Improvement nutritional value and bioactivity of ricegrass as affected of priming induced by fish protein hydrolysate

Abstract

Background: Wheatgrass (Triticum aestivum L.) is worldwide consumed and has been used for health benefit or functional or nutraceutical food while ricegrass (Oryza sativa L.) is still not well documented, which is also in the grass family (Poaceae) as wheatgrass and it is also produced with aged around 8-10 d which similar to wheatgrass production. Moreover, priming is a process for enhancing seed vigour properties and improving bioactive compounds. Utilization of fish protein hydrolysate (FPH) for liquid fertilizer is more interesting in order to increasing of nutritional value and bioactive compounds as well as antioxidant activity of many plants.Objective: To investigate the nutritional value and bioactivity of ricegrass as affected of priming process with fish protein hydrolysate.Methods: The Chainat 1 rice seeds were soaked with FPH at 0, 5, 10, 15 and 20 ppm at a ratio of rice seed to FPH as 1:5 and grown for 7 d, thereafter, the ricegrass were determined seed vigour properties, nutritional value and bioactive compounds such as chlorophyll, carotenoids, total phenolic and phytic acid. The ricegrass was extracted with water at a ratio 1:2 (ricegrass : water), then homogenized and centrifuged at 10000xg for 20 min. The thereafter, the supernatant was brought to freeze dry. The freeze-dried powder was dissolved in distilled water and brought to measure total phenolic content by Folin-Ciocalteu method. Antioxidant activities were determined by 3 assays as ferric reducing antioxidant power (FRAP), 2,2-diphenyl-1-picryl hydrazyl radical (DPPH) and 2,2'-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid radical (ABTS) methodsResults: The results showed that FPH at 10 ppm significantly improved (p<0.05) seed vigour properties including germination percentage, germination rate, height and fresh weight and nutritional values such as ash, protein, fat and carbohydrate. In addition, bioactive compounds including chlorophyll a and b, total chlorophyll and carotenoid content in ricegrass primed with 10 ppm FPH were higher than control. Phytic acid content in ricegrass primed with FPH at 5 and 10 ppm but not 15 and 20 ppm was lower than control. The ricegrass primed with FPH at 10 ppm yielded highest total phenolic content. Though, ABTS activity was not highest in rice primed with FPH at 10 ppm, DPPH and FRAP assays were highest.Conclusion: The ricegrass primed with FPH was significant improved seed vigour properties, nutritional value, bioactive compounds and antioxidant activity. The appropriate of FPH priming for ricegrass was 10 ppm because it could improve seed vigour, nutritional value and bioactive compounds including chlorophyll, carotenoid, total phenolic content and antioxidant activity determined as FRAP, DPPH and ABTS and reduce the anti-nutrient compounds as phytic acid.Keywords: Ricegrass, Fish protein hydrolysate, Nutritional value, Bioactive compound, Antioxidant