過熱蒸汽及烘烤處理對甘藷品質及抗氧化力之影響

Effects of Superheated Steam and Roasting Treatment on Quality and Antioxidant Capacity of Sweet Potatoes

翁振展(Jhen-Jhan Wong) ； 覃孟雄(Meng-Hsiung Chin) ； 王子慶(Tzu-Ching Wang) ； 楊季清(Chi-Ching Yang)

《臺灣農業化學與食品科學》 48卷1期 (2010/02) Pp. 11-18

https://doi.org/10.6578/TJACFS.2010.002

摘要

甘藷營養豐富且具有多種加工形式，如烤藷就是甚受消費者所喜愛的一種，因為在烘烤的過程中會發生梅納反應，使烘烤藷散發出誘人的香氣。但由於烘烤時間長，易使甘藷表皮發生焦黑的情形，故本研究利用過熱蒸汽熱傳快速的優點改善此問題，並比較過熱蒸汽與烘烤處理對甘藷品質與抗氧化力之差異。研究結果顯示，甘藷分別經過熱蒸汽和烘烤30 min後，發現以140℃過熱蒸汽即可使甘藷糊化度達到95%以上，而烘烤則必需在240℃。在外觀上，甘藷經過熱蒸汽加熱不會造成焦黑的情形，而以烘烤者則會發生。甘藷經過140℃熱蒸汽加熱30 min，經感官品評和質地剖面分析後，其兩者的結果相近，但在香氣上則以烘烤者較佳。整體接受度以240℃烘烤50 min者最高，140℃過熱蒸汽加熱70 min者次之。在抗氧化力方面，發現不論總酚、類黃酮、清除DPPH (1, 1-diphenyl-2-picrylhydrazyl)或FRAP (Ferric reducing ability of plasma)值皆以140℃過熱蒸汽加熱30 min者最高。

關鍵字

烘烤甘藷 ； 過熱蒸汽 ； 抗氧化力

並列摘要

Sweet potato is a very nutritious vegetable and can be processed into many kinds of forms. For example, the roasted sweet potato is a favorite for consumers, since the Millard reaction in a roasting process leads to attractive aroma. However, the long duration of roasting would also easily make sweet potatoes burnt black. Therefore, the study would take advantage of superheated steam’s swift heat-conduction to alleviate this problem. As the results showed, when sweet potatoes were broiled by superheated steam or roasted for 30 min, it was found that the degree of gelatinization of sweet potatoes could reach up to 95% by 140℃ superheated steam, while roasting temperature as high as 240℃ was needed to reach the same degree. In appearance, the sweet potatoes processed by superheated steam would not become burnt as the roasting process would do. After being processed by 140℃ superheated steam for 30 min, the sensory evaluation and profile analysis of quality between these two groups were similar, but the aroma of roasted sweet potatoes was better. The roasted sweet potato (240℃ for 50 min) had the highest overall acceptance followed by the superheated steam heated sweet potato (140℃ for 70 min). For anti-oxidant capability, it was found that the 140℃ superheated steam-heated sweet potato had the highest contents of total phenol and flavonoids, and the best scavenging ability of DPPH (1, 1-diphenyl-2-picrylhydrazyl) and FRAP (Ferric reducing ability of plasma).

並列關鍵字

Roasted sweet potato ； Superheated steam ； Antioxidant activity