Valorization of Eucalyptus wood by glycerol-organosolv pretreatment within the biorefinery concept: An integrated and intensified approach

The efficient utilization of lignocellulosic biomass and the reduction of production cost are mandatory to attain a cost-effective lignocellulose-to-ethanol process. The selection of suitable pretreatment that allows an effective fractionation of biomass and the use of pretreated material at high-solid loadings on saccharification and fermentation (SSF) processes are considered promising strategies for that purpose. Eucalyptus globulus wood was fractionated by organosolv process at 200 °C for 69 min using 56% of glycerol-water. A 99% of cellulose remained in pretreated biomass and 65% of lignin was solubilized. Precipitated lignin was characterized for chemical composition and thermal behavior, showing similar features to commercial lignin. In order to produce lignocellulosic ethanol at high-gravity, a full factory design was carried to assess the liquid to solid ratio (3–9 g/g) and enzyme to solid ratio (8–16 FPU/g) on SSF of delignified Eucalyptus. High ethanol concentration (94 g/L) corresponding to 77% of conversion at 16FPU/g and LSR = 3 g/g using an industrial and thermotolerant Saccharomyces cerevisiae strain was successfully produced from pretreated biomass. Process integration of a suitable pretreatment, which allows for whole biomass valorization, with intensified saccharification-fermentation stages was shown to be feasible strategy for the co-production of high ethanol titers, oligosaccharides and lignin paving the way for cost-effective Eucalyptus biorefinery.     

Hardening of cement based paint

A cement-based paint coating was hardened in air of different relative humidities at room temperature. The best properties were obtained when complete carbonation took place at high relative humidities and long hardening times.     

变性淀粉对肌原纤维蛋白凝胶特性的影响

分别将0%、4%、6%、8%、10%和12%的玉米原淀粉、玉米乙酰化二淀粉磷酸酯、木薯乙酰化双淀粉己二酸酯淀粉(acetylated distarch adipate,ADA)、木薯醋酸酯变性淀粉(starch acetate,SA)添加到肌原纤维蛋白溶液中,制备淀粉-蛋白复合物并测定流变特性、凝胶强度、保水性和水分子弛豫时间等指标。结果表明:添加淀粉可显著提高肌原纤维蛋白的储能模量G′,G′在42℃左右开始增加,此时肌原纤维蛋白开始变性形成凝胶,添加变性淀粉可显著延迟肌原纤维蛋白的变性温度(43~46℃)。变性淀粉添加量为8%时淀粉-蛋白复合物凝胶强度均达到最大,而原淀粉对肌原纤维蛋白的凝胶强度影响不显著(P>0.05)。添加变性淀粉的复合凝胶保水性比原淀粉保水性高约13%(P<0.05),SA-蛋白复合物与ADA-蛋白复合物保水性最高。核磁共振分析表明T2弛豫时间随变性淀粉添加量增大而减小,T22向快弛豫方向移动,说明变性淀粉的添加降低了水分子的移动性。因此,ADA-蛋白复合物对肌原纤维蛋白的流变性、凝胶强度、保水性和水分迁移影响最显著,添加10%以内变性淀粉可显著提高肌原纤维蛋白的G′和保水性,同时增大凝胶强度,降低水分迁移速率。     

Waste frying oil as a precursor for one-step synthesis of sulfur-doped carbon dots with pH-sensitive photoluminescence

Proper disposal of waste frying oil (WFO) is an important waste-management concern. In this paper, we develop a facile method to reuse WFO for one-step synthesis of sulfur-doped carbon dots (S-C-dots) with the assistance of concentrated sulfuric acid. The as-synthesized S-C-dots are uniform in size and show partial disordered graphite-like structure. Different from the doping-free or nitrogen-doped carbon dots, the S-C-dots perform a strong ultraviolet emission at 378 nm due to successful sulfur-doping. Noticeably, the S-C-dots exhibit a distinct pH-sensitive feature and the intensity of photoluminescence increases linearly in the pH range from 3 to 9. Furthermore, possessing fascinating optical properties, high photostability, and low cytotoxicity, the S-C-dots have served as fluorescent probes for cell imaging.     

Phenolic profile and antioxidant properties of a crude extract obtained from a brewery waste stream

The main aims of this study were to determine the phenolic profile of a crude extract obtained (at pilot scale) from a brewery waste stream and to evaluate the antioxidant activity of the extract. The total phenolic content was determined by the Folin–Ciocalteu assay, which revealed that 50% of the extract comprised phenolic compounds. The polyphenols, identified and quantified by RP-HPLC–DAD and HPLC-ESI–TOF-MS, were mainly flavonoids (catechin, epicatechin, gallocatechin, epigallocatechin, quercetin) and phenolic acids (ferulic acid, p-coumaric acid, caffeic acid, protocatechuic acid). The crude extract displayed a high DPPH radical scavenging activity (0.18 g/L), similar to that of BHA (0.248 g/L) and higher than that of BHT (2.54 g/L). All three tested products displayed a similar ability to decrease oxidative bleaching of β-carotene (antioxidant activity coefficient of 623.8 for the crude extract, 653.3 for BHA, 559.6 for BHT). This type of brewery waste stream may be a promising source of natural antioxidants to replace the synthetic antioxidants currently used in the food industry.     

豆腐柴果冻的制作工艺优化及其降血糖活性研究

目的研究豆腐柴果冻的最优制作工艺及其降血糖活性。方法以豆腐柴鲜叶超微粉为原料,以热处理的碳酸钙为凝固剂,通过单因素和响应面法优化豆腐柴果冻的制作工艺,并对豆腐柴果冻的感官、质构、营养成分及降血糖活性进行了分析。结果豆腐柴果冻的适宜制作条件为料液比1:17(g:m L),CaCO_3添加量0.06%,水浴温度85℃;每克豆腐柴果冻含有(23.65±1.21)mg黄酮和(155.71±10.86)mg果胶,具有抑制α-淀粉酶和α-葡萄糖苷酶活性的作用。豆腐柴果冻的降血糖活性可能与其还有丰富的黄酮和果胶有关。结论豆腐柴果冻不仅营养丰富,而且具有降血糖效应,可以作为糖尿病患者的辅助休闲食品或代餐食品。     

血浆蛋白对调理猪排品质特性的影响

本文以大豆分离蛋白、鸡蛋白为对照,探讨血浆蛋白对调理猪排品质特性的影响,对-18℃冷冻调理猪排解冻损失、压榨损失、质构特性、凝胶强度、流变特性、水分迁移和微观结构进行分析。结果表明:2.5%血浆蛋白可以改善调理猪排的品质特性,有效降低猪排的解冻损失和压榨损失(P<0.05),提高不易流动水含量和蛋白凝胶强度(P<0.05),促使微观结构更加致密。与3.0%大豆分离蛋白相比,添加2.5%血浆蛋白的猪排硬度、弹性、咀嚼性更高;与2.5%鸡蛋白相比,血浆蛋白可明显提高肌原纤维蛋白的储能模量(G')、损耗模量(G″),延迟肌原纤维蛋白的变性温度(50~65℃);蛋白种类对猪排色泽无明显影响。因此,血浆蛋白在猪排保水性、凝胶特性、质构特性、流变特性方面展现出极大优势,为血浆蛋白在肉质品中的应用提供理论基础。     

不同温度对调理鸡排低温贮藏品质特性的影响

为研究不同温度对调理鸡排低温贮藏品质特性的影响,本实验利用3 种不同的贮藏温度（4 ℃（冷藏）、－2 ℃（冰温贮藏）和－18 ℃（冷冻贮藏））对调理鸡排进行贮藏,并通过对贮藏期间调理鸡排菌落总数、颜色、持水力、质构特性等的测定以及扫描电子显微镜的观察,分析调理鸡排理化品质以及微观结构的变化情况。菌落总数分析结果表明,相比于冷藏,冰温贮藏可以将调理鸡排的货架期延长2 倍（从约4 d延长到约12 d）;理化品质分析结果表明,冰温贮藏条件下调理鸡排的持水力和质构特性都得到了更好的保持。此外,扫描电子显微镜的观察结果表明,冰温贮藏条件下鸡排的微观结构受到的损伤相较于冷藏和冻藏而言更小。虽然冷冻贮藏条件下鸡排的货架期较长（3 个月以上）,但是其持水力、质构、微观结构等品质下降也更快。而冰温贮藏在延长货架期的同时,也更好地保持了调理鸡排的品质特性。综上,本研究可为冰温贮藏在调理鸡排贮运过程中的应用提供理论参考。     

一株产耐有机溶剂脂肪酶伯克霍尔德氏菌的分子鉴定及酶学性质分析北大核心CSCD

为筛选具有潜在应用价值的产脂肪酶菌株,采用三丁酸甘油酯固体培养基从黄山松树林土壤中筛选产脂肪酶菌株,利用16S rDNA测序对筛选的菌株进行鉴定,并对其产脂肪酶酶活力参数以及酶学性质进行分析。结果表明:筛选的产脂肪酶菌株HSU-7为伯克霍尔德氏菌(Burkholderia sp. HSU-7);菌株HSU-7所产脂肪酶的最适反应温度为45℃,最适pH为5,为一种耐酸性的中温脂肪酶;菌株HSU-7发酵5 d,所产脂肪酶酶活力最大,为72.22 U/mL。同时,K^(+)、Ca^(2+)和Mg^(2+)对菌株HSU-7所产脂肪酶酶活力具有显著的促进作用,而Ni^(2+)、Cu^(2+)、Fe^(3+)和Zn^(2+)具有一定的抑制作用,该脂肪酶可耐受有机溶剂甲醇、乙醇、异丙醇和二甲基亚砜,但Triton X-100可显著抑制其酶活力;此外,该脂肪酶能耐受65℃的高温。综上,菌株HSU-7可高产脂肪酶,且该脂肪酶有较强的热稳定性,可耐受多种有机溶剂,具有很好的工业应用价值。     

Electrochemical insertion of lithium and sodium into (MoO2)2P2O7

Insertion of lithium and sodium into phosphate (MoO₂)₂P₂O₇ was investigated electrochemically to determine the usefulness as a possible cathode for ion-transfer secondary batteries. Specific charges of up to 250 mA h g⁻¹ were obtained for A/(MoO₂)₂P₂O₇ (A: Li, Na) cells with liquid organic electrolytes in the first reduction half-cycle at room temperature. Intercalation processes under constant current densities of 0.2 mA cm⁻² were reversible within the range of composition 0.85<x<4.0 for lithium and 0.5<x<3.1 for sodium in A_x(MoO₂)₂P₂O₇ (A: Li, Na), respectively. Structural changes induced by lithium or sodium intercalation were followed by ex situ X-ray diffraction measurements, and the phase change from the crystal to the amorphous was observed in both cases.