Department of Chemistry, Federal University of Lavras, University Campus, Post Office Box 3037, 37200-000 Lavras, Minas Gerais, Brazil.
Department of Food Science, Federal University of Lavras, University Campus, Post Office Box 3037, 37200-000 Lavras, Minas Gerais, Brazil.
Food Res Int. 2020 Apr;130:108925. doi: 10.1016/j.foodres.2019.108925. Epub 2019 Dec 20.
Macauba (Acrocomia aculeata) kernel oil is rich in short- and medium-chain saturated and unsaturated fatty acids, the most abundant of which are lauric and oleic acids. The oil also has high oxidative stability and contains bioactive compounds. Like other oils rich in lauric acid, Macauba kernel oil is solid at low temperatures but has a low solid fat content at room temperature. The hypothesis of this study is that the thermal and textural characteristics of Macauba kernel oil can be modified by fractionation. Fractions were obtained and analysed with respect to their fatty acid profile, oxidative stability, crystallization and melting profile, firmness and physical state at different temperatures. The fatty acid profiles of the fractions remained virtually unchanged, but the oxidative stability of stearins was greater than that of oleins. An increase in the percent enthalpy of crystallization and melting at lower temperatures was observed in oleins, with a consequent decrease in solid fat content, firmness and oxidative stability (compared with stearins) without a relevant change in the fatty acid profile, suggesting that triacylglycerols with unsaturated fatty acids were prevalent in positions sn1 and sn3 in oleins and in position sn2 in stearins. Thus, it was possible to obtain an olein with 26% less solid fat at 25 °C that was 22% less firm and that remained liquid until 3 °C below the oil, as well as a 23% firmer stearin.
巴西棕仁油富含中短链饱和与不饱和脂肪酸，其中含量最丰富的是月桂酸和油酸。该油还具有较高的氧化稳定性，且含有生物活性化合物。与其他富含月桂酸的油一样，巴西棕仁油在低温下呈固态，但在室温下的固体脂肪含量较低。本研究的假设是，通过分馏可以改变巴西棕仁油的热特性和质构特性。对各馏分进行了脂肪酸组成分析、氧化稳定性分析、结晶和熔融曲线分析、不同温度下的硬度和物理状态分析。各馏分的脂肪酸组成基本保持不变，但硬脂的氧化稳定性大于油的氧化稳定性。油中的各成分在较低温度下结晶和熔融的焓值增加，导致固体脂肪含量、硬度和氧化稳定性降低（与硬脂相比），而脂肪酸组成没有明显变化，这表明不饱和脂肪酸的三酰基甘油主要存在于油中的 sn1 和 sn3 位以及硬脂中的 sn2 位。因此，有可能获得一种在 25°C 时固体脂肪含量减少 26%、硬度降低 22%、在油的温度以下 3°C 仍保持液态的油，以及一种硬度增加 23%的硬脂。
