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1.
Development of an innovative biotechnological method for potato peeling, closer to the ‘ideal’ peeling conditions of the product, was the main objective of the present research. Studies on enzymatic hydrolysis of potato peel were conducted. The efficacy of enzymatic peel hydrolysis was expressed in terms of reducing sugar content of the enzyme solution in which potato peel was incubated. Enzyme screening revealed that an enzyme solution containing a cellulase-xylanase mixture and amylase in a ratio of 1:1 showed good peel hydrolyzing efficiency of peeled peels. To further maximise the peel hydrolysis, condition parameters were optimised using response surface methodology (RSM). At the optimised conditions of 60 °C, pH 6 and 4 h, the reducing sugar yield in the solution was maximum. Characterization of the potato peel using microscopic techniques (scanning electron microscopy (SEM), atomic force microscopy (AFM)) further illustrated degradation of cell wall and reduction in the surface roughness of the peel after enzymatic treatment, which could enhance peel loosening from the intact potato. To further ascertain the efficiency of the process, studies were conducted with the selected enzyme on intact potato tubers under optimised conditions. Easy removal of peel was observed in enzyme-treated potato tubers, which showed 0.52% peel loss by abrasive peeling. The present process employing enzymes could be applied for peeling of intact potato as an alternative to conventional peeling process.  相似文献   

2.
Cellulose nanocrystals (CNC) with high aspect ratio of 80 have been readily prepared from the inexpensive fruit shell of Camellia oleifera Abel (SCOA) for the first time. In this study, SOCA was consecutively subjected to alkali extraction, hydrogen peroxide bleaching and acid hydrolysis to remove non-cellulosic components and release CNC. The derived CNC possesses a needle-shaped structure that in average diameter and length of 6±2 nm and 500±100 nm, respectively. The crystallinity index of CNC increased to 72 % and the initial decomposition temperature raised to 230 oC. The obtained CNC was formed to nanopaper by vacuum filtration showing high visible light transmittance over 90 %. Thus SOCA derived CNC is of great practical potential to apply in the field of biomedicine, energy, packing, etc. Overall, this study is anticipated to offer new possibility for the CNC production from the inexpensive but abundant agricultural wastes.  相似文献   

3.
Cellulose fibres and cellulose nanocrystals were extracted from rice husk. Fibres were obtained by submitting the industrial rice crop to alkali (NaOH) and bleaching treatments. Nanocrystals were extracted from these fibres using sulphuric acid (H2SO4) hydrolysis treatment. The material obtained after each stage of the treatments was carefully characterized and its chemical composition was determined. Morphological investigation was performed using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Fourier transform infrared (FTIR) spectroscopy showed the progressive removal of non-cellulosic constituents. X-ray diffraction (XRD) analysis revealed that the crystallinity increased with successive treatments. The thermal stability of the rice husk fibres and cellulose nanocrystals was also investigated using thermogravimetric analysis (TGA).  相似文献   

4.
In this study, we evaluated the effects of amylopectin/amylose ratio and non-solvent type on starch nanoparticle formation including the average particle size, polydispersity index, size distribution, and nanoparticle morphology using dynamic light scattering (DLS) and scanning electron microscopy (SEM). The most uniform particles were obtained from normal corn starch with ethanol. The average particle size was 98.8 ± 1.8 nm using DLS while combination of size distribution study and SEM images showed that particle size ranged between 60 and 90 nm. A bimodal distribution was observed with two defined groups of nanoparticles when waxy corn starch (Amioca) was nanoparticulated with ethanol. SEM images of freeze dried samples and DLS size distribution curves of fresh samples showed that high amylose starch including Hylon V and Hylon VII gave uniform, spherical and small nanoparticles in the size range of 20–60 and 15–50 nm, respectively. The smallest nanoparticles were fabricated by precipitation with methanol, followed by ethanol and the largest nanoparticles were formed using acetone. Re-dispersion of nanoparticles was good when nanoparticles were fabricated using ethanol and acetone especially for Amioca, whereas redispersion of samples in aqueous PBS solution, precipitated using methanol was difficult especially in the case of Hylon VII. Stability of curcumin in the presence of 1 mg/ml native starch nanoparticles was much higher (83.7 ± 3.1%) than curcumin in phosphate buffered saline at pH 7.0 (5.5 ± 1.5%) over 10 days at ambient temperature. Interaction between iodine-potassium iodide solution and starch nanoparticles showed that the helical structures of amylose and amylopectin molecules remain in the nanoparticles and curcumin may interact with these helical structures giving it the stability which is not observed in water.  相似文献   

5.
Production of bioethanol from rice straw has attracted attention from the point of effective use of agricultural residue. Starch content is an important determinant for bioethanol production from rice straw. The overexpression of CO2-responsive CCT protein (CRCT), which is the positive regulator of starch synthesis in vegetative organs, notably increased the starch content in rice straw. To produce the bioethanol from rice straw, the dilute acid pretreatment is a general pretreatment method. Importantly, the glucose yields in liquid hydrolyzate after dilute acid pretreatment was markedly increased in the CRCT overexpression lines compared with non-transgenic rice. In addition, the overexpression of CRCT enhanced the biomass production. In contrast, CRCT did not affect on the glucose yields from cellulose in acid-insoluble residue obtained after dilute acid pretreatment. With respect to byproduct in liquid hydrolyzate which inhibits the fermentation, the formic acid content was increased, whereas the furfural, 5-hydroxymethylfurfural and acetic acid contents were unchanged by the overexpression of CRCT. These results demonstrate that genetic engineering of CRCT is an effective method to increase the bioethanol production from rice straw.  相似文献   

6.
Summary It has been disputed whether, when potato starch gelatinises and absorbs water, it generates an osmotic or matric pressure that makes the potato cells become round and separate from one another. Starch suspensions heated at 100°C in dialysis bags absorbed water, suggesting that starch swelling pressure does exist. It was quantified by heating starch suspensions at 85°C in a chamber which absorbed water through a membrane and contained an argon bubble whose volume was measured. This gave starch swelling pressures around 100 kPa, increasing non-linearly with starch concentration. A comparable estimate (a few hundred kPa) of starch swelling pressure within cooked potato tissue was obtained from the fact that it largely prevented the tissue contraction expected due to loss of turgor pressure in the first 1.5 min of boiling. A slight expansion thereafter was attributed to the combined effect of starch swelling pressure and cell wall and middle lamella degradation.  相似文献   

7.
Screening of >800 somaclones of ‘Russet Burbank’, North America’s leading French fry cultivar, for improved yield and processing quality, led to the selection of 25 advanced lines. Three replicates of 3–5 tubers each from advanced lines were assessed after 5 months storage for antioxidant and polyphenol attributes; a subject receiving increased attention among plant breeders, nutritionists, and consumers. Phytonutrients affecting antioxidant components and total antioxidant capacity per serving (150 g fresh matter; one serving size) varied significantly among tubers of the 25 somaclones as well as between these somaclones and ‘Russet Burbank’ control plants (field tuber-derived and plantlet-derived). Several phenolics, including chlorogenic acid, caffeic acid derivatives, ferulic acid derivatives as well as the flavonoid rutin, ranged in concentration from 10- to 100-fold with some lines exceeding control tuber concentrations by >7-fold. Similarly, ascorbic acid ranged >3-fold (47.21 to 208.63 mg) on a per serving basis with some lines showing significantly greater concentrations than the control plantlet derived tubers (93.82 mg) by >2-fold. Antioxidant capacity, estimated using 2,2′-azino-bis (3-ethylbenzthiazoline-6-sulphonic acid) (ABTS), ranged up to 5-fold for the advanced somaclones (2,121.34 to 11,163.07 μM trolox equivalent/serving). Less variation occurred with other antioxidant capacity tests (DPPH, Folin-Ciocalteu). Overall 17/25 lines had increased antioxidant components. HPLC assays were necessary to confirm lines with better phytonutrient profiles. Somaclonal selection offers clear benefits for phytonutrient improvement in potato and can follow selection for yield and processing attributes.  相似文献   

8.
Synthesis and structural characterizations of nitro- and aminobenzyl cellulose were carried out. Cellulose derivatives were synthesized by etherification. Nitrobenzylation produced 80 % yield by treating a mixture of microcrystalline cellulose, 4-dimethyl aminopyridine, and 4-nitrobenzyl chloride at 80 °C for 10 h. Nitrobenzyl cellulose was then reduced to aminobenzyl cellulose with 93 % yield using indium metal in ethanol and saturated aqueous ammonium chloride. In addition to their structural characterizations by FT-IR and 13C CP/MAS NMR, TGA will also be described. These reactions serve as models for future cotton fiber finishing technology with applications in flame resistance.  相似文献   

9.
Arsenic (As) contamination of the soil may affect the quality of potato tubers. When assessing the processing quality of potato cultivars, specific gravity (SG) is the measurement of choice for estimating dry matter (DM) and starch concentrations in the potato tubers. In this study, effects of the As concentration in the soil on quality parameters (SG, DM, starch concentration and total soluble solids (TSS)) of 11 potato cultivars in Bangladesh were investigated in an outdoor pot experiment with a randomized complete block design (RCBD) and three blocks, at Sher-e-Bangla Agricultural University, Dhaka, Bangladesh, from November, 2012 to March, 2013. The results showed highly significant differences between cultivars in quality parameters, except SG. Both As levels (25 and 50 mg As kg?1 soil) reduced the DM and starch concentration in the tubers of the potato cultivars compared to the control (0 mg As kg?1 soil), but had no significant effects on SG and TSS. ‘Lady Rosetta’ showed the highest SG (1.093 g cm?3), DM (23.02%) and starch concentration (16.60%). The lowest SG (1.065 g cm?3), DM (17.04%), and starch concentration (10.96%) was found in ‘Granola’. Highest TSS (5.91) was found in ‘Jam Alu’ while ‘Meridian’ had the lowest °Brix value (3.76). Bangladeshi potato farmers will benefit from the information generated regarding potato cultivation under As affected areas.  相似文献   

10.
A Box-Behnken design (BBD) was used for optimization of enzymatic hydrolysis of waste cotton fibers in order to obtain finest cellulose particles. The effect of three factors including hydrolysis time (h), substrate concentration (g/l) and enzyme loading (%) were investigated. The median size of the hydrolyzed particles was defined as the response function of the design. Results of BBD were subjected to analysis of variance (ANOVA) and a quadratic polynomial equation was developed for predicting the particle size. According to the fitted model, the optimal conditions i.e. hydrolysis time, substrate concentration and enzyme loading were suggested as 175 h, 5 g/l and 2.3 %, respectively. The suspension prepared under optimum conditions was subjected to ultrasonic treatment, and the resulted stable suspension of cellulose nanoparticles was characterized. It was found that these nanoparticles are spherical and most of them are in the range of 40–90 nm. The enzymatic and ultrasonic treatments caused an increase in the crystallinity and a decrease in the degree of polymerization of cotton.  相似文献   

11.
块茎大小与马铃薯淀粉粒度分布的关系   总被引：1，自引：0，他引：1  
淀粉粒度是衡量马铃薯淀粉品质的一个重要指标。测定了5个马铃薯品种不同大小块茎淀粉的平均粒径及离散度,得出以下结论:克新13号、克新19号、克新21号块茎质量大于250 g时其淀粉的平均粒径最大,克新18号、克新20号块茎质量在150~250 g之间其淀粉的平均粒径最大;5个品种均是块茎质量小于75 g时的淀粉平均粒径最小。5个品种之间比较表明,克新20号淀粉的平均粒径最小,克新13号在块茎质量大于75 g时其淀粉的平均粒径最大。克新13号、克新18号、克新19号、克新21号在块茎质量大于250 g时淀粉的粒度分布最均匀,克新20号块茎质量在150~250 g之间时淀粉的粒度分布最均匀。  相似文献   

12.
马铃薯生育后期产量及淀粉含量的动态变化   总被引：3，自引：1，他引：2  
块茎淀粉含量是马铃薯品种一个非常重要的品质性状,本研究对俄引薯1号、龙引薯1号、海伦3号3个不同熟期品种在生育后期不同阶段的块茎产量、淀粉含量以及淀粉产量的动态变化进行了研究。3个品种的马铃薯块茎产量从高到低的顺序为:龙引薯1号>俄引薯1号>海伦3号。随着收获期的延后,各品种的块茎产量逐渐增加,其中8月31日与9月7日间增长速度最快。淀粉含量在生育后期先增加后降低,呈抛物线趋势变化,但淀粉产量随着收获期的延后而逐渐增加。  相似文献   

13.
In this work the feasibility of extracting cellulose from cotton, sisal and flax fibers, corn stover and rice husk by means of usual chemical procedures such as acid hydrolysis, chlorination, alkaline extraction, and bleaching was analyzed. Cellulose nanowhiskers from these sources, and from commercial cellulose, were produced by the acid hydrolysis of the obtained celluloses. The final products were characterized by means of Thermogravimetric Analysis (TGA), Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Scanning Electronic Microscopy (SEM) and Atomic Force Microscopy (AFM). The chemical procedure used to obtain cellulose nanowhiskers was effective in all cases but differences on the thermal stability, chemical composition, crystallinity and morphology were found due to the dissimilar nature of the different sources. Thus, this work demonstrates that the morphology and physical properties of cellulose nanowhiskers synthesized by the same conditions are strongly dependent on their source.  相似文献   

14.
Chemically modified starch nanocrystals were used as adsorbents for the removal of aromatic organic compounds from water. The nanocrystals were chemically modified by grafting with stearate moieties which enhanced the adsorption capacity of the nanometric substrate. Their adsorption capacity ranged between 150 and 900 μmol g−1 of modified nanoparticles and the adsorption isotherms could be described accurately by the Langmuir model. The adsorption kinetics followed a two-step process with first pure adsorption of the aromatic compounds onto the surface of the nanoparticles followed by a diffusion of the compounds into the layer of surface chains grafted onto the nanoparticles. Furthermore, the feasibility of using these nanoparticles in continuous flow mode processes was confirmed using a fixed bed column setup. The fixed bed column could also be regenerated by washing with ethanol and was found not to exhibit any loss in adsorption capacity over multiples adsorption-desorption cycles.  相似文献   

15.
Purple- and red-fleshed potatoes (Solanum tuberosum L.) were evaluated for their total anthocyanin (ACY), total phenolic (PHEN), and antioxidant capacity. The ACY and PHEN compounds were distributed throughout the tubers; however, a higher concentration was found at the stem-end than the bud-end. Although ACY and PHEN concentrations in potato peel were 0.9-to 1.6-fold higher than in potato flesh, overall contribution of the peel to ACY and PHEN contents of a potato slice was ～20%. These observations differ from the widespread idea that phytonutrients are mostly accumulated in the peel of tubers. The ACY and PHEN contents of different purple- and red-fleshed potato genotypes ranged from 11 to 174 mg cyanidin-3-glucoside/100 g fresh weight and from 76 to 181 mg chlorogenic acid/100 g fresh weight, respectively, and were genotype and location dependent. High positive correlations between antioxidant capacity and ACY and PHEN suggest that these compounds are mainly responsible for the antioxidant capacity. These results provide useful and important information for potato breeders and researchers in order to increase the antioxidant capacity and functional value of purple- and red-fleshed potatoes for the food and nutraceutical industries.  相似文献   

16.
为筛选适合热带地区种植的甘薯品种,以18份甘薯种质资源为研究对象,采用生理生化方法测定块根主要营养品质,通过隶属函数与因子分析,综合评价甘薯块根营养品质特征。结果表明：不同甘薯品种间产量和营养品质指标差异显著;相关性分析表明,块根各营养品质组分既相互独立又相互联系,大多数品质指标之间具有一定的相关性;7个营养品质指标转化数据经因子分析提取3个公因子,被提取的3个公因子累积方差贡献率达85.51%,3个公因子对7个指标变量贡献范围为0.78~0.95,其中影响块根品质的关键因子依次为：可溶性糖、蔗糖、类黄酮、干率组成的公因子1,淀粉、纤维素组成的公因子2,可溶性蛋白组成的公因子3;不同甘薯品种营养品质综合评价差异达到显著水平（P<0.05）,综合评价筛选出5个综合性状优良的品种,分别为‘福建1号’‘海口3’‘美国番薯’‘文昌6’‘龙岩2’,这些品种可以用于进一步的推广利用。  相似文献   

17.
Starch granule-associated proteins (SGAPs) were extracted from various starches and analyzed using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) with silver staining. The SDS-PAGE results showed that granule-bound starch synthase (GBSS) of approximately 60 kDa was found in most starches, except waxy-type starches. Starches exhibited the presence of proteins specific to the botanical origin, including those of 22 kDa for maize; 160 and 98 kDa for potato; 140, 115, 90, and 80 kDa for wheat. These proteins could be detected from noodles prepared with the corresponding starches. The detection of the specific proteins by SDS-PAGE may be used to identify the origin of starch incorporated in various foods and industrial products.  相似文献   

18.
以菠萝蜜种子为原料提取淀粉,以木薯淀粉、大米淀粉、玉米淀粉和马铃薯淀粉为参照,采用体外消化试验测定菠萝蜜种子淀粉的快速消化淀粉、慢消化淀粉和抗性淀粉含量,并进行酶解动力学实验。结果表明:菠萝蜜种子淀粉快速消化淀粉、慢消化淀粉和抗性淀粉的含量分别为4.50%、19.65%和75.85%,酶解速率为0.60 h-1,平衡浓度为36.93%,酶解指数为41.43,血糖指数为62.45,属于中等血糖食物;菠萝蜜种子淀粉消化性、平衡浓度、酶解指数与血糖指数均高于马铃薯淀粉,而低于其他三种淀粉,酶解速率比马铃薯淀粉、木薯淀粉快,比大米淀粉、玉米淀粉慢。   相似文献   

19.
Nanocellulose was prepared by acid hydrolysis of microcrystalline cellulose (MCC) at different hydrobromic acid (HBr) concentrations. Polyvinyl alcohol (PVA) composite films were prepared by the reinforcement of nanocellulose into a PVA matrix at different filler loading levels and subsequent film casting. Chemical characterization of nanocelluloses was performed for the analysis of crystallinity (Xc), degree of polymerization (DP), and molecular weight (Mw). The mechanical and thermal properties of the nanocellulose reinforced PVA films were also measured for tensile strength and thermogravimetric analysis (TGA). The acid hydrolysis decreased steadily the DP and Mw of MCC. The crystallinity of MCC with 1.5 M and 2.5 M HBr showed a significant increase due to the degradation of amorphous domains in cellulose. Higher crystalline cellulose showed the higher thermal stability than MCC. From X-ray diffraction (XRD) analysis, nanocellulose samples showed the higher peak intensity than MCC cases. Reduction of MCC particle by acid hydrolysis was clearly observed from scanning electron microscope (SEM) images. The tensile and thermal properties of PVA composite films were significantly improved with the increase of the nanocellulose loading.  相似文献   

20.
Yellow fleshed potatoes contain significant amounts of lutein and zeaxanthin but the bioaccessibility of potato carotenoids has not yet been investigated. The purpose of this study was to estimate the in vitro bioaccessibility of carotenoids provided by potato. Lutein and zeaxanthin concentrations of boiled, freeze dried and milled samples of seven yellow fleshed potato accessions were determined by HPLC before and after different steps (gastric, duodenal and micellar phase) of in vitro digestion. The gastric and duodenal digestive stability of lutein and zeaxanthin in boiled tubers of the different accessions ranged from 70 to 95 % while the efficiency of micellarization ranged from 33 to 71 % for lutein and from 51 to 71 % for zeaxanthin. For all accessions, amounts of lutein and zeaxanthin after micellarization were significantly lower than the original amount found in the boiled samples. The accession 701862 showed the highest bioaccessible lutein concentration (280 μg/100 g, FW) and the accessions 703566 and 704218 showed the highest bioaccessible zeaxanthin concentration (above 600 μg/100 g, FW). Considering the mean potato intake in the Andes (500 g per day), the accession 701862 provides 14 % of the lutein intake suggested for health benefits and the accessions 703566 and 704218 provide 50 % more than the suggested zeaxanthin intake.  相似文献   

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