枳实副产物中柠檬苦素最佳提取条件的研究

通过单因素试验和旋转正交试验对枳实副产物中柠檬苦素的提取工艺进行优化。结果表明：最佳提取工艺参数为提取剂乙醇浓度78％、pH值6.5、料液比1∶6(w/v)、浸提温度60℃、提取时间2 h，该条件下柠檬苦素的提取率为94.2％。     

添加剂对农副产物和小麦秸秆混合青贮发酵品质的影响

【目的】随着食品业与加工业的不断发展,产生了诸如西瓜皮,蚕豆荚以及啤酒糟等大量的农副产物,造成环境的污染。为提高农副产物和小麦秸秆的饲料化程度,减小环境压力,通过探究添加剂对农副产物（西瓜皮、蚕豆荚和啤酒糟）与小麦秸秆混合青贮发酵品质的影响,为提高农副产品利用率和青贮品质研究提供借鉴。【方法】以混合农副产物（西瓜皮﹕蚕豆荚﹕啤酒糟=1﹕3﹕4）和小麦秸秆为原材料,按鲜重比100%﹕0（MW）、25%﹕75%(X25)、50%﹕50%（X50）和75%﹕25%（X75）进行混合青贮,并对各混合青贮进行添加剂处理：添加1×10⁶ cfu•g^-1布氏乳杆菌（B）,0.2% FW纤维素酶（C）和1×10⁶ cfu•g^-1鼠李糖乳杆菌（R）,以无添加剂（CON）为对照,将不同处理的200g新鲜材料装入容积为250 mL的聚乙烯塑料瓶中。在室温下青贮60 d后,开窖分析发酵品质和营养成分。不同处理的青贮饲料与原料通过两层纱布和定性滤纸过滤,浸提液用于pH测定;将原材料和青贮饲料烘干至恒重后测定干物质含量（DM）;蛋白质（CP）采用凯氏定氮法进行测定;采用范氏纤维测定法测定中性洗涤纤维（NDF）和酸性洗涤纤维（ADF）;采用蒽酮-硫酸比色法测定水溶性碳水化合物含量（WSC）;培养基培养微生物后计数;利用高效液相色谱仪分析有机酸;氨态氮含量（NH₃-N）采用苯酚-次氯酸钠比色法测定。【结果】与MW相比,X25中NH₃-N含量显著降低（P < 0.05）;X50中pH和NH₃-N含量显著下降（P<0.05）;X75中pH和NH₃-N含量显著降低,乳酸与乙酸比（LA/AA）显著升高（P < 0.05）;此外,相比于MW,X25、X50和X75显著降低丁酸含量（P<0.05）。在MW中,与对照组相比,添加C显著降低pH和NH₃-N含量（P < 0.05）,显著增加乳酸（LA）含量和LA/AA（P<0.05）。在X25中,与对照组相比,添加C显著降低pH（P<0.05),提高LA含量（P<0.05）;添加R显著降低NH₃-N含量（P<0.05）。在X50中,与对照组相比,添加C显著降低pH和NH₃-N含量（P < 0.05),添加B显著降低NH₃-N含量（P<0.05)。在X75中,与对照组相比,添加C能够显著降低pH和NH₃-N含量（P<0.05）。DM、NDF和ADF含量随小麦秸秆混合比例的增加而显著增加（P<0.05）;相比之下,CP随小麦秸秆混合比例的增加而显著降低（P<0.05）。与MW相比,X25、X50和X75显著提高了 WSC含量（P<0.05）。在X25中,与对照组相比,添加C显著降低了NDF和ADF含量（P<0.05）;在X50中,相比于对照组,添加B和C显著降低NDF含量（P<0.05）;在X75中,相比于对照组,添加B、C和R显著降低NDF和ADF含量（P<0.05）。【结论】混合农副产物（西瓜皮﹕蚕豆荚﹕啤酒糟=1﹕3﹕4）单独青贮发酵品质较差,农副产物和小麦秸秆混合青贮能够改善发酵品质,小麦秸秆和农副产物（西瓜皮﹕蚕豆荚﹕啤酒糟=1﹕3﹕4）比例为50%﹕50%和75%﹕25%时为最佳混合比例;从营养品质来看,小麦秸秆和农副产物（西瓜皮﹕蚕豆荚﹕啤酒糟=1﹕3﹕4）比例为25%﹕75%和50%﹕50%时为最佳混合比例;综合考虑发酵品质和营养价值,小麦秸秆和农副产物（西瓜皮﹕蚕豆荚﹕啤酒糟=1﹕3﹕4）最适宜的混合比为50%﹕50%,添加C能够进一步提高发酵品质,改善营养成分。     

Long-Term Effects of Fluidized Bed Combustion Material Applied at Disposal Levels on Soil Properties

This study was conducted to assess changes in soil properties of a soil that received a one-time application (360 Mg ha^?1) of fluidized bed combustion material (FBCM) 23 years earlier. Soil samples were taken at three depths (0–10, 10–20, and 20–30 cm). Samples were also collected from an adjacent field with the same soil type for control. Hot nitric acid and Mehlich 3 extractions were used for total and extractable elements. Analyses indicated improvement in soil physical and chemical properties after 23 years of FBCM application. For example at the 20- to 30-cm depth, soil pH values increased from 4.9 to 7.7, whereas calcium concentrations increased from 0.23 to 1.52 g kg^?1 with FBCM amendment. In most cases, metal concentrations were less with FBCM amendment. Results from this study demonstrated that soil physical and chemical improvements from FBCM were maintained even 23 years after an extremely high application of FBCM.     

Evaluation of Two Industrial By-products as Soil Conditioners for Reducing Potential Aluminium Toxicity and Acidity in a Palexerult of Western Spain

A field experiment evaluated the effects of surface applications of two industrial by-products (sugar foam and phosphogypsum) to an acidic Ultisol of the temperate zone in Spain to ameliorate topsoil and subsurface acidity and potential aluminium (Al) toxicity. The by-products were applied in single and combined amendments and at two different rates. Two years after their application, it was determined that applications at a low rate of sugar foam and sugar foam + phosphogypsum increased the pH and the exchangeable calcium (Ca) and reduced the exchangeable Al in the surface horizon of the soil while only a significant reduction of exchangeable Al was obtained in the subsurface horizon. Long-term amelioration of acidity and potential Al toxicity were only achieved upon the addition of these treatments at high rate. The addition of sugar foam at a high rate provides an effective practice for long-term acidity amelioration from the surface downward.     

Mineralization of Nitrogen from Biofuel By-products and Animal Manures Amended to a Sandy Soil

Transformations of nitrogen (N) from poultry litter (PL), dairy manure compost (DMC), anaerobically digested fiber (ADF), Perfect Blend 7–2–2 (PB), a compost/litter mixture (C/L), dried distillers grains from ethanol production (DG), and mustard meal from biodiesel production (MM) applied to a Quincy fine sand were investigated in an incubation experiment over 210 days. The cumulative release totals of available N after 210 days were 61, 61, 56, 44, 29, 2, and –2% for the total N in MM, PB, DG, PL, C/L, DMC, and ADF, respectively. With application of MM and DG, ammonium (NH₄-N) accumulated initially in the soil with very little nitrification, possibly because of inhibition of nitrification related to chemical compounds in the amendments. Mineralization of organic N to NH₄-N and nitrate (NO₃-N) was relatively slow from MM- and DG-amended soils, indicating the potential for using biofuel by-products as slow-release N sources for plants.     

Omega-3-Rich Oils from Marine Side Streams and Their Potential Application in Food

Rapid population growth and increasing food demand have impacts on the environment due to the generation of residues, which could be managed using sustainable solutions such as the circular economy strategy (waste generated during food processing must be kept within the food chain). Reusing discarded fish remains is part of this management strategy, since they contain high-value ingredients and bioactive compounds that can be used for the development of nutraceuticals and functional foods. Fish side streams such as the head, liver, or skin or the cephalothorax, carapace, and tail from shellfish are important sources of oils rich in omega-3. In order to resolve the disadvantages associated with conventional methods, novel extraction techniques are being optimized to improve the quality and the oxidative stability of these high-value oils. Positive effects on cardiovascular and vision health, diabetes, cancer, anti-inflammatory and neuroprotective properties, and immune system improvement are among their recognized properties. Their incorporation into different model systems could contribute to the development of functional foods, with market benefits for consumers. These products improve the nutritional needs of specific population groups in a scenario where noncommunicable diseases and pandemic crises are responsible for several deaths worldwide.     

Fish Protein Isolates Recovered from Silver Carp (Hypophthalmichthys molitrix) By-Products Using Alkaline pH Solubilization and Precipitation

ABSTRACT

Fish protein isolates (FPI) were produced from silver carp processing by-products by means of the isoelectric solubilization-precipitation method, and the quality was evaluated. The alkali-aided process led to significantly more lipid reduction (p < 0.05) compared with the acid-aided process. Similar protein types were extracted for the acid and alkali solubilization, and most protein types can be recovered from the raw materials, as observed in the sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis. The FPI was higher in total amino acids and essential amino acids (EAAs) compared with the original by-products (p < 0.05). The alkali-aided process yielded a higher nutritional and color quality than the acidic process. Furthermore, we found that alkali-aided protein had higher oxidative stability than the acid-aided protein. Our study indicates that high-quality fish proteins can be efficiently recovered from low-value silver carp processing by-products using isoelectric solubilization/precipitation, particularly the alkali-aided process, and subsequently be used in value-added human foods.     

Potential of Chitosan (Chemically Modified Chitin) for Extraction of Lead-Arsenate Contaminated Soils

Arsenic, lead, and phosphorous contamination in soils represents a health risk. Chitosan (poly-N-acetyl glucosamine) inexpensive by-product derived from chitin has been used as a metals adsorbent. Objectives of this research were to evaluate the effectiveness of chitosan solution for arsenic, lead, and phosphorous extraction from lead-arsenate contaminated soils, and evaluate the effectiveness of protonated chitosan flakes (PCF) and ferric hydroxide chitosan beads (Fe(III)-CB) for water-soluble As removal from these soils. Percentage of arsenic, lead, and phosphorous removed from the soils by chitosan solution ranged from 0.96% to 17%, 1.80% to 31%, and 0.66% to 11%, respectively. Percentage of water-soluble arsenic removed by PCF and by Fe (III)-CB ranged from 12% to 47% and 36% to 77%, respectively. Averaged over soils, Fe (III)-CB removed slightly more arsenic (As) (42 mg kg^?1) compared to Mehlich III (40 mg kg^?1) extractant. Results indicate potential for the use of chitosan as an extraction for lead-arsenate contaminated soils.     

餐厨垃圾猪粪混合厌氧发酵研究

为解决我国餐厨垃圾污染环境,资源化利用程度低的问题,本研究通过试验将餐厨垃圾与猪粪混合发酵。得到餐厨垃圾与猪粪混合厌氧发酵的最佳原料比例为1:1.5,得到餐厨垃圾与猪粪混合厌氧发酵的最佳搅拌频率为60r/min,餐厨垃圾与猪粪混合厌氧发酵的最佳温度为38°C,餐厨垃圾与猪粪混合厌氧发酵的最佳时间为10h,餐厨垃圾与猪粪混合厌氧发酵的最佳pH为7。为我国餐厨垃圾资源综合利用提供参考。     

压载水中消毒副产物碘代三卤甲烷形成机制研究

由于海水中I~-、Br~-含量较高,通过电解法处理压载水过程中会产生一定含量的碘代三卤甲烷(ITHMs),该类物质具有极强的致癌和致突变特性,在电解处理工艺过程中极易生成,难以有效控制。本研究通过次氯酸钠投加模拟实验分析消毒副产物碘代三卤甲烷的形成机制与影响因素,结果显示:(1)Na Cl O浓度由5 mg/L增加至15 mg/L时,I-THMs生成量增加24.76μg/L;(2)I-THMs的生成量随着温度的升高而增加,当温度高于20℃时I-THMs的生成量增加迅速;(3)酸性条件下,I-THMs的生成量较小,碱性条件下,I-THMs的生成量明显增大;(4)对于溶液中不同溴碘浓度比,I-THMs的生成量和各组分比例差异较大。因此,建议在压载水电解处理工艺过程中应对反应条件进行最佳优化,以期保证其处理效果的同时有效控制消毒副产物DBPs的产生。