Oils from apple seeds were extracted with the application of supercritical fluid (SFE) and Soxhlet techniques. The effect of SFE experimental variables such as pressure (10–30 MPa), temperature (40–60 °C) and carbon dioxide flow rate (1–8 L/h) on the yield, antioxidant activity and total phenolic content was investigated using a central composite design. The experimental data were fitted with a second-order polynomial equation using regression analysis. The maximum yield, obtained at the optimum processing conditions (24 MPa, 40 °C, 1 L/h of carbon dioxide flow rate, 140 min) was 20.5 ± 1.5% (w/w). For comparison, the yield from Soxhlet extraction was 22.5 ± 2.5% (w/w). Both techniques produced an oil with a fatty acids profile rich in linoleic acid. However, the extract from SFE was higher in linoleic acid (63.76 ± 4.96 g/100 g_oil) than that achieved by Soxhlet (49.03 ± 3.85 g/100 g_oil). Despite the higher unsaturated fatty acids content, SFE extracts reported a higher oxidative stability (21.4 ± 1.2 h) compared to that one extracted by Soxhlet (12.1 ± 1.1 h). This result was expport addressing the extraction of apple seed oil by supercritical fluid at pressures lower tha The most abundant phenolic compound found in the extract was phloridzin (2.96 ± 0.046 μg/gs_eed in SFE oil and 1.56 ± 0.026 μg/g_seed in Soxhlet). Instead, amygdalin, one of the antinutrients present in seeds, was not detected in the SFE oil.

Industrial relevance

The present study provided results addressing the extraction of apple seed oil by supercritical fluid at pressures lower than 30 MPa. The process allowed extracting an oil that was rich in unsaturated fatty acids, oxidative stable thanks to the high antioxidant activity, and free from anti-nutritional compounds.

中文翻译：

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从苹果种子中超临界流体萃取油：工艺优化，化学表征以及与常规溶剂萃取的比较

应用超临界流体（SFE）和索氏萃取技术从苹果种子中提取油。研究了SFE实验变量如压力（10–30 MPa），温度（40–60°C）和二氧化碳流速（1–8 L / h）对产量，抗氧化剂活性和总酚含量的影响。中央复合设计。使用回归分析，将实验数据与二阶多项式方程拟合。在最佳加工条件（24 MPa，40°C，1 L / h的二氧化碳流速，140分钟）下获得的最大产率为20.5±1.5％（w / w）。为了比较，索氏提取法的产率为22.5±2.5％（w / w）。两种技术均产生具有富含亚油酸的脂肪酸谱的油。但是，来自SFE的提取物的亚油酸含量更高（63.76±4.96 g / 100 g_油），比索氏提取液（49.03±3.85克/ 100克_油）高。尽管不饱和脂肪酸含量较高，但SFE提取物的氧化稳定性（21.4±1.2 h）比索氏提取物（12.1±1.1 h）高。该结果可解决超临界流体在较低压力下萃取苹果籽油的问题。萃取物中发现的最丰富的酚类化合物是Phloridzin（SFE油中为2.96± _0.046μg / g _sed，索氏提取物中为1.56±0.026μg/ g_种子）。相反，苦杏仁苷是种子中存在的一种抗营养物质，在SFE油中未检出。

行业相关性

本研究提供了解决压力低于30 MPa的超临界流体提取苹果籽油的结果。该方法可以提取出一种油，该油富含不饱和脂肪酸，由于其高抗氧化活性而具有氧化稳定性，并且不含抗营养化合物。