Centesimal composition, lipid profile and total phenolic compounds in raw and germinated chia seeds

Salvia hispanica L., also known as chia, is an herbaceous plant, belonging to the family Lamiaceae, native to the mountainous regions of western and central Mexico and Guatemala, has begun to be consumed in recent years in other regions of the world because of its nutritional and functional properties. Chia seed is the major plant source of the a-linolenic fatty acid, and also provides high levels of dietary fiber, proteins, vitamins, minerals, and antioxidants. Chia seeds germination seems to be able to further enhance these properties, and has been the subject of a number of studies. In general, sprouting has been shown to be a simple and inexpensive process that can improve total phenolic content and antioxidant capacity of foods. The objective of the present study was to evaluate the centesimal composition, fatty acid profile, and total phenolic content in raw and at different germination times of chia seeds. Commercial chia (Salvia hispanica L.) seeds were purchased from local markets in Rio de Janeiro, Brazil. Chia seeds were sanitized in sodium hypochlorite and then rinsed in filtered water. After this process, seeds were placed inside a plastic tray containing germination paper. Seeds were sprinkled with filtered water twice a day. Samples were collected on days 3 and 6 of germination. The raw seeds and sprouts were freeze-dried and ground to a fine powder for analysis. Protein, carbohydrate, lipid, ash and moisture analyses were performed according to the official methods. Fatty acid profile was determined by gas chromatography coupled to a mass spectrometer. The extraction method used was methanol/water (80:20, v/v). The Folin-Ciocalteau method with adaptation for microvolumes, to determine the total phenolic content in samples was used. The results showed that 6-day chia sprout had a significant increase in protein (23.78 ± 0.14 when compared to chia (18,93 ± 1,12) and 3-day sprout (20,37 ± 0,77). Another component that had a gradual increase was ash from chia seed, 3-day and 6-day sprouts (4.34 ± 0.02; 4.68 ± 0.05; 5.02 ± 0.06, respectively). Therefore, the analyses showed that total lipid content had a gradual decrease from chia seed, 3-day and 6-day sprouts (39.87 ± 0.57, 33.41 ± 0.27 and 27.69 ± 0.35, respectively). The most concentrated fatty acids found were palmitic (C16:0), oleic (C18:1n-9), linoleic (LA, 18:2n-6) and alpha-linolenic (LNA, 18:3n-3). However, for the 3 and 6 day sprouts the fatty acid content gradually decreased when compared to chia seed. While for moisture there was an increase for chia seed for 3-day sprout and a subsequent decrease for 6-day sprout. The total phenolic content of chia sprouts after 6 days of germination (8.69 ± 0.35) was lower than 3-day sprout (11.14 ± 0.59) and chia seed (12.85 ± 0.87). The consumption of a more plant-based diet is increasing worldwide, and sprouted seeds may be a promising dietary option. Chia germination process seems to increase the protein content, which may be an interesting plant-based protein intake. More studies should be conducted to verify the benefits of the consumption of chia sprouts.