减少Lyocell纤维原纤化程度的化学方法研究

论述了减少Lyocell纤维湿加工原纤化程度的化学处理方法，包括碱处理、纤维素酶处理、树脂处理以及组合化学处理方法。通过对各种化学处理方法的防原纤化效果进行的比较，提出了防止Lyocell纤维原纤化的最佳处理工艺。     

Effect of blanching and drying treatments on quality of bamboo shoot slices

The enzymes activity, texture, pectin, microstructure and colour change in bamboo shoots (Dendrocalamus latiflorus) were examined to evaluate the effect of blanching and drying treatments on quality of bamboo shoot slices (BSS). Peroxidase (POD), phenylalanine ammonia‐lyase and polyphenol oxidase in BSS will become completely inactive at 95 °C for 6‐, 9‐ and 12‐min blanching treatments, respectively. The hardness and protopectin (PP) content decreased after the blanching treatment. Meanwhile, the content of water‐soluble pectin increased initially and then decreased gradually during the blanching. After the blanching treatment, the L* and a* of BSS decreased, while b* increased, ΔE > 2. The hardness of rehydrated BSS decreased by 43.57% after freeze drying (FD), which, however, decreased more after hot air drying (HAD). The pectin of rehydrated BSS was also determined to explain the hardness change in BSS. The BSS acquired similar microstructure of fresh samples after FD, while microstructure of BSS was severely damaged after HAD. The colour of BSS changes significantly after drying treatment. However, FD can maintain better colour of BSS than HAD. The results may provide a reference for industrial production of BSS.     

Physical,thermal and structural properties of rice starch as affected by the addition of bamboo shoot shell fibres

The effects of different bamboo shoot shell fibre (BSSF) content (1, 2, 5 and 10%, w/w) on the physical, thermal and structural properties of rice starch were investigated. BSSFs significantly affected the properties of rice starch by competitive water absorption and hydrogen bonding. With increased BSSF content, the breakdown value and pasting temperature of rice starch were increased, whereas the peak viscosity, final viscosity and setback value were decreased. Thermodynamic results showed that the gelatinisation temperature and gelatinisation enthalpy of rice starch were significantly increased by the 5% and 10% BSSFs. Furthermore, BSSFs interconnected with amylose through hydrogen bonds to restrain gel-structure formation, thereby resulting in low storage modulus and loss modulus of rice starch paste. A loose structure of rice starch supplemented with 10% BSSFs was clearly visible, exhibiting the minimum values of hardness (32.12 ± 4.47 g) and adhesiveness (64.70 ± 17.32 g). Moreover, BSSFs increased the amount of short-range ordered structures but had no effect on the crystal type of rice starch. These results may contribute to the manufacture and development of fibre-enriched starchy products.     

Extrusion improved the physical and chemical properties of dietary fibre from bamboo shoot by-products

Bamboo shoot by-products are regarded as waste and environmental pollutant. This study aimed to improve the functional properties of dietary fibre from bamboo shoot by-products. After CO₂ extrusion, the particle size of CO₂-extruded bamboo fibre was 17.6% lower than that of the control, and its specific surface area was 2.85 times that of the control. The soluble dietary fibre content was significantly increased from 5.64 g/100 g to 11.05 g/100 g (P < 0.05), and the capacities for water holding, swelling and oil holding were remarkably improved. The cholesterol adsorption of CO₂-extruded bamboo fibre was increased from 96.54 μg g⁻¹ to 174.65 μg g⁻¹ (pH 7.0), and its nitrite ion adsorption capacity was increased from 503.33 μg g⁻¹ to 657.27 μg g⁻¹ (pH 2.0). In summary, the structural changes of bamboo fibre such as internal porosity, surface roughening and low crystallinity indicated that its functional properties were improved after CO₂ extrusion.     

浅议生料制醋中固态发酵的条件控制

为了更好地控制生料制醋过程中的固态发酵,对固态发酵的温度、醋醅中的氧含量和车间环境条件等对发酵的影响作了比较详细地阐述,认为把温度控制在35～42℃,这样有利于固态发酵的顺利进行,同时在醋醅表面覆盖塑料薄膜可控制氧的含量,车间管理要按5s的要求进行,并严格按照工艺要求进行操作可确保制醋工艺的顺利进行。同时,对醋醅过氧化反应的现象及预防措施作了简要说明。     

竹原纤维的碱处理及交联改性研究

以不同浓度NaOH在不同张力条件下处理竹原纤维纱线,再用乙二醛进行交联改性,对改性后纱线的结构和性能进行了表征.用XRD和FTIR研究了纱线的结晶结构.结果表明,松弛碱处理时,碱浓度为16%～18%,纤维的结晶结构变化最大,纤维素Ⅰ基本转变为纤维素Ⅱ,同时结晶度达到最小值,纤维回潮率提高.张力对纤维素的转化和结晶度的降低有阻碍作用.松弛碱处理则有利于扩大纤维的可及区,提高其交联程度,但纱线的强度下降显著;张力碱处理则有利于减少纱线交联后强度的损失.     

Ochratoxin A in red paprika: relationship with the origin of the raw material

The occurrence of ochratoxin A (OA) in paprika elaborated from peppers grown in several countries (Peru, Brazil, Zimbabwe and Spain) was studied, using an immunoaffinity clean-up column coupled to liquid chromatography and fluorescence detection. The preparation of the methyl ester (OA-Me) and liquid chromatography-electrospray-ion trap-mass spectrometry was used both to confirm the identity of the chromatographic peak that correspond to OA and to quantify it at low levels or in dirty fractions. A total of 115 strains of moulds were isolated; 85 of the fungal strains were obtained from OA contaminated paprika samples and identified as belonging to the Aspergillus Section Circumdati group (A. ochraceus) and Section Nigri group (A. niger, A. carbonarius). Among the latter ones, 31% of the A. ochraceus isolates and one A. niger were OA producers in vitro. None of the mould strains isolated from paprika samples with undetectable levels of OA or concentrations below 1 microg kg(-1) were toxin producers. Great differences in OA content in paprika samples were found, and a relationship with the climatic conditions of the geographic origin of the samples, and with cultural and technical practices in pepper manipulation is suggested.     

Improved function of bamboo shoot fibre by high-speed shear dispersing combined with enzyme treatment

With the increase in global welfare, metabolic syndrome-related diseases seriously disrupt our quality of life. Balanced diet with low calories, low glycaemic index, and high dietary fibre such as bamboo shoot fibre is needed. Functional properties of dietary fibre can be improved by processing methods. Therefore, we compared the effect of three processing methods (high-speed shear dispersing, enzyme treatment and combined treatment) on the characteristics and functions of bamboo shoot fibres. Combined treatment resulted in high SDF content (10.15%), adsorption capacity of glucose (4.45–18.18 mmol g⁻¹), nitrite ion (505.49 μg g⁻¹ [pH 2.0]), and cholesterol (333.72 μg g⁻¹ [pH 2.0]). FTIR revealed that hydroxyl groups, sugar methylene and benzene rings of aromatic compounds existed in the treated bamboo shoots. The particle size (D₅₀) decreased from 383.90 to 30.65 μm. Honeycomb-like structure was also observed through SEM. Thus, proper processing of bamboo shoot fibres can improve their functions as food ingredients.     

Inter-relationships between acidic and alkali treatments of cotton straw and wheat straw and their fibre chemical properties

The amount of lignin in the cell walls of cotton straw (CS) and wheat straw (WS) was found to be the same, but the ratio between lignin and hemicellulose was considerably lower in CS than in WS. In CS the amount of soluble acid lignin was less than 1% of the total lignin, whereas in WS it was 20%. The amount of phenolics in concentrated sulphuric acid (72%) hydrolysates of the cell wall was reduced drastically in WS compared with the amount released by diluted (1 N) sulphuric acid; this may have been due to polymerisation of low-molecular-size lignin. The amount of alkali-soluble lignin in WS was 3–7 times greater than in CS. Following acid treatment the amount of alkali-soluble lignin was reduced from 20% of the total content to 5% in WS, and from 5% to 1% in CS. Enzymic hydrolysis was 49% higher in WS cell wall than in CS cell wall. In WS, acidic and alkali pretreatments followed by cellulase treatment increased glucose yield from cellulose by 260% and 280%, respectively. In CS, acidic pretreatment did not affect the glucose yield from cellulose, whereas alkali treatment increased it by 35%.     

高原纤化Lyocell纤维的制备及其性能

为探究Lyocell纤维原纤化的生成条件,拓展高原纤化Lyocell纤维在过滤织物、覆盖面料及吸收衬垫等领域的应用,以次氯酸钠(NaClO)溶液为氧化剂,采用汽蒸处理方法制备了不同原纤化程度的Lyocell纤维,研究了NaClO溶液质量分数和热处理时间对Lyocell纤维结构及性能的影响.结果表明:在本文实验范围内,当...     

Characterisation and quality assessment of ripened sausages in relation to the origin of raw material used

An experiment was performed to characterise and to assess the quality of ripened sausages produced from different raw materials. Samples were prepared using the same production technology, starting from pork shoulders from extensively versus intensively reared animals. Chemical, sensory, and microbiological analyses were performed. The results obtained showed that the sausages made from extensively reared pigs showed a significantly higher moisture content and higher scores for red intensity and global flavour. Microbiological analyses showed no significant difference between the two kinds of sausage. Contents of lactic acid bacteria and Micrococcaceae were high in both cases.     

Comparative study of copper ion complex bamboo pulp and cotton knitted fabrics. Part II: wearability and durability

Apart from the antibacterial performance, wearability and durability are also important factors for the textile product quality. The paper mainly discusses the wearability and durability of bamboo pulp and cotton-knitted fabrics which were treated with alkali and copper ammonia solution. Washing fastness, release properties of copper ions when washing, bursting properties, abrasion resistance, permeability, moisture penetrability, and warmth retention properties of fabrics were tested to investigate the change after copper ammonia solution treatment. The results showed that although the release quantity of bamboo pulp fabrics was higher, the washing fastness of bamboo pulp fabrics was better than that of cotton fabrics. After 90 times’ washing, the copper ion complex fabrics still had good antibacterial performance. For both cotton and bamboo pulp fabrics, properties of the bursting strength, moisture penetrability and warmth retention had been improved, whereas properties of abrasion resistance and air permeability had receded.     

Lyocell纤维的原纤化控制及纤维结构的变化

Lyocell纤维的去原纤化和防原纤化加工技术是印染加工的要点。本文研究了不同碱处理方式和不同碱浓度处理对Lyocell纤维的去原纤化效果，用乙烯基单体来达到防原纤化的效果，并用烧毛评级法来表征纤维的原纤化等级。在实验结果的基础上，提出了碱处理纤维准晶区发生了准晶体解体和晶体再生长的理论假设，并从理论上分析了碱处理纤维聚集态结构的改变。解释了碱处理去原纤化及乙烯基单体接枝防原纤化的原因。结果表明，碱处理过程中纤维表面微小纤维发生了溶解，碱处理使纤维的聚集态结构发生了变化，但随着碱处理浓度增加，002峰的半高宽减小，晶粒的尺寸增大，降低了晶体取向指数。经乙烯基单体接枝的纤维表面结构发生了变化，纤维结晶度下降。     

硬脂酰氯改性碱木质素及微纳米球的制备

以制浆造纸废液中的碱木质素为原料,采用绿色低毒的硬脂酰氯对其进行化学改性,制备酯化的碱木质素,并在四氢呋喃(THF)和水的混合溶液中通过自组装制备改性碱木质素微纳米球,探讨了硬脂酰氯的加入对改性碱木质素微纳米球的影响,并进一步研究了制备工艺对改性碱木质素微纳米球尺寸的影响,以实现对改性碱木质素微纳米球尺寸的控制。结果表明,经过硬脂酰氯改性后碱木质素微纳米球粒径达到纳米级,硬脂酰氯与碱木质素的最佳质量比为3.0∶1.0,胶束呈均一的球形,平均粒径为98.7 nm,在水溶液中分散稳定性达到最优;当改性碱木质素初始浓度从2.0 mg/mL降低到0.5 mg/mL时,改性碱木质素微纳米球平均粒径从557.6 nm减小到86.2 nm;搅拌速度从750 r/min增大到1500 r/min时,改性碱木质素微纳米球平均粒径从333.6 nm减小到94.1 nm;最终含水量从60%增大到90%时,改性碱木质素微纳米球平均粒径从312.0 nm减小到103.4 nm。     

Comparative study of copper ion complex bamboo pulp and cotton knitted fabrics. Part I: copper ion contents and antibacterial performance

The paper mainly discusses the antibacterial performance of bamboo pulp and cotton fabrics which were treated with NaOH solution and copper ammonia solution. SEM, ICP-OES, and agar diffusion plate method were used to investigate the existence of copper ions and analyze the influence of treatment parameters on the copper ion content and antibacterial performance. The results show that there is significant difference for all the properties between bamboo pulp and cotton fabrics. The alkali treatment, concentration, and time period all have significant influence on the copper ion contents and antibacterial performance, and they have different influences on the bamboo pulp fabrics and cotton fabrics. The antibacterial performance not only depends on the copper ion content on the fabrics but also relate to the release action. The release ability of copper ions in bamboo fabrics is better than that in cotton fabrics. Alkali treatment makes the complex of copper ion more stable and the release rate slower.     

Quality and shelf life evaluation of pork nuggets incorporated with fermented bamboo shoot (Bambusa polymorpha) mince

Pork nuggets were processed by incorporating fermented bamboo shoot mince and their physico-chemical, microbiological and sensory characteristics were evaluated during 35 day storage at refrigeration temperature (4 ± 1 °C). Addition of fermented bamboo shoot significantly affects the pH, moisture, protein, fat, fiber, instrumental color values and texture profiles of nuggets, especially at 6% and 8% addition levels. Nuggets with 6% and 8% FBSM had significantly lower TBARS values at the end of the storage period (i.e. 0.39 and 0.33 mg malonaldehyde/kg respectively) compared to the control (0.84 mg malonaldehyde/kg). Bamboo shoot addition significantly improved the microbial and sensory qualities of the pork nuggets. Incorporation of fermented bamboo shoot at 8% level increased the shelf life of pork nuggets by at least two weeks i.e. from 21 days to 35 days at 4 ± 1 °C compared to the control.     

棉和竹浆/棉针织物的H_2O_2/TAED漂白活化体系

采用双氧水/四乙酰乙二胺(TAED)低温活化体系对棉和竹浆/棉针织物进行漂白,探讨了各主要因素对漂白效果的影响。影响漂白效果的最主要因素是双氧水质量浓度及其与TAED的摩尔分数比;适当的纯碱用量可保证双氧水和TAED反应生成过乙酸、提高织物白度,但过高的纯碱用量会使织物黄度增加。70℃漂白已能达到很高的白度,但对白度要求特别高的织物,可适当提高温度以进一步提高白度。在30%双氧水4~7 g/L、H2O2/TAED摩尔分数比2∶0.75~2∶1、纯碱1~2 g/L、70℃保温30 min的条件下,可实现近中性的练漂一浴处理,织物具有很高的白度和良好的润湿性,能满足敏感色系浅淡色染色对织物白度的要求。     

Evaluation of physico-mechanical characteristics of cashew nut shell liquid-epoxy composites with Borassus and Tamarind fruit fibres as reinforcements

In this study, Cashew Nut Shell Liquid (CNSL)-epoxy matrix-based composites reinforced with borassus and tamarind fibres were fabricated using compression moulding technique. Three different types of composites were fabricated, namely Borassus fruit fine fibre/CNSL-epoxy composites (BF composites), Tamarind fibre/CNSL-epoxy composites (TF composites) and Tamarind/Borassus fruit fine fibre CNSL-epoxy hybrid composites (HB composites). In addition, CNSL-epoxy neat polymer was also fabricated for comparison. Physical properties such as micro-hardness, void percentage, and mechanical properties like tensile, flexural, Interlaminar Shear Strength (ILSS), and impact strength were investigated. Scanning Electron Microscope (SEM) was used to study the failure mechanism of the composites. Experimental results indicate that tensile and flexural properties of BF composites were higher when compared to TF and HB composites. Micro-hardness and impact strength of HB composites were better than the others. SEM images indicated better fibre-matrix bonding in BF composites indicating improved resistance to delamination. Thus, borassus and tamarind fibre reinforced CNSL-epoxy composites can be used as an alternative material for light to moderately loaded structural engineering applications.     

酸碱处理对酪蛋白源ACE抑制肽稳定性影响的研究

在不同pH值条件下,处理酪蛋白源ACE(血管紧张素转换酶)抑制肽,以ACE抑制活性、游离氨基质量浓度以及色差值为检测指标,研究了酸碱处理对ACE抑制肽稳定性的影响。结果表明,ACE抑制肽受酸碱度影响较大,pH值为1~8的ACE抑制肽的抑制活性维持在一个较高水平,平均抑制活性达到58.33%,pH值为9~13的样品抑制活性明显降低;游离氨基质量浓度在中性条件下较高,随着酸性和碱性条件的增强,其含量逐渐降低;另外,ACE抑制肽在pH<3和pH>11条件下,随酸性和碱性条件的增强,b*值变大,颜色变深。因此,在食品加工贮藏过程中,为使酪蛋白源ACE抑制肽保持活性稳定,应避免其处于过酸或过碱的加工条件。