ABSTRACT

Fish constitutes a occasional food for the Sidama people of Hawassa, the capital city of Ethiopia’s Sidama Region and the site of a large endorheic lake. Freshly-caught fish, especially Nile tilapia or koroso in Local name, are typically fried prior to consumption. Despite the sensory qualities, fried foods are not always advisable due to the impact of frying on the nutritional quality of food. This study was designed to assess the nutritional quality of Nile tilapia that had been fried in the same palm oil over six consecutive frying cycles. The raw fish were purchased from the Lake Hawassa fish market and fried at Hawassa University by simulating local preparation methods. A gas chromatography-mass spectrophotometer (GCMS) was used for the fatty acid profile analysis and a total of 22 fatty acids were elucidated. The nutritional quality indices of fatty acids was determined by calculating the recommended formula and JMP pro 13 was used for statistical analysis. The study results revealed that the tilapia fried in the oldest, most used oil, cycles 3–6, contained high amounts of saturated and trans fatty acids, as well as high atherogenic and thrombogenic indices; however, it was also lower in essential and cis fatty acids, the hypocholesterolemic/hypercholesterolemic ratio, the per-oxidizability index, and the nutritive value index. Conversely, fish prepared earlier (cycles 1–3) with fresher oil were higher in essential fatty acids and cis fatty acids, while the hypocholesterolemic/hypercholesterolemic ratio, the per-oxidizability index, and the nutritive value index were also high. Fish fried in an earlier cycle were also low in saturated and trans-fatty acids, with a lower atherogenic index, and thrombogenic index. Therefore, it can be concluded that repeatedly using the same frying oil to prepare Nile tilapia contributed to the loss of nutritional value. Results suggest that palm oil should be limited to no more than three frying cycles to maximize nutritional intake in of fish consumption.

摘要

鱼是埃塞俄比亚锡达马地区首府哈瓦萨的锡达马人的偶尔食物，这里有一个大型内陆湖。新鲜捕获的鱼，尤其是尼罗罗非鱼或koroso在当地名称中，通常在食用前进行油炸。尽管具有感官品质，但由于油炸对食物营养质量的影响，油炸食品并不总是可取的。本研究旨在评估尼罗罗非鱼在同一棕榈油中经过六个连续的油炸周期油炸后的营养质量。生鱼购自哈瓦萨湖鱼市，在哈瓦萨大学模拟当地制备方法油炸。使用气相色谱-质谱仪 (GCMS) 进行脂肪酸谱分析，共鉴定出 22 种脂肪酸。通过计算推荐配方确定脂肪酸的营养质量指标，并采用JMP pro 13进行统计分析。研究结果表明，罗非鱼在最古老、最常用的油中煎炸，反式脂肪酸，以及高致动脉粥样硬化和血栓形成指数；然而，它的必需脂肪酸和顺式脂肪酸、低胆固醇/高胆固醇比率、过氧化性指数和营养价值指数也较低。相反，较早（周期 1-3）用新鲜油制备的鱼的必需脂肪酸和顺式脂肪酸含量较高，而低胆固醇/高胆固醇比率、过氧化性指数和营养价值指数也较高。在较早的周期中油炸的鱼的饱和和反式含量也很低-脂肪酸，具有较低的动脉粥样硬化指数和血栓形成指数。因此，可以得出结论，重复使用相同的煎炸油制备尼罗罗非鱼会导致营养价值的损失。结果表明，棕榈油应限制在不超过三个油炸周期，以最大限度地提高鱼类消费中的营养摄入量。