|ROTHSCHILD, JEFFREY - California State University|
|MENUTTI, LORENA - California State University|
|OMARY, MARIA - California State University|
Submitted to: International Journal of Food Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/7/2015
Publication Date: 5/15/2015
Citation: Rothschild, J., Rosentrater, K.A., Onwulata, C., Singh, M., Menutti, L., Jambazian, P., Omary, M.B. 2015. Influence of quinoa roasting on sensory and physiochemical properties of allergen-free, gluten-free cakes. International Journal of Food Science and Technology. 50:1873-1881. doi: 10.1111/ijfs.12837.
Interpretive Summary: Quinoa is a pseudo grain and has been a staple crop of the natives of Andean region of South America for thousands of years. It is a valuable source of quality protein, carbohydrates, essential fatty acids and micronutrients. In this study, we measured the effect of roasting on the nutrient levels, digestion, and pasting properties of quinoa. Our results showed that roasting quinoa increased the beneficial protective nutrients called anti-oxidants and polyphenols. Total phenols increased in roasted samples. Roasted quinoa will be useful for improving nutritional quality, especially, for the development of gluten-free baked goods.
Technical Abstract: Quinoa is a valuable source of quality protein, carbohydrates, essential fatty acids and micronutrients. The objective of this study was to roast quinoa and characterize it with regard to particle size, proximate, fatty acid, starch digestion, and total phenolics analyses, as well as pasting properties. Whole quinoa seeds were roasted at 177oC for 15 (R15), 30 (R30) and 45 min (R45). Triplicate batches were prepared per treatment and analyzed along with three different lots of commercial quinoa flour (CQF). Moisture decreased with roasting time (11.1 %wb for NR to 0.2% wb for R45). NR quinoa had lower protein content than all roasted flours (14.6 vs. 16.6%). Fat content increased with roasting time but was lower than that of CQF (4.8 vs. 6.1%). Fiber content was lower than all roasted flours but no different from CQF (6.5 vs. 8.9%). Ash content increased with roasting time (2.4 to 2.6%), was lower for NR samples (2.3%) but higher than CQF (2.2%). Carbohydrates decreased with roasting time and were higher for NR (71.8%) and CQF (69.7%). Increases in total saturated (0.5 to 0.6%) and monounsaturated (1.5 to 1.8%) fats were found between NR and R45. Total polyunsaturated fats showed differences only between NR (2.4%) and CQF (3.0%). At the same time, no differences were found among all samples regarding rapidly digestible (182 mg/g), slowly digestible (394 mg/g), resistant (326 mg/g) and total starch (692 mg/g). Total phenolics as measured with Folin-Ciocalteu and the novel Fast Blue BB methods showed a significant correlation (r=0.84). Peak and final viscosity increased with roasting time from 9,328 cP (R15) to 15,585 cP (R45), from 14,596 (NR) to 24,344 cP (R45), respectively, while CQF had the lowest final viscosity at 11,641 cP. These results show promise for the use of roasted quinoa in the development of healthy gluten-free baked goods.