Chanical properties, essential oil addition yielded starch foams with low water solubility but additionally reduced mechanical resistance, specially for ten OEO. Transversal section microstructure evaluation showed that TEO-foams and OEO-foams have much more compact structures and fewer porosities, which might have decreased water absorption, specially in the surface. Additionally, sturdy interactions among OEO and sweet potato starch molecules restricted the interactions between chains of amylose mylose, amylopectinamylopectin, or amylose mylopectin, possibly weakening and destabilizing the starch structure. Furthermore, sweet potato starch and critical oil foams have been far more efficient against Salmonella (Gram-negative bacteria) and L. monocytogenes (Gram-positive bacteria)Appl. Sci. 2021, 11,15 ofas the crucial oil diffuses from inside the foams towards the surface. Based on the authors, the foam structure may well influence important oil diffusion strongly. The SEM micrographs showed that the essential oil was in the 1st layer of the foam and was later displaced by water vapor during thermoforming. The foams with 10 crucial oil exerted a greater antimicrobial effect resulting from a greater volume of vital oil that diffused to the environment. The phenolic compounds present inside the foam and most likely responsible for microbial inhibition are carvacrol, thymol, therpinene, and p-cymene. For that reason, these foams showed fantastic properties to be applied as bioactive food containers. An additional strategy by Uslu and Polat [51] and Polat et al. [52], was to prepare glyoxal cross-linked baked corn starch foams using the addition of corn husk fiber, kaolin, and beeswax. Cross-linked starch foams had a extra expanded structure, as shown by SEM micrographs. That is most likely caused by a quicker gelatinization of the cross-linked starches at a lower temperature, and more quickly water evaporation during the baking method. Additionally, the cell size improved with all the cross-linkage addition amount, although cell walls of your cross-linked starch foams have been thinner than these of your native foams. Both the tensile and flexural properties on the foams have been substantially impacted by cross-linking. Foams produced from cross-linked starches were additional versatile. Inclusion in the corn husk fiber resulted in enhanced water resistance of cross-linked corn starch foams. Addition of beeswax or kaolin enhanced the cell size in the center of your foams and decreased the tensile and flexural strength; even so, these additives also lowered the water absorption with the foam trays. It can be probably that both the physical and chemical properties of fibre contributed towards the improvement in the tensile properties of the trays. For instance, the long size on the fibre permitted the formation of hydrogen bonds with beeswax and also a spreading with the fibre within the direction of tension. A comparable study was developed by Noscapine (hydrochloride) In Vitro Pornsuksomboon et al. [63] in which they obtained pretty equivalent final results, though they utilised cassava starch and citric acid as a cross-linker. The citric acid-modified cassava starch foam (CNS) had a greater density, decrease thickness, and denser structure than native cassava starch (NS). These variations in morphology are possibly resulting from various viscosity values in between the batters. Because the viscosity of CNS batter was higher compared to NS batter, NS foam was additional expandable than CNS foam. On the other hand, the 50/50 NS/CNS ratio foam exhibited a uniform distribution of cell sizes with thinner cell walls than each the NS.
