Results and Discussion

Physico‐Chemical Properties of Sonicated Raw and Roasted Chia Seeds

Table 1 illustrates the oil content, total phenolic compounds, total flavonoids, and antioxidant capacities of both raw and roasted chia seeds, obtained through ultrasonic bath and water bath extraction methods across different temperatures and extraction durations. The type of extraction, as well as the temperature and duration applied, influenced the oil content and bioactive properties of both raw and roasted chia seeds. The oil yields obtained from raw chia seeds subjected to ultrasonic‐assisted and water bath extraction for 20 min varied from 18.40% at 25°C to 28.00% at 40°C, and from 24.60% at 25°C to 25.00% at 40°C, respectively. The oil contents of raw chia seeds extracted using ultrasonic and water bath methods ranged between 22.40% (control) and 24.80% (40°C), and between 24.80% (control) and 29.80% (40°C), respectively. For roasted chia seeds, the oil yields obtained after 20 min of extraction at different temperatures using ultrasonic‐assisted and water bath extraction techniques were determined to be in the ranges of 25.67% (20 min) to 29.67% (40°C) and 23.82% (control) to 26.00% (40°C), respectively. In raw chia seeds, oil content increased with both temperature and time, with the highest values observed at 40°C for 40 min in both ultrasonic and water bath treatments, except the result observed at 40°C for 20 min in ultrasonic treatment. The highest total phenol quantity was observed in roasted chia seeds extracted using both ultrasonic and water bath methods. The highest total phenolic content observed in roasted chia seeds extracted using both ultrasonic‐assisted extraction and water bath extraction methods can be attributed to the combined effects of roasting and extraction conditions on the release and recovery of phenolic compounds. Roasting may disrupt the cellular structure of chia seeds by breaking down cell walls and weakening the interactions between phenolic compounds and macromolecules such as proteins and polysaccharides, thereby increasing the accessibility of these bioactive compounds during extraction. In addition, thermal treatment can promote the formation of certain phenolic derivatives and enhance the extractability of bound phenolics through structural modifications of the plant matrix (Nicoli et al. 1999; Xu and Chang 2008). Ultrasonic‐assisted extraction further improves phenolic recovery by generating cavitation bubbles that cause mechanical disruption of plant tissues, increasing solvent penetration and facilitating the release of intracellular phenolic compounds. Similarly, water bath extraction provides controlled heating that enhances diffusion and solubility of phenolic compounds in the extraction solvent. Therefore, the higher total phenolic content found in roasted chia seeds obtained by both extraction techniques may result from improved mass transfer, cell wall disruption, and increased liberation of phenolic compounds compared with untreated samples. For raw chia seeds, total phenolic content (TPC) extracted with the ultrasonic bath varied from 103.03 (control) to 159.94 (25°C, 20 min), whereas in the water bath system, TPC ranged from 102.76 (control) to 162.69 mg GAE/100 g (25°C, 40 min) (Table 2). Additionally, roasted chia seeds extracted under different temperatures and times in both systems showed TPC values between 153.61 (control) and 191.67 mg GAE/100 g (25°C, 20 min) for the ultrasonic system, and 154.26 (control) and 186.06 mg GAE/100 g (25°C, 40 min) for the water bath system (Table 3). While total flavonoid contents of the raw chia seeds obtained by ultrasonic bath extraction method are assessed between 43.88 (control) and 72.74 mg/100 g (25°C/20 min), total flavonoid amounts of the raw chia seeds obtained by water bath system were assessed to be between 44.36 (control) and 82.36 mg/100 g (25°C/40 min) (Table 2). Also, total flavonoid amounts (TFC) of the roasted chia seeds obtained by ultrasonic and water bath extraction methods were demonstrated to be between 48.50 (40°C/20 min) and 64.88 mg/100 g (25°C/40 min) to 45.45 (40°C/20 min) and 54.07 mg/100 g (25°C/40 min), respectively. The antioxidant activities of raw chia seeds extracted by ultrasonic and water bath extraction were determined to be 6.87 (25°C/40 min) and 6.92 mmol TE/kg (40°C/40 min) and 6.88 (25°C/40 min) and 6.91 mmol TE/kg (40°C/40 min), respectively. While antioxidant capacities of the roasted chia seeds extracted by ultrasonic bath extraction method are established between 6.84 (40°C/40 min) and 7.04 mmolTE/kg (control), antioxidant activities of the roasted chia seeds were described to be between 6.84 (25°C/20 min) and 6.88 mmolTE/kg (control). The antioxidant activity values of raw and roasted chia seeds extracted by both systems were comparable, with no significant differences observed. Roasting process did not result in a consistent increase in the antioxidant activity of chia seeds; in fact, antioxidant activity values remained within a narrow range across both raw and roasted samples regardless of the sonication parameters. In this case, it is thought that the applied processes did not have a significant effect on antioxidant activity values. The control sample exhibited a total phenolic content of 2.55 mg GAE/g, while chia seeds roasted at 90°C and 120°C showed decreased values of 2.34 mg GAE/g and 2.14 mg GAE/g, respectively (Al‐Juhaimi et al. 2024). Correspondingly, the total flavonoid contents were 13.71 mg CE/g for seeds roasted at 90°C and 12.91 mg CE/g for those roasted at 120°C (Al‐Juhaimi et al. 2024). Similarly, Ghafoor et al. (2018) reported total phenolic contents of 3.07 mg GAE/g in raw chia seeds, which increased to 3.43 mg GAE/g upon roasting. Marineli et al. (2014) determined that chia seeds contained 0.94 mg GAE/g of total phenolics. Additionally, Ghafoor et al. (2020) observed total phenol levels of 0.98 mg GAE/100 g in control samples, which declined to 0.91 and 0.88 mg GAE/100 g following roasting at 90°C and 120°C, respectively. Ahmed et al. (2024) reported that the total phenolic content of roasted chia seeds ranged from 186.59 mg GAE/100 g in the control to 429.29 mg GAE/100 g after 20 min of roasting, while total flavonoid content varied from 810.00 mg/100 g at 10 min to 903.33 mg/100 g at 5 min of roasting. Furthermore, Martínez‐Cruz and Paredes‐López (2014) determined a DPPH antioxidant capacity of 68.83%. The pronounced antioxidant activity of chia seeds is likely attributable to their high content of phenolic compounds, including phenolic acids, isoflavones, and anthocyanins (Martínez‐Cruz and Paredes‐López 2014). Total phenolic content varies with cultivar and study. For example, values of 0.88–0.92 mg GAE/g have been reported for the Sinaloa and Jalisco cultivars (Reyes‐Caudillo et al. 2008), and 1.64 mg GAE/g (Martínez‐Cruz and Paredes‐López 2014). Roasting has been shown to significantly reduce antioxidant activity, as demonstrated by Ghafoor et al. (2020), who observed a progressive decline from 88.27% in unroasted seeds to 85.76%, 79.57%, 48.44%, and 31.23% at 90°C, 120°C, 150°C, and 180°C, respectively. In agreement, Ahmed et al. (2024) reported that roasting chia seeds at 120°C for 10–20 min in a Teflon pan resulted in a marked decrease in their antioxidant capacity. The oil content of chia seeds was significantly influenced by factors such as the seed's state (raw or roasted), the processing method, temperature, and the duration of treatment (p < 0.05). In raw chia seeds, oil content increased with both temperature and time, with the highest values observed at 40°C for 40 min in both ultrasonic and water bath treatments, except the result observed at 40°C for 20 min in ultrasonic treatment. Ultrasonic processing resulted in greater oil extractability than water bath treatment under comparable conditions, which can be attributed to acoustic cavitation effects that promote cell wall disruption and enhance solvent penetration. Roasted chia seeds exhibited significantly higher oil contents than raw seeds across all treatments. This increase is likely due to structural weakening of the seed matrix during roasting, facilitating oil release during subsequent processing. However, the enhancement of oil yield at higher temperatures was often accompanied by a reduction in bioactive compounds, indicating a temperature‐dependent trade‐off between oil extraction efficiency and phytochemical retention. Both ultrasonic and water bath treatments significantly increased total phenolic content compared with control samples (p < 0.05). In raw chia seeds, the highest TPC values were observed at 25°C, particularly after 40 min of water bath treatment, suggesting that mild processing conditions promote phenolic release without inducing thermal degradation. Ultrasonic treatment at 25°C also resulted in substantial increases in TPC roasted chia, reflecting the effectiveness of cavitation in liberating bound phenolic compounds. In contrast, increasing the processing temperature to 40°C generally resulted in reduced TPC in both raw and roasted seeds. This decrease may be attributed to oxidative degradation or polymerization of thermolabile phenolic compounds under prolonged thermal exposure. Roasted chia seeds displayed higher baseline TPC than raw seeds, indicating that roasting may enhance phenolic availability through matrix modification or the formation of Maillard reaction‐derived phenolics. Also, the significant increase in total phenolic content (TPC) of roasted chia seeds after ultrasonic treatment applied at 25°C can be attributed to the enhanced mass transfer and disruption of the seed matrix caused by ultrasonic cavitation. During ultrasonication, the formation and collapse of microscopic bubbles generate localized shear forces, microjets, and turbulence, which break down cell wall structures and improve the release of bound phenolic compounds from the plant tissue. Although roasting can promote the formation of some antioxidant compounds through thermal reactions, excessive heat may also cause degradation of phenolics; therefore, the application of ultrasound at a mild temperature (25°C) provides an additional extraction mechanism without inducing significant thermal degradation. In chia seeds, many phenolic compounds are associated with cell wall components, and ultrasonic treatment facilitates their migration into the extract, resulting in higher measurable TPC values. Similar improvements in phenolic recovery after ultrasound‐assisted extraction have been reported for various plant materials, where cavitation‐induced structural disruption increased the accessibility of bioactive compounds (Chemat et al. 2017; Tiwari 2015). Therefore, the combination of roasting‐induced structural modification and ultrasound‐assisted release mechanisms likely explains the observed increase in TPC in roasted chia seeds. Total flavonoid content (TFC) followed trends similar to those observed for TPC but exhibited greater sensitivity to temperature. The highest TFC values were recorded at 25°C for extended treatment durations, particularly under ultrasonic processing for raw seeds and water bath treatment for roasted seeds. These findings suggest that flavonoids are effectively released under mild conditions but are susceptible to degradation at elevated temperatures. At 40°C, TFC decreased significantly regardless of processing method, confirming the thermal instability of flavonoid compounds. Although roasting increased initial flavonoid levels, prolonged exposure to higher temperatures during post‐roasting processing resulted in partial losses. Antioxidant activity showed relatively limited variation across treatments compared with TPC and TFC. The antioxidant activity values of raw and roasted chia seeds extracted by both systems were comparable, with no significant differences observed. Roasting process did not result in a consistent increase in the antioxidant activity of chia seeds; in fact, antioxidant activity values remained within a narrow range across both raw and roasted samples regardless of the sonication parameters. In this case, it is thought that the applied processes did not have a significant effect on antioxidant activity values. Roasting process did not result in a consistent increase in the antioxidant activity of chia seeds; in fact, antioxidant activity values remained within a narrow range across both raw and roasted samples regardless of the sonication parameters. Slight decreases in antioxidant activity were observed at higher temperatures and longer processing times, particularly when accompanied by reductions in TPC and TFC. This indicates that phenolic compounds play a primary role in antioxidant capacity, although other non‐phenolic antioxidants may contribute to maintaining relatively stable activity levels.

Sample | Process | Temperature | Time (Min) | Oil content (%) | Total phenolic content (mgGAE/100 g) | Total flavonoid content (mgQE/100 g) | Antioxidant activity (mmolTE/kg)
Raw chia seed | Control | — | — | 22.40 ± 0.79d | 103.03 ± 2.69e | 43.88 ± 3.68e | 6.90 ± 0.03
Ultrasonic bath | 25°C | 20 | 18.40 ± 0.65e | 159.94 ± 1.88a | 72.74 ± 6.62a | 6.90 ± 0.03
40°C | 28.00 ± 0.99a | 156.27 ± 0.14b | 48.60 ± 1.67d | 6.91 ± 0.04
25°C | 40 | 22.60 ± 0.80c | 153.44 ± 2.54c | 66.31 ± 5.64b | 6.87 ± 0.07
40°C | 24.60 ± 0.87b | 147.93 ± 5.44d | 55.40 ± 1.62c | 6.92 ± 0.01
Control | — | — | 24.80 ± 0.88d | 102.76 ± 1.31e | 44.36 ± 0.76e | 6.90 ± 0.01
Water‐bath | 25°C | 20 | 24.60 ± 0.87e | 142.69 ± 4.67b | 74.45 ± 4.51b | 6.90 ± 0.02
40°C | 25.00 ± 0.88c | 120.76 ± 5.05d | 51.55 ± 3.79d | 6.92 ± 0.00
25°C | 40 | 29.60 ± 1.05ab | 162.69 ± 2.13a | 82.36 ± 3.58a | 6.88 ± 0.03
40°C | 29.80 ± 1.05a | 128.61 ± 2.04c | 53.07 ± 2.81c | 6.91 ± 0.01
Roasted chia seed | Control | — | — | 25.94 ± 0.59c | 153.61 ± 5.05e | 54.50 ± 2.00d | 7.04 ± 0.06
Ultrasonic bath | 25°C | 20 | 25.67 ± 0.54d | 191.67 ± 2.81a | 57.21 ± 2.92b | 6.98 ± 0.05
40°C | 29.67 ± 0.63b | 164.19 ± 4.74d | 48.50 ± 0.57e | 6.93 ± 0.08
25°C | 40 | 25.00 ± 0.53e | 184.46 ± 2.77b | 64.88 ± 4.13a | 6.85 ± 0.05
40°C | 31.67 ± 0.67a | 182.97 ± 5.18c | 55.69 ± 2.38c | 6.84 ± 0.03
Control | — | — | 23.82 ± 0.57e | 154.26 ± 5.52d | 50.36 ± 6.08c | 6.88 ± 0.01
Water‐bath | 25°C | 20 | 25.33 ± 0.54d | 173.82 ± 3.61b | 53.26 ± 0.93b | 6.85 ± 0.01
40°C | 26.00 ± 0.55c | 152.49 ± 5.15e | 45.45 ± 1.25e | 6.84 ± 0.02
25°C | 40 | 28.00 ± 0.59b | 186.06 ± 0.14a | 54.07 ± 1.12a | 6.86 ± 0.01
40°C | 30.67 ± 0.86a | 157.80 ± 3.46c | 48.60 ± 1.59d | 6.86 ± 0.01

Phenolic compounds (mg/100 g) | Ultrasonic bath
Control | 25°C/20 min | 40°C/20 min | 25°C/40 min | 40°C/40 min
Gallic acid | 18.72 ± 1.21d | 31.42 ± 2.23b | 24.53 ± 2.08c | 33.93 ± 2.63a | 24.09 ± 1.05c
3,4‐Dihydroxybenzoic acid | 6.14 ± 0.90e | 10.23 ± 1.44d | 32.18 ± 1.54b | 40.79 ± 1.51a | 31.33 ± 3.38c
Catechin | 34.77 ± 0.63d | 76.24 ± 4.10a | 26.86 ± 0.87e | 50.19 ± 2.35b | 41.75 ± 1.10c
Caffeic acid | 0.69 ± 0.30e | 22.97 ± 1.28a | 4.08 ± 0.07d | 9.69 ± 0.98b | 7.33 ± 2.65c
Syringic acid | 0.67 ± 0.10e | 9.18 ± 0.42b | 3.26 ± 0.29c | 12.28 ± 1.42a | 2.83 ± 0.91d
Rutin | 2.23 ± 0.44 cd | 40.26 ± 3.05a | 2.53 ± 0.84c | 11.51 ± 0.50b | 0.55 ± 0.06e
p‐Coumaric acid | 0.51 ± 0.09c | 7.46 ± 0.80a | 0.54 ± 0.17c | 0.87 ± 0.08b | 0.57 ± 0.09c
Ferulic acid | 1.31 ± 0.33b | 9.06 ± 1.07a | 0.35 ± 0.08d | 0.50 ± 0.06c | 0.53 ± 0.10c
Resveratrol | 0.23 ± 0.05e | 2.29 ± 0.03a | 0.38 ± 0.11d | 0.67 ± 0.03b | 0.48 ± 0.06c
Quercetin | 0.81 ± 0.05d | 8.30 ± 0.44a | 1.78 ± 0.37b | 1.70 ± 0.31b | 1.11 ± 0.27c
Cinnamic acid | 0.10 ± 0.02c | 0.45 ± 0.13a | 0.10 ± 0.03c | 0.11 ± 0.02c | 0.32 ± 0.08b
Kaempferol | 5.05 ± 0.21e | 97.19 ± 2.81a | 67.00 ± 0.58d | 90.30 ± 0.76b | 85.91 ± 4.63c
Phenolic compounds (mg/100 g) | Water‐bath
Control | 25°C/20 min | 40°C/20 min | 25°C/40 min | 40°C/40 min
Gallic acid | 1.92 ± 0.15e | 23.07 ± 2.46a | 22.62 ± 1.98b | 12.05 ± 2.29d | 21.49 ± 1.04c
3,4‐Dihydroxybenzoic acid | 5.03 ± 1.62e | 16.18 ± 1.74c | 15.33 ± 0.92d | 21.85 ± 0.95b | 44.74 ± 0.38a
Catechin | 5.89 ± 0.38e | 47.60 ± 0.76b | 19.67 ± 1.93c | 15.76 ± 1.88d | 50.61 ± 1.52a
Caffeic acid | 0.12 ± 0.02e | 11.08 ± 0.94a | 2.02 ± 0.20d | 4.76 ± 2.23c | 9.49 ± 0.53b
Syringic acid | 0.44 ± 0.15e | 9.05 ± 1.56a | 0.79 ± 0.11d | 3.01 ± 1.51c | 7.19 ± 1.94b
Rutin | 0.83 ± 0.13e | 5.33 ± 1.03b | 3.57 ± 0.81d | 4.65 ± 1.18c | 45.20 ± 2.98a
p‐Coumaric acid | 0.17 ± 0.04d | 2.21 ± 0.96a | 1.34 ± 0.14c | 1.66 ± 0.56b | 1.30 ± 0.24c
Ferulic acid | 0.41 ± 0.14de | 4.36 ± 0.78a | 0.58 ± 0.29d | 1.65 ± 0.85c | 3.26 ± 0.67b
Resveratrol | 0.43 ± 0.03c | 0.52 ± 0.15b | 0.73 ± 0.11a | 0.20 ± 0.03e | 0.35 ± 0.02d
Quercetin | 0.57 ± 0.11d | 1.19 ± 0.15c | 1.47 ± 0.23b | 0.41 ± 0.10e | 1.54 ± 0.18a
Cinnamic acid | 7.97 ± 2.27c | 0.25 ± 0.07d | 7.92 ± 2.26c | 12.67 ± 3.63b | 15.83 ± 0.43a
Kaempferol | 66.99 ± 3.22c | 83.40 ± 0.16b | 66.13 ± 1.16c | 104.64 ± 2.16a | 15.91 ± 1.28d

Phenolic compounds (mg/100 g) | Ultrasonic bath
Control | 25°C/20 min | 40°C/20 min | 25°C/40 min | 40°C/40 min
Gallic acid | 23.90 ± 2.22*b | 14.69 ± 0.83d | 14.23 ± 0.69de | 20.07 ± 0.62c | 26.96 ± 1.83a
3,4‐Dihydroxybenzoic acid | 19.08 ± 1.78b** | 6.93 ± 0.80d | 4.32 ± 0.77e | 29.12 ± 1.96a | 18.42 ± 0.85c
Catechin | 52.50 ± 0.57c | 57.03 ± 0.53b | 19.59 ± 0.58e | 32.86 ± 1.25d | 116.46 ± 8.34a
Caffeic acid | 3.69 ± 0.79d | 3.09 ± 1.01de | 8.85 ± 0.91c | 10.31 ± 0.13b | 12.53 ± 2.30a
Syringic acid | 6.82 ± 0.02c | 2.22 ± 0.60de | 2.34 ± 0.21d | 17.38 ± 1.72a | 11.94 ± 2.18b
Rutin | 35.67 ± 3.42a | 7.19 ± 0.21d | 4.52 ± 0.24e | 30.11 ± 0.04b | 22.60 ± 1.99c
p‐Coumaric acid | 1.96 ± 0.66c | 1.45 ± 0.36d | 1.20 ± 0.32e | 5.61 ± 0.86a | 4.19 ± 1.08b
Ferulic acid | 0.47 ± 0.03e | 0.85 ± 0.30d | 1.67 ± 0.61c | 6.55 ± 0.14ab | 6.68 ± 2.38a
Resveratrol | 1.46 ± 0.48c | 0.24 ± 0.09e | 0.40 ± 0.04d | 3.55 ± 0.06b | 5.10 ± 0.47a
Quercetin | 6.84 ± 0.30c | 1.66 ± 0.33e | 2.18 ± 0.44d | 7.04 ± 0.04b | 15.12 ± 1.02a
Cinnamic acid | 1.08 ± 0.08d | 1.16 ± 0.12c | 0.80 ± 0.10e | 1.24 ± 0.21b | 2.40 ± 0.40a
Kaempferol | 1.01 ± 0.38e | 37.81 ± 0.46c | 25.84 ± 1.89d | 42.68 ± 2.60b | 53.02 ± 3.37a
Phenolic compounds (mg/100 g) | Water‐bath
Control | 25°C‐20 min | 40°C‐20 min | 25°C‐40 min | 40°C‐40 min
Gallic acid | 21.41 ± 1.22a | 21.14 ± 1.61a | 19.01 ± 1.54b | 18.25 ± 1.08c | 17.91 ± 2.49d
3,4‐Dihydroxybenzoic acid | 33.04 ± 0.88b | 28.08 ± 1.45c | 23.37 ± 4.48d | 35.12 ± 0.92a | 21.01 ± 0.76e
Catechin | 84.34 ± 0.91e | 292.57 ± 0.58a | 261.08 ± 7.78b | 235.89 ± 8.55c | 226.47 ± 0.03d
Caffeic acid | 16.31 ± 1.84a | 8.03 ± 1.16d | 13.44 ± 1.94b | 6.96 ± 0.23e | 8.39 ± 0.46c
Syringic acid | 9.44 ± 1.12 cd | 22.96 ± 2.10a | 19.05 ± 1.29b | 6.50 ± 1.05e | 9.74 ± 3.25c
Rutin | 82.69 ± 3.24a | 45.13 ± 2.90b | 45.27 ± 3.15b | 31.32 ± 4.22c | 16.69 ± 3.47d
p‐Coumaric acid | 9.85 ± 0.49a | 5.18 ± 1.49d | 6.11 ± 0.83c | 9.27 ± 1.40b | 3.45 ± 1.51e
Ferulic acid | 2.57 ± 1.01e | 3.96 ± 0.69c | 9.62 ± 0.59a | 8.14 ± 0.99b | 3.68 ± 1.81 cd
Resveratrol | 4.64 ± 0.29a | 3.88 ± 0.96b | 1.89 ± 0.47c | 1.84 ± 0.76c | 1.03 ± 0.41d
Quercetin | 7.65 ± 1.44d | 8.90 ± 1.31c | 10.51 ± 3.09b | 12.56 ± 0.31a | 5.57 ± 2.17e
Cinnamic acid | 2.82 ± 0.83b | 1.62 ± 0.35e | 1.85 ± 0.34c | 1.70 ± 0.40d | 8.08 ± 1.28a
Kaempferol | 66.13 ± 0.84b | 68.98 ± 1.65a | 41.51 ± 2.11c | 41.33 ± 2.79c | 8.19 ± 0.41d

Phenolic Compounds of Raw Chia Seeds Extracted With Ultrasonic and Water Bath Systems

The phenolic composition of raw and roasted chia seeds, obtained using both ultrasonic and water bath extraction methods under different thermal and temporal conditions, is summarized in Tables 2 and 3. Roasted chia seeds generally have higher phenolic compound content compared to unroasted seeds. The major phenolic compounds identified in raw chia seed extracts, obtained using both extraction methods, were gallic acid, 3,4‐dihydroxybenzoic acid, catechin, rutin, cinnamic acid (with the exception of extracts obtained via ultrasonic bath), and kaempferol. Quantitative analysis indicated that the concentrations of gallic acid and 3,4‐dihydroxybenzoic acid in extracts produced by ultrasonic bath extraction ranged from 18.72 mg/100 g (control) to 33.93 mg/100 g (25°C, 40 min) and from 6.14 mg/100 g (control) to 40.79 mg/100 g (25°C, 40 min), respectively, demonstrating a notable variation in phenolic content depending on extraction conditions (Table 2). While catechin contents of the raw chia seeds are established between 26.86 (40°C/25 min) and 76.24 mg/100 g (25°C/20 min), caffeic acid amounts of the raw chia seeds were characterized to be between 0.69 (control) and 22.97 mg/100 g (25°C/20 min). Rutin and kaempferol contents of the raw chia seeds were described to be between 0.55 (40°C/40 min) and 40.26 mg/100 g (25°C/20 min) to 5.04 (control) and 97.19 mg/100 g (25°C/20 min), respectively (Table 2). Gallic and 3,4‐dihydroxybenzoic acid amounts of the raw chia seeds extracted by water bath extraction method were assayed to be between 1.92 (control) and 23.07 mg/100 g (25°C/20 min) to 5.03 (control) and 44.74 mg/100 g (40°C/40 min), respectively. Catechin and caffeic acid contents of the raw chia seeds obtained by water bath system were characterized to be between 5.89 (control) and 50.61 mg/100 g (40°C/40 min) to 0.12 (control) and 11.08 mg/100 g (25°C/20 min), respectively (Table 2). While syringic acid amounts of the raw chia seeds obtained by water bath system are assayed between 0.44 (control) and 9.05 (25°C/20 min), rutin amounts of the raw chia seeds were described to be between 0.83 (control) and 45.20 mg/100 g (40°C/40 min). The concentrations of cinnamic acid and kaempferol in raw chia seeds, extracted via a water bath at varying temperatures and durations, were found to range from 0.25 mg/100 g (25°C, 20 min) to 15.83 mg/100 g (40°C, 40 min) and from 15.91 mg/100 g (40°C, 40 min) to 104.64 mg/100 g (25°C, 40 min), respectively. Gallic acid and 3,4‐dihydroxybenzoic acid amounts of the roasted chia seeds obtained by ultrasonic bath extraction method were assessed to be between 14.23 (40°C/20 min) and 26.96 mg/100 g (40°C/40 min) to 4.32 (40°C/20 min) and 29.12 mg/100 g (25°C/40 min) (Table 3). While catechin quantities of the roasted chia seeds obtained by the ultrasonic bath method are described to be between 19.59 (40°C/20 min) and 116.46 mg/100 g (40°C/40 min), caffeic acid amounts of the roasted chia seeds were assayed to be between 3.09 (25°C/20 min) and 12.53 mg/100 g (40°C/40 min). Syringic acid and routine amounts of the roasted chia seeds were determined to be between 2.22 (25°C/20 min) and 17.38 mg/100 g (25°C/40 min) to 4.52 (40°C/20 min) and 35.67 mg/100 g (control), respectively (Table 3). The amounts of quercetin and kaempferol in roasted chia seeds extracted using the ultrasonic system were found to range from 1.66 mg/100 g (25°C/20 min) to 15.12 mg/100 g (40°C/40 min) and from 1.01 mg/100 g (control) to 53.02 mg/100 g (40°C/40 min), respectively. For roasted chia seeds extracted by the water bath system, gallic acid and 3,4‐dihydroxybenzoic acid contents varied between 17.91 mg/100 g (40°C/40 min) and 21.41 mg/100 g (control) and between 21.01 mg/100 g (40°C/40 min) and 35.12 mg/100 g (25°C/40 min), respectively. Catechin levels in water bath–extracted roasted chia seeds were determined to be 84.34 mg/100 g (control) and 292.57 mg/100 g (25°C/20 min), while caffeic acid amounts range from 6.96 mg/100 g (25°C/40 min) to 16.31 mg/100 g (control). Syringic acid and rutin concentrations were found to range from 6.50 mg/100 g (25°C/40 min) to 22.96 mg/100 g (25°C/20 min) and from 16.69 mg/100 g (40°C/40 min) to 82.69 mg/100 g (control), respectively. Quercetin amounts in water bath–extracted seeds ranged from 5.57 mg/100 g (40°C/40 min) to 12.56 mg/100 g (25°C/40 min), while cinnamic acid levels are assayed between 1.62 mg/100 g (25°C/20 min) and 8.08 mg/100 g (40°C/40 min). Kaempferol amounts were identified to range from 8.19 mg/100 g (40°C/40 min) to 68.98 mg/100 g (25°C/20 min). Ghafoor et al. (2020) investigated the phytochemical composition of chia seeds roasted at 90°C, 120°C, 150°C, and 180°C. Their analysis revealed that these seeds contained a variety of phenolic acids, including gallic acid, 3,4‐dihydroxybenzoic acid, 1,2‐dihydroxybenzene, caffeic acid, chlorogenic acid, cinnamic acid, and rosmarinic acid, as well as flavonoids such as quercetin, kaempferol, rutin trihydrate, genistein, myricetin, and isorhamnetin, with concentrations ranging from 4.83 to 85.49 mg/100 g depending on the compound. The study demonstrated that roasting temperature significantly affects the retention and concentration of these bioactive compounds, highlighting their contribution to the antioxidant potential and nutraceutical value of chia seeds. A previous study reported that quercetin, chlorogenic acid, and caffeic acid were present at levels of 0.17 μg/g, 4.68 μg/g, and 30.89 μg/g, respectively (Coelho and Salas‐Mellado 2014). Analyses of chia seed extracts have revealed the presence of bioactive compounds, including chlorogenic acid, caffeic acid, quercetin, and kaempferol, at varying concentrations (Reyes‐Caudillo et al. 2008). The levels of caffeic acid detected in the chia seeds examined in the present study were in agreement with those reported in earlier investigations. These values highlight the variability of caffeic acid content across different cultivars and studies. Roasting chia seeds at 120°C for 20 min increased their caffeic (31.14 → 35.46 mg/kg) and p‐coumaric (4.17 → 5.48 mg/kg) acid contents (Ghafoor et al. 2018). UAE revealed marked differences in total phenolic content and antioxidant capacity between methanolic (149.95 ± 20.39 mg GAE/100 g; 9.90 ± 0.05 mg Trolox/100 g) and hexane extracts (60.31 ± 5.99 mg GAE/100 g; 1.11 ± 0.38 mg Trolox/100 g). Significant levels of gallic, caffeic, chlorogenic, ferulic, and rosmarinic acids, as well as myricetin, quercetin, and kaempferol, have been identified in chia seeds (Dias et al. 2017). Similarly, many species of the genus Salvia are valued for their horticultural and medicinal uses, as they contain bioactive compounds such as flavonoids (myricetin, quercetin, kaempferol) and polyphenols (chlorogenic and caffeic acids) (Reyes‐Caudillo et al. 2008; Ixtaina, Nolasco, and Tomás 2011). It has shown that ultrasonic power is a critical factor influencing the efficiency of phenolic extraction (Hussam Ahmad‐Qasem et al. 2013). The greater total phenol content in roasted chia seeds compared to unroasted seeds could also result from the reaction of Maillard reaction products formed during roasting with Folin–Ciocalteu reagent, in addition to the phenols naturally present in the seed structure (Liu et al. 2020). The antioxidant activities of the seeds did not change significantly with both extraction systems. Only the antioxidant activities of roasted chia seeds extracted at 25°C and 40°C for 20 min were found to be slightly higher than those extracted for 40 min. The differences in phenolic compound contents between water bath and ultrasound‐assisted extracted raw and roasted chia seed samples may be attributed to variations in extraction efficiency, processing conditions, and structural changes occurring during roasting. In the present study, ultrasound‐assisted extraction resulted in differences in phenolic recovery compared with conventional water bath extraction, which is consistent with previous findings indicating that ultrasonic power enhances phenolic extraction by promoting cavitation, improving solvent penetration, and disrupting plant cell structures (Carcel et al. 2012; Hussam Ahmad‐Qasem et al. 2013; Priego‐Capote and Luque De 2004). Previous studies have reported the presence of important phenolic compounds in chia seeds, including caffeic acid, chlorogenic acid, quercetin, and kaempferol, although their concentrations varied considerably depending on cultivar, environmental conditions, and analytical procedures (Reyes‐Caudillo et al. 2008; Coelho and Salas‐Mellado 2014). For example, Coelho and Salas‐Mellado (2014) reported quercetin, chlorogenic acid, and caffeic acid concentrations of 0.17, 4.68, and 30.89 μg/g, respectively, whereas the caffeic acid levels obtained in the present study were comparable with previous reports, confirming the variability of phenolic composition among different chia samples. Furthermore, roasting treatment can modify phenolic availability by inducing thermal degradation of some compounds while simultaneously increasing extractable phenolics through cell wall disruption and the formation of Maillard reaction products. Similar results were observed by Ghafoor et al. (2018), who demonstrated that roasting chia seeds at 120°C for 20 min increased caffeic acid and p‐coumaric acid contents from 31.14 to 35.46 mg/kg and from 4.17 to 5.48 mg/kg, respectively. In addition, Liu et al. (2020) suggested that the higher total phenolic content observed in roasted seeds may be partially related to the interaction of Maillard reaction products with the Folin–Ciocalteu reagent. Therefore, the differences observed between raw and roasted chia extracts obtained by water bath and ultrasound‐assisted extraction can be explained by the combined effects of extraction technique, ultrasonic energy, thermal processing, and changes in the chemical accessibility of phenolic compounds within the chia seed matrix. Overall, the phenolic compounds in chia seeds increased compared to the control when extracted using both methods at 25°C and 40°C for 20 and 40 min. Ultrasonic and water bath extraction of raw chia seeds resulted in significant increases in the concentrations of gallic acid, 3,4‐dihydroxybenzoic acid, catechin, caffeic acid, syringic acid, rutin, _p‐_coumaric acid, and kaempferol compared to the control. Ultrasonic and water bath extraction of raw chia seeds significantly increased the accumulation of phenolic compounds such as gallic acid, 3,4‐dihydroxybenzoic acid, catechin, caffeic acid, syringic acid, rutin, p‐coumaric acid, and kaempferol compared with the control group. This increase is mainly attributed to the disruption of the seed matrix, enhanced cell wall permeability, and improved mass transfer, which facilitate the release of bound phenolic compounds. Ultrasonic cavitation promotes cellular breakdown, while water bath heating improves phenolic solubility and diffusion, resulting in higher recovery of bioactive compounds (Vilkhu et al. 2008; Chemat et al. 2017). Ultrasound‐assisted extraction (UAE) improves the recovery of phenolic compounds through acoustic cavitation and enhanced mass transfer. Acoustic cavitation involves the formation and collapse of microbubbles, generating localized high pressure, temperature, shock waves, and microjets that disrupt plant cell structures and facilitate the release of intracellular phenolics. Ultrasound‐induced microstreaming also reduces the boundary layer around particles, accelerating solvent penetration and diffusion. Because these mechanical effects enhance extraction efficiency, UAE can operate at lower temperatures, minimizing thermal degradation, oxidation, and polymerization of heat‐sensitive phenolic compounds. Consequently, UAE provides higher preservation of bioactive compounds compared with conventional high‐temperature extraction methods (Vinatoru 2001; Chemat et al. 2017). Similar effects of extraction conditions on increasing phenolic compound recovery have been reported in plant materials (Dai and Mumper 2010). Notably, both raw and roasted chia seeds demonstrated elevated levels of the predominant phenolic compounds across both extraction methods, indicating that these techniques effectively enhance the phenolic profile and potential bioactivity of chia seeds. Additionally, the amounts of phenolic compounds detected in roasted chia seeds were increased when compared to raw chia seeds after ultrasonic and water bath extraction. The highest phenolic compounds in raw chia seeds eluted with ultrasonic bath extraction were observed at 25°C/20 min and 25°C/40 min extraction temperatures, while the highest extraction times for water bath extraction were 25°C/20 min and 40°C/40 min. The phenolic compounds in raw chia seeds were higher when extracted using the ultrasonic bath system compared to the water bath extraction system. Conversely, for roasted chia seeds, the phenolic compounds were higher when extracted with the water bath system than with the ultrasonic bath system. Additionally, the levels of gallic acid, caffeic acid, rutin, p‐coumaric acid, and resveratrol in roasted chia seeds extracted using the water bath system at various temperatures and durations decreased compared to the control. This decrease may have been due to the agitation speed of the water bath system and the ambient temperature.

The Fatty Acid Profile of Raw and Roasted Chia Seed Oils

The fatty acid compositions of raw and roasted chia seed oils extracted with ultrasonic and water bath systems at different temperatures and times are given in Table 4. The predominant fatty acids in raw and roasted chia seed oils extracted with both systems were linolenic, linoleic, and oleic acid. The oleic acid content of raw chia oils obtained using ultrasonic and water bath methods ranged from 9.84% (25°C/20 min) to 10.27% (control) and from 10.12% (control) to 10.36% (25°C/20 min), respectively. Similarly, the linoleic acid content of oils obtained from raw chia seeds via the ultrasonic bath method was found to be between 18.08% (25°C/40 min) and 19.25% (25°C/20 min), while linoleic acid levels in the oils from raw seeds were measured between 18.15% (25°C/40 min) and 18.42% (40°C/20 min). Linolenic acid amounts of the oils obtained from raw chia seeds treated by ultrasonic and water bath extraction systems were detected to be between 68.91% (40°C/40 min) and 70.20% (25°C/40 min) to 69.15% (40°C/40 min) and 69.97% (control), respectively. In addition, oleic acid amounts of the oils obtained from roasted chia seeds treated by ultrasonic and water bath extraction systems were assayed to be between 9.90% (25°C/40 min) and 10.15% (25°C/20 min) to 9.92% (control) and 10.03% (40°C/40 min), respectively. The total fatty acid percentages detected under the conditions of 25°C for 40 min account for only approximately 90% of the total fatty acid composition. The remaining 10% may be attributed to undetected fatty acid components, minor fatty acid derivatives, measurement limitations, and analytical losses that can occur during sample preparation and instrumental analysis. In addition, some fatty acids may be present at very low concentrations below the detection or quantification limits of the analytical method. Therefore, the missing percentage does not necessarily indicate the absence of fatty acids but may reflect the inherent uncertainties and limitations of the analytical procedure. Also, linolenic acid amounts of the oils extracted from roasted chia seeds treated by ultrasonic and water bath systems were identified to be between 69.32% (control) and 69.71% (40°C/20 min) to 69.46% (25°C/40 min) and 69.81% (40°C/40 min), respectively. Depending on the extraction and seed types, the fatty acid amounts of other extracted oils were found to be below 5.63%. In general, the oil contents of raw and roasted chia seeds increased at 40°C/40 min for both extraction methods, while increases and decreases were observed at 25°C/20 min compared to the control. In general, the increase in oil content of both raw and roasted chia seeds after extraction at 40°C for 40 min may be attributed to the enhanced release of lipids from the seed matrix due to prolonged extraction time and increased temperature. Higher temperatures can improve solvent penetration, reduce oil viscosity, and promote the disruption of cell structures, thereby facilitating the transfer of triglycerides and other lipid components into the extracted oil phase. However, the variations (increases and decreases) observed at 20°C for 20 min compared with the control group may be related to insufficient extraction energy and the heterogeneous distribution of lipids within the seed structure. At lower temperatures and shorter extraction periods, the extraction process may not completely disrupt the cellular matrix, resulting in variable oil recovery depending on seed composition, particle size, and the availability of surface lipids. Additionally, roasting can modify the cellular structure of chia seeds by inducing thermal degradation of cell walls and changes in lipid–protein interactions, which may either enhance or limit oil release depending on the severity of the treatment. Similar effects of temperature and extraction time on oil yield and lipid recovery have been reported for oilseeds, where moderate increases in extraction temperature and duration improved lipid extraction efficiency, whereas insufficient conditions caused inconsistent recovery values (Reyes‐Caudillo et al. 2008; Ixtaina, Martínez, et al. 2011; Azadmard‐Damirchi et al. 2010). The predominant fatty acid compositions of oils obtained from raw and roasted chia seeds extracted with ultrasonic and water bath extraction systems were the same, but some differences were observed in their amounts. The oleic acid content of oils extracted from raw chia seeds using the ultrasonic bath system decreased compared to the control, whereas the oleic acid content of oil extracted with the water bath system showed a slight increase. Ultrasonic treatment of raw chia seeds may reduce oleic acid content compared with controls because cavitation generates localized heat and reactive species that can promote lipid oxidation and fatty acid degradation (Pingret et al. 2013). In contrast, water bath extraction provides gentler thermal conditions, which may enhance oil release without significant alteration of oleic acid composition (Mello et al. 2017). In contrast, the linolenic acid content of oil from raw chia seeds extracted with the ultrasonic bath system varied depending on the temperature and duration of extraction, while the linolenic acid content of oil extracted with the water bath system decreased slightly compared to the control. For oils extracted from roasted chia seeds, both ultrasonic and water bath methods showed a decrease in linoleic acid content as extraction temperature and time increased, while linolenic acid content generally increased, except in the water bath extract at 25°C for 40 min. The decrease in linoleic acid content and the increase in linolenic acid content with longer extraction time and higher temperature may be related to differences in fatty acid stability, oxidation susceptibility, and extraction efficiency. Extended exposure to heat and oxygen can accelerate the degradation of linoleic acid, while longer extraction may improve the release of linolenic acid from the chia seed matrix. The exception observed in the water‐bath extraction at 25°C for 40 min may be due to mild extraction conditions that limited oxidation and resulted in different mass transfer behavior, leading to a temporary variation in fatty acid composition. Similar effects of extraction conditions on PUFA profiles have been reported by Shahidi and Zhong (2010) and Martínez et al. (2012). Additionally, the oleic acid content of roasted chia seed oils varied according to the extraction method, temperature, and duration relative to the control. These changes are likely due to the breakdown of double bonds in unsaturated fatty acids caused by heat and oxygen during processing. The extraction conditions that produced the highest oleic and linoleic acid concentrations in water bath‐extracted roasted chia seed oil were 40°C for 40 min. Overall, neither the extraction method nor the roasting conditions significantly altered the oils' fatty acid composition, although minor variations were noted in certain fatty acids. Ghafoor et al. (2020) investigated the fatty acid profile of oils obtained from chia seeds subjected to roasting at 90°C, 120°C, 150°C, and 180°C, observing a general decrease in fatty acid content with increasing temperature. The chia seed oil contained 6.48%–7.08% palmitic acid, 2.69%–2.97% stearic acid, 9.94%–10.09% oleic acid, 19.47%–20.57% linoleic acid, and 58.64%–59.84% linolenic acid. Similarly, Özcan et al. (2019a) reported that chia oils roasted in a microwave at varying power levels exhibited palmitic, stearic, oleic, linoleic, and linolenic acid contents of 7.09%–8.35%, 1.81%–2.67%, 9.18%–10.08%, 19.21%–21.17%, and 66.84%–68.71%, respectively. In a separate study, Sargi et al. (2013) documented the fatty acid composition of chia seed oil as 5.8% palmitic acid, 2.4% stearic acid, 6.1% oleic acid, 17.4% linoleic acid, and 54.4% linolenic acid. Furthermore, Hatamian et al. (2020) reported a linoleic acid content of 58.5% in chia seed oil. Roasting at 175°C for 30 min can be considered a controlled heat treatment that improves flavor, texture, and microbial safety while limiting excessive degradation of polyunsaturated fatty acids (PUFAs). Although PUFAs are sensitive to oxidation at high temperatures, their stability depends on factors such as heating time, oxygen exposure, and the presence of natural antioxidants. A moderate roasting duration helps minimize lipid oxidation compared with longer or more intense thermal treatments, allowing acceptable retention of PUFA content (Choe and Min 2006; Zamora and Hidalgo 2001).

Fatty acids (%) for raw chia seed oil | Ultrasonic bath
Control | 25°C/20 min | 40°C/20 min | 25°C/40 min | 40°C/40 min
Stearic | 0.80 ± 0.02b | 0.73 ± 0.01d | 0.76 ± 0.01 cd | 0.77 ± 0.05c | 0.92 ± 0.02a
Oleic | 10.27 ± 0.08a | 9.84 ± 0.03e | 10.10 ± 0.06b | 9.91 ± 0.07d | 10.07 ± 0.02c
Linoleic | 18.43 ± 0.03c | 19.25 ± 0.01a | 18.19 ± 0.00d | 18.08 ± 0.07e | 19.04 ± 0.03b
Arachidic | 0.22 ± 0.00b | 0.23 ± 0.00a | 0.23 ± 0.00a | 0.23 ± 0.01a | 0.23 ± 0.01a
Linolenic | 69.46 ± 0.06c | 69.16 ± 0.02d | 69.92 ± 0.04b | 70.20 ± 0.05a | 68.91 ± 0.01e
Behenic | 0.82 ± 0.02b | 0.80 ± 0.01d | 0.81 ± 0.02c | 0.81 ± 0.01c | 0.83 ± 0.02a
Fatty acids (%) | Water‐bath
Control | 25°C/20 min | 40°C/20 min | 25°C/40 min | 40°C/40 min
Stearic | 0.80 ± 0.03b | 0.80 ± 0.04b | 0.77 ± 0.02d | 0.78 ± 0.01c | 0.81 ± 0.05a
Oleic | 10.12 ± 0.07d | 10.36 ± 0.09a | 10.29 ± 0.00b | 10.17 ± 0.08c | 10.35 ± 0.06a
Linoleic | 18.37 ± 0.06c | 18.33 ± 0.03d | 18.42 ± 0.01a | 18.15 ± 0.04e | 18.39 ± 0.10b
Arachidic | 0.22 ± 0.00b | 0.23 ± 0.02a | 0.21 ± 0.01c | 0.21 ± 0.01c | 0.22 ± 0.01b
Linolenic | 69.97 ± 0.32a | 69.69 ± 0.06c | 69.58 ± 0.11d | 69.86 ± 0.11b | 69.15 ± 0.23e
Behenic | 0.82 ± 0.02b | 0.60 ± 0.02d | 0.73 ± 0.15c | 0.83 ± 0.01a | 0.83 ± 0.02a
Fatty acids (%) for roasted chia seed oil | Ultrasonic bath
Control | 25°C/20 min | 40°C/20 min | 25°C/40 min | 40°C/40 min
Stearic | 0.72 ± 0.02c | 0.69 ± 0.01d | 0.67 ± 0.04e | 0.76 ± 0.06b | 0.82 ± 0.08a
Oleic | 10.01 ± 0.08c | 10.15 ± 0.03a | 10.10 ± 0.13b | 9.90 ± 0.09d | 9.91 ± 0.06d
Linoleic | 18.70 ± 0.05a | 18.49 ± 0.03b | 18.27 ± 0.03d | 18.45 ± 0.03c | 18.50 ± 0.03b
Arachidic | 0.24 ± 0.00b | 0.25 ± 0.01a | 0.24 ± 0.01b | 0.23 ± 0.01c | 0.23 ± 0.01c
Linolenic | 69.32 ± 0.04d | 69.39 ± 0.00c | 69.71 ± 0.06a | 69.67 ± 0.03b | 69.61 ± 0.06b
Behenic | 5.63 ± 6.55a | 1.03 ± 0.00b | 1.00 ± 0.00c | 0.99 ± 0.02d | 0.93 ± 0.00e
Fatty acids (%) | Water‐bath
Control | 25°C/20 min | 40°C/20 min | 25°C/40 min | 40°C/40 min
Stearic | 0.75 ± 0.07c | 0.72 ± 0.04d | 0.78 ± 0.01a | 0.77 ± 0.01b | 0.77 ± 0.06b
Oleic | 9.92 ± 0.06e | 10.02 ± 0.04b | 9.99 ± 0.02c | 9.94 ± 0.01d | 10.03 ± 0.06a
Linoleic | 18.42 ± 0.06b | 18.33 ± 0.00c | 18.30 ± 0.02d | 18.62 ± 0.03a | 18.28 ± 0.00e
Arachidic | 0.24 ± 0.01a | 0.22 ± 0.01c | 0.23 ± 0.00b | 0.23 ± 0.00b | 0.23 ± 0.01b
Linolenic | 69.66 ± 0.11d | 69.72 ± 0.03b | 69.70 ± 0.03c | 69.46 ± 0.05e | 69.81 ± 0.03a
Behenic | 1.02 ± 0.02a | 0.99 ± 0.01c | 1.00 ± 0.01b | 0.98 ± 0.00d | 0.88 ± 0.02e

Oxidizability, Oleic, and Linoleic Desaturation Ratiosof the Oils Extracted From Chia Seeds Sonicated at Different Temperatures and Times

Calculation Lipid index values of raw and roasted chia seeds obtained by ultrasonic and water bath extraction methods are given in Table 5. The oxidizability values of raw and roasted chia seeds extracted by ultrasonic and water bath extraction at different temperatures and times were determined to be between 16.95 (40°C–40 min) and 17.12 (25°C–40 min) to 16.93 (40°C–40 min) and 17.10 (control), respectively. The oxidizability values of roasted chia seed oils obtained using the water extraction system ranged from 17.02 (25°C–40 min) to 17.06 (40°C–40 min), compared to 17.04 for both 40°C–20 min and 40°C–40 min, and the control and 25°C–20 min samples. Oleic desaturation ratios of raw and roasted chia seed oils obtained via the ultrasonic bath system were measured between 0.895 (control) and 0.900 (25°C–20 min) for raw oils, and 0.896 (25°C–20 min) and 0.899 (25°C–40 min and 40°C–40 min) for roasted oils. Similarly, oleic desaturation ratios for oils obtained with the water bath system ranged from 0.894 (40°C–40 min) to 0.897 (control) for raw oils, and from 0.894 (40°C–20 min) to 0.899 (control and 40°C–20 min) for roasted oils. Linoleic desaturation values of raw chia seed oils obtained by ultrasonic and water bath systems were between 0.782 (25°C–20 min) and 0.795 (25°C–40 min) and 0.790 (40°C–40 min) and 0.794 (25°C–40 min), respectively. For roasted chia seed oils, linoleic desaturation values were measured between 0.788 (control) and 0.792 (40°C–20 min) for the ultrasonic system, and 0.788 (25°C–40 min) and 0.792 (25°C–20 min, 40°C–29 min, and 40°C–40 min) for the water bath system. The oxidizability stability of the oil obtained from raw chia seeds extracted with ultrasonic and water bath systems at 40°C for 40 min was slightly higher than that of other oils. The slightly higher oxidative stability of chia seed oil extracted by ultrasonic‐assisted and water‐bath methods at 40°C for 40 min may be related to the preservation of natural antioxidant compounds during the mild extraction process. Although chia oil contains high levels of oxidation‐sensitive polyunsaturated fatty acids, especially α‐linolenic acid, its tocopherols and phenolic compounds can inhibit free radical formation and delay lipid oxidation (Ixtaina, Nolasco, and Tomás 2011; Shahidi and Zhong 2010). The moderate extraction temperature reduces thermal degradation of these bioactive compounds, while ultrasound improves cell disruption and oil recovery without excessive heat exposure, contributing to better oxidative stability (Chemat et al. 2017). Therefore, the combination of efficient extraction and preservation of endogenous antioxidants may explain the slightly higher oxidation resistance of chia seed oil compared with some other vegetable oils (Capitani et al. 2012). Roasting partially reduced the oxidizability value, ODR, and LDR values of the oils compared to those of raw chia oils. The generally low oleic and linoleic desaturation rates suggest that chia oil may have health benefits. Mondal et al. (2010) reported average values of 0.5 for ODR and 0.01 for LDR. In a more recent study, El‐Beltagi et al. (2022) found that the oil extracted from sesame seeds roasted using various methods exhibited oxidizability values ranging from 4.97 to 5.06, ODR values between 0.5143 and 0.5172, and LDR values from 0.0115 to 0.0136.

Indices for raw chia seed oils | Ultrasonic bath
Control | 25°C/20 min | 40°C/20 min | 25°C/40 min | 40°C/40 min
Oxidizability value (Cox) | 17.00 | 17.01 | 17.07 | 17.12 | 16.95
Oleic desaturation ratio (ODR) | 0.895 | 0.900 | 0.897 | 0.899 | 0.897
Linoleic desaturation (LDR) | 0.790 | 0.782 | 0.794 | 0.795 | 0.784
Indices | Water bath
Control | 25°C/20 min | 40°C/20 min | 25°C/40 min | 40°C/40 min
Oxidizability value (Cox) | 17.10 | 17.03 | 17.02 | 17.06 | 16.93
Oleic desaturation ratio (ODR) | 0.897 | 0.895 | 0.895 | 0.896 | 0.894
Linoleic desaturation (LDR) | 0.792 | 0.792 | 0.791 | 0.794 | 0.790
Indices for roasted chia seed oils | Ultrasonic bath
Control | 25°C/20 min | 40°C/20 min | 25°C/40 min | 40°C/40 min
Oxidizability value (Cox) | 16.99 | 16.99 | 17.04 | 17.00 | 17.04
Oleic desaturation ratio (ODR) | 0.898 | 0.896 | 0.897 | 0.899 | 0.899
Linoleic desaturation (LDR) | 0.788 | 0.790 | 0.792 | 0.791 | 0.790
Indices | Water bath
Control | 25°C/20 min | 40°C/20 min | 25°C/40 min | 40°C/40 min
Oxidizability value (Cox) | 17.04 | 17.05 | 17.04 | 17.02 | 17.06
Oleic desaturation ratio (ODR) | 0.899 | 0.898 | 0.894 | 0.899 | 0.898
Linoleic desaturation (LDR) | 0.791 | 0.792 | 0.792 | 0.788 | 0.792