Structural, functional and antioxidant properties of Lentinus edodes protein hydrolysates prepared by five enzymes

The purpose of this study was to investigate structural, functional and antioxidant properties of Lentinus edodes protein hydrolysates (LEPHs) by alcalase, protamex, trypsin, papain and neutrase. Structural and functional properties were determined using gel electrophoresis, Fourier transform infrared spectroscopy, laser scattering, fluorescence spectroscopy, emulsifying properties etc. Antioxidant activities were detected by Fe2+ chelating, hydroxyl and DPPH radical scavenging assays. Enzymatic hydrolysis destroyed secondary and tertiary structures of Lentinus edodes protein, decreased its molecular weight and particle size, particularly hydrolysate prepared by alcalase with the highest hydrolytic degree (32.86 ± 0.98 %), the smallest particle (130.77 ± 1.85 nm) and molecular weight (5.86 kDa). Moreover, alcalase hydrolysate exhibited the highest emulsifying stability, the strongest hydroxyl radical scavenging activity and Fe2+ chelating ability among LEPHs. Whilst trypsin hydrolysate displayed the highest DPPH radical scavenging, foaming and fat absorption capacity. These results provided basis for LEPH as ingredients to be used for food industry.

Structural and functional modification of kudzu starch using α-amylase and transglucosidase

The large agglomeration of starch paste in hot water, and fast retrogradation tendency and low transparency of starch gel restrict widespread application of kudzu starch. To improve the above defects, kudzu starch was modified with sequentially α-amylase (AA) and transglucosidase (TG), the latter for varying times. The results indicated that, compared to kudzu starch, amylose content and molecular weight of AA/TG-treated starches reduced by 20.07% and 69.50%, respectively. The proportion of A chain increased by 68.68%, whereas B1, B2 and B3 chains decreased by 14.28%, 48.29% and 23.44%, respectively. The degree of branching dramatically increased by 128.3%. After AA→TG treatment, the changes of starch structure enhanced the functional properties of kudzu starch. The solubility, paste clarity and gelatinization temperature increased, whereas the relative crystallinity, viscosity, storage and loss moduli decreased. Overall, the AA→TG modification would be desirable to improve the functional properties of kudzu starch to expand more large-scale application.

Non-invasive imaging modalities to study neurodegenerative diseases of aging brain

The aim of this article is to highlight current approaches for imaging elderly brain, indispensable for cognitive neuroscience research with emphasis on the basic physical principles of various non-invasive neuroimaging techniques. The first part of this article presents a quick overview of the primary non-invasive neuroimaging modalities used by cognitive neuroscientists such as transcranial magnetic stimulation (TMS), transcranial electrical stimulation (tES), electroencephalography (EEG), magnetoencephalography (MEG), single photon emission computed tomography (SPECT), positron emission tomography (PET), magnetic resonance spectroscopic imaging (MRSI), Profusion imaging, functional magnetic resonance imaging (fMRI), near infrared spectroscopy (NIRS) and diffusion tensor imaging (DTI) along with tractography and connectomics. The second part provides a comprehensive overview of different multimodality imaging techniques for various cognitive neuroscience studies of aging brain.