Influence of Heat‐Moisture Treatment and Acid Modifications on Physicochemical, Rheological, Thermal and Morphological Characteristics of Indian Water Chestnut (Trapa natans) Starch and its Application in Biodegradable Films

Abstract

Water chestnut starch was subjected to acid modification and heat‐moisture treatment. Hydrochloric acid was used for acid modification at three different concentrations (0.25 M, 0.5 M and 1 M) for 2 h. Modifications did not alter the granule morphology. Heat‐moisture treatment (HMT) resulted in slight reduction in the granular size of the starch granules. Acid modification lowered the amylose content, swelling power, water‐ and oil‐binding capacity but improved the solubility of starch to a considerable level. Light transmittance of acid‐modified (AM) starches improved significantly. A significant reduction in peak, trough, final and setback viscosity was observed by acid‐thinning. In case of heat‐moisture treated starch the final viscosity (Fv) was found to be even higher than the peak viscosity (Pv). Native water chestnut starch exhibited a lower onset temperature (To) and peak temperature (Tp) of gelatinization than the corresponding acid‐treated starches. Starch films prepared from native starch exhibited excellent pliability, whereas those prepared from AM and HMT starches showed good tensile strength. Starch films prepared from acid‐treated starches provided better puncture and tensile strength.

Physical Modification of Food Starch Functionalities

“…Supporting this concept are the results of Lee et al (2012) who subjected waxy potato starch to a wide range of temperatures (110-150 • C), moisture contents (20, 25, or 30%), and treatment times (1, 5, or 9 h) and reported increases in gelatinization transition temperatures to be proportional to increases in moisture content. However, the lack of such a relationship, or even the reverse, has also been observed, particularly at temperature and moisture extremes (≥120 • C and 25% moisture) (Chung et al 2009b, Singh et al 2009, Olu-Owolabi et al 2011, Varatharajan et al 2011, Pinto et al 2012. Under constant temperature conditions (100 • C, 16 h), Olu-Owolabi et al…”

“…In explaining trends in starch swelling and AM-leaching behaviors of waxy and normal potato starches, Varatharajan et al (2011) noted the possible interplay between factors-structural rearrangements among AM and AP chains appeared to predominate at lower HMT temperatures (80-100 • C), whereas the A→B polymorphic transition seemed to be a factor at higher temperatures (as lower-melting starch crystallites became disrupted and relative proportions of the A polymorph increased). HMT effects on starch solubility are mixed, with reports citing both increases (Singh et al 2009, Jyothi et al 2010, Olu-Owolabi et al 2011, Balasubramanian et al 2014, Sankhon et al 2014) and decreases (Abraham 1993, Lewandowicz et al 1997, Lawal & Adebowale 2005, Luo et al 2006, Adebowale et al 2009, Zhang et al 2010b, Pinto et al 2012, Yadav et al 2013, Sun et al 2014b). …”

“…Swelling power (SP) and AM leaching have most commonly been observed to decrease for HMT (compared to their respective native) starches (Hoover et al 1993;Hoover & Vasanthan 1994;Hoover & Manuel 1996b;Kurakake et al 1997;Perera et al 1997;Gunaratne & Hoover 2002;Lawal & Adebowale 2005;Luo et al 2006;Adebowale et al 2009;Chung et al 2009b;Singh et al 2009;Chung et al 2010;Güzel & Sayar 2010;Jyothi et al 2010;Varatharajan et al 2010Varatharajan et al , 2011Zhang et al 2010b;Olu-Owolabi et al 2011;Pinto et al 2012;Tattiyakul et al 2012;Kim & Huber 2013;Yadav et al 2013;Ambigaipalan et al 2014;Sankhon et al 2014;Sun et al 2014b). These reductions generally increase with an increasing treatment temperature or moisture content ( Jyothi et al 2010;Zhang et al 2010b;Pinto et al 2012;Kim & Huber 2013;Ambigaipalan et al 2014).…”

“…With regard to pasting properties, HMT starches almost always exhibit an increased pasting temperature or time, along with decreased peak and trough viscosities and breakdown, compared to native starches (Hoover et al 1993;Hoover & Vasanthan 1994;Eerlingen et al 1997;Kurakake et al 1997;Adebowale & Lawal 2003;Singh et al 2005Singh et al , 2009Stevenson et al 2005;Luo et al 2006;Adebowale et al 2009;Chung et al 2009a;Watcharatewinkul et al 2009Watcharatewinkul et al , 2010Jyothi et al 2010;Olu-Owolabi et al 2011;Pinto et al 2012;Zavareze et al 2012b;Kim & Huber 2013;Yadav et al 2013;Andrade et al 2014;Balasubramanian et al 2014;Sankhon et al 2014;Sun et al 2014a,b). HMT effects on setback and final viscosities vary among literature reports.…”

Effect of alkali-treatment on physicochemical, pasting, thermal, morphological and structural properties of Horse Chestnut (Aesculus indica) starch

“…Several studies have been carried out on modification of starch but the effect of alkali modification on starch have not been extensively studied as compared to other modifications like heat-moisture [7], enzyme [8] and acid treatments [9]. Information on the susceptibility of commercially starches is available [3,4], however, data on the effect of alkali modification on Horse Chestnut starch is not available.…”