冷凍甘藷條品質改進及甘藷加工品之開發

Abstract

以0.30%，0.45%，及0.60%，焦亞硫酸鉀溶液殺菁處理均有效抑制甘藷條褐變。若以0.30%，焦亞硫酸鉀溶液殺菁，再漂水二次後的冷凍甘藷條之二氧化硫殘留量低於30ppm。甘藷條在殺菁前先於室溫經0.30％焦亞硫酸鉀溶液浸泡10分鐘，則抑制褐變效果更佳，但是須漂水三次才能使50賤留量低於30ppm。甘藷條於殺菁前在0.6％浸泡30分鐘，因漂水後之二氧化硫殘留量仍過高，不宜採用。含焦亞硫酸鉀殺菁水經二次使用後水溶液內二氧化硫量雖然減少12~15%，但是再用來殺菁甘藷條的外觀並沒有明顯差異。 由台農57號製得之甘藷條經油炸後色澤優美，肉質感佳，且不易軟化。甘藷塊先經11%澱粉糊包覆，再沾裹粉，油炸後外觀精緻，且掉屑率低。甘藷泥適於不同模型壓成各種不同形狀藷塊。台農57號纖維多，質粗不適合製作冰淇淋，而台農62、64及66號質地佳，口感平滑細密，然而甘藷風味均嫌稍淡。台農64及66號色澤較深，所製得之冰淇淋呈淡黃色。甘藷粒取代甘藷泥所發展的冰淇淋質地較粗，顏色呈暗黃，風味欠佳。 The use of potassium metabisulfite at 0.030% or higher concentrations effectively inhibited the browning of sweet potato French fries. The residual sulfur dioxide in the raw frozen French fries was lower than 30 ppm when 0.30% potassium metabisulfite was used for blanching and followed by washing twice. The inhibition of browning was more pronounced as the shredded sweet potato was soaked in 0.30% potassium metabisulfite solution at room temperature before blanching. The residual sulfur dioxide could be reduce to below 30 ppm if the samples were washed three time. However, soaking in 0.30% metabisulfiteat 60 ¢XC resulted in higher residual sulfur dioxide even after washing several times. The sulfur dioxide content of the blanching water was reduced by 12-15% after if was used two times, and the effect of blanching remained the same. The French fries made of Tainung 57 sweet potato showed execilent quality in terms of color, mouthfeel, and appearance. Delicate fried sweet potato nugget was successfully made after the raw nugget was soaked in 11% starch paste and followed by coating batter. Mashed sweet potato was ideally used to make nuggets with various shapes. Due to the higher fiber content and coarse texture, Tainung 57 is not recommended to make ice cream. With fine texture and good mouthfeel, Tainung 62, 64 and 66 cultivars were responsible for ice cream making. However, they all contributed very little flavor to the product. In addition, Tainung 64 and 66 were responsible for the color development of the ice cream. Ice cream made from sweet potato flakes had coarse texture, dark color, and poor flavor.