Insights into the modification of physicochemical properties and digestibility of pea starch gels with barley β-glucan

Extraction, purification, structural characteristics, bioactivity and potential applications of polysaccharides from Avena sativa L.: A review

Avena sativa L. (A. sativa L.), commonly known as oat, is a significant cereal grain crop with excellent edible and medicinal value. Oat polysaccharides (OPs), the major bioactive components of A. sativa L., have received considerable attention due to their beneficial bioactivities. However, the isolation and purification methods of OPs lack innovation, and the structure-activity relationship remains unexplored. This review emphatically summarized recent progress in the extraction and purification methods, structural characteristics, biological activities, structure-to-function associations and the potential application status of OPs. Different materials and isolation methods can result in the differences in the structure and bioactivity of OPs. OPs are mainly composed of various monosaccharide constituents, including glucose, arabinose and mannose, along with galactose, xylose and rhamnose in different molar ratios and types of glycosidic bonds. OPs exhibited a broad molecular weight distribution, ranging from 1.34 × 105 Da to 4.1 × 106 Da. Moreover, structure-activity relationships demonstrated that the monosaccharide composition, molecular weight, linkage types, and chemical modifications are closely related to their multiple bioactivities, including immunomodulatory activity, antioxidant effect, anti-inflammatory activity, antitumor effects etc. This work can provide comprehensive knowledge, update information and promising directions for future exploitation and application of OPs as therapeutic agents and multifunctional food additives.

Complexation temperature regulated the structure and digestibility of pea starch-gallic acid complexes during high pressure homogenization

Formation of starch-polyphenol complexes by high pressure homogenization (HPH) is widely used to reduce starch digestibility and delay the postprandial glycemic response, thereby benefiting obesity and associated metabolic diseases. This study investigated the effect of complexation temperature on multi-scale structures, physicochemical and digestive properties of pea starch-gallic acid (PS-GA) complexes during HPH process, while also elucidating the corresponding molecular mechanism regulating in vitro digestibility. The results demonstrated that elevating complexation temperature from 30 °C to 100 °C promoted the interaction between PS and GA and reached a peak complex index of 9.22 % at 90 °C through non-covalent binding. The enhanced interaction led to the formation of ordered multi-scale structures within PS-GA complexes, characterized by larger particles that exhibited greater thermal stability and elastic properties. Consequently, the PS-GA complexes exhibited substantially reduced digestion rates with the content of resistant starch increased from 28.50 % to 38.26 %. The potential molecular mechanism underlying how complexation temperature regulated digestibility of PS-GA complexes might be attributed to the synergistic effect of the physical barriers from newly ordered structure and inhibitory effect of GA against digestive enzymes. Overall, our findings contribute to the advancement of current knowledge regarding starch-polyphenol interactions and promote the development of functional starches with low postprandial glycemic responses.