Chakraborty Kajal, Joseph Deepu
Marine Biotechnology Division, Central Marine Fisheries Research Institute , Ernakulam North, P.B. 1603, Cochin, India.
J Agric Food Chem. 2015 Jan 28;63(3):998-1009. doi: 10.1021/jf505127e. Epub 2015 Jan 14.
Crude Sardinella longiceps oil was refined in different stages such as degumming, neutralization, bleaching, and deodorization. The efficiency of these processes was evaluated on the basis of free fatty acid (FFA), peroxide (PV), p-anisidine (pAV), total oxidation (TOTOX), thiobarbituric acid reactive species (TBARS) values, Lovibond CIE-Lab* color analyses, and (1)H NMR or GC-MS experiments. The utilities of NMR-based proton signal characteristics as new analytical tools to understand the signature peaks and relative abundance of different fatty acids and monitoring the refining process of fish oil have been demonstrated. Phosphoric acid (1%) was found to be an effective degumming reagent to obtain oil with the lowest FFA, PV, pAV, TOTOX, and TBARS values and highest color reduction. Significant reduction in the contents of hydrocarbon functionalities as shown by the decrease in proton integral in the characteristic (1)H NMR region was demonstrated by using 1% H3PO4 during the course of the degumming process. A combination (1.25:3.75%) of activated charcoal and Fuller's earth at 3% concentration for a stirring time of 40 min was found to be effective in bleaching the sardine oil. This study demonstrated that unfavorable odor-causing components, particularly low molecular weight carbonyl compounds, could successfully be removed by the refining process. The alkane-dienals/alkanes, which cause unfavorable fishy odors, were successfully removed by distillation (100 °C) under vacuum with aqueous acetic acid solution (0.25 N) to obtain greater quality of refined sardine oil, a rich source of essential fatty acids and improved oxidative stability. The present study demonstrated that the four-stage refinement process of sardine oil resulted in a significant improvement in quality characteristics and nutritional values, particularly n-3 PUFAs, with improved fish oil characteristics for use in the pharmaceutical and functional food industries.
粗制的长头小沙丁鱼油经过脱胶、中和、脱色和脱臭等不同阶段的精炼。这些工艺的效率是根据游离脂肪酸（FFA）、过氧化物（PV）、对茴香胺（pAV）、总氧化值（TOTOX）、硫代巴比妥酸反应性物质（TBARS）值、罗维朋CIE-Lab*颜色分析以及¹H NMR或GC-MS实验来评估的。基于核磁共振的质子信号特征作为一种新的分析工具，用于理解不同脂肪酸的特征峰和相对丰度以及监测鱼油精炼过程的实用性已得到证实。发现1%的磷酸是一种有效的脱胶试剂，可获得FFA、PV、pAV、TOTOX和TBARS值最低且颜色降低最多的油。在脱胶过程中使用1%的H₃PO₄，结果表明在¹H NMR特征区域质子积分减少，这证明了烃类官能团含量显著降低。发现浓度为3%的活性炭和漂白土以1.25:3.75%的组合并搅拌40分钟，对沙丁鱼油具有有效的脱色效果。这项研究表明，精炼过程能够成功去除产生不良气味的成分，特别是低分子量羰基化合物。通过在真空中与0.25N的乙酸水溶液在100°C下蒸馏，成功去除了导致不良鱼腥味的烷二烯醛/烷烃，从而获得了更高质量的精炼沙丁鱼油，这种油富含必需脂肪酸且氧化稳定性得到改善。本研究表明，沙丁鱼油的四阶段精炼过程显著改善了其质量特性和营养价值，特别是n-3多不饱和脂肪酸，使鱼油特性得到改善，可用于制药和功能性食品行业。
