title: Stability of the Stevia-Derived Sweetener Rebaudioside A in Solution as Affected by Ultraviolet Light Exposure.
abstract: Rebaudioside A is a natural noncaloric high-potency sweetener extracted from the leaves of Stevia rebaudiana. With rebaudioside A use increasing in foods, understanding the factors affecting its stability is necessary. This project evaluated the degradation rate constants of rebaudioside A in water, 0.1 M phosphate buffer, and 0.1 M citrate buffer at pH 3 and 7 as a function of ultraviolet (UV) light intensity (365 nm, 0 μW/cm2for dark conditions, 27 μW/cm2for low intensity, and 190 μW/cm2for high intensity) at 32.5 °C. Rebaudioside A stability was adversely affected by light exposure. The pseudo-1st-order degradation rate constants increased significantly (P < 0.05) with increasing light intensity in all solutions. Under dark conditions, rebaudioside A in phosphate buffers was more susceptible to breakdown than in water and citrate buffers at both pH levels. However, exposure to UV light resulted in rebaudioside A degradation occurring approximately 10 times faster in citrate than in phosphate buffers at both pH levels. The sensitivity of rebaudioside A to UV light was greater in citrate buffers than in water or phosphate buffers. The use of light-protective packaging for beverages containing rebaudioside A will improve its stability.
authors.affiliation: Food Science Program, Dept. of Poultry Science, Auburn Univ., Auburn, AL, 36849, U.S.A.|Entech Instruments, Inc., 2207 Agate Court Simi Valley, CA, 93065, U.S.A.
authors.forename: Jiewen
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Food Science Program, Dept. of Poultry Science, Auburn Univ., Auburn, AL, 36849, U.S.A.
authors.forename: Leonard N
authors.initials: LN
authors.lastname: Bell
mesh_terms: D045786:Diterpenes, Kaurane / Q000737:chemistry / Q000528:radiation effects*; D018857:Food Packaging; D006863:Hydrogen-Ion Concentration; D064427:Nutritive Sweeteners / Q000737:chemistry / Q000528:radiation effects*; D018515:Plant Leaves / Q000737:chemistry; D012996:Solutions; D036625:Stevia / Q000737:chemistry*; D014466:Ultraviolet Rays
chemical_list: D045786:Diterpenes, Kaurane; D064427:Nutritive Sweeteners; D012996:Solutions; C025474:rebaudioside A
keywords: degradation; photostability; rebaudioside A; stevia; sweetener