核桃油是一种营养价值很高的食用油,烘烤过程会影响其质量和风味。本研究旨在探讨焙烧对脂肪酸组成的影响,生物活性化合物(生育酚,多酚,和植物甾醇),核桃油的抗氧化能力。此外,对香气成分和感官特征进行了评估,以全面评估烘烤后核桃油的变化。焙烧对核桃油的脂肪酸组成没有显著影响,但增加了核桃油中生育酚和多酚的含量。提高其抗氧化能力。重焙烧(160°C/20分钟)使核桃油中的植物甾醇含量降低了2.3%。总的来说,使用顶空固相微萃取-气相色谱-质谱法在冷榨和烤核桃油中检测到146种挥发性化合物,并确定了32种关键的香气化合物。芳香醛,脂肪醛,杂环化合物对芳香核桃油有显著贡献。此外,基于质量特征和感官评价的主成分分析表明,中等烘烤(130℃/20分钟,130°C/30分钟,和160°C/10分钟)提供带有甜味的核桃油,坚果,和烘烤的香气,以及高水平的亚油酸,植物甾醇,和γ-生育酚。尽管重烤(160°C/15分钟和160°C/20分钟)由于多酚含量高,增强了核桃油的抗氧化能力,油显示出令人不快的焦味。本研究表明,烘烤促进了核桃油的品质和风味,温和的条件赋予核桃油特有的丰富风味,同时保持优良的品质。
Walnut oil is an edible oil with high nutritional value, and the
roasting process influences its quality and flavor. This study aimed to investigate the effects of
roasting on the fatty acid composition, bioactive compounds (tocopherols, polyphenols, and phytosterols), and antioxidant capacity of walnut oil. Additionally, the aroma compounds and sensory characteristics were evaluated to comprehensively assess the variations in walnut oil after roasting.
Roasting resulted in no notable impact on the fatty acid composition of walnut oil but increased the content of tocopherols and polyphenols in walnut oil, increasing its antioxidant capacity. Heavy
roasting (160°C/20 min) reduced the phytosterol content in walnut oil by 2.3%. In total, 146 volatile compounds were detected in both cold-pressed and roasted walnut oil using headspace solid-phase microextraction-gas chromatography-mass spectrometry, and 32 key aroma compounds were identified. Aromatic aldehydes, aliphatic aldehydes, and heterocyclic compounds significantly contributed to fragrant walnut oil. Furthermore, the principal component analysis based on quality characteristics and sensory evaluation indicated that moderate roasting (130°C/20 min, 130°C/30 min, and 160°C/10 min) provided walnut oil with a sweet, nutty, and roasted aroma, as well as high levels of linoleic acid, phytosterols, and γ-tocopherol. Although heavy
roasting (160°C/15 min and 160°C/20 min) enhanced the antioxidant capacities of walnut oils due to high levels of polyphenols, the oils exhibited an unpleasant burnt aroma. This study showed that roasting promoted the quality and flavor of walnut oil, and moderate conditions endowed walnut oil with a characteristic-rich flavor while maintaining excellent quality.