Shortage of soluble Fe in seawater is a limiting condition for benthic seaweeds growth. Utilizing steelmaking slag as the Fe source for seaweeds growth has been proposed. Aiming to find a cost-effective method to promote Fe release, we investigate the effect of adding municipal green wastes. By conducting leaching experiments in freshwater, a sharp improvement in Fe release was observed with the addition of tangerine peel together with steelmaking slag. The flavonoids supplied from the tangerine peel, vicenin-2, apigenin, hesperidin, vitexin, hesperetin and diosmin were observed to have a promotion effect on Fe release. Formation of stable flavonoid-Fe(II) chelates changes the thermodynamic property of Fe(II) in water and disturbs the equilibrium between Fe(II) in slag and Fe(II) in water, which promotes Fe release from slag. These results demonstrate the feasibility to develop a technology for Fe supply in seawater by utilizing the mixture of steelmaking slag and municipal green wastes.
Six lactic acid bacteria strains were used to study the effects on physicochemical characteristics, antioxidant activities and sensory properties of fermented orange juices. All strains exhibited good growth in orange juice. Of these fermentations, some bioactive compositions (e.g., vitamin C, shikimic acid) and aroma-active compounds (e.g., linalool, 3-carene, ethyl 3-hydroxyhexanoate, etc.) significantly increased inLactiplantibacillus plantarumandLactobacillus acidophilussamples. DPPH free radical scavenging rates inL. plantarumandLacticaseibacillus paracaseisamples increased to 80.25% and 77.83%, respectively. Forty-three volatile profiles were identified, including 28 aroma-active compounds. 7 key factors significantly influencing sensory flavors of the juices were revealed, including D-limonene, linalool, ethyl butyrate, ethanol,β-caryophyllene, organic acids and SSC/TA ratio. The orange juice fermented byL. paracasei, with more optimization aroma-active compounds such as D-limonene,β-caryophyllene, terpinolene andβ-myrcene, exhibited more desirable aroma flavors such as orange-like, green, woody and lilac incense, and gained the highest sensory score. Generally,L. paracaseifermentation presented better aroma flavors and overall acceptability, meanwhile enhancing antioxidant activities.Keywords:orange juice;lactic acid fermentation;physicochemical characteristics;antioxidant activities;volatile profiles;sensory properties
Xiao Tu,Chenxi Duan,Siwei Wu,Shengli Fu,Jianmin Ye
Monogenean parasites are responsible for severe economic losses of both freshwater and marine aquaculture industries. Current chemotherapeutic treatments are consuming, expensive, and harmful to water quality and human health. Medicinal plants are a reliable source of alternative anthelmintic agents. In the pursuit of novel anti-monogenean drugs, in vivo anthelminthic efficacy of 26 selected phytochemical compounds was studied, by choosing Gyrodactylus kobayashi infecting goldfish ( Carassius auratus ) as a model. The screening results showed that four compounds (plumbagin (PLB), thymoquinone, osthole and psoralen) had the highest activity against G. kobayashii with EC 99 value ranging from 0.4 to 4.0 mg/L after 48-h exposure. Among these active compounds, PLB was the most efficacious one and selected for the next study. In vitro trials revealed the clear anti-parasitic effects of PLB, with complete death at 45 min of exposure at a concentration of 2.0 mg/L, withdrawal of PLB afterward did not lead to the recovery of the exposed parasites. Bathing G. kobayashii infected goldfish in PLB also significantly reduced the worm burden, with an extremely low EC 50 value of 0.09 mg/L after 48-h immersion. The results also showed that one short bath using very low concentrations of 0.4–0.7 mg/L for 30–60 min was effective in eliminating G. kobayashii infection with no visible fish toxicity. Acute toxicity assay indicated the 48-h LC 50 of PLB against goldfish was 0.657 mg/L. Furthermore, SEM analysis displayed that PLB-mediated worm killing was associated with the tegumental damages. As seen by TEM , in vivo treatment against G. kobayashii with PLB also caused vacuolization and lysis of parasite's tegument, besides, differing degrees of damage to vitelline cells were observed in treated worms. Collectively, simple chemical structure along with the potent efficacy demonstrated that PLB could serve as an ideal leading compound in the development of a commercial drug to control Gyrodactylus infections in aquaculture
危险品化学品经营许可证（带存储）