contamination has been in the news lately in some peanut-butter and
pistachio brands. First, peanut-butter brands from the US were
reported contaminated. Later on, samples from two local brands were
reported tainted. Now it’s pistachio nuts mainly from the US that are
affected, although most of the brands were voluntarily recalled just as
Salmonella bacteria are the most
frequently reported cause of food-borne illness, the US Department of
Agriculture (USDA) web-site fact sheet said. To reduce salmonellosis or
Salmonella infection, it said, a comprehensive farm-to-table approach
to food safety is necessary. Farmers, industry, food inspectors, retailers,
food-service workers and consumers are each critical links in the
The Salmonella family includes more
than 2,300 serotypes of bacteria which are one-celled organisms too
small to be seen without a microscope. Two types, Salmonella Enteritidis
and Salmonella Typhimurium, are the most common in the United States
and account for half of all human infections.
Salmonella lives in the intestinal
tract of humans and other animals, including birds. It is usually
transmitted to humans by eating food contaminated with animal feces.
Being heat-sensitive, Salmonella
present in raw meat and poultry could survive if the product is not
cooked to a safe minimum internal temperature, the USDA said.
Salmonella can also cause
salmonellosis through cross-contamination, wherein juices from raw meat
or poultry come in contact with ready-to-eat foods, such as salads.
The bacteria have been known to cause
illness for over 100 years. They were discovered by American scientist
Dr. Daniel E. Salmon.
To prevent food from Salmonella
contamination, the Philippine Nuclear Research Institute (PNRI) said
the use of irradiation may be among interventions that may be used.
Zenaida de Guzman, head of PNRI’s
biomedical research section and project leader of food-irradiation
research and development project, said that in tandem with Good
Manufacturing Practices and Hazard Analysis and Critical Control Points
the use of irradiation in food may eliminate pathogenic microbes.
“We want the public to know that we
use this technology [irradiation] to eliminate microbes, such as
Salmonella, E. coli and Listeria in food,” de Guzman told the
BusinessMirror in an interview.
De Guzman, however, was quick to say
that the peanut butter and pistachio which were recently found or still
suspected to be contaminated with Salmonella could no longer be
irradiated by the PNRI.
She explained that only raw
agricultural materials are irradiated, like the peanut in the peanut
butter, or the raw pistachio, because the finished products have
already passed a long process—from planting to harvesting, drying,
processing, up to transporting, which might have caused the
contamination, or that toxins might have already developed.
“Agricultural raw materials have many
sources of microbial contamination, including water,” she noted.
Besides, she said, food irradiation
observes certain protocols, wherein the raw food materials are
irradiated immediately after they are dried after harvest to prevent
the development of more microbes. She said if there is a big amount of
microbes present, it might require a higher dose of irradiation that
may affect the quality, taste or color of the produce.
However, she said Filipino food
manufacturers should consider irradiation to make their products free
from disease-causing bacteria.
Irradiation uses high-energy ionizing
radiation, a PNRI flyer said, to reduce postharvest losses, disinfest
fresh fruits and other agricultural products, extend shelf life of food
and agricultural commodities, such as fruits, vegetables, meat, poultry,
fish and seafood, reduce microbes that cause spoilage and eliminate
De Guzman explained that
irradiation—which uses 300 Gray (Gy) to 1,000 Gy dose, depending on the
product that will be irradiated—is safe for human and animal consumption
because there is no radioactive residue left on the product.
“It is like putting the product under
x-ray,” she noted.
The PNRI’s irradiation facility was
set up as pilot-scale in 1984 and was upgraded to semicommercial scale
in 2008. It could handle 2 tons of products per load.
It irradiates spices and dehydrated
vegetables, such as ground black and white peppers, powders like
cayenne, turmeric, onion, garlic, ginger, tamarind, chives and other
De Guzman added that there is a
growing volume of herbal products, like ampalaya and malunggay powder,
that are irradiated at the PNRI. The same with frozen fruits for export
that are used in the production of ice cream.
Fresh onions and garlic also undergo
irradiation in the PNRI facility to inhibit sprouts. It, likewise,
irradiates medical products for sterilization purposes, such as
syringes, cotton, orthopedic implants, gauze, tubings, catheters.
She said that in foreign countries 80
percent use irradiation for sterilization. In the US even pet foods are
Patties for hamburgers, hot dogs or
frozen chicken may also be irradiated.
De Guzman announced that the
Philippines may soon export mango to the US after the three-year study
affirmed the absence of seed weevil in the whole country. Luzon and
Visayas were already found to be seed weevil- free. The results of the
same study in the Mindanao situation are being awaited this year.
The mangoes for export to the US will
still be irradiated against fruit flies.
In another export prospect, de Guzman
said China is making inquiries on its possible importation of
irradiated mangoes from the Philippines.