Research On The Effects Of Different Processing Methods On The Functional Components,Quality,Digestion And Absorption Of Brown Rice Products

Brown rice is a kind of whole grain rice which has not been processed or lightly processed after the rice is hulled.Compared with polished white rice,brown rice is rich in nutrients such as protein,starch,polyphenols and flavonoids,and has many physiological health functions such as anti-oxidation which can prevent chronic diseases.At present,the thermal processing methods of brown rice products mainly include roasting,boiling,microwave and so on.Besides,there are few reports on the effects of baking,boiling,and microwave treatment on the functional components,quality,and in vitro digestion of brown rice products.In this paper,indica brown rice flour,glutinous brown rice flour,and japonica brown rice flour with processing precisions of 26%,38%,and 45% were treated by baking,boiling,and microwave processing methods and the functional composition,quality,digestion of brown rice products were studied.(1)The effect of different baking conditions on the functional components,quality,digestion and absorption of sugar-free brown rice cakes were studied.The processing accuracy increased from 26% to 45%.The protein,moisture,fat content and enthalpy value of indica brown rice flour decreased significantly(P<0.05),and the peak viscosity,valley viscosity and attenuation value increased significantly(P<0.05).The 45% sugar-free brown rice cake was the best overall quality(specific volume,baking loss,texture,sensory evaluation,color)under the conditions of baking temperature of 150°C and baking time of 15 minutes.When the baking temperature increased from 170°C to 180°C and the baking time increased from20 min to 25 min,the content of polyphenols,flavonoids,?-aminobutyric acid and the scavenging rate of DPPH and ABTS radicals were significantly decreased.In the process of simulating gastrointestinal digestion in vitro,the release of polyphenols and antioxidant properties of sugar-free brown rice cakes increased significantly within 60 minutes,and gradually stabilized after 80 minutes.(2)The effect of different cooking conditions on the functional components,quality,digestion and absorption of brown rice noodles were studied.The processing accuracy increased from 26% to 45%.The enthalpy and attenuation value of glutinous brown rice flour decreased significantly(P<0.05).45% of the brown rice noodles had the best quality(cooked strip rate,texture,color,sensory evaluation).The content of polyphenols,flavonoids,?-aminobutyric acid and the free radical scavenging rate of DPPH and ABTS in brown rice noodles showed a downward trend with the extension of cooking time,and reached the minimum when cooking for 8 minutes.In the process of simulating gastrointestinal digestion in vitro,the release of polyphenols and antioxidant activity of brown rice noodles increased significantly,which was the maximum in 2h.(3)The effect of different microwave conditions on the functional components,quality and absorption of brown rice crackers were studied.The processing accuracy increased from 26% to 45%.The enthalpy and retrogradation value of japonica brown rice flour decreased significantly(P<0.05).Milling has no obvious effect on the water content of the cake and the puffing rate of the brown rice cracker.The results showed that when the microwave time was 40 s,the overall quality(puffing rate,hardness)of the brown rice cake were the best.At the same time,polyphenols and flavonoids remained to be the most,DPPH and ABTS had the strongest free radical scavenging effect.When the microwave power is 500 W,the ?-aminobutyric acid content of 38% and 45% of the brown rice cracker is higher than that of the untreated brown rice cracker.In the process of simulating gastrointestinal digestion in vitro,the polyphenol content and antioxidant activity of brown rice crackers increased significantly with the digestion time.