Use of enzymes to elucidate the factors contributing to bitterness in rye flavour

In spite of the health-beneficial character of whole grain rye its use may be limited because of bitter taste. The impact of non-volatile chemical compounds on the bitter taste of rye was analysed by the aid of enzymatic hydrolysis, releasing potentially flavour-active compounds from the rye matrix. Whole grain rye flour–water suspension was treated with hydrolytic enzymes, whereafter portions of the rye suspensions were baked into crackers, assessed for their sensory profile as well as solubilised hydrolysis products. Heat treatment reduced the perceived bitterness. The treatment with enzyme preparation with high protease activity increased the bitterness of rye and also wheat flour both as suspension and as crackers. Other enzymes tested (with high polygalacturonase, endo-glucanase, xylanase or amyloglucosidase activity) had no significant impact on the perceived bitterness. Thus, small molecular weight peptides were considered to be a significant contributor to the bitter note of rye.     

菊芋酶解制备低聚果糖糖浆的工艺优化及功能评价

菊芋块茎富含菊糖,是制备低聚果糖（Fructooligosaccharides,FOS）的主要原料之一,新鲜菊芋块茎直接酶法加工用于功能性糖浆的制备可以丰富菊芋综合加工的应用。本研究以新鲜菊芋块茎为原料,通过系统研究菊芋内源酶、菊粉内切酶、葡聚糖内切酶、木聚糖酶、聚半乳糖醛酸酶和单宁酶在鲜菊芋酶法加工制备低聚果糖糖浆中的作用规律和酶解效果,建立并优化了酶法制备低聚果糖糖浆的工艺。结果表明,最优酶解工艺如下：菊芋浆在50℃和pH5.0条件下,加入0.08 U/g单宁酶酶解4 h,再加入0.08 U/g葡聚糖内切酶、0.08 U/g木聚糖酶、0.07 U/g聚半乳糖醛酸酶和12 U/g菊糖内切酶组合酶解8 h,酶解液浓缩2倍后获得低聚果糖糖浆成品。成品中低聚果糖和单宁的含量分别为53.72和3.11 g/L,DPPH自由基清除率、羟基自由基清除率和总抗氧化能力分别为82.23%、30.47%和2.78μmol/mL。以制备的低聚果糖糖浆为唯一碳源替代MRS培养基中的葡萄糖,植物乳杆菌、嗜热链球菌和副干酪乳杆菌的生长速率较未经酶解的菊芋原浆作为MRS培养基的唯一碳源时,分别提高了33.33%...     

菊芋的综合利用及发展前景

本文介绍了用水解法和微波法制备菊糖的工艺，以及酸水解法和酶法制备高果糖浆的工艺，并对两种提取菊糖的方法进行了简单的比较，且探讨了菊芋极其深加工产品的发展现状及广阔前景。     

Dough rheological properties in relation to cracker‐making performance of organically grown spelt cultivars

Cracker quality is highly influenced by the quality of flour. In this study, two spelt cultivars were analysed and evaluated in relation to cracker‐making performance and factors that influence cracker quality. For comparison, conventional commercial wheat flour was used. Results showed that the tested cultivars differed in their rheological properties. The obtained crackers were also of different qualities. The highest proportion in total variance of cracker quality (>45%) was due to geometric characteristics. The most significant parameter in cracker quality classification was the modified cookie factor. The tested spelt cultivars were able to produce crackers of acceptable quality characterised with lower snap back, higher cookie factor and lower hardness in comparison with control. But, spelt crackers developed less oven spring which negatively reflected to cracker texture. Among the flour and dough quality parameters, gluten quality parameters and zero shear viscosity were significantly correlated with most of the cracker quality attributes.     

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％。     

Soluble dietary fibres in Jerusalem artichoke powders: composition and application in bread

Powders of tubers from Jerusalem artichoke (Helianthus tuberosus, L.), cultivar Gigant, of different harvesting times (autumn and spring) were applied in bakery products, particularly in wheat/rye bread. The quality of this bread was compared to bread with cereal flours substituted with commercial products as Raftilin ST and Raftilose P95. Compared to standard and substituted bread, Jerusalem artichoke bread shows a high quality in organoleptic evaluation (grade I with 36.5 and 37.5 scores). In utilised Jerusalem artichoke powders (JAPs) the amount of fructan (inulin) hydrolysis to fructose during the baking process depends on its initial degree of polymerisation (dp). With JAP of autumn harvest (fructan: dpn = 9.9, dpw = 21.8) less fructose (24.6%) is formed than with those of spring harvest (fructan: dpn = 4.9, dpw = 7.1) (40.7%). Compared to this bread, substitution with commercial products Raftilin ST (inulin: dpn = 8.4, dpw = 17.4) and Raftilose P95 (fructo-oligosaccharides: dpn = 2.7, dpw = 3.0) yields 11.9% and 45.8% of fructose upon total hydrolysis, respectively. The loss of fructan content by the bakery process is 38% in bread with JAP of autumn and 43% in bread with JAP of spring harvest; Raftilin ST- and Raftilose P95-bread come up with loss of fructan content of 35% and 47%, respectively.     

菊芋全粉对米发糕贮藏品质特性的影响

目的 探究菊芋全粉添加量与米发糕品质特性之间的相关性。方法 在米发糕中添加不同比例(5%、10%、15%、20%、25%)的菊芋全粉,测定其贮藏过程(0、1、3、5、7 d)中感官品质、质构特性和体外消化特性等指标,探究菊芋全粉与米发糕品质指标之间的相关性。结果 与未添加菊芋全粉的米发糕相比,菊芋全粉的添加降低了米发糕的硬度、粘性和咀嚼性,感官评分从81.91下降到70.91,而米发糕抗性淀粉从26.02%增加至34.59%。菊芋全粉的添加能有效减缓米发糕在贮藏期间质构的劣变,贮藏第7d时,添加15%菊芋全粉的米发糕感官评分(80.83)高于对照组(66.57),且添加10%菊芋全粉的米发糕抗性淀粉高达42.23%。通过相关性分析,回复值、弹性和粘聚性是影响米发糕感官品质的主要因素,其中弹性与米发糕感官评分呈极显著负相关(P<0.01)。结论 添加菊芋全粉可有效提升米发糕的感官品质及抗消化特性,并能有效减缓米发糕在贮藏期间的质构劣变,同时也丰富了米发糕品种多样性,可为菊芋资源的开发和高值化利用、发糕制品的深度研究提供理论参考。     

Nutritional and functional added value of oat, Kamut, spelt, rye and buckwheat versus common wheat in breadmaking

BACKGROUND: Multicereal/pseudocereal blends based on major and minor seeds with high nutritional profile appear as a promising strategy, hardly explored, to obtain enhanced value grain‐based foods such as bread. RESULTS: In a preliminary stage the suitability of minor/ancient cereals (rye, oat, Kamut^® wheat, spelt wheat) and pseudocereals (buckwheat) was assessed in single (100% of wheat flour replacement) and multigrain (from 20 to 44% of wheat flour replacement) matrices. The research allowed identification of the qualitative (oat, rye, buckwheat) and quantitative (up to 75% of wheat flour replacement) grains in the mixed matrices providing enhancement of nutritional quality (higher protein content, higher mineral content, lower digestible starch, higher viscous fibre content, higher resistant starch content, source of antioxidants) and minimisation of techno‐functional impairment and sensory depreciation of the resulting breads. CONCLUSION: The quality profile of associated mixtures of oat, rye, buckwheat and common wheat flours (20:20:20:40 w/w/w/w) endorsed the proposed grain blend as suitable to make highly nutritious, modern and innovative baked goods meeting functional and sensory standards in terms of nutritional added value (improved dietary fibre fractions, minerals and antioxidant activity, slower starch hydrolysis), palatability (high sensory scores), convenience (extended keepability during storage) and easy handling during processing. Copyright © 2011 Society of Chemical Industry     

菊芋资源的开发利用

根据国内外近期研究成果,简要介绍了菊芋的生长习性及菊芋块茎的主要成分,比较系统地介绍了菊芋资源的开发现状,其中包括菊芋粉、菊芋汁、菊糖、果糖和低聚果糖等主要菊芋制品的生产、功能性及其在食品工业中的应用。     

Choice of Cereal Raw Materials and Suitable Combinations of Additives for Sensory Quality Improvement of Pastry

Effect of selected additives and their combinations on the sensory quality of final cereal products prepared from the mixture of flours (wheat T 650, rye T 930, and spelt) and from wheat flour T 512 was studied. The following sensory parameters were considered: shape (cambering); crust (color, thickness, hardness); crust/crumb (odor, taste); crumb (elasticity, porosity, color, hardness (resistance to bite); adhesiveness (to palate at longer chewing). It was found that sensory parameters increased after the application of the selected combinations of improving additive substances (ascorbic acid, enzymes and emulsifiers) and concentration of the enzyme preparation Lipopan 50 BG had a positive effect on sensory parameters and on the reduction of the applied amount of emulsifiers in the final product.     

Extraction and Enzymatic Hydrolysis of Inulin from Jerusalem artichoke and their Effects on Textural and Sensorial Characteristics of Yogurt

Inulin has become an attractive ingredient in the food industry because of its nutritional and functional characteristics. Extraction of inulin from Jerusalem artichoke and the effects of its enzymatic hydrolyzate on the textural and sensorial characteristics of yogurt were investigated. The extraction yield (98%) of inulin was obtained with dry Jerusalem artichoke powder. The thin-layer chromatography and the ion chromatogram analysis of the enzymatic hydrolyzate revealed that inulinase hydrolyzed inulin into fructooligosaccharides with degrees of polymerization from 2 to 10. Utilization of inulin and hydrolyzate in yogurts improved their textural properties. Sensorial evaluation of yogurts showed that yogurts with inulin or its hydrolyzate had a better body and smoother texture than yogurts with sucrose only. The findings of this study suggest that inulin or its hydrolyzate can partially replace sucrose in formulations in the food industry.     

菊粉酶的研究进展

菊粉酶是一类能水解β-2,1-D-果聚糖果糖苷键的水解酶,属于糖苷水解酶32家族。菊粉酶是菊芋生物炼制中的关键酶,它能将菊芋一步水解,获得高纯度的果糖浆,生产燃料乙醇、燃料丁醇、单细胞油脂、生物柴油、甘露醇和乳酸等其它工业产品,在食品、医药及生物能源等领域有着巨大的应用价值。该文介绍了菊粉的分子结构及来源,概述了菊粉酶的分类、来源、克隆表达、三维结构及应用,并对菊粉酶的未来发展方向进行了展望,旨在提高人们对菊粉酶的认识,推动菊芋生物炼制的研究。     

Zur Biotechnologie fructosanhaltiger Pflanzen

On the Biotechnology of Plants with Fructosan Content. Inulin, as to its chemical nature, is a polyfructosane. Fructosanes (fructanes) are hardly less abundant in nature than starch. However, there are only few plants with sufficient fructosane content for technological utilization. The most important of them are Jerusalem artichoke and chicory. At first this paper deals with inulin and the homologous series of fructosanes. The importance of Jerusalem artichoke and chicory as agricultural crops and their respective peculiarities are pointed out as far as they are relevant for their use as technical source materials. Inulin containing plants are of interest with respect to the production of fructose and fructose syrup and as energy plants (production of ethanol). Chicory is particularly suitable as source material for fructose-(syrup-)production, Jerusalem artichoke mainly for the production of ethanol, although principally both product groups can be obtained from chicory roots and from topinambur bulbs. If inulin containing raw materials are used for ethanol production, it's of interest that yeast invertase splits polyfructosanes of higher molecular mass considerably more slowly than inulinase and yields are less satisfactory with S. cerevisiae and increasing inulin content in the mash. If yeast types are used containing inulinase and invertase, e. g. Kl. fragilis and marxianus, satisfactory fermentation can be obtained even with these types of mashes.     

牛蒡菊糖和菊芋菊糖对酒精诱导大鼠慢性氧化损伤的防治作用

[目的：研究酒精对小鼠肾、脑、心脏及睾丸中GSH、MDA 的影响,并探讨牛蒡菊糖在保护脏器氧化损伤方面的作用并与菊芋菊糖进行比较研究。方法：雄性成年小鼠随机分为6 组(牛蒡菊糖低、中、高3 个剂量组,菊芋菊糖组,酒精模型组和空白对照组),共灌胃20d。实验结束后,分别取脑、肾、心脏和睾丸,制成10% 组织匀浆,离心,取上清液测定丙二醛(MDA)、还原性谷胱甘肽(GSH)含量。结果：1)肾脏：小鼠灌胃酒精后,GSH 含量与对照组比较差异不显著(P ＞ 0.05),灌胃酒精和不同剂量牛蒡菊糖以及菊芋菊糖后GSH 含量显著低于酒精组(P ＜ 0.05,P ＜ 0.01);小鼠灌胃酒精后MDA 含量与对照组比较显著升高(P ＜ 0.01),灌胃酒精和中高剂量牛蒡菊糖后MDA含量显著低于酒精组(P ＜ 0.05),但灌胃酒精和菊芋菊糖后MDA含量与酒精组比较差异不显著(P ＞ 0.05)。2)脑：小鼠灌胃酒精后GSH 含量与对照组比较显著降低(P ＜ 0.01),灌胃酒精和中高剂量牛蒡菊糖后GSH 含量显著高于酒精组(P ＜ 0.01),但灌胃酒精和菊糖后GSH 含量与酒精组比较无显著性差异(P ＞ 0.05);小鼠灌胃酒精后MDA 含量与对照组比较显著升高(P ＜ 0.01),灌胃酒精和高剂量牛蒡菊糖以及菊芋菊糖后MDA 含量与酒精组比较显著降低(P ＜ 0.01)。3)心脏：小鼠灌胃酒精后GSH 含量与对照组比较略有降低但无显著性差异(P ＞ 0.05),灌胃酒精和高剂量牛蒡菊糖后GSH 含量显著高于酒精组(P ＜ 0.01),但灌胃酒精和菊芋菊糖后GSH 含量与酒精组比较无显著性差异(P ＞ 0.05);小鼠灌胃酒精后MDA 含量与对照组比较无显著差异(P ＞ 0.05),灌胃酒精和高剂量牛蒡菊糖以及菊芋菊糖后MDA 含量与酒精组比较也无显著差异(P ＞ 0.05)。4)睾丸：小鼠灌胃酒精后GSH含量与对照组比较无显著性差异(P＞ 0.05),灌胃酒精和牛蒡菊糖以及菊芋菊糖后GSH含量与酒精组比较变化也无显著性差异(P ＞ 0.05);小鼠灌胃酒精后MDA 含量与对照组比较略有升高但无显著差异(P ＞ 0.05),灌胃酒精和中高剂量牛蒡菊糖后MDA 含量与酒精组比较显著降低(P ＜ 0.05),但灌胃酒精和菊芋菊糖后MDA 含量与酒精组比较无显著性差异(P ＞ 0.05)。结论：在本实验条件下,酒精能较显著地引起小鼠肾脏和脑组织的氧化损伤但对心脏和睾丸的氧化损伤较小。牛蒡菊糖和菊芋菊糖对上述器官的氧化损伤具有一定的保护作用。     

Effect of pulse flours on the physiochemical characteristics and sensory acceptance of baked crackers

Pulse flours offer nutritional alternatives to wheat flour in the production of baked snacks due to their high protein and fibre levels and low glycaemic index. In this study, broad‐bean (Vicia faba), yellow‐pea and green‐pea (Pisum sativum) flours were each blended with wheat flour at 40% in the formulation of chemically leavened crackers. The effects of flour type and baking time on the physiochemical properties, sensory acceptability, nutritional composition and antioxidant activity of the crackers were observed in comparison with 100% wheat crackers. Broad‐bean crackers had the highest protein content and antioxidant activity (13 g per 100 g DM and 38.8 mgAAE per 100 g DM, respectively). Yellow‐pea crackers had the highest fibre content (12 g per 100 g DM). Physical dimensions and colour attributes were significantly affected by pulse‐flour substitution. Yellow‐pea and broad‐bean crackers were significantly preferred by consumers compared to the control, demonstrating the potential application of these flours to improve the eating quality and nutritional profile of crackers.     

乳酸菌发酵菊芋汁及其风味的研究

对不同品种和产地的菊芋主要成分进行了测定,并利用乳酸菌对菊芋汁进行发酵,研究了不同乳酸菌在菊芋汁中的生长规律、低温存活性及发酵菊芋汁中主要风味物质。结果表明,4种乳酸菌在菊芋汁中均生长良好,最高活菌数可达到109CFU/mL;菊芋汁经乳酸菌发酵后具有良好风味,其风味的差异与发酵菌种有关;发酵菊芋汁中乳酸菌在4℃低温贮藏过程中具有较好的低温存活性,4周后活菌数保持在108CFU/mL。菊芋汁适用于开发成新的功能性乳酸菌饮料。     

The content of proteic and nonproteic (free and protein-bound) tryptophan in quinoa and cereal flours

The content of proteic and nonproteic (free and protein-bound) tryptophan and of proteins in quinoa, wheat, rice, maize, barley, oat, rye, spelt, sorghum and millet flours was determined. Protein content and proteic tryptophan of quinoa were similar to that of wheat and spelt, but higher than in other cereals. Free tryptophan in quinoa flour showed values similar to those of wheat, oat and sorghum Kalblank, lower than those of barley, spelt and pearl millet, but higher than in rice, maize, rye, sorghum DK 34 – Alabama hybrid. In addition, nonproteic tryptophan appears bound both to water soluble proteins and to proteins soluble at pH 8.9. The results are discussed regarding the importance of the nonprotein tryptophan fraction, the only one able to enter the brain, that is more easily absorbed, so guarantees a greater amount available for uptake by the central nervous system.     

Effect of heat treatment of rye flour on rye‐wheat steamed bread quality

To study the effect of heat treatment on rye flour quality, rye flour was treated by steaming, high temperature and high pressure (HTHP) and extrusion and then the pasting properties of rye flour and rye‐wheat blend, the dough rheological and steamed bread (respectively, fermented by yeast and Chinese traditional starter – Laomian) making properties of rye‐wheat blend were investigated. All three kinds of heat treatment increased the viscosity of rye flour, with the peak viscosity value followed the order 1744 cP (by steaming) >823.5 cP (by HTHP) >669 cP (by extrusion) > 626.5 cP (untreated). Dough and gluten made from mRFh (HTHP‐treated rye flour and wheat flour blend) had higher storage modulus (G′) and loss modulus (G″), which contributed to better extensibility and deformation capability. Steamed bread fermented by Laomian (LSB) made by mRFh had larger specific volume (2.26 mL g^?1), lower hardness (3510.93 g) and higher sensory scores (82.63), comparable to the quality of control samples, indicating the feasibility of adding rye flour into wheat flour for healthy product development without compromising the taste and texture.     

Effects of soaking treatment on the acrylamide and inulin contents of Jerusalem artichoke tea and its antioxidant activity

There are several studies that show that large amounts of acrylamide are detected in Jerusalem artichoke (Helianthus tuberosus L.) tea. This study examined acrylamide, inulin content and antioxidant properties of Jerusalem artichoke tea brewed in different conditions. Uniformly sliced Jerusalem artichokes were soaked in different salt and acidic solutions for 60 min at 20 °C and extracted with hot or cold water. The acrylamide content was analyzed by high-performance liquid chromatography–tandem mass spectrometry. The Inulin content and antioxidant activity were analyzed by spectrophotometer. Soaking significantly reduced acrylamide levels (p < 0.05) with the largest decrease observed for acetic acid, whereas the effects of all soaking treatments on inulin content were similar. Teas brewed using small-particle-size samples and hot water exhibited the highest acrylamide/inulin levels and antioxidant activity. Consequently, The most suitable treatment for Jerusalem Artichoke tea preparation was 1-h soaking in 1% acetic acid at 20 °C.     

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