炸油使用次數對炸油與油炸薯條品質的影響

Effect of the Frying Cycle of Soy Oil on the Quality of Oil and French Fries Products

10.6730/JAAT.201102_12(1).0005

邵貽沅(Yi-Yuan Shao)；蘇怡瑄(Yi-Hsuan Su)

薯條 ； 炸油 ； 酸價 ； p-茴香胺值 ； 共軛雙烯 ； 品質 ； French fries ； Frying oil ； Acid value ； p-Anisidine value ； Conjugated diene ； Quality

台灣農學會報

12卷1期（2011 / 02 / 01）

57 - 67

繁體中文

本研究以大豆油進行油炸市售冷凍薯條試驗，觀察炸油使用次數對其品質（黏度、酸價、p-茴香胺值、共軛雙烯）及油炸薯條品質（水份含量、油脂含量、硬度、顏色）之影響。炸油使用量為6公升，每批次薯條量為400克，油炸條件為180℃、4分鐘，共油炸49批薯條。結果顯示新鮮大豆油的黏度57.30 cp，酸價0.22 mg KOH/g，p-茴香胺值1.89，共軛雙烯0.42%；經過油炸49次後，炸油的黏度增加為1.3倍，酸價增加為3倍，p-茴香胺值增加為68倍，共軛雙烯增加為3倍。以p-茴香胺值對油脂氧化的敏感度最大。未經油炸的市售冷凍薯條水份含量、油脂含量和硬度分別為67.57%、6.98%（乾重）和771.42 gw；油炸薯條水份含量、油脂含量和硬度分別為44~48%、16~25% 和134~203 gw。油炸薯條之亮度(L(上標 *))30.02~32.53，紅色度(a(上標 *))-1.01~-1.27，黃色度(b(上標 *))0.66~2.00。油炸處理使薯條之含水量下降29~35%，含油量增加至2.2~3.6倍。

Soy oil was used to fry commercial frozen French fries. The effects of the frying cycle on oil quality (viscosity, acid value, p-anisidine value and conjugated diene) and French fries quality (moisture content, oil content, hardness and color) were examined. Each batch of French fries (400 g) was fried in 6 L of soy oil at 180 oc for 4 min and 49 cycles of frying in total were studied. The results showed the fresh soy oil had a viscosity of 57.30 cp, acid value of 0.22 mg KOH/g, p-anisidine value of 1.89 and conjugated diene content of 0.42%. Comparing with the quality of fresh soy oil, viscosity, acid value, p-anisidine value and the conjugated diene content of soy oil after 49 cycles of frying increased 1.3, 3, 68 and 3 times, respectively. Among them, the p-anisidine value was the most sensitive indicator for evaluating oil oxidation. Commercial frozen French fries had 67.57% water, 6.98% oil (dry basis) and hardness of 771.42 gw. The fried products had water content, oil content and hardness in the ranges of 44~48%, 16~25% and 134~203 gw, respectively. After frying, the French fries had color values of 30.02~32.53, -1.01~-1.27 and 0.66~2.00 for L(superscript *), a(superscript *) and b(superscript *), respectively. Frying treatment decreased water content by 29~35%, but increased the oil content of French fries 2.2~3.6 times.