Hongbo Song

Ultrasonic-Assisted Extraction of Raspberry Seed Oil and Evaluation of Its Physicochemical Properties, Fatty Acid Compositions and Antioxidant Activities

Ultrasonic-assisted extraction was employed for highly efficient separation of aroma oil from raspberry seeds. A central composite design with two variables and five levels was employed and effects of process variables of sonication time and extraction temperature on oil recovery and quality were investigated. Optimal conditions predicted by response surface methodology were sonication time of 37 min and extraction temperature of 54°C. Specifically, ultrasonic-assisted extraction (UAE) was able to provide a higher content of beneficial unsaturated fatty acids, whereas conventional Soxhlet extraction (SE) resulted in a higher amount of saturated fatty acids. Moreover, raspberry seed oil contained abundant amounts of edible linoleic acid and linolenic acid, which suggest raspberry seeds could be valuable edible sources of natural γ-linolenic acid products. In comparison with SE, UAE exerted higher free radical scavenging capacities. In addition, UAE significantly blocked H2O2-induced intracellular reactive oxygen species (ROS) generation.

The potential beneficial effects of phenolic compounds isolated from A. pilosa Ledeb on insulin-resistant hepatic HepG2 cells

Agrimonia pilosa Ledeb (AP) has already been applied in practice for the treatment of different disorders and is available to access without the provision of a medical prescription. The present study aims at investigating the effect of bioactive compounds isolated from AP on the improvement of insulin resistance, figuring out the mechanism in insulin-responsive cell lines. Five compounds were isolated from AP using column chromatography, including agrimonolide (K1), desmethylagrimonolide (K2), tormentic acid (K3), ursolic acid (K4), and quercetin (K5). Glucose metabolism was evaluated in insulin-resistant HepG2 cells. Ursolic acid had the strongest activity among all isolated compounds with the lowering value of 71.5% (1.24 mM glucose in DMEM) and 71.7% (1.23 mM) when compared to the control. K1 consisting of K2 effectively increased the insulin-mediated glycogen level in hepatocytes. At a concentration level of 20 μM, K2 significantly elevated the hepatic glucokinase (GK) activity (3.2 U min-1 mg-1 protein), followed by K1 (3.0 U min-1 mg-1 protein). Both of them significantly increased (p < 0.05) the GK activity as compared to the control. On the same lines, K2 and K1 caused a significant reduction of the glucose-6-phosphatase (G6Pase) activity and a significant change in the phosphoenolpyruvate carboxykinase (PEPCK) activity. In summary, bioactive compounds in AP may play an important role in regulating the glucose metabolism in insulin-resistant HepG2 cells and could be developed as a promising natural material for diabetes prevention and treatment.

Effect of Different Drying Method on Volatile Flavor Compounds of Lactarius deliciosus

The effect of different drying methods on volatile flavor compounds of Lactarius deliciosus was investigated, such as hotair drying, vacuum freeze drying and sunshine drying. By adopting the solid-phase micro-extraction method, volatile flavor compounds were extracted from Lactarius deliciosus, then analyzed and identified through the application of gas chromatography-mass spectrometer (GC-MS). Results indicated that different drying methods could lead to large differences in volatile flavor compounds. Main volatile flavor compounds of fresh Lactarius deliciosus involved acids and aldehydes, which accounted for 86.31%; Hot-air dried Lactarius deliciosus mainly included acids and alkene, which accounted for 87.16%; Lactarius deliciosus dried with vacuum freezed Lactarius deliciosus was mostly composed of acids, esters and aromatic substance, which accounted for 94.74%; Lactarius deliciosus dried with sunshine was constituted by acid and aldehydes, which was as high as 90.67%.

Hepatoprotective effects of raspberry ( Rubus coreanus Miq.) seed oil and its major constituents

Raspberry seed is a massive byproduct of raspberry juice and wine but usually discarded. The present study employed a microwave-assisted method for extraction of raspberry seed oil (RSO). The results revealed that omega-6 fatty acids (linoleic acid and γ-linolenic acid) were the major constituents in RSO. Cellular antioxidant enzyme activity such as superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) were investigated in HepG2 cells treated with RSO. Induction of the synthesis of several antioxidants in H2O2-exposed HepG2 cells was found. RSO increased the enzyme activity of SOD, CAT, and GPx in H2O2-exposed HepG2. Furthermore, RSO inhibited the phosphorylation of upstream mitogen-activated protein kinases (MAPK) such as c-Jun N-terminal kinase (c-JNK) and extracellular signal-regulated kinase (ERK). Taken together, the possible mechanisms to increase antioxidant enzyme activities in HepG2 may through the suppression of ERK and JNK phosphorylation. Raspberry seed oil exhibited good effects on the activities of the intracellular antioxidant enzymes and seems to protect the liver from oxidative stress through the inhibition of MAPKs.

Physiological and proteomic analyses of coix seed aging during storage

Although a series of physio-biochemical changes of coix seed occur during the storage, the underlying mechanism remains unknown. The present study aimed to investigate the aging mechanism of coix seed during storage. Proteome patterns of coix seed stored for 1-month, 5-month and 10-month at room temperature were compared using 2-dimensional gel electrophoresis (2-DE) and mass spectra. Thirty-one differentially expressed proteins (DEPs) were detected, which involved seven pathways including starch and sucrose metabolism, carbon metabolism, RNA transport, proteasome, protein processing in endoplasmic reticulum, ribosome, and RNA degradation. Sucrose synthase 1 was associated with sucrose metabolism and affected the sucrose content during the storage. Increased ambient temperature enhanced respiration of coix after 5-month storage, and overexpression of aconitate hydratase 2 promoted the generation of energy. In addition, the proteins involved in the antioxidant system and resistance stimulus of coix seed were mostly up-regulated during storage.

Discrimination of geographical origins of Chinese acacia honey using complex 13C/12C, oligosaccharides and polyphenols

The aim of this study was to predict the geographical origin of acacia honey of China through analysis of physicochemical parameters combination with chemometrics. Samples from six different origins were investigated on parameters of δ13C value, oligosaccharides and polyphenols, using EA-IRMS/LC-IRMS, GC-MS and HPLC-MS, respectively. The results indicated that the δ13C value of honey from Gansu region were lower than those of other regions. Oligosaccharides of honey from Shanxi and Shaanxi regions were both higher than other four regions. Polyphenols of honey from Shandong region was the highest and were better parameters than both δ13C and oligosaccharides in discrimination of geographical origins. Partial Least Square Discriminant Analysis (PLS-DA) showed that when all 31 different parameters were combined, a correct classification rate of 94.12% could be achieved using external cross validation method. In conclusion, the method in discrimination of geographical can be used to provide reliable and useful reference information.

Transcriptome and proteome analyses of the molecular mechanisms associated with coix seed nutritional quality in the process of breeding

In present study, the content of main nutrients in wild coix seed were significantly higher than cultivated coix seed. Transcriptome and proteome were combined to provide new insight of the molecular mechanisms linked to nutritional quality of wild coix seed and cultivated coix seed by RNA sequencing and isobaric tags for relative and absolute quantification techniques. A total of 20,039 genes and 471 proteins exhibited differential expression level in cultivated coix seed when compared with wild coix seed. These genes and proteins revealed that the pathway of flavonoids biosynthesis, starch and sucrose metabolism, lipid metabolism and amino acid metabolism were linked to nutritional quality of coix seed. Our results provided transcriptomics and proteomics information with respect to the molecular mechanisms of nutritional changes of coix seed, identified key genes and proteins that associated with the metabolism and accumulation of nutrients, and helped clarify the mechanisms of nutrient differences.

Preparation and characterisation of a novel agar oligosaccharide-iron (III) complex

This study aimed to synthesise a complex of agar oligosaccharides (AOS) with ferric iron and to evaluate its physicochemical and structural characteristics. Based on single factor, Plackett–Burman and response surface optimal experiments of three factors at three levels, the optimised chelate conditions of the AOSiron (III) complex were mass ratio of AOS to iron ions of 4.5:1 g:g, reaction temperature of 74 °C and reaction time of 60 min. Under these conditions, the iron content and total sugar content were 14.03 0.42% and 66.07 0.96%, respectively. The physicochemical analysis showed that AOS–iron (III) was soluble and steady at physiological pH, and it was easily reduced to iron (II). The structural characteristics of AOS and AOS–iron (III) were analysed by Raman spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction and Nuclear magnetic resonance, and results showed that the iron (III) ions were chelated to AOS by –OH groups and –COOH groups and widely dispersed on the AOS backbone. Therefore, AOS–iron (III) could be a candidate for iron supplementation to treat iron deficiency anaemia.