Effect of Ball Milling Treatment on Thermal, Structural, and Morphological Properties of Phosphated Starches from Corn and Pinhão

Abstract

In the previous study, the effect of chemical modification with sodium tripolyphosphate on the properties of corn and pinhão starches was evaluated. However, physical modifications also confer specific characteristics on the starch, diversifying its application. Thus, in this study, thermal (thermogravimetry [TG], differential exploratory calorimetry [DSC]), structural (X‐ray powder diffractometry [XRD], Fourier‐transform infrared [FTIR]) and morphological (field emission gun‐scanning electron microscopy) properties of native and phosphated corn and pinhão starches are evaluated before and after ball milling treatment. In addition, wavelength dispersive X‐ray spectroscopy is applied as a new technique to measure the level of phosphorus and sodium. The incorporation of phosphate groups in starches is confirmed and phosphorus and sodium are reduced after milling. The doubly modified starches show lower moisture retention capacity and lower thermal stability. All treatments reduce the gelatinization enthalpy mainly for double modified starches. Relative crystallinity is drastically reduced after the double modification. Changes in FTIR results are more pronounced after the physical treatment, corroborating with DSC and XRD results. Morphological changes are observed only in the milled samples. Thus, the double modification confer greater changes compared to the isolated modifications.

Opportunities for the Use of Brazilian Biomass to Produce Renewable Chemicals and Materials

“…The seeds, or pine nuts ( Pinhão ), have a high starch content, accounting for 64 % of the weight of the crop. In addition, Pinhão starch (PS) has a higher content of endogenous phosphorus than corn and yam starches [142] . The amylose content in PS is 19–24 % and it has a high amylopectin content (76–81 %), which reduces the digestibility of the starch and improves its chemical stability.…”

Pinhão coat extract encapsulated in starch ultrafine fibers: Thermal, antioxidant, and antimicrobial properties and in vitro biological digestion

“…The fruits of this conifer are known as pines, and the pine seed is referred to as pinhão . Each seed consists of a wrap, pulp, and embryo, fractions rich in cellulose, starch, and lipids (Beninca et al., 2020; Freitas et al., 2018; Matias et al., 2019). Despite the importance and high functionality of pinhão , few studies focus on the properties of the different parts of this plant (Branco & Rodrigues, 2016; Souza et al., 2014), being its coat particularly underexplored (Fonseca et al., 2020a; Santos et al., 2018).…”