It is common to use permitted preservatives to keep fruits, such as apples and pears, fresh for several months, a plant protection official has said.

>> Chinese pears with preservatives remain fresh after 5 months  

Allowable and proper preservatives, along with other factors including humidity and temperature, can help keep fruit fresh for 6-10 months, or even a year, a plant protection official has said. Nguyen Xuan Hong, head of the Plant Protection Department, under the Ministry of Agriculture and Rural Development, shared this information on Monday after the head of the ministry, Minister Cao Duc Phat, recently asked the department to clarify the reports that pears and apples imported into Vietnam remain fresh after five months, for the former, and nine months, for the latter. The minster also asked the department to confirm whether imported fruits contained any harmful preservatives. Vietnam currently imports apples and pears from China, the U.S., Australia and New Zealand. There are about 7,500 species of apples and 6,000 pear varieties in the world, and they can be kept with preservatives for only 15-30 days if they ripen early; for three to five months if ripened normally; and for 6-10 months, or even a year, if ripened late, depending on the variety, the Vietnam News Agency quoted Hong as saying. Besides the characteristics of each species, other factors such as temperature, humidity, and when a fruit is harvested also contribute to determining how long fruits can be kept fresh, Hong said. In order to maintain the freshness, color and flavor of fruits, people usually use substances that can prevent the production of Ethylene, a botanic hormone produced by fruits to make themselves ripen. Currently, many countries allow the use of such substances as Diphenylamine (DPA), Ethoxyquin, and 1-MCP (1-methylcyclopropene), which are all safe, for this purpose, Hong said.Vietnam has no safe preservative for long-term storage 1-MCP (1-metycyclopropene) is commonly used in the U.S., Japan, and South Korea, the official said.

Along with appropriate conditions, this chemical can keep apples unspoiled for over eight months, without affecting the fruits’ quality, color, and flavor, he said. Meanwhile, on the list of allowable plant protection drugs in Vietnam, there are almost no substances able to preserve fruits long-term, Hong pointed out, adding that this is a big disadvantage for Vietnamese fruit growers and traders. “When they find any fruit that remains fresh after several months, people often think that they have been preserved with harmful chemicals. In fact, safe preservatives can help store fruits for a long time without affecting their quality. On the contrary, if fruits were dipped in formaldehyde or other harmful chemicals, fruits will also not become rotten, but the quality and appearance will be affected, the official stressed.  Over 90% of imported fruits checked Over the past several years, the department has conducted tests on imported pears and apples, but has yet to find any risk of them containing harmful chemicals, the Vietnam News Agency quoted Hong as saying. However, excessive residue of several types of plant protection drugs have been found in apples, pears, grapes, oranges, and mandarins, he added. “Last year, the department found 17 lots of fruits containing residue beyond the acceptable levels. Only one lot has been recorded as having unacceptable levels this year, but it was not serious,” he told Dat Viet newswire. Of the total volume of fruit imported into Vietnam, more than 90 percent are brought in through official channels, and are all checked in accordance with applicable regulations, the official said. Vietnam now imports about 400,000 tons of fruit per year, according the Ministry of Agriculture and Rural Development.