High pressure-assisted vacuum-freeze drying: A novel, efficient way to accelerate moisture migration in shrimp processing.

High pressure processing (HPP), as nonthermal processing technology, has the potential to increase the drying rate due to its improvement of heat and mass exchange in different processes. In this study, the moisture migration in shrimps during HPP-vacuum-freeze drying (HPP-VFD) processes has been monitored by using low-field nuclear magnetic resonance and magnetic resonance image (MRI) in comparison with hot air-drying and VFD. Based on the T2 relaxation spectra, three water fractions corresponding to bound water (hydrogen-bonded water), immobile water (water trapped by organization structure or cell member), and free water were observed. For group B, with increasing drying time (4 to 22 hr), the transverse relaxation times of T21 , T22 , and T23 were significantly decreased (76.79%, 57.78%, and 40.9%) (P < 0.05). The content of immobile water (A22 ) and free water (A23 ) decreased (81.55% and 89.07%), whereas the bound water (A21 ) increased (7.26%). In comparison with group B, the T21 , T22 , and T23 of group C showed greater decrease (83.12%, 87.12%, and 89.57% for group C) so that HPP pretreatment could shorten the relaxation time. MRI analysis further proved that HPP-VFD drying has improved drying efficiency, and moisture migration was from the exterior to the interior part with increasing drying time. SEM analysis demonstrated that no significant damage of muscle fibers with narrower gaps was observed for groups B and C. Overall, HPP, as a pretreatment technology, could accelerate the moisture migration and improve the drying efficiency of VFD process for shrimp. PRACTICAL APPLICATION: High pressure processing (HPP) is now well known as a nonthermal processing technology and becoming increasingly acknowledged. However, there is limited information about its application in shrimp-drying process and the moisture dynamic of shrimp subjected to high pressure processing-assisted vacuum-freeze drying. This study could provide valuable information regarding the moisture status and migration in HPP-VFD shrimp monitored by LF-NMR and MRI methods. The results showed that HPP processing at 550 MPa for 10 min can be used as an interesting method for drying pretreatment, increasing its drying rate and consequently reducing its process time, and it demonstrated that the methods used in this study had good correlation coefficient with physicochemical properties of shrimp, which may be real-time and nondestructive monitoring methods for shrimp-drying process.

Identification of Cyanidin-3-arabinoside Extracted from Blueberry as a Selective Protein Tyrosine Phosphatase 1B Inhibitor.

Protein tyrosine phosphatase 1B (PTP1B) is an important target for type 2 diabetes. PTP1B inhibitors can reduce blood glucose levels by increasing insulin sensitivity. Anthocyanins often play a hypoglycemic effect, but the research about them have mainly focused on glucosidase. At present, the research about protein tyrosine phosphatase 1B (PTP1B) target is less, and the corresponding molecular mechanism is still unclear. Therefore, in this present study, anthocyanins isolated from blueberry were used to study the inhibitory activity on PTP1B. The isolated cyanidin-3-arabinoside (Cya-3-Ara) exhibited a better inhibitory activity with IC50 = 8.91 ± 0.63 µM, which was higher than the positive control (oleanolic acid, IC50 = 13.9 ± 1.01 µM), and the mechanism of PTP1B inhibition was reversible mixed pattern. The structure-activity relationship (SAR) between anthocyanins and PTP1B inhibition was investigated. The enzyme activity inhibition and molecular docking showed that anthocyanins had high selectivity for PTP1B inhibition. Further study showed that Cya-3-Ara could promote glycogen synthesis through ameliorating PTP1B-involved IRS-1/PI3K/Akt/GSK3ß pathways. Cya-3-Ara could also be regarded as a synergistic inhibitor (CI ≤ 0.54) of oleanolic acid to obtain a better inhibitory effect on PTP1B. Taken together, our study clearly illustrates the SAR between anthocyanins and PTP1B inhibition and the mechanism of Cya-3-Ara in the insulin signaling pathway.

Impact of High Hydrostatic Pressure on the Shelling Efficacy, Physicochemical Properties, and Microstructure of Fresh Razor Clam (Sinonovacula constricta).

The effects of high hydrostatic pressure (HHP) treatments (200, 300, and 400 MPa for 1, 3, 5 and 10 min) on the shelling efficacy (the rate of shelling, the rate of integrity and yield of razor clam meat) and the physicochemical (drip loss, water-holding capacity, pH, conductivity, lipid oxidation, Ca2+ -ATPase activity, myofibrillar protein content), microbiological (total viable counts) and microstructural properties of fresh razor clam (Sinonovacula constricta) were investigated. HHP treatments significantly (P < 0.05) increased shelling efficiency, water-holding capacity, pH, conductivity, and lipid oxidation, and HHP-treated razor clam showed lower levels of microorganisms and drip loss than untreated razor clam. Levels of thiobarbituric acid reacting substances (TBA) in HHP-treated razor clam were greatly increased (up to 0.93 ± 0.09 mg MDA/kg at 400 MPa for 10 min) which was caused by the formation of hydroperoxides during HHP treatment. All HHP treatments were found to have adverse effects on the activity of Ca2+ -ATPase and the content of myofibrillar protein (MP), which might be due to the substantial damage to the tertiary structure of proteins at high pressure. Moreover, scanning electron microscopy (SEM) revealed the compaction of the muscle fibers and a decrease in the extracellular space with increasing pressure and holding time. This phenomenon was mainly correlated with the compaction of muscle fibers and denaturation, aggregation, and gelation of muscle protein triggered by high pressure. In general, HHP could be applied as a safe and effective nonthermal technology to produce high-quality shelled razor clam. PRACTICAL APPLICATION: High hydrostatic pressure (HHP) is now well known as a nonthermal processing technology and becoming increasingly acknowledged. However, it has not been widely applied to shell seafood due to its uncertain influence on its quality and shelling property. This study could provide valuable information regarding the shelling efficacy, physicochemical properties, and microstructure of razor clam treated by HHP. And it demonstrated that HHP showed a positive impact on quality of razor clam treated by HHP.

[Chemical constituents and cytotoxicity assay research in small polar substances from Vitis thunbergii var. taiwaniana].

This article studied the chemical constituents from the aerial part of Vitis thunbergii var. taiwaniana. The 60% ethanol extract was eluted with 95% ethanol though HP-20 macroporous adsorption resin column. 12 compounds, including (1) betulinic acid, (2)2, 2, 2'-bis (4-hydroxyphenyl) propane bis (2, 3-epoxypropyl) ether, (3) eriodictyol, (4) trans-ε-viniferin, (5) (+)-cis-ε-viniferin, (6) kobophenol A, (7) ampelopsin A, (8) nepalensinol B, (9) cis-miyabenol C, (10) cis-vitisin B, (11) cis-gnetin H and (12) (+)-hopeaphenol, were separated by using normal phase silica gel, ODS, Sephdadex LH-20 column chromatographies and semi-preparative or preparative HPLC. Compounds 2, 5, 6, 8, 9, 10, 11 were separated from the genus Vitis for the first time and compounds 3, 7, 12 were separated from Vitis thunbergii var. taiwaniana for the first time. At a concentration of 50 µmol · L(-1), compound 6, 7 and 11 showed strong cytotoxicity against MCF-7 cell lines with the inhibition rate of 66.58%, 57.16%, 52.84%, respectively.

Hyperbaric oxygen therapy ameliorates acute brain injury after porcine intracerebral hemorrhage at high altitude.

INTRODUCTION: Intracerebral hemorrhage (ICH) at high altitude is not well understood to date. This study investigates the effects of high altitude on ICH, and examines the acute neuroprotection of hyperbaric oxygen (HBO) therapy against high-altitude ICH. METHODS: Minipigs were placed in a hypobaric chamber for 72 h before the operation. ICH was induced by an infusion of autologous arterial blood (3 ml) into the right basal ganglia. Animals in the high-altitude ICH group received HBO therapy (2.5 ATA for 60 min) 30 min after ICH. Blood gas, blood glucose and brain tissue oxygen partial pressure (PbtO2) were monitored continuously for animals from all groups, as were microdialysis products including glucose, lactate, pyruvate and glutamate in perihematomal tissue from 3 to 12 h post-ICH. RESULTS: High-altitude ICH animals showed significantly lower PbtO2, higher lactate/pyruvate ratio (LPR) and glutamate levels than low-altitude ICH animals. More severe neurological deficits, brain edema and neuronal damage were also observed in high-altitude ICH. After HBO therapy, PbtO2 was significantly increased and LPR and glutamate levels were significantly decreased. Brain edema, neurological deficits and neuronal damage were also ameliorated. CONCLUSIONS: The data suggested a more serious disturbance of tissue oxygenation and cerebral metabolism in the acute stage after ICH at high altitude. Early HBO treatment reduced acute brain injury, perhaps through a mechanism involving the amelioration of the derangement of cerebral oxygenation and metabolism following high-altitude ICH.

[Analysis of renal protein expressions of spontaneously hypertensive rat intervention by three different Chinese medicine compounds for hypertension].

OBJECTIVE: To observe the differential protein expression profile of three different Chinese medicine compounds on spontaneous hypertensive rat, which were Banxiabaizhutianma Decoction, Dihuangyinzi Decoction and Tianmagouteng Decoction, and to elaborate their function characters and regulation pathway using the principal component analysis and analyze the basic theory of different treatment of hypertension. METHODS: Give three compounds to 6-week-old SHR (Spontaneous hypertensive rat) as experimental group and captopril to 6-week-old WKY (Wistar-Kyoto rat) as control group by gavage. Monitor the blood pressure of rat tail to 24-week-old and then all rats were decapitated. Extracte the rental protein to finish two-dimensional electrophoresis experiments and get the differential protein spots using PDQuest software. Study the three different compounds' effect of trend on SHR blood pressure using PCAC principal component analysis. RESULTS: The blood pressure of SHR remained rising from 6-week-old to 10-week-old, when Tianmagouteng Decoction had a significant anti-hypertension effect. But as the blood pressure of SHR remained high, Banxiabaizhutianma Decoction and Dihuangyinzi Decoction performed better in lowering blood pressure. At last, renal protein expression profile analysis showed that there were 84 significantly different proteins between SHR and WKY of 24-week-old and the PCA result showed that the principal component extraction was 95.951%, it was sure that Tianmagouteng Decoction and Banxiabaizhutianma Decoction had significantly changed rental protein spots on SHR while Dihuangyinzi Decoction had not. CONCLUSION: In the early stages of rising blood pressure, Tianmagouteng Decoction has significant anti-hypertensive effect. But when the blood pressure remain high, Banxiabaizhutianma Decoction and Dihuangyinzi Decoction are superior to Tanmagouteng Decoction in anti-hypertension. Banxiabaizhutianma Decoction and Tianmagouteng Decoction can significantly improve rental protein spots on SHR while Dihuangyinzi Decoction can not.

Physico-chemical and antioxidant properties of four mango (Mangifera indica L.) cultivars in China.

Four principal mango cultivars (Tainong No.1, Irwin, JinHwang and Keitt) grown in southern China were selected, and their physico-chemical and antioxidant properties were characterized and compared. Of all the four cultivars, Tainong No.1 had highest content of total phenols, ρ-coumaric acid, sinapic acid, quercetin, titratable acidity, citric acid, malic acid, fructose, higher antioxidant activities (DPPH, FRAP) and L(*), lower pH, PPO activity and individual weight. Keitt mangoes showed significantly (p<0.05) higher contents of ß-carotene, ρ-hydroxybenzoic acid, sucrose, total sugar, total soluble solid, catechin, succinic acid and higher PPO activity. JinHwang mangoes exhibited significantly (p<0.05) higher individual weight and PPO activity, but had lower content of total phenols, ß-carotene and lower antioxidant activity. Principal component analysis (PCA) allowed the four mango cultivars to be differentiated clearly based on all these physico-chemical and antioxidant properties determined in the study.

[Study on the effect of high hydrostatic pressure treatment on the secondary structure of mushroom polyphenoloxidase by SRCD and FTIR].

The secondary structure of the mushroom polyphenoloxidase treated by the high hydrostatic pressure (HHP) was analyzed by the synchrotron radiation circular dichroism (SRCD) and Fourier transform infrared spectroscopy (FTIR). The alpha-helix content of mushroom PPO was decreased after HHP treatment, which indicated that the secondary structure of PPO was changed. There was a discrepancy of the result of the secondary structure content between untreated or HHP-treated mushroom PPO analyzed by SRCD and FTIR spectra, and this discrepancy may be due to the different determination temperature, the concentration of the PPO solution and the spectra analysis method etc. The fluorescence spectra showed that the fluorescence intensity of the mushroom PPO was decreased after HHP treatment, and a red shift was observed after HHP treatment, which indicated that the tertiary structure of the enzyme molecule has been modified.

[Effects of high pulsed electric field on the secondary and tertiary structure of lipoxygenase].

The effect of pulsed electric field (PEF) on the secondary and tertiary structure of lipoxygenase (LOX) in a buffer solution was analyzed using far UV-circular dichroism (CD) and fluorescence spectrophotometry, respectively. The secondary and tertiary structure of LOX changed after PEF treatment. The CD spectra of LOX also changed, with the intensity of two negative peaks and the content of alpha-helix significantly decreased (p < 0.05). The decrease in alpha-helix content in LOX showed a good linear correlation with the electric field strength. The fluorescence intensity of LOX increased, and the relative fluorescence intensity of the two characteristic peaks of LOX emission spectra at 337 nm and 583 nm also showed a good linear correlation with the electric field strength. These results showed that the activity inactivation of LOX may be due to the alteration in secondary structure, and both had a good relation.

[The characteristic analysis of several mineral contents in Chinese orange juice].

A study was carried out on the contents of mineral elements such as K, Ca, Na, and Mg in seven different orange varieties, namely Pineapple orange, Hamlin, Trovita, Jincheng, 1,232 Tangor, Olinda Valencia and Delta Valencia, by flame atomic absorption spectrometry. The results indicated that the content sequence of different nutritional elements was K > Mg > Ca > Na, with a range of 1,233.75-1,866.23, 77.51-167.15, 49.32-125.29 and 1.22-9.26 mg x L(-1) respectively. The range scale of the four elements was largely consistent with the reference value of AIJN (Association of the Industry of Juices and Nectars from Fruits and Vegetables of the European Union). The samples can be clustered into 2 groups by factor analysis, and lower Na content would be the characteristic of the Valencia varieties. All these data would offer important information for orange juice adulteration determination and quality evaluation.