干燥过程气体成分对蔬菜干制品质的影响

采用自制的QTM试验装置对蔬菜进行气调干制试验，研究了不同温度条件下气体成分对苦瓜片、萝卜丝和香葱干制品质量的影响。结果表明：采用N₂或CO₂进行气体调节，降低干燥过程气体的O₂含量，可明显提高蔬菜干制品叶绿素含量和降低干制过程维生素C质量分数的损失。用指数函数拟合蔬菜干制品的叶绿素含量与O₂含量间的关系，用幂函数拟合维生素C质量分数损失率与O₂含量间的关系，回归方程置信水平都大于95%。     

环境因素对自然气调下双孢蘑菇呼吸速率影响的初步研究

研究了温度、容器内顶隙气体体积与双孢蘑菇体积比、O₂浓度、CO₂浓度及处理时间t对双孢蘑菇呼吸速率的影响，并采用多因素方差分析、重回归分析法，确定了双孢蘑菇呼吸速率的显著性影响因素，结果表明：温度对双孢蘑菇呼吸耗氧率R_O2、二氧化碳生成率R_CO2、呼吸商RQ的影响比体积比的影响更显著；25、18和4℃时，O₂浓度、CO₂浓度及时间t 3因素中，时间t对R_CO2的影响最大，而12℃时，CO₂浓度对R_CO2的影响最大；12℃时，随着体积比的增大，CO₂浓度、时间t的影响作用减弱，O₂浓度作用增强。     

嫩茎花椰菜在不同气调贮藏下叶绿素和维生素C的降解及活化能研究

通过检测叶绿素和维生素C的变化，试验确定了花椰菜气调贮藏中主要成份的降解为一级动力学反应；根据Arrhenius方程，确定了不同气调贮藏条件下花椰菜主要成份的表观活化能。在两种温度2℃和8℃，两种气体组分3% O₂，2% CO₂，95% N₂和6% O₂，6% CO₂，88% N₂组合条件下贮藏试验，结果表明在2℃，3% O₂，2% CO_{2相似文献}   

不同气体成分贮藏对大久保桃果实品质的影响

该文研究了大久保桃在不同气体成分下贮藏60 d以及出库后在20℃下货架期3 d后果实硬度、褐变指数、可溶性固形物含量、pH值、膜透性、出汁率和感官品质的变化。结果表明，1%的O₂对桃果实产生伤害，表现为表面色泽非正常变化、桃固有风味丧失并产生严重异味；(5～10)%O₂、(5～10)%CO₂气体成分能够在60 d的贮藏期内保持桃果实的品质，尤其是10%O₂＋10%CO₂处理较好地保持了果实的风味、质地和色泽，出库后果肉不褐变。与冷藏对照相比，气调贮藏能有效地延缓果实软化，抑制pH值和出汁率的升高，但对可溶性固形物的影响不大；在相同O₂浓度下，随CO₂浓度升高(<10%)，果实在货架期期间的软化程度、褐变指数下降幅度、pH值上升程度和膜透性增加幅度均增大，表明果实能够进行正常后熟。本研究推荐的大久保桃果实气调贮藏的适宜气体指标是10%O₂＋10%CO₂。     

气调贮藏对双孢蘑菇细胞超微结构的影响

为了揭示气调贮藏抑制双孢蘑菇褐变的作用机理,采用透射电镜法对气调贮藏条件下双孢蘑菇细胞超微结构的变化进行观察,分析了双孢蘑菇细胞超微结构完整性与组织褐变度之间的关系,结果表明:双孢蘑菇贮藏过程中组织细胞的完整性与褐变度密切相关,适宜的气调环境能够显著抑制双孢蘑菇贮藏过程组织细胞的降解,从而延缓组织褐变。     

不同气调包装方式的冷却猪肉在冷藏过程中的微生物变化

冷却猪肉分别采用真空包装、CO-MAP(CO+CO₂+N₂)包装、高氧-MAP(高浓度O₂+CO₂+N₂)和低氧-MAP(低浓度O₂+CO₂+N₂)包装后，在(4±1)℃贮存3周，每周测定各项微生物变化。结果表明：1)CO-MAP组可抑制腐败细菌的生长，除对乳酸菌抑制作用较弱外，对假单胞菌、肠杆菌科菌和热死环丝菌均具有很强的抑制作用     

板兔气调干制的影响因素分析和状态参数优化

以提高板兔质量为目的，采用自行研制的小型气调干燥机(QTM)实验设备，分别以氮气、二氧化碳气体及氮气和二氧化碳气体体积各为50%的混合气体置换部分空气作为干燥介质对板兔进行气调干制试验。采用正交实验，分析了不同状态的气体成分对板兔干制品质量的影响。结果表明：降低干燥室气体的氧气含量可显著降低板兔干制品过氧化值和酸价，提高板兔质量。在气体的氧气含量相同状况下，充氮降氧效果最好。此外，还对板兔充氮降氧干燥过程的状态参数进行了优化。     

双孢蘑菇护色保鲜技术研究

以双孢蘑菇为试验材料,研究不同的褐变抑制剂对双孢蘑菇保鲜效果的影响，通过正交试验筛选出双孢蘑菇MA贮藏中有利于色泽保持的最适褐变抑制剂配比。研究结果表明，对双孢蘑菇贮藏保鲜效果较好的褐变抑制剂及其浓度为：0.1%的无水亚硫酸钠溶液、0.06%～0.10%的抗坏血酸溶液、0.8～2.6 mmol/L的半胱氨酸溶液；保鲜液最佳配比为2 mmol/L半胱氨酸、0.05%抗坏血酸、0.15%无水亚硫酸钠、浸泡时间8 min。     

铝箔复合膜气袋对温室气体吸附性的试验研究

为了解气袋对温室气体气样的吸附性，采用气相色谱仪对5 L气袋中CH₄、SF₆、CO₂、和N₂O标准气体浓度进行了连续监测。结果表明，CH₄、SF₆、CO₂和N₂O气体浓度的变异系数分别为6.72%，0.95%，3.86%和6.56%，气袋对4种温室气体的吸附性均不显著，该气袋用于以上温室气体的测定是可行的。     

不同组分气调包装牛肉冷藏保鲜效果的研究

为延长生鲜牛肉的货架期，保持良好色泽，该文研究了以不同比例组合的CO₂、O₂、N₂作为气调包装对低温保藏的新鲜牛臀肉品质的影响。以真空包装为对照，对保藏期间牛肉色泽、菌相变化、失重率、pH值、挥发性盐基氮等参数跟踪分析，确定最佳的气调包装组分为45% O₂、45% CO₂和10% N₂ ，温度0～4℃，在此条件下牛臀肉可以保藏20 d，并保持色泽稳定。     

双孢菇片微波真空干燥特性及工艺优化

为解决双孢菇的干制问题,采用微波真空干燥技术对双孢菇片进行干燥试验,研究双孢菇片的干燥特性,并与热风干燥、真空干燥和冷冻干燥方法进行比较。研究结果显示,微波真空干燥时,微波强度对双孢菇片的干燥速率有显著影响,而真空度影响较小,最优的干燥参数为：微波强度为17.4 W/g,真空度70 kPa,干燥时间20 min,含水率可达6.9%。通过对比4种干燥方法的干制时间及产品的复水率、色泽和维生素C含量,可知微波真空干燥的菇片品质接近冷冻干燥,明显优于热风干燥和真空干燥,而微波真空干燥在干制时间方面要比冷冻干燥明显缩短。微波真空干燥是适合双孢菇片的有潜力的干制技术。     

水分胁迫对温室双孢菇动态发育品质及水分利用效率的影响

为研究基质水分胁迫对双孢菇全育期内菇形的动态发育、产菇品质的影响,确定温室双孢菇适宜、高效的施水方案,以"奥吉1号"品种为试验材料,于2020年8月进行双孢菇全育期基质水分胁迫试验。该试验设置正常T1(基质饱和持水率的80%～90%)、轻度水分胁迫T2(基质饱和持水率的70%～80%)、中度水分胁迫T3(基质饱和持水率的60%～70%)、重度水分胁迫T4(基质饱和持水率的50%～60%)4种水分处理方案,出菇期测定双孢菇发育动态、单菇品质、区域产菇品质、产量与水分利用效率(Water Use Efficiency,WUE)。结果表明:1)菇盖与菇柄的形态指标、出菇品质与基质含水量呈正相关,菇高受水分胁迫影响不明显。2)盖厚、茎粗、菇高的发育经历逐渐增长、快速增长和缓慢增长3个阶段。在T4水处理下菇厚、茎粗的最大值比T1水处理减少26.1%、24.9%,出菇时间延迟16.5 h(P0.05)。随着水分胁迫的加剧,菇柄与菇盖的生长速率峰值逐步提前,迅速增长期延长。3)在T2水处理下,双孢菇WUE和产菇数最高,相比T1水处理提高2.3%和9.2%(P0.05),出菇产量和优质菇率略低于T1水处理。4)双孢菇结菇前期和后期可进行轻度水分胁迫提高WUE,形成耐旱机制。快速发育期内应保持基质充足含水量,以提高双孢菇品质,加快出菇时间。该研究为双孢菇水分精准管理提供理论依据。     

Nitrogen release from air‐dried biosolids for fertilizer value

Mineral‐N production by air‐dried biosolids was measured in an Australian tenosol type soil with two moisture conditions over 70 days, using a controlled laboratory incubation procedure. The biosolids were from both air‐drying pans and stockpiles. Inorganic‐N components (NH₄‐N, NO₃‐N and NO₂‐N) were present in all biosolids, with higher concentrations in samples from air‐drying pans compared with stockpiles of 1 yr age. Nevertheless, significant production of NO₃‐N occurred in moist soil amended with all air‐dried biosolids. In contrast, saturated soil amended with air‐dried biosolids generally showed a net loss of inorganic‐N compounds during incubation, presumably owing to denitrification. In the saturated soil, only biosolids from air‐drying pans provided NO₃‐N production from existing NH₄‐N. The results indicated that biosolids from air‐drying pans provided the most robust production of NO₃‐N, compared with aged material from the stockpiles, owing to the reduced N content and increased stability of the organic fraction in stored biosolids. However, the rates of N‐mineralization in the tenosol soil were substantially lower than reported for more fertile soil types and most of the organic‐N content of the biosolids remained undegraded by day 70. The biosolids thus may substantially remain to provide improved properties of soil, such as structure and water‐holding capacity. The results suggest that anaerobically digested biosolids from air‐drying pans are potentially highly consistent products that could be effective replacements for inorganic‐N fertilizer in agricultural production.     

Effect of the storage conditions of soil samples on carbon and nitrogen extractability

Concentrations of carbon and nitrogen extractable by 0.05 M K₂SO₄ (C_ext and N_ext, respectively) in 14 soils of different ecosystems vary from 16 to 205 and from 4 to 53 mg/kg, respectively. The portion of C_ext in soil organic matter is 0.06 to 0.38% of total carbon, and the portion of N_ext is 0.12–1.05% of total nitrogen. The storage of samples and their preparation to analysis differently affect the extractability of elements. The concentration of C_ext is less variable than the concentration of N_ext. An increase in C extractability (by 1.4–6.7 times) is a common feature of all soils under drying; at the following incubation of dried soils, the extractability of C decreases by 28–56%. The extractability of N increases not only under drying (by 1.5–7.1 times) and the following incubation of samples (by 25–60% to 2–3 times), but also under freezing of most soils and at the incubation of fresh and defrozen samples. A close direct correlation is observed between the initial water content of soil and the relative increase in C extractability under drying and N extractability under freezing and drying.     

香菜微波干燥的试验研究

以提高蔬菜干制品质为目的，考察干燥因素对香菜微波干燥生产率及其品质的影响，用正交试验设计方法，探讨干燥功率、物料层厚度及排湿风速对香菜微波干燥特性及干制香菜品质和能耗的影响，利用极差分析和方差分析确定香菜微波干燥最优工艺参数。结果表明：不同微波干燥参数对香菜微波干燥特性和干制品质及能耗有不同的影响，风速对物料干燥速率、香菜干制品的品质指标影响最大，物料脱水过程主要处于恒速阶段，微波干燥功率为1．125W／g，物料层厚度为1．5cm，风速为60m／min时，可确保香菜干燥后的食用价值且便于储存，而且能耗较低。     

不同压块模式对双孢菇生产的影响

中国双孢菇栽培工艺较为传统,产量不高,为了促进以牛粪和麦秸为主要原料的食用菌基质化利用效率,开展了双孢菇栽培基质压块工艺的试验研究。本试验采用传统工艺(方案1)和2种基质压块工艺(方案2:紧实度400 kg/m3,方案3:紧实度500 kg/m3)的双孢菇栽培效果进行对比。结果表明,方案1出菇时间为36 d,方案2和方案3出菇时间为38 d,压块工艺使出菇时间延长2 d但并不会影响双孢菇的正常生产;方案1、2、3的双孢菇单产分别为0.198、0.205和0.279 kg/kg,方案3提升最为显著,单产提高了40.9%;方案1、2、3的双孢菇栽培实际面积分别为5.4 m2、4.7 m2和3.8 m2,随着压块工艺紧实度的增加节约栽培占地面积越多;方案1、2、3的双孢菇总产量分别为22.5 kg、23.3 kg和31.7 kg。综合以上结果,本研究认为方案3为最优基质压块工艺,有效的提高了双孢菇产量、节约了栽培面积、降低了成本,该研究为基质压块工艺的实际应用奠定了理论基础。     

Approaching a Standardized Method for the Hot-Water Extraction of Peat Material to Determine Labile SOM in Organic Soils

Peatland soils are the most effective and important long-term terrestrial carbon (C) storages. To estimate potential C loss, a valid characterization of soil decomposability, in particular the labile fraction, is of great interest. One of the most labile fractions is hot-water-extractable organic matter (HWOM), often measured as hot-water-extractable carbon (C_hwe) and nitrogen (N_hwe). Various studies describe different extraction procedures for mineral soils. Because of methodical differences, it is difficult to compare extracted HWOM amounts directly to each other. For peatland soils, few studies exist. The aim of the present study is the development of a standardized method for the hot-water extraction of peat materials. Therefore, we extracted HWOM in various replicates from different peats on the basis of a standardized extraction method for mineral soils (1 h extraction at 100 °C). We tested how differences in soil/water ratios, extract treatment (filtering vs. not filtering), and sample pretreatment (freeze drying vs. air drying) influence HWOM amounts. The results clearly illustrated the influence of changing soil/water ratios on HWOM amounts. Mean C_hwe concentrations ranged between 8 and 34 g kg^?1 whereas N_hwe ranged between 0.2 and 2.6 g kg^?1. We recommend the extraction under soil/water ratios of 1/800 to provide sufficient volume of solvent for C_hwe. If relative differences for N_hwe amounts are greater than 15 percent, samples should be extracted again under soil/water ratios greater than 1/300 to avoid analytical errors due to unintended dilution effects. Filtering of centrifuged and decanted extracts before analysis is not necessary. Peat material should be either air dried or freeze dried before extraction.