Revitalizing flaxseed oil: Novel strategies for improved stability, nutrition, and taste

In response to the increasing consumer demand for sustainable and health-conscious choices, our research focused on enhancing the nutritional quality, stability, and flavor of flaxseed oil. Our primary objectives included boosting polyphenol levels, improving oxidative stability, and alleviating the bitter taste. Additionally, we aimed to minimize the oxidation of cyclolinopeptides and increase lipid alcohols at the expense of lipid aldehydes.

Through the optimization of polyphenol transfer from press cake to oil, we achieved a remarkable 3.1-fold increase in polyphenol content (3.16 ± 0.10 mg/100g). This enhancement extended the shelf life by 22.73±0.58% compared to conventional flaxseed oil. Notably, a comprehensive sensory evaluation indicated reduced bitterness in the optimized flaxseed oils, which could be explained by a 35% decrease in the cyclolinopeptide ratio of CLC:CLB, suggesting a lower proportion of oxidized cyclolinopeptides. GC-MS analysis revealed significant changes in volatile oxidation profiles, with a 90% decrease in hexanal and a 60% decrease in nonanal, along with increased levels of corresponding lipid alcohols.

Further optimization involved omitting centrifugation to obtain a veiled flaxseed oil. While fatty acid profiles and tocopherols remained unchanged, these oils demonstrated superior oxidative stability in rancimat measurements. Notably, there was a 20 ± 1.2% increase in diacylglycerol content. LC-MS analysis unveiled a diverse polyphenol profile, with 59 compounds identified exclusively in the optimized flaxseed oil not subjected to centrifugation or filtration. The rise of quinic acid from 0.31 ± 0.04 to 3.37 ± 0.21 mg/100g in unfiltered oils contributed to an improved antioxidant capacity, as confirmed by ABTS, DPPH, and FRAP assays.
In conclusion, our study introduces a novel approach that leverages polyphenol transfer from side streams in oil production. This method not only significantly improves the shelf life, nutritional quality, and sensory attributes of flaxseed oil but also aligns with contemporary consumer preferences for sustainable and health-enhancing products.