稻米油特征参数的测定与脂肪酸组成分析_张继光.pdf

食品工业 2023 年第44卷第 4 期 313 分析检测稻米油特征参数的测定与脂肪酸组成分析张继光，曲良冉，李南，蒋绍松，吕世懂*1.昆明市粮油饲料产品质量检验中心（昆明 650118）；2.云南省粮油产品质量监督检验站（昆明 650118）；3.云南昆明国家粮食质量监测站（昆明 650118）摘要采用气相色谱、高效液相色谱和化学滴定法等手段,对我国不同产地的7个市售稻米油的特征参数及脂肪酸组成进行了分析测定,并与青刺果油等14种同步测定的植物油的脂肪酸组成进行了全面的比较研究。结果表明:稻米油的折光指数为1.465 61.467 7;相对密度d2020为0.918 60.922 1;碘值为100.1107.3 g/100 g;皂化值为184.7188.7 mg/g;谷维素含量在2 516.8021 833.32 mg/kg之间;脂肪酸组成以油酸C181(39.38%42.26%)、亚油酸C182(36.23%39.86%)、棕榈酸C160(15.22%17.38%)为主,不饱和脂肪酸含量在79.66%81.39%之间。与其他14种植物油的脂肪酸相比:棕榈酸C160以稻米油为最高(16.48%),油酸C181含量以橄榄油为最高(77.18%),亚油酸C182以火麻籽油为最高(55.27%),亚麻酸C183以美藤果油为最高(49.02%),不饱和脂肪酸以杏仁油为最高(95.12%),稻米油的油酸与亚油酸比值为1.0011.161,单不饱和脂肪酸与多不饱和脂肪酸的比值为0.9811.151,与世卫组织推荐的黄金比例11比较接近。此外,稻米油的碘值、皂化值等多项特征参数与青刺果油较为接近。研究结果表明稻米油具备良好的、平衡的脂肪酸组成比例和较高的营养价值,也为消费者选择适合自身所需的营养价值、保健功能的食用植物油提供了参考依据。关键词稻米油;青刺果油;特征参数;脂肪酸组成Determination of Characteristic Parameters of Rice Bran Oil and Analysis of Fatty Acid CompositionZHANG Jiguang,QU Liangran,LI Nan,JIANG Shaosong,L Shidong*1.Kunming Grain and Oil and Feed Product Quality Inspection Center(Kunming 650118);2.Yunnan Province Grain and Oil Products Quality Supervision and Inspection Station(Kunming 650118);3.Yunnan Kunming National Grain Quality Testing Station(Kunming 650118)Abstract By using gas chromatography,high performance liquid chromatography and chemical titration,the characteristic parameters and fatty acid composition of seven rice oil from different producing areas in China were analyzed and determined,and the fatty acid composition of 14 kinds of vegetable oil such as Prinsepia utilis Royle oil was compared in a comprehensive way.The results showed that the refractive index of rice oil was 1.465 6-1.467 7,the relative density was 0.918 6-0.922 1,iodine value was 100.1-107.3 g/100 g,the saponification values ranged from 184.7 to 188.7 mg/g,and the content of glutamate ranged from 2 516.80 to 21 833.32 mg/kg.The fatty acid composition was mainly oleic acid(39.38%-42.26%),linoleic acid(36.23%-39.86%),palmitic acid(15.22%-17.38%),and the unsaturated fatty acid content was 79.66%-81.39%.Compared to the fatty acids of 14 other vegetable oils,palmitic acid was the highest in rice oil(16.48%),oleic acid was the highest in olive oil(77.18%),linoleic acid was the highest in hempseed oil(55.27%),and linolenic acid was the highest in martenseed oil(49.02%).The highest unsaturated fatty acids were found in almond oil(95.12%).The ratio of oleic acid to linoleic acid in rice oil was 1.001 to 1.161,and the ratio of monounsaturated fatty acid to polyunsaturated fatty acid was 0.981 to 1.151,which was close to the golden ratio of 11 recommended by WHO.In addition,the iodine value and saponification value of rice oil were similar to those of Prinsepia utilis Royle oil.The results of this study showed that rice oil had good and balanced fatty acid composition and high nutritional value,and also provided a reference for consumers to choose edible vegetable oil suitable for their own nutritional value and health function.Keywords rice bran oil;Prinsepia utilis Royle oil;characteristic parameters;fatty acid composition*通信作者水稻（Oryza sativa L）是禾本科稻属植物，是仅次于玉米的世界第二大粮食经济作物。米糠作为稻谷加工过程中的副产物，约占稻米质量的6%，含油率在12%23%之间，与我国大豆含油量相当1-3。稻米油俗称米糠油，是从稻谷糠粉中提取的天然食用植物油，含有丰富的谷维素、植物甾醇、维生素衍生物生育酚和生育三烯酚以及角鲨烯等活性成分4-9，脂肪酸组成主要以油酸、亚油酸、棕榈酸为主，油酸与亚油酸的比值接近11，不饱和脂肪酸含量在80%左右10。由于稻米油由良好的、平衡的脂肪酸组成，这使其在食品工业 2023 年第44卷第 4 期 314 分析检测高温油炸条件下很稳定，适合作为煎炸、烘焙优选油11-12。油脂的脂肪酸组成与碘值、皂化值等特征参数，是判断油脂真实性的重要参考依据，也是评判食用油“营养与健康”的重要指标。国家粮油加工业“十三五”发展规划指出要坚持多油并举，积极开发米糠油，大力发展橄榄油和牡丹籽油等新型健康木本食用油。基于此，文章选择了我国7个不同产地的成品稻米油，对其折光指数、相对密度、碘值、皂化值、谷维素5个特征参数进行了测定。同时将稻米油和市场上备受推崇的橄榄油与批准为新资源食品的美藤果油、牡丹籽油、茶叶籽油，还有市场消费占比较大的大豆油、菜籽油、花生油以及其他功能性植物油脂（南瓜籽油、火麻仁油、沙棘籽油等）共计14种，对其脂肪酸组成进行了分析比较。以期为稻米油的深度开发和综合利用奠定基础，为消费者选择适合自身所需的营养价值、保健功能的食用植物油提供参考依据。1材料与方法1.1试剂与材料37种脂肪酸甲酯混合标准品、纯度99%的谷维素标准品（西格玛公司）；甲醇、异辛烷、异丙醇、乙醇（色谱纯，默克公司）；其余试剂为分析纯。试验用水均为一级水。7个稻米油和其他14种植物油均为市售，详细信息如表1所示。1.2仪器与设备AL 204型电子分析天平（分度值0.000 1 g）、SL-5000XLS型移液器（梅特勒-托利多公司）；Abbemat 3 200数字式自动折光指数测定仪、DMA 500密度计（奥地利安东帕公司）；Waters 2 695高效液相色谱仪（配2 489紫外检测器，美国沃特世公司）；JADE-PAK氨基柱（250 mm4.6 mm，5 m，广州太玮生物科技有限公司）；Trace1310气相色谱仪（配氢火焰离子化检测器，美国赛默飞世尔科技公司）。1.3方法折光指数、相对密度按参照文献13进行测定；碘值的测定按GB/T 55322008动植物油脂 碘值的测定14；皂化值按照GB/T 55342008动植物油脂 皂化值的测定15；谷维素含量的测定按照LS/T 6121.22017粮油检验 植物油中谷维素含量的测定 高效液相色谱法16测定稻米油中谷维素的含量。脂肪酸组成按照GB 5009.1682016食品安全国家标准 食品中脂肪酸的测定17中第三法归一化法，仪器条件及数据处理按参照文献18。2结果与分析2.1稻米油特征参数分析按照1.3小节中的方法和条件，分别对7个稻米油样品的特征参数进行分析，测定结果如表2所示。样品编号产品名称食品产地样品编号产品名称食品产地A1米糠油浙江台州B5茶叶籽油云南普洱A2稻米油上海嘉定B6美藤果油云南西双版纳A3稻米油广东深圳B7牡丹籽油安徽铜陵A4压榨稻米油黑龙江哈尔滨B8食用橡胶籽油云南西双版纳A5稻米油江西南昌B9南瓜籽油河北邯郸A6米糠油浙江衢州B10亚麻籽油内蒙古锡盟A7稻米油河南信阳B11火麻籽油广西河池B1大豆油云南昆明B12杏仁油北京市延庆区B2低芥酸菜籽油云南曲靖B13青刺果油云南丽江B3花生油山东临沂B14沙棘籽油山西太原B4橄榄油上海市浦东区表1样品信息特征参数样品编号变化范围平均值A1A2A3A4A5A6A7折光指数(n40)1.465 91.465 61.467 71.466 31.466 51.466 81.466 01.465 61.467 71.466 4相对密度(d2020)0.919 10.919 30.922 10.918 60.920 70.920 10.919 40.918 60.922 10.919 9碘值(I)/(g100 g-1)102.6104.8103.5103.6102.2107.3100.1100.1107.3103.4皂化值(KOH)/(mgg-1)186.4187.8186.4184.7188.7186.2186.1184.7188.7186.6谷维素含量(mgkg-1)4 028.072 532.2821 833.322 516.88 623.3811 585.764