AOAC Official Method 967
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70F04B02029F4674915183007765B632 |
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文件大小(MB)： |
0.06 |
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页数： |
1 |
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日期： |
2016-2-28 |
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文本摘录（文本识别可能有误，但文件阅览显示及打印正常，pdf文件可进行文字搜索定位）：
16.13.11,AOAC Of fi cial Method 967.24,Filth in Mush rooms,First Ac tion 1967,(For mag gots, mites, etc., in canned, fresh frozen, freeze-dried,and de hy drated prod ucts.),A. Insects (First Action 1967; Final Action 1989),(a) Canned mushrooms.—Pour contents of can evenly over,weighed No. 8 sieve. Use 8 in. (20 cm) sieve, for containers of net,weight <3 lb (1.4 kg) and 12 in. (30 cm) sieve for larger containers.,Drain 2 min, and reweigh sieve and mushrooms to determine,drained weight mushrooms.,Rinse container, and use rinsings and several additional portions,water to rinse mushrooms on sieve (ca 500 mL total). Combine,drained liquid with rinsings and filter through ruled paper. Examine,residue on paper microscopically and determine total number of,maggots in liquid.,Place 100 g drained mushrooms in high-speed blender,945.75B(c) (see 16.1.01). Add 300 mL H2O and blend 30–45 s at ca,3000 rpm. Attain proper speed quickly by using setting of 1.5–2′,final setting on variable transformer for few s at start. Fragments of,mushrooms after blending should be 3–5 mm long. Pour mixture,into nested set of 8 in. (20 cm) Nos. 20, 40, and 140 sieves,945.75B(r) (see 16.1.01). Rinse tissue 2–3 min with spray of tap,water from aerator, 945.75B(a) (see 16.1.01). Discard material on,No. 20 sieve. Transfer residue from No. 40 sieve to 600 mL beaker,with H2O and bring total volume to ca 100 mL. Add 5 mL saturated,aqueous crystal violet solution and heat to bp. Pour stained mixture,into No. 40 sieve. Wash mushroom tissue, and maggots, if any, to,edge of sieve and remove excess stain with tap water from aerator.,Using wash bottle containing commercial 5.25% NaOCl solution,and gentle spray of tap water from aerator, alternately spray tissue,with H2O and NaOCl solution until stain has been removed from,mushroom tissue. Wash tissue into 600 mL beaker and transfer to,ruled paper, using vacuum. Avoid obscuring maggots with,mushroom tissues. (Not more than 2–3 papers should be necessary.),Transfer residue from No. 140 sieve to 600 mL beaker with H2O,and repeat staining, bleaching, and filtering as above.,Examine papers for maggots and other extraneous materials at,10–30′. Maggots are stained dark violet. Determine number of,maggots in 100 g drained mushrooms and add to this value the,number in proportionate amount of drained liquid calculated as,follows:,100,Total g drained mushrooms,total ′ number of maggots in liquid,(b) Fre s h , f ro z e n , f re e z e - d r i e d , and de hy drated,mush rooms.—For fresh and frozen mush rooms weigh 170 g test,por tion, and for dried mush rooms weigh 15 g test por tion, into,suit able con tainer, and add enough H2O to im merse mush rooms.,Soften mush room tis sue by soak ing sev eral hours or, al ter na tively,by heat ing on steam bath or sim mer ing 11,2–2 h as nec es sary,fol lowed by cool ing 30–60 min to fully rehydrate. Quan ti ta tively,trans fer con tents to high-speed blender with 300 mL wa ter and,pro ceed as in (a), be gin ning “?blend 30–45 s at ca 3000 rpm.”,Ref er ences: JAOAC 49, 576(1966); 50, 514(1967); 59, 353(1976).,(For dried [not powdered] products.),B. Light Filth (Procedure),Thoroughly mix test product and weigh 15 g test por tion. Transfer,mushrooms to trap flask, 945.75B(h)(4) (see 16.1.01), add H2O, and,let soak several hours, preferably overnight on steam bath, or boil,30 min. Cool to room temperature, add 30 mL heptane, 945.75C(l),(see 16.1.01), and churn contents by hard, rapid pounding of,mushrooms against bottom of flask, using vertical movement of,rubber plunger. Trap off twice, filter, and examine microscopically.,2006 AOAC INTERNATIONAL……
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