D CONTROL (treenut, peanut and coconut processing)

D CONTROL (treenut, peanut and coconut processing)

Summary

Significant hazards a r Aflatoxin. r Salmonella.

Control measures

Initial level (H 0 ) r Use all control methods described under primary processing for most

effective control. r Protect incoming materials and equipment from birds and rodents.

Increase (ΣI) r Store in moisture proof containers at moisture levels <8% (aflatoxin). r Maintain dry processing equipment and environment. r Salmonellae will not increase on dried tree nuts, peanuts, or coconut.

Reduction (ΣR) r Roasting will reduce salmonellae to some extend, depending on moisture

available.

Testing

r Color screening of nuts and peanuts is useful for ingredients. r Testing finished product for aflatoxins presents sampling issues except

for homogeneous products such as peanut butter. r Testing for salmonellae is useful.

E. coli testing may be a useful indicator.

Spoilage

r Packaging in moisture impermeable films provides adequate protections. a In particular circumstances, other hazards may need to be considered.

Comments. Control of mycotoxins in nut products consists essentially of control at the raw material or primary processing stages. Sorting and diverting discolored, rejected nuts for other uses as previously described is an important, commonly used means to reduce mycotoxins to acceptable levels in finished products.

End product testing is widely practised, both by manufacturers and regulatory agencies. Because the percentage of peanuts containing aflatoxins is usually very low, but the level in individual nuts can be very high, it is impossible to guarantee the absence of aflatoxin in batches for processing. End-product testing provides a further level of assurance of the absence of aflatoxins. Testing of peanut butter, which is a more or less homogeneous product, is a useful check on color sorting and other procedures used on nut batches before processing.

Moisture control in equipment and the environment is necessary to reduce the risk of growth of bacterial pathogens (e.g. salmonellae) in the processing system. Procedures for maintaining, replacing, cleaning, and disinfecting equipment must address this potential hazard. Greater reliance on dry cleaning rather than wet systems is one effective means. Roasting can destroy enteric pathogens. This process should be used as a point of separation between raw nut storage and handling and the process product environment.

MICROORGANISMS IN FOODS 6

The risk of salmonellae in desiccated coconut can be controlled by immersing the raw coconut meat in water at 80 ◦

C for 8–10 min (Schaffner et al., 1967) and then preventing recontamination during oven drying and subsequent handling (Simonsen et al., 1987).

V Oilseed products

A Effects of processing on microorganisms In modern plants, extraction of oils from oilseeds usually involves the use of solvents, often n-hexane.

As a result, no microbiology is likely.

B Spoilage Hydrolytic or “soapy” rancidity can occur in confectionery containing fat through the introduction of

lipolytic enzymes from moulds present in ingredients such as coconut, milk products, egg albumin, and cocoa. This is especially serious with fats high in lauric acid, i.e. fats in coconut oil, palm kernel oil and butter fat, but not from cocoa butter, illipe fat, palm oil or peanuts, which do not contain lauric acid (Minifie, 1989).

C Pathogens Problems with pathogens are unlikely in oilseeds products. Aflatoxin is sometimes formed, but is rarely

of commercial significance.