Annealing treatment of ulluco starch: Effect of moisture content and time on the physicochemical properties

Abstract

Annealing is a modification method that can improve the physicochemical properties of starch. The effect of moisture content (MC) and time (t) on the physicochemical properties of ulluco starch obtained by annealing (ANN) modification was studied.The results showed the ulluco-modified starches improved physicochemical properties such as solubility, water-holding capacity (WHC), oil-holding capacity (OHC), pasting properties, and the texture of the gel formed. Furthermore, the ordered structure and granules shape of starches were not significantly affected by the ANN modification. Regarding the influence of the process parameters on the properties of the modified starches, MC was the one that influenced the most, followed by t.The ANN treatment applied to ulluco starch proved to be an efficient, low cost, and green method for improving its physicochemical properties. This study showed that the native and physically modified ulluco starch is an industrial alternative to starches obtained from traditional crops, contributing to food security. Novelty impact statement:Annealing is a physical method used to modify starch that can improve the physicochemical characteristics of the material. It is also a low-cost and environmentally friendly method. The modification of starches is an alternative to add value to different crops.

Influence of Ulluco Starch Modified by Annealing on the Physicochemical Properties of Biodegradable Films

“…All samples exhibited a band at 3300 cm −1 corresponding to the stretching of hydroxyl groups (–O–H) [ 11 ]. A previous report observed that the native ulluco starch and the modified starches presented the same band at 3446 cm −1 [ 7 ]. However, there was a slight shift in the signal in the films analyzed.…”

“…The XRD patterns of biodegradable films are presented in Figure 3 . All samples showed a typical B-type crystal structure similar to the native ulluco starch [ 7 ]. This structure showed characteristic peaks at around 5.6° 2θ and 17° 2θ (peak with strong diffraction intensity) and with small peaks at around 15°, 20°, 22°, and 24° 2θ.…”

“…Ulluco tubers ( Ullucus tuberosus Caldas) were acquired at a local market in Ibagué (Colombia). The native starch (amylose content 27.9%) and the annealing modified starch (ANNS) were obtained according to the methodology described by Valcárcel-Yamani [ 12 ] and modified by Parra et al [ 7 ]. In brief, after adjusting the moisture content (MC) at 50% (S1), 60% (S2), and 70% (S3), the starch was heated at 55 °C for 8 h (S1) or 24 h (S2 and S3).…”

“…The treatments were selected considering the best physicochemical properties of modified starch to obtain biodegradable films. These properties were evaluated and discussed in a previous study [ 7 ].…”

“…Starch can be enzymatically, chemically, or physically modified to overcome these drawbacks. Annealing (ANN) is a physical modification in which a reorganization of starch granules occurs at temperatures between the glass transition ( Tg ) and the onset of gelatinization ( To ) and with an excess of moisture [ 7 ]. The main effects of annealing on the material are increased crystallinity, thermal stability, granule size and molecular mobility, and reduced water absorption capacity [ 8 ].…”