Effect of Pretreatments on Color, Functional and Pasting Properties of White (D ioscorea rotundata ) and Yellow Yam (D ioscorea cayenensis ) Varieties

Effect of particle size of sesbania gum on its modification, structure and performances

Sesbania gum (SG), as an environmentally friendly and resourceful natural polymer, has attracted a lot of attention due to its favorable properties. The size distribution of SG powders was broadened owing to the growth. Therefore, it inevitably resulted in the differences in reaction activity, structure and properties of different SG particles. The results showed that small SG particles exhibited higher reaction activity in cross-linking, carboxymethylation and oxidation than its large counterparts. Compared with those of large SG particles, the sedimentation volume of small SG particles could be reduced by 1.1 mL, while their substitution degree of carboxymethyl groups and aldehyde content could be increased by 0.0824 and 18.11 %, respectively. The swelling capacity, freeze-thaw stability, acid and alkali resistance of small SG particles were greater than those of large SG particles, but their retrogradation was weaker than that of large counterparts. The crystalline degree of small SG particles consisting of more long molecular chains could be reduced by 9.8 % compared to large SG particles. The DSC curve of small SG particles was significantly different from that of large SG particles, while the difference in TGA curves between small particles and large particles was relatively small. The enthalpy change of small SG particle was reduced by 48.4 J/g compared to large SG particles. The peak viscosity, final viscosity, breakdown and setback of tapioca starch were obviously influenced by the addition of small SG particles. And their emulsification stability was also better than large SG particles.

Partial Replacement of Maltodextrin by Sweet Potato Flour (Ipomoea Batatas L. Lamarck) in the Development of a Shake Beverage

Sweet potato flour contains low-glycemic complex carbohydrates and, when it is ingested, prevents insulin spikes and prolongs the feeling of satiety. The aim of this study was to elaborate and to verify the acceptability of the shake with the total or partial substitution of maltodextrin for sweet potato flour. To elaborate the shake beverage, we used a 22 factorial design, with three central points, thus generating seven formulations. For the taste, color, texture, appearance, acceptance and attitude of purchase properties, sensory tests were conducted using a nine-point hedonic scale and panelists (n = 50). The highest acceptability formulations, formulations 3 (10% sweet potato flour; 25% maltodextrin) and 7 (0% sweet potato flour; 25% maltodextrin), were submitted to pH, moisture, ash, protein, lipid, crude fiber and total carbohydrate analyses. The statistical difference between the formulations from the T test (p < 0.05) was verified for the moisture, ash and lipid parameters. Formulation 3 presented higher values of moisture (93.26 ± 0.57) and lipids (1.91 ± 0.01), and formulation 7 had higher values of ash (0.39 ± 0.01). The results of the sensorial and physicochemical analyses of the shake indicate that sweet potato flour shows potential for the elaboration of this drink.