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Objective: To study the application of Lipozyme RM IM in the synthesis of human milk fat substitutes and its structural changes during recycling. Methods: Using sn-2 high palmitate triglyceride and free fatty acid as the substrates, human milk fat substitutes mainly consisting of 1, 3-dioleoyl-2-palmitoylglycerol (OPO) and 1-dioleoyl-2-palmitoyl-3-linoleoylglycerol (OPL) were synthesized synchronously under the catalysis of Lipozyme RM IM. The amounts of OPO and OPL, oleic acid, linoleic acid, total palmitic acid and sn-2 palmitic acid as evaluated against the Chinese breast milk lipid database, and the activity, secondary structure and endogenous fluorescence intensity of the lipase were investigated as a function of the number of cycles of enzyme recycling. Results: At the first cycle of recycling, the relative contents of OPO and OPL in human milk fat substitutes were 19.41% and 17.04%, respectively. The relative contents of oleic and linoleic acid in the total fatty acids were 35.63% and 22.30%, respectively. The relative contents of total palmitic acid and sn-2 palmitic acid were 28.80% and 52.40%, respectively. When Lipozyme RM IM was recycled for the 17th time, the relative contents of OPO and OPL in human milk fat substitutes were 8.50% and 7.62%, respectively. The relative contents of oleic and linoleic acid in the total fatty acids were 28.62% and 13.38%, respectively. The relative contents of total palmitic acid and sn-2 palmitic acid were 38.26% and 58.40%, respectively. All of them fell within the range of breast milk lipids in China. However, the lipid composition of the enzymatically synthesized product was far from the range. Conclusion: Lipozyme RM IM, with excellent transesterification ability, could be repeatedly used up to 17 times in the synthesis of human milk fat substitutes in this study, proving good recycling properties. This study provides a reference for the extensive application of lipase in synthesis of human milk fat substitutes and the recycling of lipase in the synthesis of human milk fat substitutes in a continuous reactor.

为提高水代法提取油茶籽油的提油率，将油茶籽经过脱壳、粉碎、过筛、加水过胶体磨、离心分离得到乳状液，经冻融破乳后离心分离得油茶籽油。以提油率为指标，探究了加热冻融、乙醇冻融、调pH冻融、加盐冻融等冻融破乳方法对水代法提取油茶籽油的影响，并通过共聚焦激光扫描显微镜对破乳前后乳状液的微观结构进行了观察。结果表明：乙醇冻融和加盐冻融使油茶籽的提油率降低；调pH可提高提油率，在pH为8时提油率为92.17%；加热冻融法是最佳的冻融破乳方法，在加热温度60 ℃、加热时间20 min条件下，提油率最高，达到92.57%；加热冻融处理后油滴聚集，粒径明显增大。采用加热冻融法对乳状液进行破乳可有效提高水代法提取油茶籽油的提油率。 In order to improve the oil extraction rate of oil-tea camellia seed oil by aqueous extraction method, the oil-tea camellia seed was treated by peeling, crushing, sieving, mixing with water through colloid mill and centrifugation to get the emulsion, and the oil-tea camellia seed oil was obtained by centrifugation after freeze-thaw demulsification. With the oil extraction rate as the index, the effects of freeze-thaw demulsification methods, such as heating freeze-thaw, ethanol freeze-thaw, pH adjustment freeze-thaw, salt freeze-thaw, on the extraction of oil-tea camellia seed oil by aqueous extraction method were studied. The microstructure of the emulsion before and after demulsification was observed by confocal laser scanning microscope. The results showed that ethanol freeze-thaw and salt freeze-thaw reduced the oil extraction rate. The oil extraction rate increased by adjusting pH, and it was 92.17% at pH 8. Heating freeze-thaw was the best method of freeze-thaw demulsification. Under heating temperature 60 ℃ and heating time 20 min, the oil extraction rate was the highest, reaching 92.57%. After heating freeze-thaw, the oil droplets gathered and its particle size increased significantly. Demulsification of emulsion by heating freeze-thaw method can effectively increase the oil extraction rate of oil-tea camellia seed oil by aqueous extraction method.

水剂法提取油茶籽油时产生严重的乳化，是制约其应用的“瓶颈”。为明确其乳化液产生机制，对水剂法提取油茶籽油产生的乳化液中主要蛋白进行了分离与结构表征。结果表明：提取的粗蛋白在pH 2.0、4.0、6.0、8.0和pH 10.0条件下均表现优良的乳化特性；经初步纯化的蛋白组分（PEP）主要为7个分子质量为10～35 kDa的条带，其中13 kDa蛋白最多；PEP中谷氨酸、精氨酸和天冬氨酸含量较高，分别为（40.36±0.14）%、(14.51±0.09)%、(7.74±0.03)%；二级结构中α-螺旋、β-折叠、β-转角和无规卷曲含量分别为25.71%、31.55%、19.07%和23.83%，其中β-折叠含量最高；PEP溶液具有较高的内源荧光强度和表面疏水性。推测PEP为水剂法提取油茶籽油过程中乳化液形成的重要因素之一。It is unavoidable emulsification in the process of aqueous extraction of oil-tea camellia seed oil. To explore the generative mechanism of emulsion, the proteins in the oil-tea camellia seed oil emulsion were separated and its structural characteristics was investigated. The results showed that the crude proteins separated from the emulsion had excellent emulsifying properties at pH 2.0,4.0,6.0,8.0 and pH 10.0. The purified proteins(PEP) were seven major subunits/proteins with a molecular weight arranged from 10 kDa to 35 kDa, among them, the 13 kDa protein was the most. The PEP was rich in Glu, Arg and Asp, and their contents were (40.36±0.14)%, (14.51±0.09)% and (7.74±003)%, respectively. The contents of α-helix, β-folded, β-corner and random coil in PEP were 25.71%, 31.55%, 19.07% and 23.83%, respectively, among which the content of β-folded was the most. Moreover, the solution of PEP exhibited a high endogenous fluorescence intensity and surface hydrophobicity. It is hypothesized that the PEP is one of the important factors in the formation of emulsion during the extraction of oil-tea camellia seed oil by aqueous method.

Bamboo shoot is a healthy food rich in dietary fiber (DF). However, its highly insoluble DF and fibrous texture limit its application in industrially processed foods. To achieve industrial processing of bamboo shoot, cellulase was used to improve the physical characteristics of bamboo shoot DF in this study. After enzymatic hydrolysis, the content of soluble DF (SDF) of bamboo shoot increased by 99.28% (from 5.53% to 11.02%) significantly (p < 0.01). At the same time, the effect of enzymatic‐modified bamboo SDF (EMBSDF) on streptozotocin‐induced type 2 diabetes rats was explored. Results demonstrated that the high dose of EMBSDF (312.8 mg/kg) treated rats showed significant improvements in terms of glucose tolerance and insulin sensitivity (p < 0.01) compared with the diabetes rats. Meantime, it was observed that the levels of glucagon‐like peptide‐1, adiponectin and interleukin‐4 of high dose of EMBSDF compared with diabetes rats were increased (p < 0.01) by 57.79%, 159.13%, and 6.17%, respectively. The tumor necrosis factor‐α, C‐reactive protein, and leptin levels were decreased (p < 0.01) by 62.89%, 31.53%, and 7.84%, respectively. Furthermore, apparent kidney and pancreas histology improvements were found in high‐dose and mid‐dose EMBSDF‐treated diabetes rats. These results indicated that the modified DF significantly improved diabetes. [ABSTRACT FROM AUTHOR]

Hyperlipidemia has been suggested to be associated with dysregulation of lipid metabolism and gut microbiota. The present study prepared microencapsulated rice bran (MRB) with high stability based on in situ rice bran oil embedding and investigated the effects of MRB on lipid metabolism and gut microbiota in hyperlipidemic mice induced by high‐fat diet (HFD). Results showed that compared to HFD fed mice, lipid levels in serum and hepatic lipid accumulation were reduced in mice fed with MRB, which was potentially associated with the fact that MRB decreased the expression of genes related to lipogenesis (Srebp1c, Acc, Hmgcr, and Fas) and increased the expression of genes related to lipid catabolism (Hsl, Atgl) and oxidation (Acox, Cpt1, Ucp1) (p < 0.05). In gut, MRB supplementation significantly elevated the abundance of beneficial bacteria, such as Dubosiella and Faecalibaculum. In addition, significant increase in short‐chain fatty acid was observed in mice from MRB groups when compared to HFD groups (p < 0.05). Overall, this study suggested that MRB could alleviate the hyperlipidemia induced by HFD, which was related to the alteration of lipid metabolism and gut microbiota. [ABSTRACT FROM AUTHOR]

BACKGROUND: The hard double‐walled structure of Ganoderma lucidum spore powder (GLSP) is difficult for the human body to digest, so it is very important to break the wall of GLSP. In this study, the wall of GLSP was broken by mechanical milling at room temperature (MM‐R) and ultra‐fine grinding at low temperature (UFG‐L), respectively. RESULTS: Compared with MM‐R, UFG‐L could better retain the sporangium powder's morphological and structural integrity. During in vitro digestion, compared with unbroken GLSP, the released amounts of polysaccharides and triterpenes from broken GLSP were significantly increased, and they increased with the increase of specific surface area. The bioaccessibility of polysaccharide and triterpene from unbroken GLSP after the intestinal stage were 29.52% and 5.37%, respectively. The bioaccessibility of polysaccharides and triterpene from broken GLSP by MM‐R after the intestinal phase were 39.73–72.45% and 16.44–24.97%, while those by UFG‐L were 44.53–104.18% and 12.96–32.90%, respectively. CONCLUSION: The active ingredients of broken GLSP showed better digestion and absorption abilities than unbroken GLSP. Moreover, the specific surface area of GLSP by UFG‐L was lower than that by MM‐R, and the bioaccessibility of GLSP by UFG‐L was higher than that by MM‐R. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Nonenzymatic glycosylation of proteins can generate advanced glycosylation end products, which are closely associated with the pathogenesis of certain chronic physiological diseases and aging. In this study, we characterized the covalent binding of cyanidin‐3‐glucoside (C3G) to bovine serum albumin (BSA) and investigated the mechanism by which this covalent binding inhibits the nonenzymatic glycosylation of BSA. The results indicated that the covalent interaction between C3G and BSA stabilized the protein's secondary structure. Through liquid chromatography‐electrospray ionization tandem mass spectrometry analysis, we identified the covalent binding sites of C3G on BSA as lysine, arginine, asparagine, glutamine, and cysteine residues. This covalent interaction significantly suppressed the nonenzymatic glycosylation of BSA, consequently reducing the formation of nonenzymatic glycosylation products. C3G competitively binds to nonenzymatic glycosylation sites (e.g., lysine and arginine) on BSA, thereby impeding the glycosylation process and preventing the misfolding and structural alterations of BSA induced by fructose. Furthermore, the covalent attachment of C3G to BSA preserves the secondary structure of BSA and hinders subsequent nonenzymatic glycosylation events. [ABSTRACT FROM AUTHOR]

The antioxidant activities of lycopene (LY), lutein (LU), chlorogenic acid (CA), and delphinidin (DP) were tested in vitro on H9c2 cell-based models. Some indicators, such as the generation of reactive oxygen (ROS), the quantification of cell antioxidant activity (CAA), and the expressions of SOD, GSH-Px, and CAT, were calculated to examine their antioxidant interactions. From our results, the phytochemical mixtures (M1: CA-LU: F3/10, M2: DP-CA: F7/10, M3: DP-LY: F5/10) displayed strong synergistic effects based on the generation of ROS and the quantification of CAA. However, great antagonistic bioactivities were seen in the combinations of LY-LU: F5/10 (M4), CA-LU: F9/10 (M5), and DP-LY: F7/10 (M6). Western blotting analysis indicated that the possible mechanism underlying the synergistic antioxidant interactions among phytochemical combinations was to enhance the accumulation of Nrf2 in the nucleus and the expression of its downstream antioxidant enzymes, HO-1 and GCLC. The combinations (M1–M3 groups) showed significant protection against the loss of mitochondrial membrane potential than individual groups to avoid excessive ROS production. The M4–M6 groups exerted antagonistic protective effects compared with the individual groups. In addition, lutein and lycopene absorption was improved more because of the presence of chlorogenic acid and delphinidin in the M1 and M3 groups, respectively. However, delphinidin significantly reduced the cellular uptake of lycopene in the M6 group. It appeared that antioxidant interactions of phytochemical combinations may contribute to the restoration of cellular redox homeostasis and lead to an improvement in diet quality and collocation. [ABSTRACT FROM AUTHOR]

To study the immunomodulatory effects and safety of an antioxidant supplement composed primarily of Haematococcus pluvialis, selenium-enriched yeast, bee pollen extract, and vitamin E. Three different dosages (0.1, 0.2, and 0.4 g/kg bw) were administered via gavage once daily for 30 days in mice. The impact of this antioxidant supplement was observed on various parameters, including spleen index, thymus index, splenic lymphocyte transformation activity, delayed- type hypersensitivity, antibody-producing cell levels, hemolytic complement 50 (HC50), carbon clearance rate, phagocytic activity of macrophages, and natural killer cell activity. The potential carcinogenicity of the test materials, and their genotoxic effects on cells and the reproductive system were assessed through the Ames test, bone marrow micronucleus assay, and mouse sperm abnormality test, respectively. Subacute toxicity was investigated through a 30 day feeding trial. Results showed that compared to the control group, the middle and high-dosage groups exhibited significant increase in OD difference by 10.32% (P<0.05) and 14.29% (P<0.01), respectively. It indicated that the antioxidant supplement promoted splenic lymphocyte proliferation and transformation capacity in mice. In the high-dosage group, the difference in ear swelling between the left and right ears increased by 8.02% (P<0.05), and the number of antibody volumes increased by 22.12% (P<0.05). It suggested that the antioxidant supplement significantly improved delayed-type hypersensitivity and antibody-producing cell capacity. Importantly, no acute toxicity, genotoxicity, or subacute toxicity were observed. It is demonstrated that the antioxidant supplement is safe for consumption and significantly enhances immunity. [ABSTRACT FROM AUTHOR]