No abstract

Microfluidization has been applied to modify starch granules. The study was conducted to investigate the effect of microfluidization on the structure and thermal properties of cassava starch–water suspension (20% w/w). The means of optical microscopy, SEM, FTIR spectroscopy, XRD, and DSC were applied to analyze the changes in microstructure, crystallinity, and thermal property. Microscopy observations revealed that native starch granules were oval, round, and truncated in shape. After the microfluidization treatment, a bigger starch granule was partially gelatinized, and a gel‐like structure was formed on a granular surface. No significant difference in XRD patterns of the samples were observed and all samples exhibited A‐type allomorph. Crystallinity decreased with the pressure. Sample treated at 150 MPa contains 17.1% crystalline glucan polymer, lower than that of native granules which have crystallinity of about 25.8%. A lower crystallinity means poor order of crystalline glucan polymer structure in starch granules. The disruption of crystalline order within the granule was also observed by FTIR measurement. Thermal analysis using DSC indicated that the microfluidization treatment brought about a significant decrease of melting enthalpy. The gelatinization enthalpy was 12.0 and 3.0 J/g for the native sample and samples treated under the 150 MPa, respectively. The results indicate that high‐pressure microfluidization process induced the gelatinization of cassava starch, which is evaluated by a percentage of the degree of gelatinization, due to a pronounced decrease with increasing microfluidizing pressure.

Sacred lotus (Nelumbo nucifera) has long been used as a food source and ingredient for traditional herbal remedies. Plant parts contain neuroprotective agents that interact with specific targets to inhibit Alzheimer’s disease (AD). Organic solvents including methanol, ethyl acetate, hexane, and n-butanol, are widely employed for extraction of sacred lotus but impact food safety. Seed embryo, flower stalk, stamen, old leaf, petal, and leaf stalk of sacred lotus were extracted using hot water (aqueous extraction). The extractions were analyzed for their bioactive constituents, antioxidant and anti-AD properties as key enzyme inhibitory activities toward acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and β-secretase 1 (BACE-1). Results showed that the sacred lotus stamen exhibited significant amounts of phenolics, including phenolic acids and flavonoids, that contributed to high antioxidant activity via both single electron transfer (SET) and hydrogen atom transfer (HAT) mechanisms, with anti-AChE, anti-BChE, and anti-BACE-1 activities. To enhance utilization of other sacred lotus parts, a combination of stamen, old leaf and petal as the three sacred lotus plant components with the highest phenolic contents, antioxidant activities, and enzyme inhibitory properties was analyzed. Antagonist interaction was observed, possibly from flavonoids–flavonoids interaction. Further in-depth elucidation of this issue is required. Findings demonstrated that an aqueous extract of the stamen has potential for application as a functional food to mitigate the onset of Alzheimer’s disease.