鲮鱼油炸过程中棕榈油指标的变化与控制

本研究对鲮鱼油炸过程中棕榈油指标的变化进行了感官及理化分析,并采用"Dalsorb吸附剂+板框过滤"的方法,对油炸后的棕榈油进行处理。结果表明:随着油炸时间的延长,棕榈油色泽逐渐加深、流动性及透明度逐渐变差,并且有大量鱼渣出现;棕榈油的酸价、羰基价、极性组分随油炸时间的延长不断增大(酸价由初始0.06 mg KOH/g上升至2.34 mg KOH/g,羰基价由初始3.64meq/kg上升至17.70 meq/kg,极性组分由初始3.07%上升至15.1%),过氧化值的变化无明显规律;其中酸价、极性组分变化更接近国标上限,可优先做为评价指标,但考虑到极性组分检测时间长的原因,建议在线监控以酸价指标为主。采用"Dalsorb吸附剂+板框过滤"的方法,能够明显的降低煎炸后棕榈油的酸价指标(酸价由2.36 mg KOH/g下降至1.50 mg KOH/g),对羰基价和极性组分的处理效果不明显。

Change and Control of Palm Oil Index in the Frying Process of Dace

The change of palm oil index during the frying process of dace was evaluated by sensory and physicochemical analysis in this study, and the "Dalsorb adsorbent + plate filtration" method was used for palm oil treatment after frying. Results show that with the increase of frying time, the color of palm oil was gradually deepened, the liquidity and transparency were gradually degraded, and a large amount of fish dregs appeared. The acid value (from 0.06 mg KOH/g to 2.34 mg KOH/g), carbonyl value (from 3.64 meq/kg to 17.70 meq/kg) and polar component (3.07% to 15.1%) of palm oil increased with the increase of frying time, and there was no obvious change in the peroxide value. The change of acid value and polar component was closer to the upper limit of the national standard and could be used as evaluation index. In addition, the online monitoring should be mainly based on acid value index due to the reason for long detection time of the polar component. The "Dalsorb adsorbent + plate filtration" method could significantly reduce the acid value (from 2.36 mg KOH/g to 1.50 mg KOH/g), and the changes of carbonyl value and polar components were not obvious.