The current consumer demand for fresh food and the interest in caring for the environment have driven the development of biodegradable film packaging to replace synthetic films to preserve the integrity of food. The objective of this work was to evaluate the effects of starch modifications (oxidized, cross-linked, and dual: oxidized/cross-linked), starch concentration (1 and 2%), and glycerol concentration (5 and 15%) on water vapor permeability (WVP), mechanical properties (tensile strength and elongation), optical, and structural properties of films based on “hawthorn” yam starch. The WVP of the films was 4.4 × 10−10 to 1.5 × 10−9 g/m∗s∗Pa, where the films with oxidized yam starch showed a 58.04% reduction concerning the native starch. The tensile strength of oxidized yam starch films showed a decrease of 17.51% with an increase in glycerol concentration. For the 1% starch concentration, elongation increased by 17.03% when the glycerol concentration was increased from 5 to 15%. Modification of starch, starch concentration, and glycerol have a significant effect on the barrier, mechanical, physical, and structural properties of films made with yam starch, where films made with oxidized yam starches at a concentration of 1% starch and 5% glycerol showed the best responses of the properties evaluated.

In Colombia, it is necessary to produce native and modified starches for the use of amylaceous raw materials of major socioeconomic importance. In this study, the effects of the acetylation process on structural, morphological and functional properties of native starches yam, Dioscorea spp. (D. alata and D. rotundata) were evaluated. Chemical modification by esterification with acetic anhydride was performed at different reaction times, and morphological and structural changes were assessed using the following techniques: infrared spectroscopy (FTIR), X-ray diffraction and scanning electron microscopy (SEM). Acetylation produced slight changes in the granule morphology, and a decreased degree of crystallinity (DC) associated with a slight increase in the amylose content was observed. The introduction of acetyl groups into the starch structure caused a decrease in the gelatinization temperature and an increased retro gradation tendency. The acetylated starches had low degrees of substitution (DS<0.2), meaning they can be used in the food industry, considering that they showed greater stability, greater water absorption capacity and better solubility than native starches.

Almidón de yuca variedad Corpoica – TAI fue modificado con α-amilasa comercial, para evaluar el efecto de la temperatura alrededor de la temperatura de pasta, tiempo de reacción y relación enzima/sustrato (E/S) sobre el grado de hidrólisis y producción de almidones modificados enzimáticamente. Los almidones modificados presentaron equivalentes de dextrosa (DE) entre 13 y 92 %, valores de rendimiento (Y) hasta del 45.5%. El análisis Microscopia de barrido electrónico (SEM) mostró que los gránulos presentaron exo-corrosión en concordancia con el grado de hidrólisis. La cristalinidad aumento después de la modificación y la morfología del granulo fue diferente comparada con el almidón nativo. Los almidones hidrolizados presentaron un aumento en la estabilidad (breakdown) y disminución en el asentamiento (setback). La temperatura de gelatinización se incrementó con la cristalinidad y disminuyó con el contenido de amilosa. Los almidones hidrolizados fueron más susceptibles a la retrogradación o pérdida de agua (sinéresis).

Currently, comes up the need to develop and produce modified starches that allow enhancing their applicability as additives in food industry. In this, the effect of biocatalysis time and type of drying (forced convection and vacuum drying) on the morphological, structural and pasting properties of enzymatically modified cassava starch granules was evaluated. The application of amyloglucosidase generated a degree of hydrolysis ranging between 35.87 and 41.02% equivalents of dextrose (ED), in addition, it caused significant changes in starch granules morphology. At structural level, modified starch reveals substantial changes with respect to control, where FT-IR spectra show the displacement of absorption bands by tension or bending in the region between 900 and 1100 cm-1 due to the breakdown of α-D-glucosidic bonds α-D-(1,4) or α-D-(1,6), increasing swelling, absorption and solubility in water properties. Likewise, significant changes are reported in pasting properties together with an increase in stability in techno-functional properties of hydrolyzed starches dried in vacuum.

Starch blends are a technological alternative aimed at the development of starchy matrices that exhibit improvements in some physicochemical properties from interactions between their individual components. Native cassava and yam starches were mixed in different proportions and the effect of the blend on the structural, physicochemical, and pasting properties was evaluated. The viscosity behavior as a function of temperature revealed a significant non-additive effect on the pasting parameters of all the blends with respect to the individual native starches. Similarly, non-additive variations were evident in the crystallinity index of some mix ratios (NSB-2: 40.11%). Likewise, the difference in the amylose content of each native starch (20.88-25.66%) possibly exerted an effect on the resulting semicrystalline characteristics of the blends and the gelatinization behavior. Hence, the botanical origin and the proportion of starch blends play an important role in the behavior of the resulting physicochemical properties and in vitro digestibility. Polymeric blends were obtained with a low tendency to retrogradation and lower crystallinity index values compared to their native counterparts and a regulated water absorption capacity, all potentially desirable characteristics in the food industry.