Effect of Glycerol Content on the Properties of Potato Flour Films

Abstract

Potato flour films are prepared by using glycerol as a plasticizer in the content range of 10–40% (w/w). The mechanical properties, opacity, water resistance performance, and glass transition temperature of potato flour films are studied. The tensile strength of films decrease with increases in glycerol content. The elongation at break increase with increases in glycerol content from 10% to 20% (w/w) and then decrease as glycerol content increased. Film samples are more transparent at higher glycerol content. Sorption isotherms of films plasticized with the highest concentration of glycerol show the highest water affinity and binding sites. As glycerol content increases, the water solubility index and water vapor permeability of films increases, while the water contact angle decreases significantly. The glass transition temperature decreases with the increase of glycerol content. The results show that the potato flour could be used to prepare film successfully with glycerol as the plasticizer.

Structural, thermal and dielectric properties of glycerolized hydrogen‐bonded polyvinyl alcohol films

“…It is observed that the T g decreased from 88.2°C for pure PVA to 37.8°C for PVA film with 40 wt% glycerol. A lowering of the glass transition temperature with higher glycerol content is also found in the previous studies with other matrices 44–46 …”

“…A lowering of the glass transition temperature with higher glycerol content is also found in the previous studies with other matrices. [44][45][46] To conclude on this DSC study, one can say that the addition of glycerol in the elaboration of PVA significantly influences both the glass transition temperature (confirming a softening effect of the PVA matrix) and the crystallinity of the polymer, as summarized in Table 1 first present the dielectric behavior of PVA alone (without glycerol) as the standard for this study. In Figure 3, the influence of water inclusion in the air-dried PVA matrix at room temperature is clearly visible compared to the vacuum-dried film at 80 C. The effect of moisture is not a parameter of interest in this paper and will be the subject of a specific study later in an approach to integrate this polymer as a sensitive material for a humidity sensor.…”

Valorization of Amaranth (Amaranthus cruentus) Grain Extracts for the Development of Alginate-Based Active Films

“…OP is associated to particles dispersion in the film matrix, once they can block light, causing more light scattering within films [37]. These results are consistent with other authors' work, who showed that potato flour films are more transparent at higher glycerol content [38]. The EB value of sample 7 (0% phenolic compounds and 0.37% glycerol) was 12.19 ± 5.06% and TS value was 1.12 ± 0.25 MPa.…”

Optimizing the Functional Properties of Starch-Based Biodegradable Films

“…The initial increasing trend in the opacity index (or decreasing trend in the transparency) as the starch concentration in the thermoplastic solution increased from 4 to 5.5% (opacity index increased from ~10 to 30) can be explained by the increase in undissolved starch aggregates in the film. More specifically, because starch granule swelling, disruption, dissolution and gelatinization are not complete, starch ghost particles occur, which form aggregates after drying the films, eventually leading to increased light scattering, and thus opacity [59,60]. However, the following decreasing trend in the opacity index from ~30 to 10 when the starch concentration increased from 5.5 to 7% wt could presumably be attributed to the fact that the remaining ordered structure of the starch granules became so compact that it did not allow the particles to swell due to the increase in compressibility [61], and therefore the light subsequently scattered.…”