Totani Nagao, Ono Mika, Burenjargal Munkhjargal, Ojiri Yuko
Faculty of Nutrition, Kobe-Gakuin University, Nishi-ku, Kobe, Japan.
J Oleo Sci. 2007;56(9):449-56. doi: 10.5650/jos.56.449.
Used frying oil recovered from food manufacturing companies in Japan and recycled often shows lower carbonyl (COV) and peroxide values (POV) than oil simply heated at 180 degrees C for 20 h does. In this study the reasons for the low COV of oil used for deep-frying were investigated by employing model experiments and actual commercial frying. The results suggested that in actual frying, the factor most influencing the low COV was vaporization of carbonyl compounds, together with steam generated from water contained in frying foodstuffs. It was also suggested that the low levels of COV were attributable partly to inhibition by protein, amino acids exuded from frying foodstuffs, and starch, and slightly to the effects of natural antioxidants in fresh oil and frying foodstuffs, oil absorption by frying foodstuffs, and dilution of oil in use by fresh oil added between uses. On the other hand, the chemical properties of oil in a fryer and in batter coatings of deep-fried foods made with the former oil were checked. Content of polar compounds (PC) and color score were obviously worse in the oil extracted from batter coatings than in that in the fryer, but there were no differences in COV or content of triacylglycerol (TG) of the two oils.
从日本食品制造公司回收并循环使用的用过的煎炸油，其羰基（COV）值和过氧化物值（POV）通常比仅在180℃加热20小时的油更低。在本研究中，通过模型实验和实际商业煎炸，对用于油炸的油的低COV值的原因进行了调查。结果表明，在实际煎炸中，对低COV值影响最大的因素是羰基化合物的汽化，以及油炸食品中所含水分产生的蒸汽。还表明，低COV值部分归因于油炸食品渗出的蛋白质、氨基酸和淀粉的抑制作用，以及新鲜油和油炸食品中天然抗氧化剂的作用、油炸食品对油的吸收以及使用期间添加的新鲜油对使用中的油的稀释作用。另一方面，对油炸锅中的油以及用该油制作的油炸食品面糊涂层中的油的化学性质进行了检查。从面糊涂层中提取的油的极性化合物（PC）含量和颜色评分明显比油炸锅中的油差，但两种油的COV值或三酰甘油（TG）含量没有差异。
