard-ous material, bacterial, or viral pathogen might be present.Clean hands, clothing, and equipment after contact thoro
20、ughly.7.5 Follow local water safety laws and practices in fieldstudies. Check with local enforcement agencies because theselaws vary from one area to another.7.6 A current food handlers certificate might be required bylocal law for the cleaning, handling, and preparation of fish andshellfish samples
21、.7.7 Chemical and microbiological analysis of the testsamples should be undertaken prior to sensory analysis. Ifpotential contaminants are known to be hazardous, then sen-sory assessment must be by odor evaluation only.7.8 Panelists must read a statement that they are aware ofthe requirements of the
22、 test procedure. Prior to testing, allpanelists must sign an informed consent form between them-selves and the sponsoring organization (see CFR Regulations21, Part 50).7.9 Every attempt should be made to prevent further con-tamination of the samples. Panelists and sample preparers andservers must av
23、oid introducing extraneous odors during prepa-ration and testing from the use of products such as scentedhand soap, hand creams, hairspray, perfume, odorous writinginstruments or inks, etc.8. Sampling Procedures8.1 See Practice D 3696 for conducting laboratory exposureof fishes.8.2 See Ref (1).49. S
24、ample Preparation9.1 The method of sample preparation should result inuniform samples for panelists. Preparation of homogeneouspooled samples is recommended because there might be flavorvariation between fish, as well as within individual fish, such asdifferences between the anterior and posterior p
25、ortions of a fishand dark versus light muscle areas of the fish.9.1.1 For fresh fish, scale, if necessary, eviscerate andremove the head, tail, and large bones or shell crustaceans andmolluscs. Thaw frozen fish in a refrigerator (4C) for up to 18h.9.1.2 Wash each fish in cold running water for 60 s.
26、 Shredthe fish flesh (with or without skin) or the entire flesh portionof shellfish (de-shelled) in a food processor for 4 s usingchopping blades to provide a homogeneous sample. Weigh out20-g samples, the number of which is equivalent to the numberof panelists. Wrap each 20-g aliquot or sample in h
27、eavy-dutyaluminum foil (see Appendix X1), and code foil packages witha three-digit code for identification in sensory analysis. Keepsamples refrigerated at all times prior to cooking.9.1.3 Preparation by steaming is preferable to other cookingmethods such as frying, baking, or microwaving because it
28、minimizes other flavor changes that would result from elevatedtemperatures and allows the preparation of individual, uni-formly cooked samples.9.1.4 Arrange foil-wrapped samples in a single layer on arack in a steamer to allow adequate steam circulation. Do notpuncture any of the packages. Cook the
29、samples over steam for7 min, and serve from electrical warming trays to maintain aconstant sample temperature of 70C during panel sessions.The samples should be served to all panelists after an equiva-lent interval of time. No samples should be held longer than 15min.9.2 An alternative method of sam
30、ple preparation is the useof heat-sealable polyethylene bags. The bags containing 20-gsamples are boiled for 5 min in rapidly boiling water with thismethod. For all sample wrapping materials, the degree towhich the material might impact the flavor of the fish must beknown and addressed.10. Procedure
31、s for Training a Sensory Panel for FlavorImpairment of Fish10.1 See Refs (2 and 3).10.1.1 Individuals who are selected to participate as sensorypanelists should be selected for their experience and ability todetect and quantify the off-flavors (when possible) from thesuspected contaminant source; th
32、ey should be trained in theevaluation procedure, and their performance should be vali-dated before testing begins, as recommended in Ref (2). Alltraining and test evaluations should be documented, andrecords should be retained.10.2 Determine the training needs based on the specific testobjective. Te
33、sts may include attribute recognition, attributeintensity ratings, or difference tests, or some combinationthereof (3). Panelists must be familiar with the test procedureand any scale(s) to be used for evaluating the samples.10.3 Terminology and Characteristics:10.3.1 A limited lexicon specific for
34、the descriptors andreferences for odors and flavors for fish and contaminants isincluded in Appendix X2 and Appendix X3.NOTE 1Reference ASTM E-18-04-22 Descriptive Analysis Lexicon.4The boldface numbers in parentheses refer to the list of references at the end ofthis practice.E 1810 96 (2004)210.3.2
35、 Odor recognition tests should include some of thecontaminants if they are known to be present in the fish.10.4 Prepare training samples that are characteristic ofvarious odors and flavors and various intensity levels. UseAppendix X2 and Appendix X3 as a guide. Evaluate a series ofconcentrations, st
36、arting with easily distinguished samples, andproceed to more difficult discriminations. Check the consis-tency of individual panelists performance (2).11. Sensory Testing Procedure11.1 In these studies, there are a number of factors thatshould be considered in the design and execution of the testing
37、procedure. There might not be an available control or referencesample against which to compare test samples in some situa-tions. The number of available samples might be limited, thusrestricting the number of replications in the test design.Samples might differ visually, and the difference might bed
38、ifficult to disguise, thus leading to sample bias. An odorevaluation of the fish might be the only feasible test methoddue to hazards from contaminants. If flavor is evaluated,panelists must be instructed to expectorate all samples.11.2 Experimental Designs With a Control SampleReferto Practice D 36
39、96.12. Sensory Testing Facility12.1 See Ref (4). All sensory testing procedures should beconducted in an appropriately designed facility. One importantconsideration for this facility is the requirement for a cookingarea with its own ventilation system that is separated from thesensory panel evaluati
40、on area. There should also be an efficientair removal system in the sensory panel evaluation area.13. Instructions to Panelists for Odor Evaluations13.1 When testing samples with weak odors, instruct pan-elists to smell an empty glass container to facilitate adaptationto extraneous odors and to allo
41、w for better discriminationbetween samples. For aroma evaluation, it is recommendedthat samples be placed in closed glass containers for anevaluation of the headspace odors. This is especially helpfulfor samples with weak aromas.13.2 Present samples in random order and instruct paneliststo evaluate
42、them from left to right.13.3 Instruct panelists to cut open the foil sample packageor plastic sample bag containing the cooked fish sample, andsniff (use two to three short “bunny” sniffs). For all remainingsamples the panelists should sniff in the same manner, keepingthe distance from the nose, num
43、ber of sniffs, and length ofsniffing constant.13.4 Instruct panelists to smell the back of the hand or acontainer of clean potable water before testing samples andbetween samples to help “zero” the nose and to preventadaptation to the odors.14. Instructions to Panelists for Flavor Evaluations14.1 In
44、struct panelist to do the following:14.1.1 Rinse the mouth well with warm (50 6 1C) odorand flavor-free water before starting the flavor evaluation.14.1.2 Taste the samples in the order presented.14.1.3 Expectorate each sample; do not swallow the sample.14.1.4 Rinse the mouth well with warm-temperat
45、ure water(50 6 1C) between samples for a predetermined amount oftime to clear the mouth of residual flavors.14.1.5 Wait a predetermined amount of time before tastingsubsequent samples to prevent taste fatigue; be consistent.14.1.6 Additional methods to clear the mouth include un-salted soda crackers
46、 or a 50:50 blend of warm water (50C) androom temperature sodium-free carbonated water.14.2 If residual flavors persist, repeat the procedure ofrinsing and resting.15. Procedure for Data Collection15.1 Attribute RecognitionUse to describe, rank, and ratethe overall intensity of specific odor and fla
47、vor attributes of asample, including odors or flavors, or both, that contribute tooff characteristics. If available, a highly trained sensory panelis the most sensitive method to use for data collection (see Ref(5).15.2 Difference TestingA triangle or duo-trio differencetest is used to assess whethe
48、r there is a difference between thecontaminated sample and a known control, if available (see Ref(3).16. Data Handling16.1 Statistical analysis of the data will depend on the typeof test and test design. Reference (3) contains statisticalanalyses appropriate for various sensory tests. Specific datah
49、andling methods for descriptive tests are presented in Ref (5).17. Data Interpretation17.1 Action criteria will depend on the policy of theregulatory authorities responsible for monitoring the specificaquatic site from which the samples were obtained.18. Keywords18.1 descriptive testing; discriminative testing; fish; flavors;odors; off flavors; off odors; scaling; sensory analysis; shell-fish; taint; tasteE 1810 96 (2004)3APPENDIXES(Nonmandatory Information)X1. PREPARATION OF WRAPPED CODED SAMPLES FOR STEAMING (COOKING) AND PRESENTATION FOR SENSORYANALYSISFIG. X1.1
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