Table 1.

Processing techniques to improve nutritional characteristics, sensory properties, and convenience of cereal by-products

Processing technique	Improvement/benefit	References
Fractionation by milling
(i) Dry fractionation (ultra-fine grinding)	Decrease in particle size (40 µm) improves the nutritional potential by increasing the solubility or release of bioactive compounds Controlled milling time (10 s) improves the vitamin E and oryzanol concentration in rice bran by 22 and 31%	Hemery et al. (2011a), Bohm et al. (2003), Stone and Minifie (1988), Schramm et al. (2007)
(ii) Supercritical carbon dioxide fractionation	Improve shelf life of rice bran by reducing free fatty acids and prevents the loss of bioactive components in rice bran oil by 50%	Dunford and King (2000)
(iii) Micro fractionation and high pressure micronization	Change in physicochemical properties by redistribution of insoluble to soluble dietary fiber fractions and starch digestibility in wheat	McAllister and Sultana (2011), Wu et al. (2007), Chau et al. (2007)
Fermentation and enzymatic treatment	Provides optimum pH for enzymatic degradation of phytates and tannins thus increasing the soluble iron, zinc, and calcium several folds in millets. Reduction in polyphenols (11–22%) and Flavonoids (40–51%) in pearl millet bran	Coulibaly et al. (2011), Kohajdová and Karovičová (2007), Blandino et al. (2003), Jha et al. (2015)
	Improves in vitro starch digestibility (86%) by increasing soluble solids and the synthesis of certain amino acids and B vitamins in millets	Saleh et al. (2013), Delcour et al. 2012, McKevith (2004)
	Bioprocessing of wheat bran can produce cinnamoyl-oligosaccharides having potential prebiotic properties The β-glucan from oat bran can selectively support the growth of lactobacilli and bifidobacteria	Mussatto and Mancilha 2007, Charalampopoulos et al. (2002)
Germination or malting	In vitro starch and protein digestibility improved by 14–26% and 86–112% respectively in different millets	Saleh et al. (2013)
	Increased extractability and bio-accessibility of calcium, iron, and zinc in finger millet seed coat was 68, 23, 75 g/100 g	Krishnan et al. (2012)
	Significant reduction in phytates (30–80%) and polyphenols (14–42%) and increased HCl extractable major and minor minerals during germination (2–6 days) in pearl millet	Abdelrahaman et al. (2007)
	Folate and easily extractable phenolic acids increased in rye bran	Liukkonen et al. (2003)
	Significant improvement in γ- aminobutyric acid (GABA) by 2–3%, oryzanol (168 ± 1.0–377 ± 1.0 mg/100 g), dietary fiber, ferulic acid in rice bran	Pradeep et al. (2014), Patil and Khan (2011)
Heat treatment
(i) Hydrothermal treatment	Increased shelf life by denaturing lipases Reduction in phytate by 46–77%. Improved zinc bioaccessibility from 23 g/100 g in native to 47 g/100 g in treated finger millet seed coat	Thanonkaew et al. (2012), Slavin et al. (2001), Pradeep et al. (2014), Krishnan et al. (2012)
(ii) Extrusion	Increased crude fat (18.7–31.1 mg/100 g), total tocotrienol (15.58 ± 6.07–22.77 ± 12.07 mg/100 g) and vitamin E (27.40 ± 2.89–32.0 ± 11.26 mg/100 g) content in rice bran Improve texture and palatability, low cost, decrease insoluble dietary fiber in extruded oats, rice and wheat bran by 17.74, 7.46 and 5.1% Increase soluble dietary fiber in oats, rice and wheat extruded by 36.81, 22.77 and 9.95%	Cheftel (1986), Gualberto et al. (1997), McKevith (2004)