Quality Evaluation Focusing on Tissue Fractal Dimension and Chemical Changes for Frozen Tilapia with Treatment by Tangerine Peel Extract.

This work aimed to establish an effective approach to evaluate the quality of frozen fish, focusing on changes in fish tissue structure and chemical composition during storage. Fresh tilapia samples were treated by coating with tangerine peel (TP) extract and then stored at -4, -8 and -18 °C, respectively, for 40 days. The frozen fish tissues were analyzed for structural and chemical changes. Fractal dimension, which quantifies the porous structure formed in the tissue samples, texture properties including hardness and springiness, and moisture content and water activity all decreased during the storage, while the extents of lipid oxidation, measured as peroxide value and thiobarbituric acid concentration, and protein degradation, monitored with total volatile basic nitrogen and trichloroacetic acid soluble peptides, increased. The change rates of these parameters decreased with decreasing the storage temperature and by applying TP extract. A model was developed for predicting fractal dimension, which indicated the quality of preserved tilapia and thus can be used to predict the shelf life under different storage temperatures. The results demonstrated that TP extract could extend the shelf life of frozen tilapia by 35-45% by inhibiting changes in tissue structure, moisture loss, lipid oxidation and protein degradation during frozen storage.

Anti-inflammatory activity and chemical composition of the essential oils from Senecio flammeus.

Many species from Senecio genus have been used in traditional medicine, and their pharmacological activities have been demonstrated. This study investigated the chemical composition and anti-inflammatory activities of essential oils from Senecio flammeus. A total of 48 components representing 98.41 % of the total oils were identified. The main compounds in the oils were α-farnesene (11.26 %), caryophyllene (8.69 %), n-hexadecanoic acid (7.23 %), and α-pinene (6.36 %). The anti-inflammatory activity of the essential oils was evaluated in rodents (10-90 mg/kg bw) in classical models of inflammation [carrageenan-induced paw edema, 12-O-tetradecanoyl-phorbol-13-acetate (TPA)-induced ear edema, and cotton pellet-induced granuloma]. The essential oils at doses of 10, 30, and 90 mg/kg bw significantly reduced carrageenan-induced paw edema by 17.42 % (P < 0.05), 52.90 % (P < 0.05), and 66.45 % (P < 0.05) 4 h after carrageenan injection, respectively, and significantly reduced myeloperoxidase activity (P < 0.05). The essential oils (10, 30, and 90 mg/kg) also produced a significant dose-dependent response to reduce TPA-induced ear edema by 20.27 % (P < 0.05), 33.06 % (P < 0.05), and 53.90 % (P < 0.05), respectively. The essential oils produced significant dose-response anti-inflammatory activity against cotton pellet-induced granuloma that peaked at the highest dose of 90 mg/kg (49.08 % wet weight and 47.29 % dry weight). Results demonstrate that the essential oils of S. flammeus were effective in the treatment of both acute and chronic inflammatory conditions, thereby supporting the traditional use of this herb.

Extraction of brown pigment from Rosa laevigata and its antioxidant activities.

CONTEXT: Rosa laevigata Michx. (Rosaceae), widespread in China, contains many valuable nutrients and has long been used as food and medicine in Chinese folklore. Nowadays, due to its favorable property of coloring, the brown pigment of R. laevigata has an attractive potential as an available additive in food. OBJECTIVE: The aims of this study were to optimize the extraction process of brown pigment from R. laevigata and investigate its antioxidant activities on the basis of its abilities to scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, hydroxyl radical and superoxide radical. MATERIALS AND METHODS: Extraction conditions of brown pigment from R. laevigata were investigated through an orthogonal design of L9(3)4 assay. Ethanol concentration, extraction temperature, time, and ratio of material to solvent were the main factors affecting the extraction rate. Subsequently, the antioxidant activity of brown pigment was assessed using DPPH method, while hydroxyl radicals and superoxide free radicals were respectively determined by the Fenton-RhB (Rhodamine B) system and using the pyrogallol-luminol system. RESULTS: The optimum extraction conditions were determined: temperature 70°C, ethanol concentration was 60%, extraction time 2 h and ratio of material to solvent was 1:6. Brown pigment showed a good radical scavenging activity, and exhibited a concentration-dependent inhibition of hydroxyl radical and superoxide free radical at low concentrations. When the concentration of brown pigment was 1 mg/mL, the scavenging percentage of hydroxyl radical reached 67.33%. DISCUSSION AND CONCLUSION: The brown pigment of R. laevigata could potentially be used as a promising natural antioxidant in the food and pharmaceutical industries.

[Concentration of biyankang extracts using multi-stage membranes separation].

Multi-stage membranes processes, including ultrafiltration and nanofiltration are used in concentration of Biyankang extracts at room temperature, and the concentrations of main active ingredient in retentions after membrane processes were determined by HPLC. The results showed that the removal rate of water is about 45%, and the cost is only one fourth of the vacuum heating method. The retention rates of buddleoside and ephedrine hydrochloride are above 80% and 90% respectively, which meet the efficient concentration and energy-saving needs. The concentration method of Biyankang with multi-stage membranes processes provides some instructive theories and experimental foundations.