RESUMEN

Polysaccharides have been considered as a group of promising candidate for preventing the protein-polyphenol haze formation in beverages. In order to select effective polysaccharides to prevent the haze formation, four protein-polyphenol haze model systems were successfully established using two proteins (i.e., gelatin and bovine serum albumin) and two polyphenols (i.e., procyanidin [PC] and epigallocatechin gallate [EGCG]). Among seven common polysaccharides, 0.5 mg/mL pectin, 0.05 mg/mL xanthan gum, and 0.01 mg/mL guar gum demonstrated the maximum potential for preventing the formation of four protein-polyphenol hazes. Ultraviolet-visible spectrophotometry confirmed that polysaccharides affected protein-polyphenol interactions. Fluorescence spectrophotometry combined with microscale thermophoresis data indicated the relative affinities of polyphenol to protein and polysaccharide determined the mechanism of polysaccharide for preventing the haze formation. In bovine serum albumin (BSA)/gelatin-EGCG system, polysaccharides (pectin, xanthan gum and guar gum) competed with BSA/gelatin to bind EGCG for prevention the formation of BSA/gelatin-EGCG haze. However, in BSA/gelatin-PC system, polysaccharides (pectin, xanthan gum, and guar gum) formed a ternary complex (protein-tannin-polysaccharide) for increasing the solubility of protein-polyphenol aggregation. From apple juice results, the reduction rates of guar gum in two apple juice systems (gelatin-PC, BSA-PC) were 21% and 56% within 8 weeks, indicating guar gum might be the most effective polysaccharide in preventing the haze formation. PRACTICAL APPLICATION: This experiment data could be used for development of polysaccharide products for prevention of protein-polyphenol haze formation in beverages.

Asunto(s)

Bebidas/análisis , Bebidas/normas , Polifenoles/química , Polisacáridos/química , Proteínas/química , Manipulación de Alimentos , Galactanos , Mananos , Gomas de Plantas , Albúmina Sérica Bovina

RESUMEN

Radix Aconiti Lateralis Preparata (Fuzi) is an important, toxic traditional Chinese medicine that has been widely used in clinical practice. Due to the toxicity of its raw materials, it needs to be processed before application. The changes in the physicochemical properties of Fuzi starch during processing were evaluated by scanning electron microscopy, X-ray diffraction and differential scanning calorimetry. The results showed the following: morphological properties changed from spherical to irregular and polygonal particles, while the particle size increased significantly; amylose content and solubility decreased significantly; swelling power and water-binding capacity increased significantly; the X-ray diffraction peak disappeared, and the crystallinity decreased; and the gelatinization temperature and enthalpy decreased significantly. The properties of Fuzi starch were similar to those of pregelatinized starch. These results indicated that Fuzi starch undergone repeated processes of gelatinization and aging, which destroyed the original crystal structure of the starch.