acid profile, etc.) (Jiamyangyuen et al. 2005a). Rice bran protein isolates have
promising emulsification properties and solubility; consequently, they are used in
food products as a natural emulsifier (Lee et al. 2004). Emulsion properties and
solubility of rice bran protein hydrolysates make them suitable for use in products
like toppings, beverages, coffee whiteners, confectionary, meat, and bakery products
(Hamada 2000). Rice bran protein extracts have been added in liquid foods like milk
and other drinks and baked goods like bread to increase the protein content of
products without compromising their quality (Watchararuji et al. 2008;
Jiamyangyuen et al. 2005b). Rice bran proteins can be used in infant foods as it
has balanced amino acid profile and hypoallergenic nature (Wang et al. 1999).
Edible films having good tensile strength can be made from rice protein concentrates in amalgamation with polysaccharide pullulan (Shih 1996). Rice bran protein
(RBP) was used to make edible protein film in a study conducted by Adebiyi et al.
(2008). It was observed that the puncture strength (PS) of RBP films increased up to
pH 8.0 and then decreased. PS of protein films depends on the degree of protein
purity, quality, and composition. Shin et al. (2011) concluded from their study that
composite films, with 4% RBP and 4% gelatin, were the most desirable with regard
to the physical property of films, having the highest TS of 28.42 MPa. These results
suggest that the RBP/gelatin blend film can be applied to food packaging.
16.8 Alternative Applications
16.8.1 RBO Emulsion
Cold-pressed oils without additional synthetic antioxidants have adequate shelf
stability and improved safety as they retain higher levels of natural antioxidants
(Singer et al. 2008). Cold-pressed rice bran oil (CPRBO) comprises endogenous
antioxidants (oryzanols, tocotrienols, tocopherols), having the potential for use in the
prevention of oxidative damages and promotion of health. Thanonkaew et al. (2015)
designed an emulsion-based delivery system to protect CPRBO against lipid oxidation, though maintaining good physical stability and oral bioavailability, using
glyceryl monostearate (GMS) as an emulsifier. An oil-in-water emulsion was successfully formed with relatively small droplets (d < 200 nm) from CPRBO. Bernardi
et al. (2011) developed a nanoemulsion which composed of 10% rice bran oil, 10%
surfactants sorbitan oleate/PEG-30 castor oil, 0.05% antioxidants, and 0.50% preservatives formulated in distilled water. The nanoemulsion was stable, non-irritating,
increased the relative hydration of the skin, the skin oiliness, and maintained normal
skin pH values. Such emulsions find its applications in the cosmetic industry in
sunscreen formulations (Coppini et al. 2001), anti-aging products (Patel and Naik
2004), topical formulations (Lilitchan et al. 2008), and in the pharmaceutical industry as an alternative treatment for skin diseases like atopic dermatitis and psoriasis
(Bernardi et al. 2011; Lerma-García et al. 2009).
16 Rice (Oryza sativa) Bran
415
promising emulsification properties and solubility; consequently, they are used in
food products as a natural emulsifier (Lee et al. 2004). Emulsion properties and
solubility of rice bran protein hydrolysates make them suitable for use in products
like toppings, beverages, coffee whiteners, confectionary, meat, and bakery products
(Hamada 2000). Rice bran protein extracts have been added in liquid foods like milk
and other drinks and baked goods like bread to increase the protein content of
products without compromising their quality (Watchararuji et al. 2008;
Jiamyangyuen et al. 2005b). Rice bran proteins can be used in infant foods as it
has balanced amino acid profile and hypoallergenic nature (Wang et al. 1999).
Edible films having good tensile strength can be made from rice protein concentrates in amalgamation with polysaccharide pullulan (Shih 1996). Rice bran protein
(RBP) was used to make edible protein film in a study conducted by Adebiyi et al.
(2008). It was observed that the puncture strength (PS) of RBP films increased up to
pH 8.0 and then decreased. PS of protein films depends on the degree of protein
purity, quality, and composition. Shin et al. (2011) concluded from their study that
composite films, with 4% RBP and 4% gelatin, were the most desirable with regard
to the physical property of films, having the highest TS of 28.42 MPa. These results
suggest that the RBP/gelatin blend film can be applied to food packaging.
16.8 Alternative Applications
16.8.1 RBO Emulsion
Cold-pressed oils without additional synthetic antioxidants have adequate shelf
stability and improved safety as they retain higher levels of natural antioxidants
(Singer et al. 2008). Cold-pressed rice bran oil (CPRBO) comprises endogenous
antioxidants (oryzanols, tocotrienols, tocopherols), having the potential for use in the
prevention of oxidative damages and promotion of health. Thanonkaew et al. (2015)
designed an emulsion-based delivery system to protect CPRBO against lipid oxidation, though maintaining good physical stability and oral bioavailability, using
glyceryl monostearate (GMS) as an emulsifier. An oil-in-water emulsion was successfully formed with relatively small droplets (d < 200 nm) from CPRBO. Bernardi
et al. (2011) developed a nanoemulsion which composed of 10% rice bran oil, 10%
surfactants sorbitan oleate/PEG-30 castor oil, 0.05% antioxidants, and 0.50% preservatives formulated in distilled water. The nanoemulsion was stable, non-irritating,
increased the relative hydration of the skin, the skin oiliness, and maintained normal
skin pH values. Such emulsions find its applications in the cosmetic industry in
sunscreen formulations (Coppini et al. 2001), anti-aging products (Patel and Naik
2004), topical formulations (Lilitchan et al. 2008), and in the pharmaceutical industry as an alternative treatment for skin diseases like atopic dermatitis and psoriasis
(Bernardi et al. 2011; Lerma-García et al. 2009).
16 Rice (Oryza sativa) Bran
415