Sorption Isotherms and Drying Rates of Jerusalem Artichoke (Helianthus tuberosus L.)

Moisture sorption properties and drying behavior of Jerusalem artichoke roots were investigated. Sorption isotherms of dehydrated and freeze-dried material, its water insoluble components, fructose, glucose and sucrose were determined at 10, 25 and/or 40°C. Adsorption-desorption isotherms indicated a combination of sorption by soluble sugars, in the crystalline, amorphous and aqueous solution state, and sorption by polymeric material such as cellulose, inulin and protein. In drying experiments conducted at 50, 65, 80, and 95°C, and also at 65°C and four air velocities and four bed depths, it was found that temperature and drier load conditions are of critical importance to drying behavior, drying time and finished product color. Increasing the air velocity from 2.0 to 4.2 m/set, at a temperature of 65°C and a bed depth of 10.5 cm, did not change the rate for drying 1 cm cubes.     

Sensory quality and appropriateness of raw and boiled Jerusalem artichoke tubers (Helianthus tuberosus L.)

BACKGROUND: The aim of the present study was to investigate the sensory attributes, dry matter and sugar content of five varieties of Jerusalem artichoke tubers and their relation to the appropriateness of the tubers for raw and boiled preparation. RESULTS: Sensory evaluation of raw and boiled Jerusalem artichoke tubers was performed by a trained sensory panel and a semi‐trained consumer panel of 49 participants, who also evaluated the appropriateness of the tubers for raw and boiled preparation. The appropriateness of raw Jerusalem artichoke tubers was related to Jerusalem artichoke flavour, green nut flavour, sweetness and colour intensity, whereas the appropriateness of boiled tubers was related to celeriac aroma, sweet aroma, sweetness and colour intensity. In both preparations the variety Dwarf stood out from the others by being the least appropriate tuber. CONCLUSION: A few sensory attributes can be used as predictors of the appropriateness of Jerusalem artichoke tubers for raw and boiled consumption. Knowledge on the quality of raw and boiled Jerusalem artichoke tubers can be used to inform consumers on the right choice of raw material and thereby increase the consumption of the vegetable. © 2012 Society of Chemical Industry     

Feeding Jerusalem artichoke (Helianthus tuberosus) to pigs

Weaned pigs were fed diets with added Jerusalem artichoke for 28 days. In a first trial, the pigs received raw tubers in addition to their normal ration. In a second trial, the pigs received dried Jerusalem artichoke (10–60 g kg^-1) in the diet. Pigs eating the raw tuber had significantly increased body weight gains due to the consumption of the raw tuber, but significantly decreased feed efficiency. Adding dried Jerusalem artichoke to the diet significantly increased weight gains. Feed efficiency was improved, but not significantly. Faecal valeric acid concentration was significantly increased in animals eating Jerusalem artichoke.     

复合酶在菊芋粉发酵生产燃料乙醇中的应用

菊芋是一种可选择的酒精发酵原料.研究用菊芋粉生产燃料乙醇的工艺参数,在单因素试验的基础上用正交试验进行工艺参数的优化.确定最佳工艺条件为:料水比为1:4.5(m/v),复合酶添加量0.2%,发酵温度36℃,酵母液用量为6mL,发酵pH值为5.0,发酵时间24 h.在此工艺条件下酒精度可达10.8%voi,酒精产率达34.10%.技术经济分析说明,使用复合酶和酵母发酵菊芋粉生产燃料乙醇是可行的.     

Changes in extractability and antioxidant activity of Jerusalem artichoke (Helianthus tuberosus L.) tubers by various high hydrostatic pressure treatments

This study investigated changes in the extraction characteristics of Jerusalem artichoke (Helianthus tuberosus L.) tubers (JA) using high hydrostatic pressure (HHP) treatment alone and in combination with enzymes and/or fermentation. HHP treatment of JA increased the soluble solid content and decreased the turbidity compared to the control group that received hot-water extraction. This indicates improved extractability of JA by HHP treatment alone or in combination. Combined HHP treatment with enzymes increased the contents of non-reducing sugars, fructooligosaccharide (FOS), and free amino acids in the extracts compared to those of control, thus activating browning reaction. Extraction of fermented JA by HHP treatment with or without enzyme showed increased polyphenol content as well as improved 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and superoxide dismutase (SOD) like activity compared to the control group. Taken together, HHP treatment of fermented JA with enzymes significantly improved the extractability of bioactive molecules such as phenolics and FOS compared to conventional water extraction or HHP treatment alone. Our results provide useful information for the improvement of raw material extraction by HHP treatment in combination.     

In vitro prebiotic activity of inulin-rich carbohydrates extracted from Jerusalem artichoke (Helianthus tuberosus L.) tubers at different storage times by Lactobacillus paracasei

In the present work the in vitro prebiotic activity of inulin-rich carbohydrates using Lactobacillus paracasei as probiotic microorganism was determined. With this purpose, inulin-rich carbohydrates samples from Jerusalem artichoke tubers stored at 4–5 °C during different times along an overall period of 8 months were extracted. Extraction yield, inulin content and average polymerization degree of inulin-rich carbohydrates samples were also determined. For all samples, extraction yield and inulin content decreased with storage time. In particular, inulin content exhibited values within the range of commercial food grade inulin (≥ 85%). Average polymerization degree values decreased with storage time ranging from 12.1 to 8.3. The in vitro prebiotic activity of inulin-rich carbohydrates samples was assessed using a prebiotic activity score which considered the growing ratio relative to glucose of L. paracasei as well as of the enteric bacteria Escherichia coli when such carbohydrates were used as C source. Inulin-rich carbohydrates extracted from tubers cold-stored during 4 months showed the highest prebiotic activity score, even higher than the corresponding to a commercial food grade inulin, indicating that this sample should be used as a prebiotic food ingredient, representing a potential alternative to the available commercial inulin obtained from chicory roots.     

Scale‐up batch fermentation of bioethanol production from the dry powder of Jerusalem artichoke (Helianthus tuberosus L.) tubers by recombinant Saccharomyces cerevisiae

This study is a first exploration of industrial bioethanol production from the dry powder of Jerusalem artichoke (Helianthus tuberosus L.) tubers by recombinant S. cerevisiae 6525. Scale‐up fermentation of bioethanol production from the dry powder of Jerusalem artichoke tubers by recombinant Saccharomyces cerevisiae 6525 was carried out at the scale of 50 and 500 L agitating fermentors. For the 50 L fermentor, 85.67 g/L of ethanol was obtained within 72 h of fermentation, and the ethanol yield was 90.1%. For the 500 L fermentor, the highest ethanol concentration of 77.00 g/L was achieved at 84 h, and the ethanol yield was 81.01%. These results indicated that a relatively high yield of ethanol could also be obtained from a scaled‐up fermentation of Jerusalem artichoke powder. Thus, it may be feasible to use a Jerusalem artichoke tuber feedstock to carry out ethanol fermentations using the recombinant S. cerevisiae 6525 for industrial production. Copyright © 2016 The Institute of Brewing & Distilling     

Norwegian‐grown Jerusalem artichoke (Helianthus tuberosus L.): morphology and content of sugars and fructo‐oligosaccharides in stems and tubers

BACKGROUND: Two field trials growing Jerusalem artichoke (Helianthus tuberosus L.) are discussed. Twenty genetic variants were compared in order to find genotypes suitable for Norwegian production. A second trial investigated the above‐ground part of early and late variants. RESULTS: The highest yield (28.7 t ha^?1) and highest amount of tubers per plant was obtained in early variants, e.g. the white Tysnes gave 1.72 kg tubers plant^?1. Early variants had a markedly lower portion of smooth tubers. Late variants gave the most preferable tuber shape, but low yield. Only a weak correlation was found between dry matter content and total content of fructo‐oligosaccharides (FOS) (r = 0.255) in the tubers. The mean content of FOS including sucrose through all variants was found to be 116 g kg^?1 fresh weight (FW) or 550 g kg^?1 dry weight (DW). The average chain length of FOS in the tubers was found to be DP3.9. There was no difference in tuber FOS content between early and late variants. The highest above‐ground amount biomass was found for the late variants when harvested in September. The content of soluble carbohydrates was found to be highest in stalks in August (sucrose and FOS major compounds). CONCLUSION: Early variants give the highest tuber yield under Norwegian growing conditions. Late variants give highest above‐ground biomass. Copyright © 2010 Society of Chemical Industry     

菊芋微波真空干燥过程的水分扩散特性及模型拟合

为了探究菊芋微波真空干燥过程中水分变化规律,本文考察了不同微波强度对菊芋干燥特性的影响。采用Weibull分布函数和Dincer模型对干燥曲线进行拟合,并结合尺度参数(α)、形状参数(β)、滞后因子(G)、干燥系数(S)等分析了干燥过程的传热、传质机制。结果表明:除1.28 W/g外,菊芋整个干燥过程分为升速、恒速和降速3个阶段,且微波强度越大,最大干燥速率愈高,升速阶段历时越短。β介于1.314～2.175之间,表明干燥过程并非完全由内部扩散主导。G为1.043～1.188,且随微波强度增大而减小。毕渥数(Bi)介于0.179～5.762之间,说明干燥过程物料温度变化由内部导热和边界对流换热共同控制。基于Weibull分布函数、Dincer模型和Fick第二定律得到的水分扩散系数分别为D_cal=5.922×10?8～2.717×10?7 m2/s、D_eff=7.570×10?7～1.799×10?5 m2/s、D*_eff =2.353×10?9～7.546×10?9 m2/s;同样微波强度下,其大小依次为:D_eff>D_cal>D*_eff。2.32 W/g下,干燥样品亮度(L*值)最大,为69.05。微波强度愈大,样品色泽参数a*和b*值越小。SEM图片显示:适宜的微波强度下,干燥菊芋细胞结构规则,部分区域含有孔洞;1.28 W/g样品的细胞皱缩明显,而高微波强度下(2.70和3.04 W/g)干燥样品部分组织结构坍塌,细胞内物质外泄。     

HACCP体系在食品包装纸及其制品生产中的应用

探讨了危害分析与关键控制点(HACCP,Hazard Analysis and Critical Control Point)体系在食品包装纸及其制品生产中的应用,根据HACCP的基本原理,对食品包装纸及其制品的生产流程进行了分析,找出了危害因素,确定了关键控制点和关键限值,并对关键控制点的监控和纠偏措施进行了讨论。     

牛蒡菊糖酶法提取

采用固定化酶法提取牛蒡菊糖。结果表明酶水解提取牛蒡菊糖的最佳工艺为：13.5g/100mL 中性蛋白酶、pH 7、固液比1:15、50℃、酶水解6h,菊糖提取率为14.57%;固定化酶制备最佳工艺为：以甲醛(40%):NaOH(2mol/L)=2:3 为凝结液、pH7.5、壳聚糖2.5g/100mL、60℃、加酶量7.5mg/mL,固定8h,酶活力回收率可达到39.13%;固定化酶提取牛蒡菊糖最适条件为：pH7、固液比1:15、60℃、固定化酶加入量13. 5 g/100mL、酶解5h,在此条件下菊糖提取率达到12.89%。固定化酶的稳定性与游离酶相比有显著的提高,连续反应10 次后,固定化酶仍然具有良好的使用性能,此时牛蒡菊糖的提取率为9.42%。     

黑菊芋对小鼠肠道菌群及其短链脂肪酸产生的影响

为研究黑菊芋对小鼠肠道菌群及其短链脂肪酸产生的影响,将50只KM小鼠随机分为空白组、低聚果糖组、黑菊芋低、中、高剂量组,连续灌胃给药15d,采用16S rDNA高通量测序和气相色谱-质谱技术分别检测小鼠肠道微生物组成和盲肠内容物中短链脂肪酸含量变化.结果显示:与空白组相比,黑菊芋不会影响小鼠的正常生长,能够调节小鼠肠道...     

Physicochemical characteristics of inulins obtained from Jerusalem artichoke (Helianthus tuberosus L.)

The physicochemical characteristics (thermal stability, glass transition temperature and degree of crystallinity) of inulins, obtained from the tubers of four varieties Jerusalem artichoke (Helianthus tuberosus L.) grown in Bulgaria—Energina, Verona, Topstar and Spindel, were investigated. The inulins obtained had molecular weight from 4,882 to 5,600 Da (degree of polymerization around 30 fructose units). The experimental data from differential scanning calorimetry showed that the glass transition temperature of inulins is between 51 °C and 55 °C. It was found that the first transition (due to evaporation of the unbound water) starts from 77 to 80 °C. The second transition phase started between 152 and 158 °C, and it determines the limit of inulin thermal stability. The data from differential thermal analysis confirmed the results of differential scanning calorimetry with slight differences in the starting temperatures and durations of the phase transitions. X-ray analysis showed that the degree of crystallinity of inulins is very low (except for Spindel inulin—21%).     

同步糖化发酵菊芋生产酒精中黑曲霉菌株的选育

使用以菊粉为惟一碳源的培养基从自然界中分离出6株产菊粉酶较强的菌种，其中黑曲霉SL-08还可以最大程度地提高塞尔雏亚酵母Z—06的发酵活力和耐酒精能力，通过紫外和亚硝基胍诱变，得到菌株SL-09，酶活提高近两倍。以菊芋粉为底物，利用黑曲霉SL-09和塞尔雏亚酵母Z-06采用同步糖化与发酵法，30℃发酵60h，使发酵醪酒精体积分数达到19．0％，转化率为理论转化率的86％。