Compositional and Sensory Analyses of Sweetpotatoes after X-ray Irradiation Quarantine Treatment

Abstract

<jats:p>Sweetpotato [<jats:italic>Ipomoea batatas</jats:italic> (L.) Lam.] roots of two Hawaii-grown clones were treated with 100 to 600 Gy X-ray irradiation and evaluated for quality before and after cooking. Root moisture content, surface color, and glucose and fructose concentrations were not affected by irradiation treatment for either the red-skin, yellow-flesh (RY) or the white-skin, purple-flesh (WP) clones. Firmness decreased at higher doses for RY roots, but not for WP roots. The alcohol insoluble solids and the starch concentrations of raw roots decreased linearly in response to increasing dose for both clones. Maltose decreased at higher doses in cooked RY roots only. Irradiation had the greatest effect on sucrose concentrations, which increased linearly in response to dose as starch concentrations decreased. A sensory panel perceived sweetpotato roots treated with 600 Gy irradiation as sweeter than control roots. Panelists found the overall acceptability to be the same for control and 600 Gy treated roots for both clones.</jats:p>

Storage Quality and Composition of Sweetpotato Roots after Quarantine Treatment Using Low Doses of X-ray Irradiation

“…Grated root tissue (10 g) between 100 and 500 Gy (Lu et al,1986). In a previous study, a 600 Gy dose did not reduce the overall quality or taste of purple-fl eshed and yellow-fl eshed sweetpotatoes (Wall, 2004). Hallman (2001) also found that orange-fl eshed roots treated with a 300 Gy dose did not differ from control roots in color or organoleptic ratings.…”

“…Hallman (2001) also found that orange-fl eshed roots treated with a 300 Gy dose did not differ from control roots in color or organoleptic ratings. However, slight decreases in fi rmness and starch concentrations were observed in some roots 2 weeks after treatment with doses below 600 Gy (Wall, 2004). Specifi cally, fi rmness decreased linearly with increasing irradiation dose for yellow-fl eshed roots, but not for purple-fl eshed roots (Wall, 2004).…”

Quality of fresh‐cut purple‐fleshed sweet potatoes after X‐ray irradiation treatment and refrigerated storage

“…In sweet potatoes, variety and irradiation dose are important factors that affect the firmness during storage. Wall () reported that firmness of red‐skin yellow‐fleshed sweet potatoes decreased linearly with increasing irradiation dose up to 600 Gy, but white‐skin purple‐fleshed sweet potatoes retained firmness. Consequently, irradiation at 1000 Gy did not increase softening of PFSP cubes compared with nonirradiated samples on any storage day (Table ).…”

“…Wall () indicated that irradiation at 400‐Gy dose increased redness in the internal colour of PFSP roots compared with control samples. Consistent with this result, a duller colour was observed in 1000 Gy treated samples after 14 days (Table ), but based on hue angle value ( h °), no colour difference was determined in any samples on day 14.…”

“…Irradiation doses up to 1000 gray (Gy) have been permitted by the US Food and Drug Administration for use on fresh produce (Federal Register, 1986), including fresh-cut fruits and vegetables. In earlier studies, the effects of gamma and X-ray irradiation on storage quality and composition of whole sweet potato roots were determined (Hayashi & Kawashima, 1982;Lu et al, 1986;Wall, 2004Wall, , 2005. In this study, the objective was to determine the effects of X-ray irradiation on the physical quality, microbial populations and anthocyanin content of fresh-cut purple-fleshed sweet potato (PFSP) cubes during 2 weeks of refrigerated storage.…”