Pretreatments Alter Safflower Seed Oil Concomitants and Volatile Compounds

A comparative study has evaluated how microwave, enzymatic, and sequential pretreatments alter the physicochemical qualities, lipid concomitants, and volatile compound profiles of safflower seed oil. Published in Chemical and Biological Technologies in Agriculture by Zhi Qin, Ling-Biao Gu, Zhen-Yang Wang, Shuai-Bo Wang, Guo-Qiang Zhang, Jin-Chu Yang, Yong-Ming Xu, Zhao Qin, Hua-Min Liu, and Yu-Xiang Ma, the laboratory investigation examined oils extracted from untreated seeds alongside seeds treated with microwave radiation, enzyme assistance, or a sequential microwave followed by enzyme combination. Across all tested preparation routes, the underlying high-linoleic fatty acid pattern was maintained, with unsaturated fatty acids consistently accounting for approximately 90% of the total fatty acids present.

Physical color indicators shifted across all processing approaches compared to untreated seed extractions. Every pretreatment decreased oil lightness while producing measurable increases in both redness and yellowness. Chemical stability metrics also demonstrated route-specific divergences among the resulting oils. Acid values increased following all pretreatment steps. In contrast, peroxide values rose predominantly in oils harvested from microwave-treated seeds, whereas oil obtained through enzyme-assisted pretreatment showed peroxide values that remained comparable to the baseline untreated oil.

Analyses of lipid concomitants revealed differing sensitivities between major micronutrient classes under the varying seed processing regimes. Concentrations of alpha-tocopherol exhibited stability across the experimental groups, maintaining levels between 640.67 and 679.60 mg/kg. Conversely, total phytosterol concentrations showed significant increases depending on the treatment route. Untreated seed oil yielded 350.15 mg/100 g of total phytosterols, microwave-treated oil contained 357.18 mg/100 g, enzyme-treated oil measured 376.10 mg/100 g, and sequentially treated oil reached 389.71 mg/100 g. The two enzyme-containing treatment protocols produced significantly higher phytosterol concentrations than either the untreated control or the microwave-only approach.

Volatile profiles assessed through complementary headspace solid-phase microextraction–gas chromatography–mass spectrometry and headspace gas chromatography–ion mobility spectrometry expanded dramatically following seed preparation. Semiquantitative total volatile abundance rose from 6.20 × 10³ µg/kg in the untreated oil to 4.62 × 10⁴ µg/kg following enzyme-assisted pretreatment, 9.44 × 10⁴ µg/kg after microwave pretreatment, and 1.56 × 10⁵ µg/kg under the sequential combination. The single pretreatments drove divergent chemical classes: enzyme-assisted processing yielded an acid-dominated volatile profile, whereas microwave heating generated volatiles primarily associated with pyrazines, pyrroles, furans, and aldehydes.

Sequential microwave and enzyme pretreatment generated both the highest overall volatile abundance and the broadest distribution of functional chemical classes. Chromatographic profiling confirmed elevated diversity across nitrogen-containing heterocycles, alcohols, phenolic volatiles, aldehydes, acids, and esters in the sequentially treated oil samples. These distinctive chemical patterns were independently validated by multivariate statistical evaluations and ion-mobility fingerprints, which corroborated the treatment-dependent sample clustering and differentiation initially observed through mass spectrometry analyses.

The study authors concluded that microwave and enzymatic pretreatments modify safflower seed oil through distinct compositional mechanisms, with sequential application exerting additive effects on physicochemical properties and volatile constituents. While providing a chemical framework for tailoring specific extraction pretreatments to yield desired compound profiles, the researchers noted key experimental limitations. Specifically, formal sensory evaluations and targeted identifications of key odor-active compounds remain necessary before reaching definitive conclusions regarding aroma quality or broader consumer acceptance.

Subject of Research: Safflower seed oil pretreatments and volatile profiles

Article Title: Effects of microwave and enzymatic pretreatments on lipid concomitants and volatile profiles of safflower seed oil: complementary HS-SPME-GC-MS and HS-GC-IMS analyses of volatiles

Article References: Qin, Z., Gu, L.-B., Wang, Z.-Y., Wang, S.-B., Zhang, G.-Q., Yang, J.-C., Xu, Y.-M., Qin, Z., Liu, H.-M., & Ma, Y.-X. (2026). Effects of microwave and enzymatic pretreatments on lipid concomitants and volatile profiles of safflower seed oil: complementary HS-SPME-GC-MS and HS-GC-IMS analyses of volatiles. Chemical and Biological Technologies in Agriculture. https://doi.org/10.1186/s40538-026-01136-2

Image Credits: AI Generated

DOI: 10.1186/s40538-026-01136-2

Keywords: safflower seed oil, microwave pretreatment, enzymatic pretreatment, volatile profiles, phytosterols, lipid concomitants, GC-MS, ion mobility spectrometry, Effects, microwave, enzymatic, pretreatments