Mass Production Method for Rice Protein Isolate and Nutritional Evaluation

Abstract

Production of RPIWe developed a method for mass production of rice protein isolate (RPI) and evaluated its nutritional quality in rats. To obtain thick slurry, rice flour was mixed with a 0.6% Termamyl 12OL-solution (1:2, w/v) at room temperature (-23°C). The slurry was heated at 97°C for 2 hr with stirring. Gelatinization and liquefaction occurred simultaneously. RPI obtained by filtration and washing with boiling water, was more than 90% pure protein (dry matter basis). It also contained 6.4% dietary fiber, 1.3% ash, and 1.1% carbohydrate. RPI diets (40-50%) allowed the maximum growth in rats comparable to that with 25% casein diet.The general scheme for preparation of RPI is displayed in Fig. 1. To obtain thick slurry, 5 kg of rice flour were mixed with 1OL of distilled water containing 0.6% Termamyl 120L at room temperature (~23°C) and the mixture was vigorously stirred with a motor-driven propeller shaft until the rice flour completely dispersed. Then the mixture was indirectly heated in a boiling water bath and maintained at 97°C for 2 hr (usually reached 97°C within 45 min). Gelatinization and digestion of starch simultaneously occurred. After digestion, the mixture was vacuum filtered through cheesecloth. The precipitate was washed three times with 5L of boiling water to remove sugar syrup and remaining enzyme. The precipitate was washed three times with 5L ethanol (99%) and dried in air at room temperature (=23"C). The preparation was labelled RPI.

Procesamiento en seco de harina de chía (Salvia hispanicaL.): caracterización química de fibra y proteína Dry processing of chía (Salvia hispanicaL.) flour: chemical characterization of fiber and protein

“…Sin embargo, tanto la harina como la FRP exhibieron estar limitadas por los aminoa´cidos lisina y triptofano, siendo el ma´s significativo el segundo, que mostro´un valor de 9,5 g/kg de proteı´na en la harina y de 8,0 g/kg de proteı´na, en comparacio´n con el esta´ndar de FAO, que es de 11 g/kg de proteı´na. Dicho valor puede ser considerado aceptable si se compara con los resultado obtenidos para proteı´nas tanto de harina como de aislado de lupino donde se reporta un valor de 6 g/kg de proteı´na para ambas muestras (Lqari, Vioque, Pedroche, & Milla´n, 2002) asıć omo para proteı´nas del salvado de arroz (7 g/kg de proteı´na), pero resulto´inferior al reportado para el aislado proteı´nico del mismo salvado de 12 g/kg de proteı´na (Wang, Hettiarachchy, Burks, & Siebenmorgen, 1999) y otras fuentes usadas de forma convencional, como aislado proteı´nico de soya con 12 g/kg de proteı´na y caseı´na con 14 g/kg de proteı´na (Morita & Kiriyama, 1993).…”

Effects of Rice Proteins from Two Cultivars,KoshihikariandShunyo, on Cholesterol and Triglyceride Metabolism in Growing and Adult Rats

“…22,23) Both proteins were prepared by the alkaline extraction method (Shimada, Inc., Nagaoka, Japan). 11,19) Casein (CAS) and soy protein isolates (SPI) were obtained from Fontera (Kanagawa, Japan), and Fuji Oil Co. (Osaka, Japan), respectively. The chemical composition of these dietary proteins was analyzed, and it is shown in Table 1.…”

“…Yoshida et al reported that the serum and liver levels of total cholesterol and total lipids in rats fed 15% rice protein was close to that of a casein group, indicating that rice protein is not likely to have a hypocholesterolemic effect like soy protein, even though it increased fecal bile acid excretion as compared with casein. 8,9) But, Sugano et al 10) and Morita et al 11,12) found that rice protein exerted a cholesterol-lowering effect on serum and liver levels, with higher fecal excretion at more than 20% protein levels. This hypocholesterolemic effect of rice protein was confirmed by Tran and Nicolosi in hamsters, indicating that rice protein lowered plasma total cholesterol and reduced early atherosclerosis as efficaciously as soy protein.…”

Improvement in theIn VivoDigestibility of Rice Protein by Alkali Extraction Is Due to Structural Changes in Prolamin/Protein Body-I Particle

“…It is a major source of energy and protein, and has been getting increasing attention as a healthy, nutritious, and hypoallergenic foodstuff, 1,2) reportedly including hypocholesterolemic and hypolipidemic effects comparable to soy protein. [3][4][5] The proteins in rice endosperm include glutelin, prolamin, globulin, albumin, etc. Two major proteins, glutelin and prolamin, are storage proteins.…”