Currently, dry fractionation is employed to extract dietary fiber (DF) from food processing bypuroduct owing to its advantages of low energy and eco-friendly. Procedures of dry fractionation mainly include milling and air classification. Soybean meal (SBM) is a processing byproduct rich in DF. Few studies have used dry fractionation to extract SBM dietary fiber (SMF), and the physicochemical properties, structural characteristics, and activity of SMF extracted via dry fractionation remain unclear. Herein, SMF was prepared via dry fractionation and results showed that compared with that of SBM without pores and high crystallinity, SMF had loose and porous surface and low crystallinity. Moreover, the water holding capacity, oil holding capacity and swelling ability of SMF were significantly higher than SBM. After 24 h of in vitro fecal fermentation, the SMF group produced abundant short chain fatty acids (SCFA) such as acetic, propionic, and butyric acids and the total SCFA production was substantially higher than that in the inulin (INL) group. SMF also promoted the relative abundance of beneficial bacteria such as Prevotella, Dialister, and Bifidobacterium and reduced the relative abundance of harmful bacteria such as Escherichia-Shigella. In conclusion, SMF extracted via dry fractionation can significantly alter the relative abundance and diversity of gut microbiota and promote the production of SCFA, which is conducive to the regulation of the human gut microbiota. This study can provide insights into the preparation of DF via dry fractionation and provide theoretical basis for SMF to be used as a prebiotic.

In this research, the effect of selenium (Se) enrichment on dough fermentation characteristics of yeast and the possible mechanisms was investigated. Then, the Se-enriched yeast was used as starter to make Se-enriched bread, and the difference between Se-enriched bread and common bread was investigated. It was found Se enrichment increased CO2 production and sugar consumption rate of Saccharomyces cerevisiae (S. cerevisiae) in dough fermentation, and had positive impacts on final volume and rheological index of dough. The mechanism is possibly related to higher activity and protein expression of hexokinase (HK), phosphofructokinase (PFK), pyruvate kinase (PK), citrate synthase (CS), isocitrate dehydrogenase (ICD), and α-ketoglutarate dehydrogenase (α-KGDHC) in Se-enriched yeast. Moreover, Se-enriched bread (Se content: 11.29 μg/g) prepared by using Se-enriched yeast as starter exhibited higher overall acceptability on sensory, cell density in stomatal morphology, and better elasticity and cohesiveness on texture properties than common bread, which may be due to effect of higher CO2 production on dough quality. These results indicate Se-enriched yeast could be used as both Se-supplements and starter in baked-foods making.

Earthworms are rich in protein and are considered a good source of edible insect protein. However, there has been limited research on the bioactivity of earthworm protein hydrolysates. The present study investigated the immunological impact of earthworm protein autolysate (EPA) on Cyclophosphamide (CTX)-induced immunosuppressed mice model. The results revealed that the Degree of Hydrolysis (DH) and percentage of soluble peptide content of the EPA were 22.38% and 77.92%, respectively. EPA was efficient in treating CTX-dropped mice's immunosuppression as well as intestinal inflammation. The peptide sequences of the EPA digestion products were identified, and ten top-scoring peptides were obtained using the PeptideRanker and HPepDOCK assessment, whose activity was validated in the macrophage model, with WNWLLPLMLG having the best immunomodulatory activity. Therefore, EPA may be a potential resource for immunomodulatory peptides, and autolysis can be a reliable technique for preparing peptides.

为探究不同蛋白酶预酶解对玛咖蛋白胃肠消化程度及消化产物免疫调节活性的影响,该研究选用中性蛋白酶、碱性蛋白酶、木瓜蛋白酶、菠萝蛋白酶以及复合蛋白酶分别对玛咖蛋白进行预酶解,再经模拟胃肠消化得到五组消化产物.利用TNBS法、福林酚法等测定消化产物的得率、水解度、可溶性肽含量及游离氨基酸含量,再以小鼠巨噬细胞RAW 264.7为模型探究消化产物的免疫调节活性.结果表明,经五种蛋白酶的预酶解,玛咖蛋白消化产物的水解度、可溶性肽含量和游离氨基酸含量分别提高了35％、5％～16％及37％～92％,且消化产物促进巨噬细胞分泌TNF-α的作用无明显降低.经菠萝蛋白酶预酶解得到的消化产物的免疫调节活性最高,该消化产物含有15154条分子量小于3000 u的肽段;在经活性评分及分子对接预测的与TLR2和TLR4受体存在相互作用最强的10个肽段中,NPYPFFGFSI的免疫调节活性最高;HOMO分析结果表明该肽的活性位点位于酪氨酸上.上述结果表明预酶解可在不影响玛咖蛋白免疫调节活性的条件下提高玛咖蛋白的可消化性.

Earthworms are emerging sources of edible animal proteins. Earthworm extracts exhibit good in vivo antioxidant activity after oral administration. To better understand the antioxidant activity of earthworms, antioxidant peptides derived from earthworm proteins after gastrointestinal digestion were isolated and identified, and their structure-activity relationships were analysed in this research. Results showed that earthworm protein gastro-intestinal digestion products exhibited good antioxidant activity, and 6030 peptide sequences were identified after separation using ion-exchange and gel-chromatography columns. Eleven peptides were screened using computer simulation activity scores, among which AFWYGLPCKL, WPWQMSLY, and GCFRYACGAFY showed the best antioxidant activities. Highest Occupied Molecular Orbital (HOMO) analysis indicated that N29-H10, O122- H38, and the peptide bond binding sites of serine and leucine were active sites of peptides AFWYGLPCKL, GCFRYACGAFY, and WPWQMSLY, respectively. This study provides a new understanding of substance basis of antioxidant activity in earthworms and contributes to application of earthworm proteins as antioxidants in health-foods.

The effects of exogenous protease pre-enzymolysis treatment on the degree of gastrointestinal digestion and antioxidant activity of earthworm proteins were examined following gastrointestinal digestion. Five proteases were used to prepare different hydrolysates of earthworm proteins, and changes in the degree of hydrolysis, molecular weight distribution, and in vitro antioxidant activities of these enzymatic hydrolysates were investigated based on simulated gastrointestinal digestion in vitro. Among these hydrolysates, the degree of hydrolysis of the alkaline protease hydrolysate was the highest at 40.81%. The rates of DPPH and ABTS free radical scavenging were 27.36 and 175.46 μmol TE/g, respectively, and the ORAC value was 0.70 μmol TE/mg. Following gastrointestinal digestion, the degree of hydrolysis, rate of DPPH free radical scavenging, and ORAC value of the alkaline protease hydrolysate increased by 94.06%, 72.21%, and 120%, respectively, compared with the products obtained via direct gastrointestinal digestion of earthworm proteins. A total of 10 823 peptides with molecular weight ＜3 ku were identified in GHEWP, and 11 peptides with the highest activity scores were screened using bioware.ucd.ie to determine their activity threshold score for synthesis and verification. Among these, the peptides ATSGFFVY, HCFVLY, HLASGWY, HRYSDF, and HYANMY had the highest comprehensive antioxidant capacities. The quantum chemical calculation results revealed that the active sites of ATSGFFVY, HCFVLY, HRYSDF and HYANMY might be located at Tyr-8, Tyr-6, Tyr-3, and Tyr-2, respectively, and the active site of HLASGWY may be located at Trp-6. The findings of this study indicate that pre-enzymatic hydrolysis using alkaline protease can enhance the degree of digestion of earthworm proteins and also the antioxidant activity of their gastrointestinal digestion products.

Maca is a functional food with anti-inflammatory activity, and it is rich in protein. Currently, inflammatory bowel disease (IBD) is a common gastrointestinal disease. However, there is little research focusing on the effect of maca protein (MCP) on IBD. In this study, we extracted MCP from maca root and explored its effect and mechanism on improving dextran sodium sulfate (DSS)-induced IBD in mice. The results indicated that MCP intervention alleviated the clinical symptoms and colon tissue damage of mice with DSS-induced colitis and inhibited the expression of inflammatory factors. Moreover, it can modulate the gut microbiota composition in mice with DSS-induced colitis. The regulation is achieved by reducing the relative abundance of the IBD-exacerbating key bacterial genera: Lachnospiraceae_NK4A136_group, Bacteroides, Desulfovibrio, Prevotella, Helicobacter and Sutterella, while increasing the relative abundance of the IBD-alleviating key bacterial genera: norank_f_Muribaculaceae, Lactobacillus, Oscillospira, Akkermansia and Bifidobacterium. MCP can also promote the production of short-chain fatty acids (SCFAs). The further western blotting results indicated that MCP can regulate the Treg/Th17 immune balance in mice with colitis via the SCFAs-GPR41/43/HDAC1 signaling pathway. Overall, MCP can alleviate colitis by comprehensively regulating the gut microbiota and inflammatory response. It may be a promising functional component that reduces the risk of colitis by maintaining intestinal health.

Maca is an edible functional plant with antihypertensive activity. However, there is still no clear understanding of ACE inhibitory substances in maca. In the present study, six novel angiotensin-converting enzyme inhibitor (ACEI) peptides (RSRGVFF, LGHPVFRNK, HGSCNYR, KANLGFRF, GGGHKRLY and SSYLGRN) were found in maca protein hydrolysates using in silico tools and molecular docking. RSRGVFF revealed prominent ACE inhibitory activity with an IC 50 value of 5.01 μM as a mixed-type ACE inhibitor. An analysis of the structure-activity connection demonstrated that the arginine at N-terminal is the most likely active residue in RSRGVFF, and two phenylalanines at the C-terminal also contributed to its inhibitory activity. Thus, these results indicate that maca protein may be one of the substances that leads to antihypertensive activity. This provides a new perspective to understanding the ACE inhibitory activity of maca and offers valuable insights to enlighten the structure-activity relationship of ACEI peptides.

Maca is a protein-enriched edible plant with immunomodulatory activity. However, the role of proteins in the immunomodulatory activity of maca is unclear. In this study, peptide products of maca proteins obtained through in vitro gastrointestinal digestion were isolated and purified, and the immunomodulatory activities of these peptides were assessed in macrophages (RAW 264.7 cells). The results show that the maca protein hydrolysate enhanced the phagocytic capacity and NO, TNF-α, and IL-6 secretion of RAW 264.7 cells. Forty-five peptides from known proteins of maca or the cruciferous family were identified by ultraperformance liquid chromatography-tandem mass spectrometry in the hydrolysate, and the peptide RNPFLP exhibited the strongest immunomodulatory activity. Antibody blocking, siRNA, pathway inhibitors, and western blot assays showed that RNPFLP-activated RAW 264.7 cells through the NF-κB and MAPK signaling pathways mediated by TLR2 and TLR4 receptors. An analysis of the structure-activity relationship showed that the N9-H60 active site in arginine plays an important role in the immunomodulatory activity of RNPFLP. This study provides a new understanding of the immunomodulatory activity of maca.

The aim of this study was to investigate the effect of selenium enrichment on the gel properties and gastrointestinal digestive properties of egg white. Results of texture profile analysis, scanning electron microscopy and differential scanning calorimetry showed that the heat-induced gel of selenium-enriched egg white (EW-2) exhibited higher gel strength, smoother microstructure, and higher thermal denaturation temperature than ordinary egg white (EW-1), which might be due to the change of ovomucin and ovotransferrin content. The gastrointestinal digestive products of the EW-2 protein contained a higher proportion of small peptides and more free amino acids than those of EW-1. Results of oxygen radical absorbance capacity and cellular antioxidant activity assays indicated that digestive products of the EW-2 protein exhibited stronger antioxidant activity than those of the EW-1 protein. In summary, Se enrichment improved heat-induced gel properties of egg white, and promoted the gastrointestinal digestion of egg white protein.

Duck egg white (DEW) is considered as an abandoned protein resource. For a higher-value utilization, preparation of immunomodulatory peptides from the extracted ovalbumin in DEW was explored. Among the hydrolysates catalyzed by five proteases, papain hydrolysate (PH) shows the highest degree of hydrolysis and the strongest immunomodulatory activity. PH could significantly enhance the phagocytic capacity and promote the NO, TNF-α, and IL-6 secretion of RAW 264.7 cells, involving toll-like receptor 2 and 4. After purification, nine identified peptides were synthesized to confirm the immunomodulatory effect, and five of them exhibit a strong activity. The peptide, TQIDKVVHFDKLPGF, presents the highest immunomodulatory activity. Moreover, the results of molecular docking indicate that nine peptides interacted with toll-like receptor 2 and 4 and all show good affinity. Furthermore, three peptides with high affinity and strong immune activity were selected for interaction site map analysis. Three peptides could form hydrogen bonds with the receptor and bind stably, which contributes to the immunomodulatory activity of the peptide. Results suggest that DEW can be a promising source of immunomodulatory peptides.

The utilization of photochemical reaction channel based on radical process is rarely reported, which might be a very efficient and feasible strategy for improving generation of Type I reactive oxygen species (ROS). In this work, a double ionic-type aggregation-induced emission luminogen (AIEgen) of TIdBO was developed as a photosensitizer, of which the potential photocyclization characteristic involving an electron-transfer process had a positive effect on Type I ROS generation in aggregates under continuous light irradiation. Its noticeable photodynamic therapy (PDT) performance and self-monitoring of PDT process by the relationship between cellular morphology change and fluorescence intensity enhancement were achieved. In addition, it showed a good killing ability to microbes and specific interactions with microbes but not cells by regulating the incubation time. These intriguing results reveal a feasible design principle for the implementation of efficient PS preparation in clinical treatment under hypoxic conditions.

Chinese water chestnut peels are a kind of vegetable processing waste containing many active components such as polysaccharides, the structure of which remains unknown. To elucidate the structure of polysaccharides from Chinese water chestnut peels, two polysaccharides named WVP-1 and WVP-2 were isolated. WVP-1 (3.16 kDa) consisted of mannose (1.75 %), glucose (84.69 %), galactose (6.32 %), and arabinose (7.24 %), while WVP-2 (56.97 kDa) was composed of mannose (3.18 %), rhamnose (1.52 %), glucuronic acid (1.42 %), galacturonic acid (4.83 %), glucose (11.51 %), galactose (36.02 %), and arabinose (41.53 %). Linkage and NMR data indicated that WVP-1 was composed mainly of →4)-α-d-Glcp(1→ and a certain proportion of →3)-β-d-Glcp-(1→, including linear and branched polysaccharides simultaneously. WVP-2 was a pectin-like polysaccharide with →4)-α-d-GalpA6Me-(1→ units and the branch points of →3,4)-α-l-Arap-(1→, →3,6)-β-d-Galp-(1→. WVP-2 exhibited stronger potential antioxidant and immunomodulatory activities than WVP-1 in vitro. These results provide a foundation for the further study of polysaccharides from Chinese water chestnut peels.

采用超声结合水提的方法提取东革阿里的多糖,通过L9(34)正交试验确定最佳提取条件.利用柱层析纯化得到一种含糖醛酸的新型多糖组分Ali-1;通过分子量检测和单糖组成分析对Ali-1进行基本结构表征;采用氧自由基吸收能力(ORAC)和人血红细胞溶血模型测定多糖的抗氧化活性,并同时测定红细胞内活性氧物质(ROS)、丙二醛(MDA)水平和过氧化氢酶(CAT)、超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)抗氧化酶活力的变化.结果 表明:东革阿里多糖最佳提取条件为料液比1∶40、浸提温度95℃、超声波破碎功率300 W、浸提时间2h,最适条件下东革阿里的粗多糖得率为10.09％;Ali-1的平均分子量为14.3 ku,主要由木糖、阿拉伯糖、葡萄糖醛酸和半乳糖醛酸组成,其摩尔比为:4.43∶1.10∶1∶1.14;Ali-1的QRAC值为302.48±2.71 μmol Trolox/g,且Ali-1的预处理使得AAPH损伤的人血红细胞内的ROS和MDA水平降低,使红细胞恢复到正常状态;虽SOD、GSH-Px和CAT平均酶活力降低,但结果表明较弱的红细胞也受到了保护.综上所述,经分离纯化后的东革阿里多糖组分Ali-1可以保护人血红细胞免受AAPH的损伤,具有较好的抗氧化活性.

A novel acid polysaccharide (PPRLMF-2) with the Mw of 137,123 Da and a triple-helix conformation was first isolated from the pulp of Rosa laevigata Michx fruit. Structural characterization showed that PPRLMF-2 consisted of rhamnose (7.6%), arabinose (26.5%), xylose (3.5%), mannose (0.9%), glucose (5.7%), galactose (31.9%) and galacturonic acid (23.9%). The methylation and NMR (1D and 2D) analysis revealed that PPRLMF-2 contained 16 types of glycosidic linkages. The immunomodulatory activity assays indicated that PPRLMF-2 could significantly enhance phagocytosis, the secretion and mRNA expression of cytokines in RAW 264.7 cells. Additionally, SR, GR, TLR-2, and TLR-4 were the main pattern recognition receptors (PRRs) of PPRLMF-2 to upregulate the p-ERK, p-JNK, p-p38, and p-p65. These results suggested that PPRLMF-2 could recognize the PRRs of the macrophages to enhance the immunomodulatory activity via activation of the MAPKs and NF-κB signaling pathways. This study provides important implications of PPRLMF-2 as an attractive immunomodulatory functional food.

A polysaccharide, Ali-1, was isolated from the roots of Eurycoma longifolia, a popular traditional medicinal herb in Malaysia. The structure of Ali-1 was characterized by monosaccharide, methylation, and NMR data analyses. The average molecular weight of Ali-1 is 14.3 ku, and it is composed of arabinose (14.31%), xylose (57.69%), galacturonic acid (13.03%), and glucuronic acid (14.86%). The main chain comprises (1→4)-linked xylose residues. It has branch points in the main chain; (1→2,4)-linked xylose residues, 1,2-linked glucuronic acid residues, and 1,2-linked arabinose residues form the branches, and the branches are terminated with T-linked galacturonic acid residues and T-linked arabinose residues. Ali-1 significantly improves the pinocytic and phagocytic abilities of RAW264.7 cells and facilitates cytokine secretion according to an immunostimulation assay. These results demonstrate that Ali-1 has potential as a functional supplement for people with compromised immune systems.