'Liquid smoke' from rice shows potential health benefits

Liquid smoke flavoring made from hickory and other wood — a mainstay flavoring and anti-bacterial agent for the prepared food industry and home kitchens — may get a competitor that seems to be packed with antioxidant, antiallergenic and anti-inflammatory substances, according to a new study in ACS' Journal of Agricultural and Food Chemistry. It is the first analysis of liquid smoke produced from rice hulls, the hard, inedible coverings of rice grains.

Mendel Friedman, Seok Hyun Nam and colleagues explain that wood from trees is typically used to produce liquid smoke, added to meat and other foods for a smoky taste. But other types of plants can also be burned to make the popular seasoning. Rice is a prime candidate, with 680 millions tons produced worldwide each year. Hulls account for 136 million tons of that amount and often go to waste. The researchers wondered rice hulls could be put to good use in a liquid form as a food flavoring, and did the first studies needed to determine if rice hull smoke is safe enough for food use.

The scientists found that liquid smoke from rice hulls may be healthful. Their tests on laboratory cell cultures found that liquid rice hull smoke worked as an antioxidant that could help fight off diseases. It also helped prevent inflammation, which is associated with many different health problems did not trigger an allergic response. "New food uses of a major agricultural byproduct may benefit the environment, farmers, and consumers," the report stated. "However, it is necessary to demonstrate that rice hull smoke is safe. The present study was designed to contribute to this assessment."

The authors acknowledge funding from the Rural Development Administration, Republic of Korea.