Modulation of starch digestibility using non-thermal processing techniques:A review

Obesity and type 2 diabetes are widespread throughout the world, especially in developed countries. Starch is an important part of human staple food, the modulating of starch digestibility is conducive to reducing postprandial blood glucose levels and alleviating the chronic disease caused by high caloric intake. The digestion properties of starch are correlated with its structural features, including crystallization, amylose/amylopectin ratio, non-starch components, etc. Among the modified methods applied to regulate starch digestibility, non-thermal processing techniques(NTPT) receive extensive attention due to the characteristics of safety, environmental friendliness and high efficiency. The influence and mechanism of NTPT on the digestion properties of starch are discussed in this review, including ultrasounds, high pressure, γ-irradiation, etc. NTPT induces the alternation of morphological and structural characteristics of native starch, changing their sensitivity to enzymes. The effects of NTPT on the digestibility of starch are highly related to the processing parameters and structure characteristics of native starch. The review shows that NTPT is an effective way to modulate the digestion properties of starch and prevent people from suffering from chronic diseases such as obesity and type 2 diabetes.

Physicochemical, structural characterization, and antioxidant activities of chondroitin sulfate from Oreochromis niloticus bones

In this study,chondroitin sulfate was extracted from Oreochromis niloticus bones(OCS)and isolated to three fractions(OCS-1,OCS-2,and OCS-3).The physicochemical properties and structure characterization including monosaccharide,disaccharide compositions,molecular weight(Mw)of OCS were determined by HPAEC,HPLC-SAX,HPGPC,FT-IR spectra,and 1D/2D NMR.Moreover,their thermal properties,crystalline structure,and microstructure were also analyzed.Results showed that their Mw were between 10 kDa and 50 kDa.CS-6 was the predominant disaccharide unit in four OCS,and the CS-4/CS-6 ratios were close to CS from shark cartilage.Besides,the results of antioxidant activity showed that different fractions of OCS had a distinct DPPH radical,hydroxyl radical,and ABTS+radical scavenging activity.OCS-1 has the highest scavenging activities in DPPH and hydroxyl radical compared with other fractions,which showed a higher medicinal value.Those findings may lay some theoretical basis for the potential application development of OCS.

Transcriptomic characteristics and impaired immune function of patients who retest positive for SARS-CoV-2 RNA

Coronavirus disease 2019(COVID-19),caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection,has become a global public health crisis.Some patients who have recovered from COVID-19 subsequently test positive again for SARS-CoV-2 RNA after discharge from hospital.How such retest-positive(RTP)patients become infected again is not known.In this study,30 RTP patients,20 convalescent patients,and 20 healthy controls were enrolled for the analysis of immunological characteristics of their peripheral blood mononuclear cells.We found that absolute numbers of CD4^(+)T cells,CD8^(+)T cells,and natural killer cells were not substantially decreased in RTP patients,but the expression of activation markers on these cells was significantly reduced.The percentage of granzyme B-producing T cells was also lower in RTP patients than in convalescent patients.Through transcriptome sequencing,we demonstrated that high expression of inhibitor of differentiation 1(ID1)and low expression of interferon-induced transmembrane protein 10(IFITM10)were associated with insufficient activation of immune cells and the occurrence of RTP.These findings provide insight into the impaired immune function associated with COVID-19 and the pathogenesis of RTP,which may contribute to a better understanding of the mechanisms underlying RTP.