Isolation and Characterization of Starch from Pearl Millet (Pennisetum typhoidium) Flours

Abstract

Pearl millet, an underutilized crop, is a relatively good source of nutrients and has varied uses over cereals. New applications must be explored to popularize the millet. In the present study, flour and isolated starch from pearl millet cultivars-Kalukombu and Maharashtra Rabi Bajra (MRB)-were investigated for physicochemical properties, nutritionally important starch fractions and x-ray diffraction. The yield of starch was significantly low (Kalukombu: 34.5 g/100 g and MRB: 39.4 g/100 g) with traces of non-starch components (protein, fat, and ash) indicating its purity. Starch could be classified as non-waxy type based on low amylose content (2.86-4.96 g/100 g). Low amylose lead to fragility of swollen starch granules which disintegrated easily at 65°C as observed in swelling power and solubility. Isolated starch was characterized with low water-and oil-holding capacity which could be attributed to the low protein content and absence of fiber in the starch. However, MRB starch showed higher oil uptake compared to flour, possibly due to its larger surface area that increased oil uptake. X-ray diffraction patterns showed sharp peaks at 2θ values 15 and 23º and a diffused peak at 2θ of 17 and 18º which is characteristic of A-type pattern. Low resistant starch (RS) and high readily digestible starch (RDS) content observed in the isolated starch could be attributed to the A-type pattern of starch which is more susceptible to enzyme hydrolysis and also due to elimination of structural obstruction to amylase hydrolysis during the process of starch isolation and gelatinization.

Starches of two water yam (Dioscorea alata) varieties used as congeals in yogurt production

“…Interestingly, the moisture content and the water activity of the water yam starches significantly differed ( p < 0.05) between the samples (Figures and ), although they were lower to extend the shelf life of the water yam starches (CAC, ). Other studies on starches reported similar trends of 10–12% for millet, corn, and cocoyam starches, which were considered to be within the acceptable range and beneficial in terms of storage and keeping quality of the starches (Mepba, Eboh, Eko, & Ukpabi, ; Suma & Urooj, ). According to Aguilera et al.…”

“…The water activity was lowest in A100 (0.41) and highest in . Other studies on starches reported similar trends of 10-12% for millet, corn, and cocoyam starches, which were considered to be within the acceptable range and beneficial in terms of storage and keeping quality of the starches (Mepba, Eboh, Eko, & Ukpabi, 2009;Suma & Urooj, 2015). According to Aguilera et al (1995), high amounts of moisture in flour and starches may results in caking due to aggregation of particles into lumps, which subsequently lowers their quality and functionality.…”

Physicochemical, rheological, morphological, and in vitro digestibility properties of cross-linked starch from pearl millet cultivars

“…[4] Pearl millet (Pennisetum glaucum L.), one of the important type of millets, belongs to the family gramineae and it is widely cultivated around the world primarily in India and Africa. Suma and Urooj [7] reported starch content in pearl millet in the range from 62.8% to 70.5% among different Indian genotypes. Due to decreased water supplies, decreased area under corn cultivation, adverse salinity, low cost of growing pearl millet crop, starch from pearl millet needs to be explored more so that it can become better substitute than other conventional starch sources.…”

Effect of modified resistant starch of culinary banana on physicochemical, functional, morphological, diffraction, and thermal properties

“…Starch is the storage polysaccharides of green plants and is a major dietary component in all human populations. [1] It is composed of a number of monosaccharide or sugar (glucose) linked together with α-D- (1)(2)(3)(4) and/or α-D-(1-6) linkages. [2] Starch is deposited in the fruit in the form of granules, partially crystalline, whose morphology, chemical composition, and super molecular structure are characteristics of each particular plant species.…”

“…Amylose is essentially linear polymer in which glucose residues are α-D-(1-4) linked typically constituting 15 to 20% of starch. Amylopectin, the major component of starch is a larger branched molecule with α-D- (1)(2)(3)(4) and α-D- (1)(2)(3)(4)(5)(6) linkages. This biopolymer constitutes an excellent raw material to modify food texture and consistency.…”