COCOA BEAN REJECTS DUE TO MOLD
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Center for Food Safety & Applied Nutrition FDA Technical Bulletin Number 5 |
A. METHOD FOR COCOA BEANS (V-18)
This method specifies procedures applicable to the analysis of raw cocoa beans to determine:
a. CPG 7105.12 Defect Action Levels for Cocoa Beans
b. Moldiness of Fungal Decay -- Species of molds which appear in beans as a visible growth in the nibs (cotyledons) belong to three classes of fungi: Phycomycetes, Ascomycetes, and Fungi Imperfecti. Within the Phycomycetes, Mucor sp. and Circinella sp. produce a coarse weblike growth of mycelial strands scattered over the surface. Eurotium repens of the Ascomycetes is frequently found; it produces a thick matted mass of mycelial growth containing small, round yellowish bodies (the ascocarps) which are readily visible when the bean is cracked open. The ascocarps are scattered throughout the mycelium both on the surface of the cotyledons and between the folds. Among the Fungi Imperfecti, species of Aspergillus are most commonly found. A. flavus produces a dark grayish-green mass of mycelium and spores and, in cases of thick matted growth on the surface of the cotyledons, a dusty mass of spores arises when the bean is cracked open. A. tamarii produces a dark brown mass of mycelium and spores. A. niger occurs only occasionally and produces a dark-colored area on the bean caused by the production of a mass of blackish brown spores. These aspergilli are associated with cocoa beans having a high moisture content. Aspergilli contamination indicates poor drying and storage practices. The extent of mold damage to individual beans can vary widely. In some beans a few hyphal strands may be present, while in extreme cases the inside of the bean may be completely covered with a thick matted mass of mold filaments and masses of spores accompanied by visually apparent disintegration of the cocoa bean tissue. Between these extremes, defective beans may exhibit any gradation of contamination by invading molds.
b. Visual Examination -- Crack open each bean and break into small pieces (nibs) along the natural folds of the cotyledons to expose the internal surfaces of the nibs.1 Examine each bean in a good light without the aid of a magnifier2 and classify according to (4)c.
c. Classification of Reject Beans -- Beans should be classified as follows:
(i) Moldy -- Any bean showing extensive mold affecting 1/4 or more of the exposed nib material. Do not classify as moldy any beans with:
Figure V-4 illustrates cocoa bean rejects due to mold.
Figure V-4
COCOA BEAN REJECTS DUE TO MOLD
1Examination of beans can be accomplished with facility by using a cracking board made from a 15 in. square sheet of 1/4 in. aluminum or plywood drilled with one hundred 7/8 in. holes, equally spaced in 10 rows of 10 holes each. Place the board on a large sheet of paper on a hard surface. Scatter the beans on the board to fill the holes. Sweep the excess beans off with the hand and adjust any empty or double-filled holes so that each of the 100 holes contains one bean. Crack open each bean by placing an iron bolt (about in. in diameter and about 3 in. long) on the bean and gently tapping the head of the bolt with a hammer.
2Magnifiers may be used by analysts to confirm the identification
of conditions initially observed by the unaided eye. Magnifiers may also
be used for familiarization with the range of damage characterizing specific
lots.)
(ii) Insect Infested or Insect Damaged - any bean showing insects (fragments or whole insects), insect excreta, webbing, or tunneling. Describe kind and extent of insects present in subsample under "Remarks" in (4)d.
(iii) Moldy and Insect Infested or Insect Damaged -- any bean that is both moldy and insect infested or insect damaged.
d. Report -- Record results of examination as follows:
| Code or Lot No. ____ | Subsample No. | |||
| 1 | 2 | 3 | etc. | |
| No. of insect-infested beans | ||||
| No. of moldy beans | ||||
| No. of moldy and insect-infested beans | ||||
| Total Rejects | ||||
| Remarks: |
||||
b. Report -- Tabulate and report amounts of each category of filth and extraneous matter per weight of sample or subsamples.
(1) Chadd, Eileen M., Cocoa -- Cultivation, Processing and Analysis, Interscience Publishers, Inc., New York, 1953.
(2) Gecan, J. S., and P. M. Brickey, Jr. "Cocoa Bean Histology and Comparative Micromorphology of Internal Bean Infesting Insects," , U.S. Food and Drug Administration, Internal Bulletin, Washington, DC, 1967.
(3) Cocoa Bean Import Survey 1959-1960, U.S. Department of Health, Education, and Welfare, Food and Drug Administration, Washington, DC.
B. METHOD FOR CANDY (V-22)
This method describes a general macroscopic procedure applicable to most candy products for determination of relatively obvious extraneous contamination. The term "candy" includes a wide variety of products manufactured from diverse ingredients. The type and extent of contamination in a finished product may vary substantially, depending on the ingredients used. Each ingredient introduces the potential for contamination due to distinct sources associated with its production, transport, and storage prior to incorporation into the candy product. Selection of a suitable method for analysis of any specific product material should therefore take into account the ingredients in the product as well as the techniques used in its production and storage. Additional methods for utilizing various selective digestion techniques to recover microscopic particulate and extraneous contaminants from candy are available in AOAC.
Because each raw material and processing method has unique contamination problems, it is essential to review the establishment inspection report and relevant defect profiles of product ingredients in order to identify likely routes of contamination and to determine suitable analytical procedures. Ingredients which are incorporated into a candy product with only slight changes in physical character may be easily separated from the product for selective analysis to detect visible moldy or insect-damaged portions. In some cases the external coating, such as chocolate, may be the suspect ingredient; in other cases it might be the starch-molded centers or whole nuts contained in the product. If the layers carry varying amounts and types of contaminants, they should be analyzed separately.
Where the finished candy may have become contaminated during the processing or in storage, a thorough macroscopic examination of the exterior is most important. Holes, tears, or other damage to the packaging material in which the candy is contained may occur from infestation by insects or other pests during storage. Molds may develop on the product from improper storage conditions. Other signs of contamination may include excrement from insects or rodents, insect cast skins, chewing and webbing, or other evidence of defilement.
b. Visual Examination -- Before opening bulk or individually packaged candy, carefully examine the packaging material for any signs of damage by rodents, insects, or other causes. If insect-bored holes were detected, determine, if useful, whether holes were made by entrance or exit of the insects (AOAC 973.63). Examine macroscopically the entire contents of consumer size packages where portions will be selected later for microscopic analysis. For assorted candies, examine each variety separately, as appropriate. Examine the surface of the candy for gross contamination with the naked eye or by using a low-power magnifier. Cut open, as appropriate, to determine any internal damage. Describe any damage found. Note the presence of any live insects.
c. Report -- For each subsample, report defective product units or pieces according to the type of defect and determine the percent of each.
Brickey, P.M., J.S. Gecan, and A. Rothschild, "Method for Determining
Direction of Insect Boring through Food Packaging Materials," JAOAC
56: 640-642, 1973.
Table
of contents
A. METHOD FOR PLANT GUMS (V-24)
This method describes procedures for detecting and measuring contamination caused by gross extraneous filth and/or decomposition in plant gums and for determining the percent of reject product material due to insect damage, mold or other adhering filth. The method involves direct visual examination and separation of contaminants.
Gums are hydrocolloids (hydrophilic colloids). Their water-binding properties make them an important ingredient for improving the texture of foods. The method is applicable, but not limited, to the "natural" gums listed in Table V-1.
Plant gums are subject to contamination by field and storage insects, birds, rodents, and other animals. Mold growth can also result from improper drying or storage conditions.
b. Visual Examination and Report -- Examine "throughs" and "overs" on the sieve(s). Follow Chapter V, Section 8A(4)b. through d. for examination, classification, and reporting of contaminants.
b. Visual Examination and Report -- Follow Section 8.A(5)b. through d. for examination, classification, and reporting of reject product material.
Light Filth in Crude Plant Gums, AOAC 969.45
NATURAL GUMS COVERED BY THE PLANT GUM METHOD
| Type | Name of Gum | Source | Production |
| Plant Exudates | Arabic | Acacia species, trees | Africa |
| Tragacanth | Astragalus species, shrubs | Asia Minor, Iran, Syria, Turkey | |
| Karaya | Sterculia urens Roxb., tree | India | |
| Ghatti | Anogeissus latifolia Wall., tree | India and Ceylon | |
| Plant Extracts | Pectins | Citrus species, peel, and Malus sylvestris Mill., apple, pomace | United States |
| Arabinoga- lactan (larch gum) | Larix species, larch trees | United States | |
| Plant Seed Flours | Locust bean (carob bean) | Ceratonia siliqua L., carob tree | Near East and Mediterranean |
| Guar | Cyamopsis tetragonoloba, (L.) Taub., guar plant | India and Pakistan | |
| Psyllium Seed | Plantago species, plantain | India and Mediterranean | |
| Quince Seed | Cydonia oblonga, Mill., quince tree | Iran | |
| Seaweed Extracts | Agar | Gelidium species and other red algae | Japan |
| Alginates | Macrocystis pyrifera (L.) C.A. Agardh. and other brown algae (kelp) | United States | |
| Carrageenan | Chondrus species, Gigartina species, and other red algae | Maine and Europe | |
| Furcellaran | Furcellaria fastigiata (Hudson) Lamouroux, a red alga | Denmark and Norway |
A. METHOD FOR CASEIN AND SODIUM CASEINATE (V-26)
This method describes a procedure for determining contamination in casein and sodium caseinate caused by discrete particulate filth from insects, birds, and other sources. The method involves direct separation of contaminants from the product by screening.
Casein is a white to yellowish granular protein precipitate made from skim milk by the action of dilute acid or rennet. Sodium caseinate, a white powder, is produced by treating casein with a dilute NaOH solution and then spray-drying the soluble material.
These products are used as protein supplements in dietetic foods, bakery products, stews, and soups. Sodium caseinate is also used as a binder, emulsifier, a whipping agent in food products, and as a prime constituent of nondairy cream.
These products may become contaminated with manure and plant fragments, insect and rodent filth, feathers, and other extraneous material.
a. Sample Preparation -- Draw a representative or selective number of analytical units from the sample, depending on the history of the lot.
b. Visual Examination -- Sift a minimum of 100 g of the subsample on an appropriately sized sieve. Examine for whole insects, rodent pellets, and other extraneous materials.
c. Report -- Report results, using the format in AOAC 970.66B(i).
A. METHOD FOR MICROSCOPIC DETECTION OF FISH TISSUE IN CRAB MEAT OR CRAB CAKES (V-27)
This method describes a microscopic procedure for the detection of fish tissues which may be substituted in whole or in part for crab meat. Crab meat products are prepared from the meat derived from any of several species of edible crabs, including blue, king, queen, tanner, Dungeness, red, and stone crabs, which are members of the Class Crustacea in the Phylum Arthropoda.
Some manufacturers of crab cakes may add fish meat to their product. With the following method, it is possible to detect the presence of as little as 1% fish meat in experimental batches.
b. Microscopic Examination -- Mount bits of the muscle fiber in acidified chloral hydrate-glycerol solution on slides, warm slide to clear tissues, and examine with a compound microscope. The striations on the fish muscle are indistinct as contrasted with the distinct striations of crab muscle fiber. Weigh any foreign tissues found and estimate percent present in the product.
c. Report -- Report presence of any fish meat and the approximate percent (by weight) found.
(1) Food Microscopy, J. G. Vaughn, Ed., Chapter 9, "Fish," Academic Press, New York, 1979.
(2) Freeman, C. C., "Cod or Crab," FDA Papers, Sept. 1967,
pp 20-22.
Table
of contents
B. METHOD FOR DETERMINATION OF PARASITES IN FIN FISH (V-28)
This method describes procedures for the determination of parasites in fish by visual examination. Gross visual examination is effective when the parasites are visible on the exposed surfaces of the fish or when the fish flesh is sufficiently transparent for the parasite to be seen against the background of food material. Up to 95% of the parasitic nematodes recovered by methods for digestion of fish can be detected by macroscopic examination. Macroscopic examination for parasites may be performed in conjunction with organoleptic examinations for decomposition.
Parasites in the edible flesh of fish are a naturally occurring defect. Among the parasites that infest fin fish are species of the Protozoa, three phyla of helminths and the parasitic copepods of the Class Crustacea.
b. Helminths -- The three distinct phyla of helminths found as parasites in fin fish are the Platyhelminthes, Nematohelminthes, and Acanthocephala.
(ii) Roundworms (Nematoda). Pollock and other coastal fish of Norway may be heavily parasitized by larvae of Hysterothylacium aduncum. Cod are routinely candled in several countries for detection and removal of macroscopic nematodes before packaging.
(iii) Spiny-headed worms (Acanthocephala). These worms live in the intestine and are attached to the wall by a protrusible proboscis covered with recurved hooks; the worms vary in length from less than an inch to more than a foot. The body of individuals from most species is elongate, flattened and capable of extension. No digestive tract is present at any stage of their life cycle; food is absorbed directly from the host's intestine.
c. Copepoda -- Copepods are free-swimming microcrustacea. They are the most numerous marine crustaceans in many habitats, both in species and as individuals. Copepods are usually bottle-shaped and generally range in size from less than 1 mm up to 50 mm; One genus, Pennela, reaches 250 mm in length. Many species are fish parasites. Among members of the Order Lernacopodorda, the females at one stage of development become immovable in the tissues of the host fish.
(ii) Fresh Fish with Pigmented Flesh or Processed or Frozen Fish -- Do not fillet. Prepare breaded products as in (iii) below.
(iii) Removal of Breading -- Frozen products should be thawed at room temperature in a beaker of appropriate size. After thawing, pour a hot (50oC) solution of 2 % sodium lauryl sulfate in water over the fish in increments of 100 mL per 300 g of product. Stir with a glass rod for 1 min. Allow to stand for at least 10 min or until breading separates from the flesh. Transfer individual portions to a No. 10 sieve nested over a No. 40 sieve. Wash the breading through the No. 10 sieve with a gentle stream of warm tap water. Examine the No. 40 sieve containing the breading periodically, using UV light [see caution, part (4)c. below]. Parasites will appear fluorescent under this light. Note any parasites detected and record for the report. Discard the breading by backflushing the No. 40 sieve with tap water.
b. Candling of White-Fleshed Fish -- Examine both sides of each prepared fillet on a light table. The intensity of the light must be sufficient to be transmitted through the flesh. Parasites should appear as irregularly spaced dark shadows in the translucent flesh. Parasites may be isolated for identification by dissection of the fish flesh. Isolated parasites should be fixed by the methods outlined in the specific parasite descriptions [see (4)d. below]. Suspect specimens which are not identified should be fixed in 10% formalin as in (4)d.(i) below.
c. Ultraviolet Examination of Dark-Fleshed Fish -- Visually examine each portion, de-breaded or de-skinned as necessary, on both sides under a desk lamp or similar light source. A magnifying desk lamp (II.(7)) may be used. Report findings as described below. Conduct UV examination in a darkened room. Examine each portion on both sides with reflected longwave UV light (366 nm wavelength). Parasites should fluoresce blue or green under this wavelength light. Fish bones and connective tissues, which also fluoresce blue, may be differentiated by their regular distribution and shape. Bone fragments will be rigid when probed. For UV examination of breading, see 7.B.(6)a.(v) above. Caution: Never expose unprotected eyes to UV light from any source, either direct or reflected. Always wear appropriate eye protection, such as goggles having uranium oxide lenses, welder's goggles, etc., when such radiations are present and unshielded. Keep skin exposure to UV radiations to a minimum.
d. Fixation of Parasites -- Parasites from lots which are actionable shold be fixed as described below and submitted to FDA headquarters for identification.
Figure V-5
CYSTS CONTAINING PARASITES IN FIN FISH
A -- Cysts containing tapeworm larvae (Triaenophorus on tullibee(0.3X))
B -- Female copepod (Sphyrion lumpi on rosefish (0.3X))
C -- Enlarge view of A (1X)
D -- Enlarged view of B showing internal attachment by means of the Sphyrion (1.5X))
(iii). Cestodes -- The elongate, flattened larvae (pleurocercoids or spargana) are white to cream-colored and have an anterior holdfast organ. Unencapsulated pleurocercoids of Diphyllobothrium latum L�he, the broad fish tapeworm of man, are 1 to 5 mm in width and up to 20 to 40 mm in length. The encapsulated pleurocercoids of Triaenophorus crassus Rudolphi are 2 to 4 mm wide and may be fixed in FAA for identification.
(iv). Nematodes -- Nematode larvae are cylindrical and highly variable in size, ranging from less than 0.25 mm to more than 100 mm in length and from 0.01 to 2 mm in diameter. Different species have different amounts of pigmentation; some appear white or cream-colored, others pinkish to red, and some tan or brownish. Some types are encapsulated and others are not; the same kind of nematode may even have some individuals encapsulated and others free in the same host. Nematodes are frequently coiled in the flesh of the fish, either in elongated spirals like a corkscrew or in flat coils. For identification, isolated nematodes should be fixed in glacial acetic acid for at least 1 hr. They should be transferred to 70% ethanol with 10% glycerol for storage and/or shipment.
(v). Acanthocephala -- For further identification, each larva must be dissected from its capsule and placed in distilled water for 1 hr at 2-5o C. This procedure relaxes the worm; the hydrostatic pressure causes the proboscis to evert. Cystacanths with everted proboscis should be fixed in warm (50oC) FAA.
(vi). Copepods -- These crustaceans are seldom found complete on marketed fish; however, the mouthparts may be found in ulcerous lesions 20 to 30 mm in diameter at the surface of the fish flesh. For identification, the affected area is cut from the flesh and fixed in 95% ethanol.
Editor's Note: Agency policy concerning sampling and criteria for regulatory action has changed considerably since the original publication of the following Multiple Sampling Plan. The plan may no longer be valid in many cases. Readers are advised to consult the Office of Seafood for current agency policy regarding sampling and regulatory actions involving parasites in fish.
e. Multiple Sampling Plan (3 subsamples)
(ii) If 1 to 5 parasites are recovered in the first subsample, examine the two additional subsamples.
(iii) If 6 or more parasites are recovered in the first subsample, the lot is actionable.
(iv) If the average number of parasites found in the 3 subsamples is less than 2 per kg, the lot is considered passable.
(v) If the average number of parasites found in the three subsamples is 2 or more per kg, the lot is actionable.
f. Report -- Report total number of parasites found per weight of sample(s) examined, and average number per kg. As appropriate, state identity of parasites.
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