consumption of rice has increased from 50 to 65 kg per annum and the worldwide
rice consumption during the year 2015–2016 has been estimated to be 478.441
million metric tons, whereas as estimated by United States Department of Agriculture, world’s rice production during the year 2016–2017 was 481.5 million metric
tons (Statistica 2016). China and India are the top producers of rice in the world and
contribute over 25% and 23%, respectively, to the world’s rice production (Ali and
Devarajan 2017).
Rice is an annual plant which can rise to the height of 1–1.6 m. It has branched
arching to pendulous inflorescence 32–48 cm long and can be grown anywhere, even
on mountain area with the use of water-controlling terrace systems or on a steep hill
(Orthoefer 2005; Sanghi and Tiwle 2015). The paddy grain comprises the husk,
bran, germ, and endosperm. Rice bran is obtained by removing the bran layer which
represents 8% of rice paddy by-products during the milling process (Sharif et al.
2014).
Annual rice bran production is up to 610 million metric tons (Gul et al. 2015). The
bran removed during polishing of rice comprises of 18–22% oil, fatty acids, protein,
dietary fiber, minerals (phosphorus, iron, and magnesium), and functional compounds such as unsaponifiable lipids like γ-oryzanols, polycosanols, phytosterols,
squalene, tocopherols, tocotrienols, and carotenoids (Oliveira et al. 2011; Sookwong
et al. 2007; Zhang et al. 2010). In Asian countries like Indonesia and India, rice bran
is largely being fed to cattle. However, since ages, Japan contemplated rice bran as a
valuable source of oil with therapeutic benefits and is known as “Heart Oil” in Japan
(Pal and Pratap 2017). In western countries also, it has acquired the status of a
“Functional Food” or a “Health Food”. Now, in several Asian countries, RBO is
emerging as a popular cooking oil, mainly for deep and shallow frying applications
(CAC 2003). Although whole rice bran in itself does not have anti-cholesterol
properties, its oil offers nutritional benefits. It contains vitamin E (tocopherol and
tocotrienol) and γ-oryzanol which, like antioxidants, eliminate or prevent free
radicals’ formation which may cause damages to the body, and also inhibit proliferation of certain diseases such as some cancers and cardiovascular diseases. It has a
good composition of triglycerides, diglycerides, monoglycerides, fatty acids, phospholipids, and unsaponifiable lipids (Wilson et al. 2000, 2007; Most et al. 2005).
Due to the medicinal importance, RBO is nowadays extensively used in pharmaceutical, chemical, and food industries. It is an ideal oil for making margarine and
shortenings with good palatability, smooth plasticity, and spreading qualities (Gosh
2007; Liang et al. 2014). Not only RBO, rather rice bran is also used to improve
nutritive value in various food formulations like bread, cakes, noodles, pasta, and ice
creams without having any detrimental effect on their functional and textural
properties (Sookwong and Mahatheeranont 2017).
398
U. Yadav et al.
rice consumption during the year 2015–2016 has been estimated to be 478.441
million metric tons, whereas as estimated by United States Department of Agriculture, world’s rice production during the year 2016–2017 was 481.5 million metric
tons (Statistica 2016). China and India are the top producers of rice in the world and
contribute over 25% and 23%, respectively, to the world’s rice production (Ali and
Devarajan 2017).
Rice is an annual plant which can rise to the height of 1–1.6 m. It has branched
arching to pendulous inflorescence 32–48 cm long and can be grown anywhere, even
on mountain area with the use of water-controlling terrace systems or on a steep hill
(Orthoefer 2005; Sanghi and Tiwle 2015). The paddy grain comprises the husk,
bran, germ, and endosperm. Rice bran is obtained by removing the bran layer which
represents 8% of rice paddy by-products during the milling process (Sharif et al.
2014).
Annual rice bran production is up to 610 million metric tons (Gul et al. 2015). The
bran removed during polishing of rice comprises of 18–22% oil, fatty acids, protein,
dietary fiber, minerals (phosphorus, iron, and magnesium), and functional compounds such as unsaponifiable lipids like γ-oryzanols, polycosanols, phytosterols,
squalene, tocopherols, tocotrienols, and carotenoids (Oliveira et al. 2011; Sookwong
et al. 2007; Zhang et al. 2010). In Asian countries like Indonesia and India, rice bran
is largely being fed to cattle. However, since ages, Japan contemplated rice bran as a
valuable source of oil with therapeutic benefits and is known as “Heart Oil” in Japan
(Pal and Pratap 2017). In western countries also, it has acquired the status of a
“Functional Food” or a “Health Food”. Now, in several Asian countries, RBO is
emerging as a popular cooking oil, mainly for deep and shallow frying applications
(CAC 2003). Although whole rice bran in itself does not have anti-cholesterol
properties, its oil offers nutritional benefits. It contains vitamin E (tocopherol and
tocotrienol) and γ-oryzanol which, like antioxidants, eliminate or prevent free
radicals’ formation which may cause damages to the body, and also inhibit proliferation of certain diseases such as some cancers and cardiovascular diseases. It has a
good composition of triglycerides, diglycerides, monoglycerides, fatty acids, phospholipids, and unsaponifiable lipids (Wilson et al. 2000, 2007; Most et al. 2005).
Due to the medicinal importance, RBO is nowadays extensively used in pharmaceutical, chemical, and food industries. It is an ideal oil for making margarine and
shortenings with good palatability, smooth plasticity, and spreading qualities (Gosh
2007; Liang et al. 2014). Not only RBO, rather rice bran is also used to improve
nutritive value in various food formulations like bread, cakes, noodles, pasta, and ice
creams without having any detrimental effect on their functional and textural
properties (Sookwong and Mahatheeranont 2017).
398
U. Yadav et al.