Because hydroxypropyl starch (HPS) represents an important chemical modification of starch, extensive studies on hydroxypropylation are being carried out at various research centers worldwide. The present review summarizes development of methods for determination of the MS (molar substitution)/DS (degree of substitution) of hydroxypropyl starch, location of hydroxypropylation reaction sites in granules and on amylose and amylopectin molecules, and factors affecting reaction efficiency. Also presented is an overview of changes of physicochemical properties of starch that result from hydroxypropylation. Specifically reviewed are the effects of hydroxypropylation on granule morphology, crystallinity, thermal properties, swelling, and solubility; pasting, paste, and retrogradation properties; rheological and textural properties of HPS gels; and digestibility and uses of HPS.

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The gut microbiota structure has been proposed to be involved in longevity. In this study, trajectories of age-related changes in gut microbiota were analyzed by comparing the gut microbiota composition from long-lived families. A specific bacterial community pattern and signature taxa of long-lived people were found in long-lived families, such as the enrichment of Enterobacteriaceae in all age groups and the higher abundances of Christensenellaceae, Verrucomicrobiaceae, Porphyromonadaceae, Rikenellaceae, Mogibacteriaceae, and Odoribacteraceae in long-lived elderly and the positive correlation between them. The cumulative abundance of the core microbiota was approximately stable along with age, but the genera and species in the core microbiota were rearranged with age, especially in Ruminococcaceae and Lachnospiraceae. Compared with the control group, the proportions of Lachnospiraceae, Roseburia, and Blautia were significantly higher in participants from the long-lived village, but their abundances gradually decreased along with age. Based on functional predictions, the proportions of pathways related to short-chain fatty acid metabolism, amino acid metabolism, and lipoic acid metabolism were significantly higher in the long-lived elderly compared with the offspring group. The trajectory of gut microbiota composition along with age in participants from long-lived families might reveal potential health-promoting metabolic characteristics, which could play an important role in healthy aging.

Summary Influences of ultrasonic treatment on structure and functional properties of salt‐soluble protein from Moringa oleifera seeds (MOSSP) were explored. The results indicated that the ultrasonic treatment destroyed spherical structure of MOSSP and transformed the spherical structure into irregular fragments. The content of β‐turn, α‐helix and random coils in MOSSP significantly increased, but with extending the ultrasound time, the content of β‐turn, α‐helix and random coils had no significant change. SDS‐PAGE results showed that sonication could stabilise the primary structure of MOSSP. The surface hydrophobicity and emulsification were significantly reduced, but sonication could improve the solubility and foaming properties of MOSSP within a certain range.

Impact of high-speed jet (HSJ) treatment on morphology, crystalline structure, retrogradation, thermal and rheological properties of Arenga pinnata (Wurmb.) Merr starch (APS) was investigated. Decreasing with the number of HSJ treatment passes were the turbidity values of pastes (long-term retrogradation), the gelatinization enthalpy, and the crystallinity. Scanning electron microscopy showed APS granule structure was degraded into tiny round particle and thin sheet structures. X-ray diffraction illustrated that the C-type X-ray pattern was changed toward a weak A-type X-ray pattern. With further increases in the number of passes, the weak A-type pattern was changed to amorphous pattern. Dynamic oscillation analysis revealed that HSJ treatment significantly altered the viscoelasticity of APS. During a dynamic frequency sweep, G′ values and G″ at 10 Hz decreased from 589.9 Pa (HSJ0) to 194.9 Pa (HSJ8) and from 101.6 Pa (HSJ0) to 24.5 Pa (HSJ8), respectively, implying that HSJ treatment had a great influence on the elasticity of the APS gel. The results indicated that degradation of APS granular and crystalline structure was mainly involved and HSJ treatment was a potential physical modification technique.