Iodized unrefined salt delivers micronutrients, says study

Iodized unrefined salt (coarse solar salt or raw salt), when properly packed and stored, can retain the prescribed iodine level for consumers for more than a year.

This was found in iodine retention studies on locally produced solar salt conducted by the Department of Science and Technology-Industrial Technology Development Institute (DOST-ITDI).

In a study of unrefined salt produced locally, researchers of the ITDI’s Food Processing Division noted that most salt producers could not meet the standard specifications for salt iodization.

Purity of local salt ranges from 76 to 92 percent (wet basis) with moisture content of 8 to 19 percent. This is in sharp contrast to the specifications for iodized salt under the ASIN Law, which promotes salt iodization nationwide and sets a minimum purity of 97 percent sodium chloride on a dry weight basis or 93 percent on a wet weight basis and a moisture content of four percent if refined and seven percent if unrefined.

ITDI said this situation, coupled with the influx of cheap imported salt owing to increasing trade liberalization, puts local salt producers at a disadvantage.

"With keener competition and the enforcement of the ASIN Law (Republic Act 8172), it is imperative for local producers to improve their product," the agency said.

Hence, the results of the ITDI study are of great help. This would help salt producers improve their production methods to obtain high quality, allowing them to compete with imported salt and, at the same time, comply with quality standards prescribed under the ASIN Law.

The positive results of the ITDI study also led to the issuance by the Subcommittee on Standardization of the Salt Iodization Program (under the ASIN Law) of provisional standards for raw salt that can be iodized.

These temporary standards specify a minimum purity of 90 percent (dry basis) and a maximum moisture content of 10 percent, while other impurities remain as specified in the ASIN Law’s implementing rules and regulations.

These standards are also transitory and based on a tacit agreement among the Bureau of Food and Drugs (BFAD), the Standardization Subcommittee and salt producers.

While the provisional standards are in place, salt producers must continuously work to improve the quality of their salt and make their product more suitable for iodization.

In their study, the ITDI-FPD researchers iodized coarse solar salt (79.3 percent purity, wet basis) and fine salt (92.6 percent purity) at two levels (0.01 and 0.012 percent potassium iodate).

The salt was packed in 0.002-inch thick polyethylene bags and stored in an environment with 85 percent relative humidity to simulate the average humidity in the country.

Samples of both types of salt were then stored at two conditions of ambient (28 to 30 degrees Celsius) and at abuse temperature of 40 degrees Celsius.

Changes in the salt’s iodine content were monitored biweekly. The chosen packaging material, though very thin, proved to be an effective moisture barrier.