Effect of steam parboiling and hot soaking treatments on milling yield, physical, physicochemical, bioactive and digestibility properties of buckwheat (Fagopyrum esculentum L.)

Abstract

Post-harvest hydrothermal processing of grains are targeted at improving milling performances and nutritional properties. In this study, the effects of two hydrothermal processes, namely steam parboiling and soaking in boiling water for different durations on properties of buckwheat (Fagopyrum esculentum L.) grown in the Indian Himalayan regions were assessed. Both treatments significantly improved milling yield. Changes in grain section morphology were evidenced under scanning electron microscope. Milder processing for 5 and 10 min mostly exerted annealing effect, represented by increased intensities of X-ray diffraction peaks. Starch gelatinization occurred upon prolonged processing for 15 and 20 min. This resulted in decreased crystallinity, increased sedimentation volume, paste thinning during rapid viscosity analysis and lower thermal transition in differential scanning calorimetry. Marginal changes in oil uptake suggested limited protein denaturation. Natural antioxidant compounds were variably denatured. Maillard browning was indicated by CIE L* a* b* colour and antioxidant levels. The starchy flour samples showed partial resistance to enzymatic amylolysis post retrogradation. Soaking in boiling water can be considered as a feasible alternative to conventional steam parboiling for better milling yield of buckwheat. Altered physicochemical and nutritional properties of buckwheat suggested that the hydrothermally modified flours can be used in ready to eat therapeutic food products.

Effects of parboiling and infrared radiation drying on the quality of germinated brown rice

“…The results of this current research were consistent with Roy et al. (2019) and Bualuang et al. (2012).…”

“…However, Sirisoontaralak et al (2015) reported that germination had no effect on L* of GBR, when compared with BR. The results of this current research were consistent with Roy et al (2019) and Bualuang et al (2012). Chungcharoen et al (2015) and Roy et al (2019) reported that gelatinization of starch altered the color from murky white to translucent white, resulting in lower L*.…”

“…(2015) and Roy et al. (2019) reported that gelatinization of starch altered the color from murky white to translucent white, resulting in lower L* . Besides, a reduction in whiteness or changed color could be due to the Maillard reaction in parboiled rice.…”

“…The results were consistent with Bualuang et al (2012), Borompichaichartkul et al (2007), who reported that parboiling significantly improved HRY. Besides, drying hardens the gelatinized rice grains, leading to higher HRY (Roy et al, 2019). Parboiling also caused protein degradation, which subsequently filled the voids in starch granules, giving rise to lower grain fissures (Bualuang et al, 2012).…”

Effect of Buckwheat Groats Processing on the Content and Bioaccessibility of Selected Minerals

“…Groats, produced from roasted and dehulled grains, are the most popular products obtained from buckwheat in many European countries and Japan [ 15 ]. Unit operations used in processing may affect the bioaccessibility of minerals to varying extent, changing the content of elements, but also causing degradation or formation of absorption inhibitors or stimulants, and the chemical species or salt solubility of a specific element may vary depending on the physical parameters and duration of the process [ 16 ]. The use of different methods of buckwheat groats production, using for that purpose different buckwheat grains, causes the nutritional value of groats available on the market to be different.…”