Combined effect of microwave and ultrasonication treatments on the quality and stability of sugarcane juice during cold storage

The main objective of this study was to investigate the combined effect of microwave (MW) treatment (2450 MHz for 120 s), ultrasonication (US) (24 KHz, 20 °C for 20 min) and combined treatment (MW-US) on the quality and stability of sugarcane juice (SCJ) during 21 days of storage at 4 °C. The effect of the treatments and storage time on physicochemical, bioactive compounds (total phenolic, flavonoids and ascorbic acid content) and microbial analysis of SCJ. No significant (P < 0.05) changes were observed in °Brix, while there was an increase in pH and a decrease in titratable acidity in all treatments. Compared to US and MW, MW-US treatments was more effective in preserving colour attributes, total phenolic and flavonoids contents, ascorbic acid and antioxidant capacities of the SCJ during storage. The results regarding the microbial count indicate that more microbial safety and longer shelf life was achieved by MW-US. MW-US treatment is an effective technology for improving the safety and shelf life of SCJ by minimising quality changes, retaining bioactive compounds and reducing microbial growth during storage.     

喷施硝酸稀土对甘蔗钾素吸收、运转和分配的影响

应用同位素示踪技术和放射自显影技术研究了甘蔗苗期和分蘖期喷施300mg/L硝酸稀土对钾素吸收、运转和分配的影响。结果表明,稀土元素处理能促进甘蔗根部及叶片对钾素(86Rb)的吸收和向外运转以及在生长旺盛部位的累积。生长盛期喷施300mg/L硝酸稀土也能显著提高甘蔗叶片全钾量。     

机器视觉技术在甘蔗等经济作物节水灌溉中的运用展望

机器视觉作为人眼的替代,在精度测量及检测方面具有更安全、稳定和易于实现智能化的特点。从机器视觉与甘蔗等农作物生长需水模型研究、甘蔗等农作物病害施药的定靶喷施、水肥耦合的定量施肥模型构建、不同土壤含水保水特性以及机器视觉在节水灌溉设备上的运用等5个方面探讨及展望高效节水灌溉的新途径,为实现精确、高效的节水灌溉提供导向和理论依据。     

The influences of fiber feature and polymer melt index on mechanical properties of sugarcane fiber/polymer composites

The fiber characteristics (i.e., the fiber type, morphology, and dimension) and polymer melt flow index (MFI) significantly affected mechanical properties of sugarcane fiber/HDPE composites. The length and diameter of sugarcane fibers followed a lognormal distribution before and after compounding. The long fibers had a significant reduction in the dimension and aspect ratio during compounding. However, the short fibers had close values in these two properties before and after compounding. For the resultant sugarcane fiber/polymer composites, the HDPE resins with a low MFI value presented high tensile and impact strengths. Because of high sugar content, the pure rind fiber had a poor performance as filler in the HDPE resins with respect to the raw bagasse fiber and alkali‐extracted bagasse fiber. On the other hand, the aspect ratio was proportional to the mechanical performance of the fibers in the HDPE resins. As a result, the fibers with a large aspect ratio and low sucrose content improved the strength properties of the resultant composites. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5607–5619, 2006     

甘蔗收割机切割系统耙齿注塑成型翘曲变形分析

针对传统甘蔗收获机切割系统甘蔗喂入困难问题,设计了新型的甘蔗耙齿,将其安装在切割器上,以甘蔗收割机切割系统耙齿制品为研究对象,为了避免注塑成型方案加工使新型耙齿易出现翘曲的现象,文章利用Moldflow模流分析软件和正交试验方法,研究了保压压力、保压时间、熔体温度和模具温度对制品翘曲的影响。结果表明,保压压力对翘曲缺陷影响最大,保压时间的影响最小。根据正交试验结果,选择了最优工艺对翘曲进行了优化,结果显示,当保压压力为120 MPa,保压时间为12 s,熔体温度为220℃,模具温度为55℃时,耙齿的翘曲量最小。     

带壳百香果与甘蔗汁混酿复合果酒工艺研究

将带壳百香果和甘蔗汁作为原料酿造复合果酒,并研究其发酵工艺。 运用单因素试验和正交试验对发酵破壳时间、原料配比、原料初始含糖量、主发酵温度及主发酵时间进行优化。 结果表明,百香果甘蔗复合果酒的最优工艺条件为：百香果发酵破壳时 间5d,百香果与甘蔗汁配比1∶3（g∶mL）,调节原料初始含糖量至32.5%,于发酵温度24℃条件下发酵9d。 在此最佳工艺条件下,百香果甘蔗复合果酒感官评分达到79分,酒精度达到14.1%vol,色泽呈玫瑰红色,澄清透亮,具有典型的百香果浓郁香气和甘蔗汁的清 香风味。     

蔗梢多酚类化合物抗氧化与抗肿瘤活性研究

研究从蔗梢中分离到的8种多酚类化合物的抗氧化活性和抗肿瘤活性。采用DPPH自由基清除能力、氧自由基吸收能力（ORAC）和ABTS自由基清除能力综合评价多酚化合物的体外抗氧化活性,MTT法评价多酚化合物的体外抗肿瘤活性。实验表明,8种化合物中槲皮素的DPPH自由基清除能力显著（p<0.05）高于阳性对照Trolox;咖啡酸抑制CNE2（人鼻咽癌细胞）增殖的活性最强,槲皮素抑制SGC7901（人胃癌细胞株）增殖的活性最强,2-（3,5-二羟苯基）-5-羟基-苯并呋喃和槲皮素能较强地抑制Hela（人宫颈癌细胞株）的增殖。蔗梢中的8种多酚类化合物均具有较强的抗氧化活性和一定的抗肿瘤活性,可作为保健食品和保健品的开发原料。      

甘蔗收获机械剥叶元件优化设计方法的研究

阐述了一种快捷、高效的适用于丘陵地带的小型甘蔗收获机械关键部件——排刷式剥叶元件的优化设计方法。剥叶元件的优化设计是基于数值模拟正交试验的方法，根据正交试验原理，并考虑剥叶元件特殊的材料特性和工作特性，在大型CAE软件ANSYS上分别建立不同因素水平的剥叶元件的三维有限元模型，给定边界约束条件和载荷进行有限元分析计算，利用大型数理统计学软件SPSS对计算结果进行方差分析和回归分析，从而快速地寻找出剥叶机构最佳的设计参数。     

Sugarcane cell wall structure and lignin distribution investigated by confocal and electron microscopy

Lignocellulosic plant cell wall is considered a potential source for second generation biofuels. The plant cell wall is a highly complex structure mainly composed of cellulose, hemicelluloses, and lignin that form a network of crosslinked fibers. The structural organization of the sugarcane cell wall has not been previously analyzed in detail, and this analysis is a prerequisite for further studies on the recalcitrance and deconstruction of its biomass. In this work, cellulose and lignin localization were investigated by confocal laser scanning microscopy. In addition, the internode sugarcane cell wall structural organization was analyzed by electron microscopy. Internode stem anatomy showed a typical monocot structure consisting of epidermis, hypoderm, and vascular bundles scattered throughout ground parenchyma tissue and surrounded by sclerenchyma fibers. Confocal images of safranin labeled sugarcane showed that lignin distribution was predominant in the vessel elements, cell wall corners (CC), and middle lamella (ML), while cellulose‐rich cell walls were randomly distributed in the ML and organized in the other cell wall layers. KMnO₄ cytochemistry revealed that lignin was predominantly distributed in secondary cell walls, ML and CC. Cell wall sublayers (S1, S2, and S3) were identified and measured by transmission electron microscopy. Our results provide insights that may help further understanding of sugarcane cell wall organization, which is crucial for the research and technology of plant‐based biofuel production. Microsc. Res. Tech. 76:829–834, 2013. © 2013 Wiley Periodicals, Inc.     

Effect of several factors on peracetic acid pretreatment of sugarcane bagasse for enzymatic hydrolysis

BACKGROUND: Lignocellulose should undergo pretreatment to enhance its enzymatic digestibility before being saccharified. Peracetic acid (PAA) is a strong oxidant that can remove lignin under mild conditions. The sulfuric acid in the PAA solution also can cause degradation of hemicelluloses. The objective of the present work is to investigate the effect of several factors on peracetic acid pretreatment of sugarcane bagasse. RESULTS: It was found that PAA charge, liquid/solid (l/s) ratio, temperature, time, interactions between PAA charge and l/s ratio, temperature and time, all had a very significant effect on the enzymatic conversion ratio of cellulose. The relative optimum condition was obtained as follows: PAA charge 50%, l/s ratio 6:1, temperature 80 °C and time 2 h. More than 80% of the cellulose in bagasse treated under the above conditions was converted to glucose by cellulase of 20 FPU g^?1 cellulose. Compared with H₂SO₄ and NaOH pretreatments under the same mild conditions, PAA pretreatment was the most effective for enhancement of enzymatic digestibility. CONCLUSION: PAA pretreatment could greatly enhance the enzymatic digestibility of sugarcane bagasse by removing hemicelluloses and lignin, but removal of lignin was more helpful. This study can serve as a step to further optimization of PAA pretreatment and understanding the mechanism of enhancement of enzymatic digestibility. Copyright © 2007 Society of Chemical Industry