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Tartary buckwheat was used as raw material to extract tartary buckwheat protein, and the enzymatic hydrolysis conditions of tartary buckwheat protein lipid-lowering peptides were screened by single factor and response surface optimization experiments using the inhibition rate of pancreatic lipase as index. The amino acid composition and lipid lowering activity of lipid-lowering peptides were studied. The results showed that the lipid-lowering peptides obtained from tartary buckwheat protein with bromelain had higher inhibitory activity on pancreatic lipase. The optimal enzymatic hydrolysis conditions were hydrolysis time 2.1 h, hydrolysis temperature 62.0 ℃, substrate concentration 3.23%, pH7.0 and enzyme substrate ratio 0.4%. Under these conditions, the inhibitory rate of pancreatic lipase was 81.22%±0.16%. Amino acid analysis showed that essential amino acids, hydrophobic amino acids and acidic amino acids accounted for 27.82%, 32.11%, 35.86%, and the ratio of arginine to lysine was 2.28. The EC50/IC50 values of sodium taurine cholic acid binding rate, cholesterol esterase inhibition rate and pancreatic lipase inhibition rate were 9.136, 3.902 and 0.051 mg/mL, respectively. The results provided a new idea and theoretical basis for the high-value utilization of tartary buckwheat resources and the development of tartary buckwheat protein active peptides.

Plant seed oils are rich in unsaturated fatty acids and lipid-soluble active ingredients, which have become a hot spot of research in recent years. In this study, a novel low-temperature continuous phase transition extraction device was utilized to extract passion fruit seed oil and its lipid composition, quality properties and hypolipidemic activity were investigated. The extraction rate of passion fruit seed oil by low-temperature continuous phase transition extraction was 20.37 %, which was about twice as much as that of solvent extraction (10.80 %). The contents of unsaturated fatty acids, vitamin E and β-carotene in passion fruit seed oil extracted by low-temperature continuous phase transition were 84.00 %, 21.03 μg/g and 6.28 μg/g, respectively, which were significantly better than those of solvent extraction. The acid value, peroxide value and saponification value of the resulting passion fruit seed oil were 0.275 mg/g, 0.034 g/100g and 185.175 mg/g, respectively. Passion fruit seed oil exhibited good hypolipidemic activity, and the IC50 of its inhibitory effect on pancreatic lipase and cholesterol esterase were 97.19 μg/mL and 48.08 μg/mL, respectively. Further 3T3-L1 cell experiments concluded that passion fruit seed oil not only reduces lipid production in cells, but also reduces triglyceride, total cholesterol, and low-density lipoprotein cholesterol content in cells, while elevating high-density lipoprotein cholesterol content. This study provides a theoretical basis for the development and utilization of passion fruit seed oil as a functional lipid.

To study the optimal enzymatic hydrolysis conditions and uric acid-lowering activity of lipid-lowering peptides from quinoa protein, this study used quinoa as raw material to extract protein, and used pancreatic lipase inhibition rate as the activity index. The enzymatic hydrolysis process of lipid-lowering peptides was optimized by single factor experiment and response surface analysis. The pancreatic lipase inhibitory activity, sodium taurocholate binding activity, cholesterol esterase inhibitory activity, xanthine oxidase inhibitory activity and amino acid composition of quinoa protein peptides were analyzed and characterized. The results showed that the optimal enzymatic hydrolysis conditions of lipid-lowering peptides from quinoa were as follows: pH1.6, enzymatic hydrolysis temperature 42.9 ℃, substrate concentration 3.03%, enzymatic hydrolysis time 1 h and enzyme to substrate ratio 0.2%. The theoretical value of inhibition rate of pancreatic lipase was 90.43%, and the actual value was 90.93%±0.10%. The optimal enzymatic hydrolysates showed excellent effect of lowering lipid in vitro. The IC50 of pancreatic lipase inhibition rate and cholesterol esterase inhibition rate were 7.49 μg/mL and 4.73 mg/mL, respectively. Meanwhile, the EC50 of taurocholic sodium binding rate was 0.53 mg/mL. In addition, the optimal enzymatic hydrolysates showed good xanthine oxidase inhibition effect (IC50=5.97 mg/mL), indicating that it had the uric acid-lowering effect in vitro. Amino acid analysis showed that quinoa protein peptides were rich in essential amino acids (34.23%), and the percentage of hydrophobic amino acid and acidic amino acid were 34.11% and 31.66%, respectively. The quinoa protein peptides had high lipid-lowering and uric acid-lowering activities in vitro, which provided a theoretical basis for the high-value application of quinoa protein peptides.

In this study, the effects of laser power on the microstructure and mechanical properties of Inconel 718 formed by SLM were systematically studied. The results show that with the increase in laser power from 285 W to 360 W, the increase in working temperature in the molten pool promoted the evaporation of gas and the vaporization of the low-melting-point alloy components, and the relative density gradually increased from 99.31% to 99.79%. In addition, with the increase in laser energy density, the microstructure gradually coarsened from columnar dendrites to cellular crystals. The nano-hardness of the material decreased with the increase in laser power. The nano-hardness of four groups of samples from 285 W to 360 W decreased form 3.43 GPa to 2.09 GPa, and the elastic modulus decreased form 205.72 GPa to 199.91 GPa.

Taking Jinding Xiehua Suli pear from Ningling County as the main raw material, lactic acid bacteria suitable for fermentation of pear juice were screened. The fermentation technology of Suli pear juice with lactic acid bacteria was optimized by orthogonal test based on single-factor experiments and the volatile component of the Suli pear juice with lactic acid bacteria after optimization were analyzed dynamically. The results showed that the best fermentation conditions were as follows: Rhamnose Lactobacillus:Lactobacillus acidophilus:Bifidum lactobacillus lactis=1:1:1 (V/V), the initial pH was 4.5, the amount of lactic acid bacteria addition was 4%, the amount of sugar addition was 10%, and the fermentation time was 50 h. Under this condition, the VC content was 14.17 mg/100 mL, the total acid content was 7.66 g/L, the total phenol content was 3.68 mg/mL, the total flavonoids content was 6.25 mg/mL, the DPPH free radical scavenging rate was 90.05%, and the sensory score was 80.60. The volatile components of Suli pear juice after 0, 30, 40 and 50 h fermentation were analyzed by the gas chromatography-mass spectrometry (GC-MS). A total of 55 volatile substances were detected. With the prolongation of fermentation time, the types and contents of volatile substances increased. There were 7 kinds of volatile components in the raw Suli pear juice, the volatile components of pear juice after 30 and 40 h fermentation were 27 kinds, and increased to 46 kinds of volatile components after 50 h fermentation when higher alcohols, higher esters and higher acids were produced in large quantities, which brought lactic acid bacteria the sour and sweet taste and unique flavor of Suli pear juice.

The selenium-rich Moringa oleifera leaves protein was extracted from the selenium-rich Moringa oleifera leaves. The preparation of angiotensin-converting enzyme (ACE) inhibitory peptides from selenium-rich Moringa oleifera leaves was optimized by single factor experiments and response surface method. The ACE inhibitory activity, amino acid composition and selenium content of the optimal enzymatic hydrolysate were analyzed and characterized. The results showed that the optimal hydrolysis conditions of ACE inhibitory peptides were as follows: time 3 h, pH7.5, enzyme to substrate ratio 0.23%, substrate concentration 5.97% and temperature 39.2 ℃. The ACE inhibitory peptides prepared under these conditions showed strong ACE inhibitory activity (IC50=0.522 mg/mL), rich in essential amino acids (24.05%) and hydrophobic amino acids (20.6%), and the selenium content was 1.86 times that of the raw material of Moringa oleifolia leaves. The ACE inhibitory peptides of selenium-rich Moringa oleifolia leaves protein had dual characteristics of functional factor and natural food. This study could provide theoretical basis for the development of antihypertensive drugs and related functional foods.

Active phased array antenna typically featured high performance, high device integration, and high heat flux, making it difficult to dissipate heat. Diamond, the substance with the closest arrangement of atoms in nature, has the advantages of a high thermal conductivity and strong adaptability to the space environment. The batch applications of high-thermal-conductivity diamonds for the thermal management of the phased array antennas of the inter-satellite links were introduced in this paper. The diamond was developed by the direct-current arc-plasma chemical vapor deposition method. The product size, thermal conductivity, precision, and application scale all met the engineering requirements. The high-precision assembly of the diamond and the structural frame enabled the efficient heat collection and transfer from the distributed point heat sources of multiple transmit/receive (T/R) modules. Verified on the ground, the thermal matching design between the diamond and the metal frame exhibited an outstanding heat dissipation performance. After four satellites using the diamonds were launched, the flight data showed good antenna thermal control, with temperature gradients of the T/R modules less than 2.2 °C, further verifying the rationality and effectiveness of using high-thermal-conductivity diamonds in the thermal design and implementation of antennas.

Casein phosphopeptides (CPPs) are good at calcium-binding and intestinal calcium absorption, but there are few studies on the osteogenic activity of CPPs. In this study, the preparation of casein phosphopeptide calcium chelate (CPP-Ca) was optimized on the basis of previous studies, and its peptide-calcium chelating activity was characterized. Subsequently, the effects of CPP-Ca on the proliferation, differentiation, and mineralization of MC3T3-E1 cells were studied, and the differentiation mechanism of CPP-Ca on MC3T3-E1 cells was further elucidated by RNA sequencing (RNA-seq). The results showed that the calcium chelation rate of CPPs was 23.37%, and the calcium content of CPP-Ca reached 2.64 × 105 mg/kg. The test results of Ultraviolet–Visible absorption spectroscopy (UV) and Fourier transform infrared spectroscopy (FTIR) indicated that carboxyl oxygen and amino nitrogen atoms of CPPs might be chelated with calcium during the chelation. Compared with the control group, the proliferation of MC3T3-E1 cells treated with 250 μg/mL of CPP-Ca increased by 21.65%, 26.43%, and 28.43% at 24, 48, and 72 h, respectively, and the alkaline phosphatase (ALP) activity and mineralized calcium nodules of MC3T3-E1 cells were notably increased by 55% and 72%. RNA-seq results showed that 321 differentially expressed genes (DEGs) were found in MC3T3-E1 cells treated with CPP-Ca, including 121 upregulated and 200 downregulated genes. Gene ontology (GO) revealed that the DEGs mainly played important roles in the regulation of cellular components. The enrichment of the Kyoto Encyclopedia of Genes and Genomes Database (KEGG) pathway indicated that the AMPK, PI3K-Akt, MAPK, and Wnt signaling pathways were involved in the differentiation of MC3T3-E1 cells. The results of a quantitative real-time PCR (qRT-PCR) showed that compared with the blank control group, the mRNA expressions of Apolipoprotein D (APOD), Osteoglycin (OGN), and Insulin-like growth factor (IGF1) were significantly increased by 2.6, 2.0 and 3.0 times, respectively, while the mRNA levels of NOTUM, WIF1, and LRP4 notably decreased to 2.3, 2.1, and 4.2 times, respectively, which were consistent both in GO functional and KEGG enrichment pathway analysis. This study provided a theoretical basis for CPP-Ca as a nutritional additive in the treatment and prevention of osteoporosis.

Free radicals are associated with aging and many diseases. Antioxidant peptides with good antioxidant activity and absorbability are one of the hotspots in antioxidant researches. In our study, pearl shell (Pinctada martensii) meat hydrolysate was purified, and after identification by proteomics, six novel antioxidant peptides SPSSS, SGTAV, TGVAS, GGSIT, NSVAA, and GGSLT were screened by bioinformatics analysis. The antioxidant peptides exhibited good cellular antioxidant activity (CAA) and the CAA of SGTAV (EC50: 0.009 mg/mL) and SPSSS (EC50: 0.027 mg/mL) were better than that of positive control GSH (EC50: 0.030 mg/mL). In the AAPH-induced oxidative damage models, the antioxidant peptides significantly increased the viability of HepG2 cells, and the cell viability of SGTAV, SPSSS, and NAVAA were significantly restored from 79.41% to 107.43% and from 101.09% and 100.09%, respectively. In terms of antioxidant mechanism by molecular docking, SGTAV, SPSSS, and NAVAA could tightly bind to free radicals (DPPH and ABTS), antioxidant enzymes (CAT and SOD), and antioxidant channel protein (Keap1), suggesting that the antioxidant peptides had multiple antioxidant activities and had structure–activity linkages. This study suggests that the antioxidant peptides above are expected to become new natural materials for functional food industries, which contribute to the high-value applications of pearl shell meat.

Previous studies from our lab have shown that the antimicrobial peptide F1 obtained from the milk fermentation by Lactobacillus paracasei FX-6 derived from Tibetan kefir was different from common antimicrobial peptides; specifically, F1 simultaneously inhibited the growth of Gram-negative and Gram-positive bacteria. Here, we present follow-on work demonstrating that after the antimicrobial peptide F1 acts on either Escherichia coli ATCC 25922 (E. coli) or Staphylococcus aureus ATCC 63589 (S. aureus), their respective bacterial membranes were severely deformed. This deformation allowed leakage of potassium and magnesium ions from the bacterial membrane. The interaction between the antimicrobial peptide F1 and the bacterial membrane was further explored by artificially simulating the bacterial phospholipid membranes and then extracting them. The study results indicated that after the antimicrobial peptide F1 interacted with the bacterial membranes caused significant calcein leakage that had been simulated by different liposomes. Furthermore, transmission electron microscopy observations revealed that the phospholipid membrane structure was destroyed and the liposomes presented aggregation and precipitation. Quartz Crystal Microbalance with Dissipation (QCM-D) results showed that the antimicrobial peptide F1 significantly reduced the quality of liposome membrane and increased their viscoelasticity. Based on the study's findings, the phospholipid membrane particle size was significantly increased, indicating that the antimicrobial peptide F1 had a direct effect on the phospholipid membrane. Conclusively, the antimicrobial peptide F1 destroyed the membrane structure of both Gram-negative and Gram-positive bacteria by destroying the shared components of their respective phospholipid membranes which resulted in leakage of cell contents and subsequently cell death.

Casein phosphopeptides have been studied widely for their ability to chelate calcium. However, systematic studies on the effects of casein phosphopeptides (CPP) on calcium absorption in vitro and in vivo are scarce. The purities of two commercially available products, CPP1 and CPP2, are 18.37 and 25.12%, respectively. Here, the in vitro calcium binding capacity of CPP2 was 142.56 ± 7.39 mg/g, which was higher than that of CPP1 (107.15 ± 6.27 mg/g). The calcium transport results in a Caco-2 monolayer model indicated that, relative to controls, CPP1 and CPP2 increased calcium transport by 21.78 and 53.68%, respectively. Subsequent animal experiments showed that the CPP2-Ca-H group (1% Ca, 0.4% CPP2) had significant increases in the femur index, serum Ca2+ and serum osteocalcin levels, and femoral Ca content. The CPP2-Ca-H animal also had decreased serum alkaline phosphatase levels, parathyroid hormone content, and urinary pyridinoline content. Overall, our results demonstrated that CPP2 had stronger effects on promoting calcium uptake than CPP1.

Concentrating photovoltaic power generation technology is a highly efficient way of utilizing solar energy resources with the efficiency limited by cell cooling conditions. For the heat dissipation problem from multi-point solar cell cooling, a microchannel heat sink is used to resolve the issue. Ammonia is chosen as the working fluid and two diamond microchannel heat sinks in series for the 16 simulated solar cells cooling with typical size. The heat sink consists of 31 triangular microchannels, each with a hydraulic diameter of 237 μm and a flow path length of 40 mm. It is experimentally verified that the diamond microchannel heat sink has excellent multi-point heat source heat dissipation capability. The surface temperature of the heat source can be controlled below 65.9 °C under the heat flux of 351.5 W/cm2, and the maximum temperature difference between the multi-point heat sources is only 1.4 °C. The effects of heat flux, mass flux and inlet state on the flow boiling heat transfer capacity within the series heat sinks were investigated and the ranges of the operating conditions are as follows: heat flux 90.8–351.5 W/cm2, mass flux 108–611 kg/(m2s), saturation temperature 15–23 °C and inlet temperature 15–21 °C. The results show that within the range of experimental conditions, the flow boiling heat transfer capacity of the series heat sink increases with the increase of heat flux and is less influenced by the mass flux, showing the typical two-phase heat transfer characteristics dominated by the nucleation boiling mechanism. Between the upstream and downstream heat sinks, the thermal resistance of the upstream heat sink is larger and the temperature uniformity of the downstream heat sink is poor because of the difference of the inlet state.

A heat pump in the aerospace industry can significantly reduce the area of radiator by elevating the rejection temperature. Especially for a Lunar base, the heat pump can improve the heat rejection capability of the thermal control system to adapt the high-temperature environment. However, gravity on the Lunar (about 1/6 g) may have an adverse impact on a gas-oil separator of the heat pump, and solving this problem is the key for a heat pump used on Lunar base. At present, the gas-oil separator all based on gravity separation theories, the researches under low or micro gravity were blank. In this work, a gravity separation model based on a single-particle principle was built, and the effects of the vapor velocity, the oil droplet initial velocity, and the oil droplet diameter were investigated under normal gravity. Then the variations of the separation efficiency under Lunar gravity were discussed and the numerical calculation results showed that the separation efficiency was reduced when the vapor velocity or droplet initial velocity increased in a certain height of the separator whenever under normal or Lunar gravity. Particularly, the separation efficiency under Lunar gravity was reduced from 99% to 55% than it under normal gravity.

The residue rich in protein (up to 88.78%) obtained from round scad (Decapterus maruadsi) after oil extraction, was hydrolyzed by Alcalase to produce antioxidative peptides. The hydrolysate was separated by ultrafiltration, Sephadex G-15 and RP-HPLC, and the active fractions were screened by 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis (3-ethylbenzothiazoline- 6 sulphonic acid) diammonium salt (ABTS), reducing power and oxygen radical absorbance capacity (ORAC). The obtained peptide with the highest antioxidative activity was then analyzed by HPLC and LC-MS/MS and its anti-aging effect was examined using Caenorhabditis elegans (C. elegans) model. The peptide (Ile-Leu-Gly-Ala-Thr-Ile-Asp-Asn-Ser-Lys, 1153.4 Da), identified by LC-MS/MS showed the highest antioxidant activity. C. elegans fed with the selected peptide had longer lifespan, higher survival rate, superoxide dismutase (SOD) and catalase (CAT) activities than the control group (P＜0.05), demonstrating the promising anti-aging effects of the antioxidant peptide from defatted round scad.

Natural stilbenes have unique physiological effects, such as anti-senile dementia, anti-cancer, anti-bacterial, lowering blood lipid, and other important biological functions, which have attracted great attention from scholars in recent years. In this study, two stilbene compounds, resveratrol (RES) and polydatin (PD), were isolated from Mulberry (Morus alba L.), and their antioxidant activity and mechanism were investigated. The results showed that the contents of RES and PD in mulberry roots were 32.45 and 3.15 μg/g, respectively, significantly higher than those in mulberry fruits (0.48 and 0.0020 μg/g) and mulberry branches (5.70 and 0.33 μg/g). Both RES and PD showed high antioxidant potential by DPPH, ABTS free-scavenging methods, and ORAC assay, and provided protection against oxidative damage in HepG2 cells by increased catalase (CAT) activity, superoxide dismutase (SOD) activity, and Glutathione (GSH) content, and decreasing generation of reactive oxygen species (ROS), lactate dehydrogenase (LDH) level, and malondialdehyde (MDA) content. Therefore, RES and PD treatment could be effective for attenuating AAPH-induced oxidative stress in HepG2 cells. This study will promote the development and application of stilbene compounds. Furthermore, the RES and PD could be used as antioxidant supplements in functional foods, cosmetics, or pharmaceuticals, contributing to health improvement.

The immature honey pomelo fruit (IPF) is a huge agro-industrial by-product generated during pomelo planting. Although IPF is rich in nutrients, more than 95% of IPF is discarded annually, which causes resource waste and a serious environmental problem. Here, we report a novel continuous phase transition extraction technology (CPTE) to improve the comprehensive utilization of IPF by sequentially generating high value products and solve pollution problems related to their disposal. First, essential oil was successively extracted by CPTE at a yield of 1.12 ± 0.36%, in which 43 species were identified. Second, naringin extraction parameters were optimized using the response surface methodology (RSM), resulting in a maximum extraction rate of 99.47 ± 0.15%. Finally, pectin was extracted at a yield of 20.23 ± 0.66%, which is similar to the contents of commercial pectin. In conclusion, this study suggested that IPF was an excellent potential substrate for the production of value-added components by CPTE.

There is an increasing demand from consumers for natural antimicrobial substances that can be used for food preservation. This study is focused on establishing the conditions to enhance the production of antimicrobial substances by the probiotic Lactobacillus paracasei Subsp. Tolerans FX-6 from Tibetan kefir. The culture conditions were optimized by using response surface methodology, and remarkably the optimized conditions increased the antimicrobial activity by more than 80%. Further characterization revealed that the antimicrobial substances exhibited a broad spectrum of antimicrobial activity against a variety of Gram-positive and Gram-negative bacteria and fungi. Moreover, the antimicrobial substances were highly tolerant to heat and enzyme treatment. Excitingly, the antimicrobial substances were fractionated by HPLC and the sub-fractions generated showed stronger antimicrobial activity than nisin, a highly effective bacteriocin currently used as a food preservative. Overall, these results demonstrate a novel approach to produce effective antimicrobial substances for use as natural preservatives in food.

The current work aimed to clarify the effects of four structured lipids, including monoglycerides with docosahexaenoic acid (2D-MAG), diacylglycerols with caprylic acid (1,3C-DAG), triglyceride with caprylic acid at sn-1,3 and DHA at sn-2 position (1,3C-2D-TAG) and caprylic triglyceride on the oxidative stability of stripped soybean oil (SSO). The results revealed that compared to the blank group of SSO, the oxidation induction period of the sample with 2 wt% 2D-MAG and that with 1,3C-DAG were delayed by 2−3 days under accelerated oxidation conditions (50 °C), indicating that 2D-MAG and 1,3C-DAG prolonged the oxidation induction period of SSO. However, the inhibitory effect of α-tocopherol on SSO oxidation was reduced by 2D-MAG after addition of 2D-MAG to SSO containing α-tocopherol. 2D-MAG exhibited different antioxidative/pro-oxidative effects in the added/non-added antioxidants system. Compared to caprylic triglyceride, DHA at the sn-2 acyl site induced oxidation of structured lipids, thus further promoting the oxidation of SSO. The antioxidant was able to inhibit not only the oxidation of DHA in the SSO, but also the transesterification of sn-2 DHA to sn-1/sn-3 DHA in the structured lipid.