细粒魔芋精粉及其复合胶的特性与应用研究

采用胶体磨湿法粉碎工艺制备得到细粒魔芋精粉,在该细粒魔芋精粉中添加10%(w/w)黄原胶制备得到复合胶。对该复合胶及细粒魔芋精粉水溶胶的流变特性以及两者在冰淇淋中的应用进行了比较研究。结果表明,与正常粒度魔芋精粉比较,细粒魔芋精粉的溶胀速度快,溶胶粘度低;相同浓度与测定条件下,复合溶胶的粘度数倍高于细粒魔芋精粉溶胶的粘度,切稀现象也比同粘度魔芋溶胶更为明显;以参考用量为0.25%的复合胶作为稳定剂应用于冰淇淋中时,也同样使冰淇淋浆料粘度显著提高,并导致其产生明显的切稀现象,相应冰淇淋制品的粘稠感明显低于以     

低温液氮粉碎对绿茶粉品质影响

为减少茶叶粉碎过程中热敏性物质损失,提出茶叶低温液氮粉碎的新方法。该论文以绿茶为原料,在粉碎过程中添加液氮,比较常规粉碎与低温液氮粉碎方法处理对绿茶粉品质的影响。结果表明,与常规粉碎法相比,液氮粉碎法的出粉率高,所得的茶粉泡制成的茶汤在色泽、滋味和品质评分上明显占优,其水浸出物中茶多酚、咖啡碱、游离氨基酸、可溶性蛋白、可溶性糖等功效成分的质量分数分别高出25.12%、10.12%、9.50%、6.75%、12.63%、9.05%;2种茶粉的香气成分组成基本相同,但液氮粉碎法所得茶的茶粉中法呢烯、橙花叔醇、1H-吲哚、己酸-3-己烯酯、五甲基庚烷、苦杏仁苷、3-甲基丁酸2-甲基丙酯质量分数分别高出10.88%、13.70%、14.06%、5.61%、2.08%、24.39%、5.68%。表明液氮粉碎能较好的保留茶粉的品质,为液氮粉碎在绿茶加工中的应用提供参考。     

水葫芦规模化脱水作业前粉碎预处理方案中试比选

该文以建成的水葫芦中试示范工程为试验平台,通过对脱水前不同的工程预处理方案进行比较研究,并分析各处理环节的成本构成,以期为水葫芦规模化处理处置工程获得低本高效的整体解决方案提供理论依据。结果表明,从不同粉碎处理方式的能耗角度考虑,采用打捞船粗粉后二次粉碎的预处理方式有利于降低水葫芦脱水环节的能耗,粉碎和脱水处理1 t水葫芦需2.5 kW·h;通过对不同的打捞处置方案分析发现,采用打捞船粗粉处理上岸方式,可大大降低其转驳成本,减少岸上粉碎环节,从而提高粉碎和脱水处理能力,降低作业环节成本,并且打捞船粗粉方式的减容率达70.61%,使转驳运输能力提高3.4倍;水葫芦经厌氧发酵后的固液分离效果明显优于水葫芦直接固液分离,其脱水残渣含水率为62.89%,脱水1 t经厌氧发酵处理后的水葫芦仅需0.06 h和0.7 kW·h。该研究结果为最终形成"打捞船粗粉碎-转驳-二次粉碎-脱水"的水葫芦处理处置工程方案奠定了坚实基础。     

包菜废弃物好氧堆肥初始条件研究

为建立适宜叶类蔬菜废弃物的快速好氧堆肥工艺,以包菜废弃物为主要堆肥原料,探索包菜废弃物直接堆肥或添加少量辅料情况下堆肥的可能性,以及叶菜废弃物细碎程度对堆肥效果的影响,共设置两个试验。试验一,调节包菜废弃物和秸秆粉混合物料初始含水量分别至70%、65%、60%、55%、50%,结果表明,当含水量低于70%时,混合物料外观以秸秆粉的黄褐色为主,且含水量在最优状态时（50%～60%）,碳氮比难以在理想状态（20～40）。试验二,以不粉碎、不添加秸秆的包菜废弃物堆肥为对照,设置不粉碎、粗粉碎、细粉碎3个处理（均添加5%秸秆）,测定堆肥温度、pH、有机质、养分、种子发芽指数和电导率。结果表明,包菜废弃物直接堆肥能完成整个堆肥过程;相较于对照,添加秸秆粉显著提升了堆肥温度、pH、有机质及种子发芽指数,降低了养分含量和电导率;粉碎程度对有机质、养分、种子发芽指数、电导率没有显著影响。因此,高含水量的包菜废弃物在不脱水、不粉碎的情况下,添加少量秸秆即可取得较好的堆肥效果。     

羽毛蛋白粉高效利用研究

采用物理加工与生物加工结合的方法，即先超微粉碎至微米级后再用解朊酶进行体外水解处理的方法对羽毛粉进行饲料化研究，通过研究发现经处理的羽毛粉比对照组（未经处理过的羽毛粉）的可溶性蛋白质含量和溶解度分别比原来增加了3.37倍和3.38倍，胃蛋白酶消化率提高了15%，表明此加工工艺可大大提高羽毛粉的生物学效价。     

机械超微粉碎与不同粒度常规粉碎对红茶理化特性的影响

为探究机械超微粉碎对茶叶物性及功能成分浸出特性的影响,该文通过超微粉碎和常规粉碎2种方法制备超微红茶粉和4种粒度的粗粉红茶粉,研究了5种茶粉的粒度分布、微观形貌、比表面积、结晶度、表面氧碳元素比、中红外图谱和功能成分的浸出特性。结果表明:常规粉碎不同粒度茶粉间差异较小,而超微粉碎较大程度地改变了茶叶的物料性质。超微粉碎后,茶粉粒度减小至微米级,比表面积增大,茶粉的结晶度降低,表面暴露的纤维素和半纤维素相对含量增多,而中红外谱图显示超微粉碎茶粉的官能团结构并没有改变。沸水浸提过程中茶多酚、咖啡因、可溶性糖和水浸出物的溶出结果表明:5种茶粉功能成分的浸出量都随时间的增加而增加,经过一段时间后达到平衡。在达到浸出平衡时,不同粒度茶粉的茶多酚和咖啡因含量差异不显著,超微茶粉的可溶性糖含量为4种粗粉的2倍左右,水浸出物比粗粉茶粉提高10%以上。上述研究结果表明:超微粉碎能够有效减小茶粉的粒度,破坏植物的细胞壁结构,使内部成分暴露于表面,此外,组织结构和细胞壁的破坏使不溶的纤维成分转化成可溶性成分,可溶性糖和水浸出物显著增多,超微粉碎能够在一定程度上提高茶粉的有效利用率。     

超微粉碎对桑叶粉理化性质的影响

为拓展超微粉碎技术在食品添加剂和药品开发中应用,以桑叶为原料,分别对桑叶粗粉进行干法超微粉碎2 、4、6、8 h,得到4种不同粒径大小的桑叶超微粉,并对桑叶粗粉与4种超微粉的理化性质进行比较。研究结果表明,超微粉碎能明显减小桑叶粗粉的颗粒粒径（P＜0.05）,随着超微粉碎时间的增加,超微粉的粒径减小,粉体的粒径分布范围变窄,比表面积和体积密度显著增加（P＜0.05）,休止角、滑角和膨胀性显著降低（P＜0.05）,水溶性/持水力、持油力、蛋白质的水溶性和多糖的水溶解性均有不同程度的增加,但多酚含量变化不显著（P＞0.05）。扫描电镜结果显示,粗粉经超微粉碎后,其颗粒呈零散的分布形态。说明超微粉碎可改善桑叶粉的部分理化性质,可将这些性质应用于食品添加剂和常规食品开发与加工中。所得研究结果将为超微粉碎技术在桑叶食品中工业化应用提供数据支持和理论依据。     

魔芋辐照接枝丙烯酸及其产物吸水性能的研究

研究了魔芋-丙烯酸辐照接枝共聚条件及产物的吸水性能,结果表明接枝最佳配方为:魔芋粉∶丙烯酸∶NaOH(9.5mol/L)∶水=3g∶21ml∶17.8ml∶131ml。丙烯酸与魔芋粉配比为7∶1(体积质量比);丙烯酸中和度55%;辐照后胶体最佳烘干温度30℃,该温度下40~80目颗粒吸水倍数较大,常温120min时达最大吸水866.5倍。温度对产物吸水和胶体保水有一定影响,以60℃以下为宜。pH对产物吸水倍数影响明显,但不及离子浓度对产物吸水倍数的影响大。     

气流和机械碾轧超微粉碎香菇柄的效果比较

为了提高香菇副产物菇柄的附加值,应用气流粉碎和机械碾轧粉碎2种工艺分别对菇柄进行超微处理。对气流粉碎工艺中的分级机转速,机械碾轧粉碎工艺中的主机频率、风机频率等操作参数进行了单因素分析,进一步结合分段线性拟合法对2种工艺的加料速度进行了优化,分别得出了2种工艺的较适工艺条件;并对二者的粉碎效果、处理时间、能耗和出品率进行了比较。结果显示:气流粉碎的较适工艺条件为:分级机转速2 400 r/min,加料速度12 kg/h;机械碾轧粉碎的较适工艺条件为:主机频率44 Hz,风机频率42 Hz,加料速度5 kg/h。2种超微粉碎方式都能获得10μm以下的微粉,与机械碾轧粉碎相比,气流粉碎的分级精度较高,处理时间缩短了56.43%,但出品率较低,能耗为前者的4.77倍。总体来看,机械碾轧粉碎更适合规模化生产,该研究为超微粉碎技术应用于香菇柄深加工利用提供了技术依据。     

石墨烯溶胶配施化肥对土壤中养分流失的影响

通过土柱淋溶试验研究了石墨烯溶胶配施化肥后对土壤中养分流失的影响,以探究石墨烯溶胶的保肥作用。试验共设计5个石墨烯溶胶浓度,进行4次淋溶,测定每次淋溶液以及4次淋溶后的土壤的电导率、氮、磷、钾含量。结果表明:(1)石墨烯溶胶与化肥配施于土壤中后对淋溶液的电导率、氮、磷及钾的含量均有影响,且添加的石墨烯溶胶浓度越大影响越明显。添加石墨烯溶胶处理后的淋溶液中,硝态氮、总氮、磷的含量最大可分别降低88.2%,80.9%和84.7%。(2)4次淋溶后,添加石墨烯溶胶处理的土壤中氮、磷、钾的含量及电导率与对照相比均有增加,其中对总氮、总磷的持留效果最大可提高175.0%和59.3%,但对铵态氮的持留无明显效果。(3)石墨烯溶胶对淋洗液和土壤的pH影响不明显。石墨烯溶胶与肥料施入土壤中,可明显减少土壤中养分的淋溶损失,对土壤中的养分有明显的持留效果,具有保肥的作用。     

Grain-size effect on the structure and antiobesity activity of konjac flour

The effect of high-frequency oscillatory type ball-mill treatment on the structure and antiobesity activity of konjac flour was investigated. The grain size of konjac flour changed from 657.3 microm (d(50)) to 23.7 microm (d(50)) after 4 h of treatment. The structural change of the konjac flour with different grain size was characterized by using X-ray diffraction (XRD) differential scanning calorimetry (DSC). The results indicated that the crystallinity decreased and the diffraction peak drifted not only by when the crystallization region was reduced but also when the crystalline structure was changed. With the decrease of the grain size and crystallinity, the konjac flour grain, especially the 4 h milled konjac flour, swelled more rapidly and led to the improvement of the antiobesity effect. Compared with the native konjac flour, the 4 h milled konjac flour could significantly decrease the body weight and total wet weight of fat of nutritional obese rats (P < 0.05) and also decreased the contents of triglyceride, glucose, and high-density lipoprotein in blood of nutritional obese rat significantly (P < 0.05), which meant the grain-size effect of konjac flour improved its antiobesity activity notably.     

一株产常温葡甘聚糖酶的芽孢杆菌的分离、鉴定及产酶发酵条件的研究

以魔芋生粉为唯一碳源的筛选培养基,从魔芋废渣中分离筛选出一株可以降解魔芋生粉的细菌菌株,编号为LS-6。根据16SrDNA序列和生理生化特性,将该菌株鉴定为枯草芽孢杆菌Bacillus subtilis。胞内外葡甘露聚糖酶酶活分析结果表明,LS-6产生的葡甘聚糖酶为胞外酶。LS-6产生葡甘聚糖酶的最佳培养基组分和条件是：1%魔芋生粉,0.5%酵母粉,0.5%NaCl,培养基初始pH为6.0,最佳发酵条件是25℃,摇床转速200r/min,培养48h。酶解产物的高效液相色谱分析结果表明,LS-6粗酶液的酶解产物主要为葡萄糖和甘露糖。LS-6的分离为进一步克隆常温葡甘聚糖酶基因和产酶工程菌的构建奠定了基础。     

Use of Solvent Retention Capacity Profile to Predict the Quality of Triticale Flours

The solvent retention capacity test (SRC) was used to evaluate flour functionality for end use applications and select wheat for production of flour with required functionality, but there is little information about SRC test application on triticale flour quality. The ability of flour to retain a set of four solvents produces a flour quality profile for predicting bakery performance. The objective of this study was to evaluate the capacity of SRC and its micro test to determine the potential quality of 25 triticale flours, as well as studying the relationship between the SRC parameters and flour chemical composition. The SRC parameters of triticale flours were correlated with the flour components that have been proposed by the method: sucrose SRC‐pentosan (r = 0.57), carbonate SRC‐damaged starch (r = 0.80), lactic SRC‐glutelin (r = 0.42), water SRC‐all hydrophilic constituents (damaged starch [r = 0.72], protein [r = 0.61], glutelin [r = 0.66], pentosan [r = 0.46]). Triticale flours have shown higher water and sodium carbonate SRC, similar sucrose SRC, and lower lactic SRC values than published results of typical flours used for cookie production. Summarizing, the high level of association found between SRC and micro SRC parameters with flour composition and quality flour tests evidence that either the SRC profile or the micro test SRC could be used to determine the potential quality of triticale flours.     

魔芋葡甘聚糖酯化改性产物对空气中SO2吸附及抑菌效果研究

以魔芋葡甘聚糖为原料,分别采用苯甲酸、醋酸和没食子酸对魔芋葡甘聚糖进行酯化改性,研究了改性pH值、温度及改性处理时间对改性产物吸附空气中SO2和抑菌效果的影响,优化了改性工艺参数,得到了有较好使用效果的天然的有机大分子空气净化材料.研究结果表明:当采用苯甲酸为魔芋葡甘聚糖酯化改性剂时,改性产物对空气中的SO2吸附效果和抑菌作用效果优于使用醋酸和没食子酸的改性产物.其改性处理温度50℃,反应时间2 h,pH值3,改性反应产物对空气中SO2的吸附率可达98.7%,抑菌率可达到86.3%.     

Textural Comparisons of Gluten‐Free and Wheat‐Based Doughs,Batters, and Breads

Studies were conducted with two newly developed gluten‐free bread recipes. One was based on corn starch (relative amount 54), brown rice (25), soya (12.5), and buckwheat flour (8.5), while the other contained brown rice flour (50), skim milk powder (37.5), whole egg (30), potato (25), and corn starch (12.5), and soya flour (12.5). The hydrocolloids used were xanthan gum (1.25) and xanthan (0.9) plus konjac gum (1.5), respectively. Wheat bread and gluten‐free bread made from commercial flour mix were included for comparison. Baking tests showed that wheat and the bread made from the commercial flour mix yielded significantly higher loaf volumes (P < 0.01). All the gluten‐free breads were brittle after two days of storage, detectable by the occurrence of fracture, and the decrease in springiness (P < 0.01), cohesiveness (P < 0.01), and resilience (P < 0.01) derived from texture profile analysis. However, these changes were generally less pronounced for the dairy‐based gluten‐free bread, indicating a better keeping quality. Confocal laser‐scanning microscopy showed that the dairy‐based gluten‐free bread crumb contained network‐like structures resembling the gluten network in wheat bread crumb. It was concluded that the formation of a continuous protein phase is critical for an improved keeping quality of gluten‐free bread.     

Assessment of home-based processing methods to reduce the phytate content and phytate/zinc molar ratio of white maize (Zea mays)

Various methods of processing maize suitable for household use in rural Malawi, Central Africa, were investigated for their ability to reduce its phytate content and phytate/zinc molar ratio. These methods included fermentation, germination, and soaking. Penta- and hexainositol phosphates were measured by HPLC, and zinc was measured by atomic absorption spectrophotometry. Natural lactic fermentation of maize flour slurries resulted in 88% phytate retention compared to unprocessed, unrefined maize flour porridges, whereas lower phytate retention was observed when a starter culture (61%) or germinated flour (71%) was also used. Fermentation of cooked maize flour porridges with germinated flour added resulted in 54-85% retention of phytate compared to controls. Soaking maize flour or pounded maize and decanting excess water resulted in 43 and 49% retention of phytate, respectively. The latter soaking procedures were simple and effective and were suitable for household use in rural Malawian communities.     

Application of a Micro Z‐Arm Mixer to Characterize Mixing Properties and Water Absorption of Wheat Flour

This study applied the use of a new small‐scale apparatus, the micro Z‐arm mixer, which has analogous mixing action to that of the traditional valorigraf and farinograph. A novel methodology has been developed for prediction of water absorption replacing the traditional titration method. The basis of this technique is a common characteristic of wheat flour samples: a reasonably constant slope (20–25.7 BU%) of the relationship between dough resistance and the amount of water present during mixing. Using an average slope value, prediction of water absorption was possible from a single measurement using a simple equation and with a standard error of 1.65%. Applications of the new mixer to cereal research are highlighted, including investigation of the effects of flour protein content and protein composition on mixing properties and water absorption. When protein content and protein composition have been systematically altered by the addition of isolated proteins into the flour, both dough development time (DDT) and water absorption increased when protein content was increased by glutenin addition and decreased when protein content was decreased by starch addition. Gliadin addition decreased DDT; gluten addition slightly increased DDT; glutenin addition significantly increased DDT. Water absorption was not affected by altering the glutenin‐to‐gliadin ratio, but it changed in proportion to the amount of protein added. The effect of HMW‐GS composition on the mixing requirement obtained with the micro Z‐arm mixer and with the 2‐g mixograph was also investigated using a set of single‐, double‐, and triple‐null lines for HMW‐GS coding genes. While subunits coded on the GluD1 locus were most important for determining the mixing requirement in both cases, the sample ranking was different in the two mixing actions. A better differentiation ability of the micro Z‐arm mixer was established for triple‐ and double‐null lines.     

不同亲水胶体对带鱼鱼糜凝胶品质的影响

为确定合适的亲水胶体种类及其添加量,以带鱼鱼糜为原料,通过测定凝胶强度、质构(硬度、粘聚性、弹性和咀嚼性)、白度、持水性和凝胶溶解度等指标,分析瓜尔胶、魔芋胶和沙蒿胶3种亲水胶体对带鱼鱼糜凝胶品质的影响。结果表明,瓜尔胶、魔芋胶和沙蒿胶均能提高带鱼鱼糜凝胶强度,但相同添加量下魔芋胶的改善效果最好,而瓜尔胶对鱼糜凝胶强度的影响不显著。魔芋胶能显著改进带鱼鱼糜凝胶的质构特性;瓜尔胶添加量为2.0%时鱼糜凝胶硬度、弹性、咀嚼性、粘聚性比对照组低;沙蒿胶对鱼糜凝胶的粘聚性影响显著,当添加量为1.5%或2.0%时,带鱼鱼糜凝胶的咀嚼性、硬度增加,弹性下降。瓜尔胶、魔芋胶和沙蒿胶均能提高带鱼鱼糜持水性,降低鱼糜凝胶白度和溶解度,但对鱼糜凝胶色泽的影响不显著。扫描电镜结果显示,1.5%魔芋胶处理组形成的鱼糜凝胶表面规则有序、网络结构致密均一。综合比较,添加1.5%魔芋胶能有效改善带鱼鱼糜的凝胶品质。本研究结果为提高带鱼鱼糜制品品质及生产研发提供了一定的理论依据。     

Konjac Polysaccharides Affect the Quality,Cell Structure,and Moisture Balance of Baked Bread

The effect of addition of konjac glucomannan (KGM) and its derivative konjac superabsorbent polymer (KSAP) on fresh bread quality and its influence on bread staling were investigated. Both KGM and KSAP decreased the hardening rate of the bread crumb and retarded amylopectin retrogradation. Loaf quality of the KGM bread and KSAP bread were therefore improved, because collapse of gas cells during bread processing was prevented. Thermogravimetric analysis (TGA) showed that the presence of KGM and KSAP increased compartmentalized water and slowed release of the compartmentalized water. Deconvolution of TGA showed an alteration of the distribution of free and bound water and its interaction with starch and gluten. Additionally, by monitoring water‐binding strength and changes during storage by a_w measurements, it was found that water release from konjac polysaccharide‐enriched bread was extended over time compared with the release from control bread. The presence of KGM and KSAP significantly reduced the staling rate of bread.