Compendium of the most significant studies with reference to properties, intake, effects.

Joy JM, Lowery RP, Wilson JM, Purpura M, De Souza EO, Wilson SM, Kalman DS, Dudeck JE, Jäger R. The effects of 8 weeks of whey or rice protein supplementation on body composition and exercise performance. Nutr J. 2013 Jun 20;12:86. doi: 10.1186/1475-2891-12-86.

Abstract.  Therefore, the purpose of the study was to determine if the post-exercise consumption of rice protein isolate could increase recovery and elicit adequate changes in body composition compared to equally dosed whey protein isolate if given in large, isocaloric doses.

Kumagai T, Kawamura H, Fuse T, Watanabe T, Saito Y, Masumura T, Watanabe R, Kadowaki M. Production of rice protein by alkaline extraction improves its digestibility. J Nutr Sci Vitaminol (Tokyo). 2006 Dec;52(6):467-72. doi: 10.3177/jnsv.52.467.

Abstract.  A simple method to process rice protein and improve its digestibility was tested from the viewpoint of its application to food manufacturing.

Shih FF. An update on the processing of high-protein rice products. Nahrung. 2003 Dec;47(6):420-4. doi: 10.1002/food.200390093.

Abstract. This report provides an update on the processing of these sources for rice proteins. Methods of protein processing are highlighted including the traditional alkaline extraction, enzyme-assisted extraction, and the novel uses of physical treatment prior to water extraction. Also discussed are effects of processing on the functional and nutritional properties of rice protein.

Liu K, Zheng J, Chen F. Effect of domestic cooking on rice protein digestibility. Food Sci Nutr. 2019 Jan 24;7(2):608-616. doi: 10.1002/fsn3.884.

Abstract. The effects of washing, soaking, and common domestic cooking methods (normal cooking, high-pressure cooking, and microwave cooking) on protein content, in vitro protein digestibility, and amino acid composition of japonica and indica rice were investigated.

Koo WW, Lasekan JB. Rice protein-based infant formula: current status and future development. Minerva Pediatr. 2007 Feb;59(1):35-41.

Abstract. Rice is the world's leading staple cereal food and is the major source of protein for many parts of the world. Rice is among the first solid foods fed to infants in many cultures, in part because of its hypoallergenicity from lack of gluten. Nutritional quality of rice protein compares favorably with other cereal proteins including wheat, oat and barley.

Lu X, Ma R, Qiu H, Sun C, Tian Y. Mechanism of effect of endogenous/exogenous rice protein and its hydrolysates on rice starch digestibility. Int J Biol Macromol. 2021 Dec 15;193(Pt A):311-318. doi: 10.1016/j.ijbiomac.2021.10.140.

Abstract. The role of endogenous/exogenous rice protein and its hydrolysates in the enzymatic hydrolysis resistance of rice starch was investigated.

Dupont C, Bocquet A, Tomé D, Bernard M, Campeotto F, Dumond P, Essex A, Frelut ML, Guénard-Bilbault L, Lack G, Linglart A, Payot F, Taieb A, Kalach N. Hydrolyzed Rice Protein-Based Formulas, a Vegetal Alternative in Cow's Milk Allergy. Nutrients. 2020 Aug 31;12(9):2654. doi: 10.3390/nu12092654.

Abstract. This paper aims towards a better understanding of hydrolyzed rice protein formulas (HRPF), of the characteristics of rice proteins, their appropriateness to feeding cow’s milk protein allergy children, their suitability to restore normal growth, and their potential interaction with the acquisition of cow’s milk protein tolerance.

Likittrakulwong W, Poolprasert P, Srikaeo K. Effects of extraction methods on protein properties obtained from paddy rice and germinated paddy rice. PeerJ. 2021 May 4;9:e11365. doi: 10.7717/peerj.11365.

Abstract. Rice protein has attracted considerable attention recently due to its physiological effects. This study extracted the proteins from paddy rice (PR) and germinated paddy rice (GPR) using three methods i.e., alkaline, sodium dodecyl sulfate (SDS) reagent and enzymatic extractions.

Rice proteins are natural, plant-based proteins that are industrially produced from rice (organic and non-organic, transgenic or non-transgenic) by separation from starch. Separation is by sieving, grinding and drying. The result is a fine, greyish white or light yellow powder.

What they are used for and where

They are mainly used in foods, as an alternative to milk proteins for allergy and digestibility problems and to soya proteins. They have high amounts of essential amino acids, although they are not complete proteins as they lack certain amino acids, which can however be stored in the human body by mixing rice protein powder with another protein source.

They are composed of four main proteins: globulin, albumin, prolamin and glutenin. The endosperm (the plant tissue that surrounds the seed) contains the proteins, which are composed of alkali-soluble globulin (approximately 75%), salt-soluble globulin (approximately 10%), albumin (approximately 5%) and alcohol-soluble glutenin (approximately 3%). Rice proteins are easy to digest and absorb and improve gastrointestinal peristalsis. However, applications of rice proteins in the food sector are limited due to their low water solubility.

They are cholesterol-free, have low sensitivity and high nutritional value. Unlike protein powders, such as pea protein, they have a discreet and unobtrusive taste.

Allergies. Compared to milk, wheat or soya proteins, they have not presented any allergy problems.

Vegan diet. They are totally free of animal products and by-products.

Food

Thickener and stabiliser to increase protein content, can be used in soy sauce, protein drink, milk drink, ice cream, vegetable meat.

Cosmetics

Rice proteins are incorporated into personal care products such as hair shampoos or skin creams and cleansers as conditioning agents.

Excipient in the animal feed industry to increase the content of essential amino acids.

Safety

This report addresses the safety of rice-derived cosmetic ingredients including rice protein, finding no danger to human health (2).

Typical optimal commercial product characteristics Rice proteins

The dietary factor plays a crucial role in the management of cancer cases and has attracted the attention of researchers as an option to combat this disease.Both in vitro and in vivo, scientific studies have shown that rice and its derivatives show encouraging results in the prevention of this disease. The mechanism of the anti-cancer effect is suggested, in part, through the enhancement of bioactive compounds such as vitamin E, phytic acid, gamma oryzanol and phenols (1).

Rice proteins studies

References_____________________________

(1) Scientific Evidence of Rice By-Products for Cancer Prevention: Chemopreventive Properties of Waste Products from Rice Milling on Carcinogenesis In Vitro and In Vivo
Bee Ling Tan, Mohd Esa Norhaizan
Biomed Res Int. 2017; 2017: 9017902. Published online 2017 Jan 22. doi: 10.1155/2017/9017902

(2) Amended final report on the safety assessment of Oryza Sativa (rice) Bran Oil, Oryza Sativa (rice) Germ Oil, Rice Bran Acid,Oryza Sativa (rice) Bran Wax, Hydrogenated Rice Bran Wax, Oryza Sativa (rice)Bran Extract, Oryza Sativa (rice) Extract, Oryza Sativa (rice) Germ Powder, Oryza Sativa (rice) Starch, Oryza Sativa (rice) Bran, Hydrolyzed Rice Bran Extract, Hydrolyzed Rice Bran Protein, Hydrolyzed Rice Extract, and Hydrolyzed Rice Protein. Int J Toxicol. 2006;25 Suppl 2:91-120. doi: 10.1080/10915810600964626.