Antioxidant system for the preservation of vitamin A in Ultra Rice.
BACKGROUND
Ultra Rice grains are micronutrient-fortified, extruded rice grains designed to address specific nutritional deficiencies in populations where rice is a staple food. Vitamin A and some of the B vitamins, as well as iron and zinc, are target nutrients for fortification through Ultra Rice technology. Vitamin A is sensitive to degradation. Therefore, the original Ultra Rice formulations included stabilizers, some of which were not approved as food additives in all of the receiving markets.


OBJECTIVE
To develop a new antioxidant system for improving vitamin A storage stability in Ultra Rice grains, while complying with international food regulations.


METHODS
Ten formulations were prepared containing various combinations of hydrophilic and hydrophobic antioxidants, as well as moisture stabilizers. Accelerated vitamin A storage stability tests were conducted at 25 degrees, 35 degrees, and 45 degrees C with 70% to 100% relative humidity.


RESULTS
The most stable samples contained one or more phenolic antioxidants, a water-soluble antioxidant, and stabilizing agents. The best results were obtained by using butylated hydroxyanisole (BHA) in combination with butylated hydroxytoluene (BHT) as the hydrophobic antioxidants and ascorbic acid as the hydrophilic antioxidant. Citric acid and sodium tripolyphosphate (STPP) were used to chelate metal ions and to stabilize moisture, respectively. The best formulations retained more than 85% and approximately 70% of the added vitamin A at 25 degrees and 45 degrees C, respectively, after 24 weeks storage.


CONCLUSIONS
The best antioxidant system, composed of generally accepted food additives, improved vitamin A stability while reducing the price, thus greatly improving the commercial viability of Ultra Rice grains for use as a ricefortificant.
Li
Yao Olive
YO
Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College St., Toronto, ON M5S 3E5, Canada.
Lam
Jane
J
Diosady
Levente L
LL
Jankowski
Shirley
S
D000975:Antioxidants / Q000378:metabolism*; D001205:Ascorbic Acid / Q000378:metabolism; D002083:Butylated Hydroxyanisole / Q000378:metabolism; D002084:Butylated Hydroxytoluene / Q000378:metabolism; D019343:Citric Acid / Q000378:metabolism; D005503:Food Additives / Q000378:metabolism*; D005511:Food Handling / Q000191:economics / Q000379:methods*; D005527:Food, Fortified; D008670:Metals / Q000378:metabolism; D012275:Oryza / Q000378:metabolism*; D010636:Phenols / Q000378:metabolism; D011122:Polyphosphates / Q000378:metabolism; D014801:Vitamin A / Q000378:metabolism*; D014802:Vitamin A Deficiency / Q000517:prevention & control; D014867:Water / Q000502:physiology
D000975:Antioxidants; D005503:Food Additives; D008670:Metals; D010636:Phenols; D011122:Polyphosphates; D014867:Water; D014801:Vitamin A; D002084:Butylated Hydroxytoluene; D002083:Butylated Hydroxyanisole; D019343:Citric Acid; C005692:triphosphoric acid; D001205:Ascorbic Acid