Effects of Cross-Linking on Physicochemical and Film Properties of Lotus (Nelumbo nucifera G.) Seed Starch

Abstract

Lotus seed starch was cross-linked using sodium trimetaphosphate (STMP) in varying amounts (1, 3, and 5%), and its rheological, pasting, thermal, and physicochemical properties were investigated. These cross-linked lotus seed starches (CL-LS-1, CL-LS-3, CL-LS-5) were also used to produce films (CL-LSFs), which were then examined for their mechanical characteristics, water vapor permeability, moisture content, opacity, thickness, and water solubility. After cross-linking, the solubility, amylose content, and swelling power of all the starch samples decreased. Cross-linking resulted in an increased pasting temperature, while peak viscosity (PV) decreased, with CL-LS-5 exhibiting the lowest peak viscosity (1640.22 MPa·s). In comparison to native starch, the thermal characteristics of CL-LS demonstrated greater gelatinization temperatures (To, Tp, Tc) and gelatinization enthalpy (ΔHgel). The gelatinization enthalpy of CL-LS varied between 152.70 and 214.16 J/g, while for native LS the value was 177.91 J/g. Lower moisture content, water solubility, and water vapor permeability were observed in the CL-LSFs. However, the cross-linking modification did not produce much effect on the film thickness. The highest tensile strength (12.52 MPa) and lowest elongation at break (26.11%) were found in CL-LSF-5. Thus, the starch films’ barrier and mechanical qualities were enhanced by cross-linking.

Benign electrolytic modifications of starch: effects on functional groups and physical properties

“…Peak viscosity (PV) gauges the maximum viscosity achieved by starches when a temperature-dependent balance is struck between swelling and leaching. 35…”

“…Starch granules with lower water absorption and smaller size demonstrate less development of final viscosity upon cooling. 35…”

“…The pasting properties of starches were assessed using a Rapid Visco Analyzer (MCR-52, Anton Paar, Graz-8054, Austria) following the testing conditions outlined by Chandak et al 35 A starch suspension (1.2 g of dry starch in 13.8 g of deionized water) was initially equilibrated at 50 °C for one minute, then heated from 50 °C to 95 °C at a rate of 6 °C per minute, and maintained at 95 °C for 2.7 minutes. Subsequently, the suspension was gradually cooled back to 50 °C at the same rate and held at that temperature for 2 minutes.…”

Polymer blends of poly(lactic acid) and starch for the production of films applied in food packaging: A brief review

“…230 After the addition of glycerol, the aqueous dispersion is heated to a temperature of ∼75-95°C to obtain a gelatinized starch dispersion, which is then molded and dried to produce the film (Figure 4). [231][232][233][234][235][236][237][238][239] Gelatinization is able to improve film-forming properties compared to non-gelatinized starch. 240 It is difficult to find in the literature a work in which the starch used for the production of films has not been gelatinized, reinforcing the important role of plasticizers.…”

Avocado seed discoveries: Chemical composition, biological properties, and industrial food applications

“…The avocado seeds can also be utilized as alternative/non-conventional starch sources (Rivera-González et al, 2019). Its starch fraction (27.3 % yield) have low total dietary fibers (7.32 %) (Rivera-González et al, 2019), which can be useful as a thickener, emulsifier, and gelling agent in different food applications ( Dhull et al, 2022 , Chandak et al, 2022 , Chandak et al, 2022 ). The avocado starch contains 15–16 % amylose, with a gelation range at 56–74 °C having good water absorption capacity (22–24 g of water/g of starch), solubility (19 %–20 %), swelling power (28 g–30 g of water/g of starch), and a maximum viscosity (380 BU–390 BU) which makes it an ideal ingredient for gelling and thickening, pharmaceuticals and biodegradable packaging materials for foods ( Chel-Guerrero, Barbosa-Martín, Martínez-Antonio, González-Mondragón, & Betancur- Ancona, 2016 ).…”