Oxidative stability of crude palm oil after deep frying akara (Fried Bean Paste)

Abstract For this study 47 samples of crude palm oil (CPO) were collected, consisted of what had been used for 4 hours around the city of Salvador-Bahia. To evaluate the quality of CPO were analyzed: Total Polar Compound (TPC; %) by Adsorption Chromatography (AC), Testo 270 and Fricheck; Free fatty acids (FFA; % oleic acid), Color (CIELab); Total Carotenoids (TC; ppm), induction time (IT, h) and fatty acids composition (g 100 g-1). The TPC analysis by Testo 270 and Fricheck showed a poor linear correlation with AC (0.69 and 0.60 respectively). Otherwise 44.70% and 36.95% of samples were completely oxidized, according to CA and IT methods. All samples presented TC (11.01-331.45 ppm) and yellow color predominance. Trans fatty acids, C18:1t in 17.02% and C18:3t in 65.65% of the samples were identified. The results demonstrate the need in the deep frying control, respect to techniques used during process. As well the improvement of the quality of palm oil fresh, can minimize the degradation process during th deep frying.

摘要：本研究共收集47份粗棕榈油（Crude Palm Oil, CPO）样本，均采自巴西巴伊亚州萨尔瓦多市周边，为经4小时煎炸使用后的粗棕榈油。为评估粗棕榈油的品质，本研究对多项指标进行了检测：总极性化合物（Total Polar Compound, TPC；单位：%），分别采用吸附色谱法（Adsorption Chromatography, AC）、Testo 270检测仪与Fricheck检测仪进行测定；游离脂肪酸（Free Fatty Acids, FFA；以油酸计，%）；色泽（采用CIELab色空间表征）；总类胡萝卜素（Total Carotenoids, TC；单位：ppm）；诱导时间（Induction Time, IT；单位：h）；以及脂肪酸组成（单位：g/100g）。Testo 270与Fricheck的TPC检测结果与AC法的线性相关性较差，相关系数分别为0.69与0.60。依据AC法与诱导时间法判定，分别有44.70%与36.95%的样本已完全氧化。所有样本均检出总类胡萝卜素，含量区间为11.01~331.45 ppm，且色泽以黄色调为主。本研究在17.02%的样本中检出反式油酸（C18:1t），在65.65%的样本中检出反式亚麻酸（C18:3t）。研究结果表明，需针对煎炸过程中的工艺操作强化煎炸用油管控；同时，提升新鲜棕榈油的品质可有效减缓其在煎炸过程中的降解进程。