1、Designation: E1810 12Standard Practice forEvaluating Effects of Contaminants on Odor and Taste ofExposed Fish1This standard is issued under the fixed designation E1810; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of la
2、st revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 The flavor quality of fish and shellfish (hereinaftercollectively termed “fish”) can be related to their exposure tocomp
3、ounds that might be present in the food chain and thewater in which they live. High-quality fresh fish have alow-intensity aroma and flavor impact. Certain compoundsmight cause deterioration of, or change to, the flavor of thefishs flesh. Examples of sources of contaminants include woodor other proc
4、essing effluent, odorants of detergents, microbialgenesis, accidents involving petroleum products, industrialsewage, farm runoff, and feedstuffs. Although many knowncontaminant compounds can be detected by instrumentalmeans, the presence of many unknown contaminants is firstdetected through odor and
5、 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 Practice D3696.1.2 The va
6、lues stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.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 establish appro-priate s
7、afety 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:2D3696 Practice for Evaluating an Effluent for Flavor Im-pairment to Fish Flesh3E253 Terminology Relating to
8、 Sensory Evaluation of Ma-terials and Products2.2 Federal Documents:421 CFR Part 50 Protection of Human Subjects3. Terminology3.1 DefinitionsSee Terminology E253.4. Summary of Practice4.1 Fish that are suspected of having been exposed tocontamination are to be processed and maintained for sensoryana
9、lysis 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 at4C or below, necessary for preservation of the product.Samples
10、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. Individually foil-wrapped aliquotsof 20-g fish (sufficient to provide all panelists with nearlyi
11、dentical 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 and taste of exposedfish. This procedure may be used as evide
12、nce 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-sional.6. Apparatus6.1 Aluminum Foil, heavy-duty, approximately 0.5
13、-mmthickness, or1This practice is under the jurisdiction of ASTM Committee E18 on SensoryEvaluation and is the direct responsibility of Subcommittee E18.06 on Food andBeverage Evaluation.Current edition approved March 1, 2012. Published April 2012. Originallyapproved in 1996. Last previous edition a
14、pproved in 2004 as E1810 96 (2004).DOI: 10.1520/E1810-12.2For 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 to the standards Document Summary page onthe ASTM website.3Wit
15、hdrawn. The last approved version of this historical standard is referencedon www.astm.org.4Code 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
16、 States.6.2 Polyethylene Bags, heat-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 prepared and eviscerated in the fieldshould be visually
17、 evaluated to see if the outer coating on skinor shell has evidence of contamination. Determine if thecoating should be disturbed or is significant to results. If thecoating can be disposed of, wiping the skin or shell ispreferable to washing. Use paper towels to wipe the fish clean.Do not use water
18、 containing the effluent or the dilution water(river, lake, and so forth). In the event that no clean water isavailable, the fish should be transported to a source of cleanwater for cleansing, eviscerating, and freezing.7.2 Do not taste fish that have died or are suspected ofhaving died as a result
19、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 contents of thev
20、iscera 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 thoroughly.7.5 Follow
21、 local water safety laws and practices in fieldstudies. Check with local enforcement agencies because theselaws vary from one area to another.7.6 Acurrent food handlers certificate might be required bylocal law for the cleaning, handling, and preparation of fish andshellfish samples.7.7 Reasonable a
22、ssurance of pertinent chemical and micro-biological safety of the test samples should be assessed beforesensory tests. If potential contaminants are known to behazardous, then sensory assessment must be by odor evaluationonly.7.8 Panelists must read a statement that they are aware ofthe requirements
23、 of the test procedure. Prior to testing, allpanelists must sign an informed consent form between them-selves and the sponsoring organization (see 21 CFR Part 50).7.9 Every attempt should be made to prevent further con-tamination of the samples. Panelists and sample preparers andservers must avoid i
24、ntroducing 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 D3696 for conducting laboratory exposureof fishes.8.2 See Ref (1).59. Sample
25、Preparation9.1 The method of sample preparation should result inuniform samples for panelists. Preparation of homogeneouspooled samples is recommended because there might be flavorvariation among fish, as well as within individual fish, such asdifferences between the anterior and posterior portions
26、of a fishand dark versus light muscle areas of the fish.9.1.1 For fresh fish, eviscerate and remove the head, tail,and large bones or shell crustaceans and molluscs. Thaw frozenfish in a refrigerator (4C) for up to 18 h.9.1.2 Observe if the outer coating on skin or shell hasevidence of contamination
27、. Determine if the coating should bedisturbed or is significant to results. If the coating can bedisposed of, wiping the skin or shell is preferable to washing.Shred the fish flesh (with or without skin) or the entire fleshportion of shellfish (de-shelled) in a food processor for 4 susing chopping b
28、lades. Mix shredded fish muscle thoroughly toprovide a homogeneous sample. Weigh out or portion 20-gsamples of the composite mixture, the number of which isequivalent to the number of panelists factored by the number ofreplicates. Wrap each 20-g aliquot or sample in heavy-dutyaluminum foil (see Appe
29、ndix 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 or baking because it minimizes otherflavor changes that would resu
30、lt from elevated temperaturesand allows the preparation of individual, uniformly cookedsamples. Pretested microwave oven procedures that do notovercook samples or expose samples to food-reactive equip-ment can be used.9.1.4 Arrange foil-wrapped samples in a single layer on arack in a steamer to allo
31、w adequate steam circulation. Do notpuncture any of the packages. Cook the samples over steam for7 min, and serve from electrical warming trays to maintain aconstant sample temperature of 70C during panel sessions. Nosamples should be held longer than 15 min. The samplesshould be served to all panel
32、ists after an equivalent interval oftime.9.2 An alternative method of sample 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 mig
33、ht impact the flavor of the fish must beknown and addressed.10. Procedures 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
34、 the off-flavors from the suspected contami-nant source; they should be trained in the evaluation procedure,and their performance should be validated before testingbegins, as recommended in Ref (2). All training and testevaluations should be documented, and records should beretained.5The boldface nu
35、mbers in parentheses refer to the list of references at the end ofthis practice.E1810 12210.2 Determine the training needs based on the specific testobjective. Tests may include attribute recognition, attributeintensity ratings, or difference tests, or some combinationthereof (3). Panelists must be
36、familiar with the test procedureand any rating scale(s) to be used for evaluating the samples.10.3 Terminology and Characteristics:10.3.1 A limited lexicon specific for the descriptors andreferences for odors and flavors for fish and contaminants isincluded in Appendix X2 and Appendix X3.10.3.2 Odor
37、 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, Appendix X3, and Ref (4) as guides. Evaluate aseries of concentrations
38、, starting with easily distinguishedsamples, and proceed to more difficult discriminations. Checkthe consistency 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 testi
39、ngprocedure. 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 b
40、edifficult 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 D3
41、696.12. Sensory Testing Facility12.1 See Ref (5). 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 evaluat
42、ion 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 low intensity aromas,instruct panelists to smell an empty glass container to facilitateadaptation to extraneous odors an
43、d to allow for better discrimi-nation between samples. For aroma evaluation, it is recom-mended that 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 panelist
44、sto evaluate 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
45、the nose, number of sniffs, and length ofsniffing constant.13.4 Instruct panelists to smell the back of their 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 Eva
46、luations14.1 Instruct panelists 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 wi
47、th warm-temperature 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-salt
48、ed soda crackers 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 speci
49、fic odor and flavor 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(6).15.2 Difference TestingAn appropriate ASTM differencetest is used to assess whether 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 f
