Starch Digestibility and Physicochemical and Cooking Properties of Irradiated Rice Grains     

Luís Fernando Polesi  Manoel Divino da Matta Junior  Silene Bruder Silveira Sarmento  Solange Guidolin Canniatti-Brazaca 《水稻科学》2017,24(1):48-55

This study evaluated the starch digestibility, physicochemical properties and cooking characteristics of polished rice (varieties IRGA417 and IAC202) subjected to the doses of 0 (as the control), 1, 2 and 5 kGy of gamma radiation. The highest dose decreased the apparent amylose content, peak viscosity, water absorption and volume expansion. Irradiation increased the solid loss by 119% and 187% for IAC202 and IRGA417, respectively, when comparing the higher dose with the control. For IAC202, irradiation decreased the rapidly digestible starch and increased the slowly digestible starch (SDS) and resistant starch (RS). IRGA417 showed an elevation of SDS and a reduction in RS. And 1 kGy dose of gamma radiation generated the highest level of RS for both the two varieties and presented the smallest changes in other physicochemical and cooking properties.  相似文献   

Effects of Continuous Steaming on Milling Characteristics of Two Indica Rice Varieties     

N.VENKATACHALAPATHY  R.UDHAYAKUMAR 《水稻科学》2013,20(4):309-312

Parboiling improves milling characteristics of rice in a positive manner,which has been found to influence consumers demand and acceptability.A laboratory model of continuous steaming unit was fabricated and tested with two indica rice varieties,fine (ADT39) and coarse (CO43) rice,at three different soaking temperatures (50,60 and 70 ℃) for 4 h and five residence times of steaming (1.0,1.5,2.0,2.5 and 3.0 min).The effects of continuous steaming on milling characteristics of rice were studied and compared with the values obtained from the control experiment (open steaming process under laboratory conditions).The favourable conditions for continuous parboiling of the fine variety ADT39 were identified as soaking at 70 ℃ for 4 h and 3.0 min residence time of steaming.These conditions showed head rice outturn of 74.0%.The favourable processing conditions for the coarse variety CO43 were found to be 4 h of soaking at 60 ℃ and steaming of 3.0 min residence time,and at these conditions the head rice outturn was 73.9%.  相似文献   

The Effects of Downstream 3513bp of UL56 on Characterization of Duck Enteritis Virus     

MAO YaQing  ZHANG Bing  WANG TuanJie  HOU LiDan  HUANG XiaoJie  LIU Dan  ZHAO JunJie  LI QiHong  WANG LeYuan  LI JunPing  YANG ChengHuai 《中国农业科学》2019,52(23):4390-4397

【Objective】Duck enteritis virus (DEV) taxonomically belongs to family Herpesviridae and infects ducks, geese, and swans, which results in high mortality and decreased egg production in domestic and wild waterfowl. Several DEV whole genomic sequences were published, which contained 158-162 kb. Compared with DEV vaccine strain, the virulent DEV strain for vaccine evaluation had a 3513-bp insertion, resulting to UL56 frameshift mutation. At present, there are few papers about DEV gene function and pathogenic mechanism. To study the effect of the 3513-bp insertion on DEV characterization, a recombinant DEV with the 3513-bp deletion was constructed.【Method】The extracted DEV genomic DNA was used as template to amplify the UL56-u and UL56-d of the upstream and downstream ends of UL56 gene, respectively. The two homologous arm fragments were cloned into pMD18T-Simple vector, and the recombinant plasmid pT-UL56ud was obtained. The recombinant plasmid pT-UL56ud was cut by MluI enzyme, and after electrophoretic recovery and dephosphorylation, the recombinant plasmid pT-UL56-RFP was obtained by inserting RFP expression box into pT-UL56ud. After DEV was inoculated with duck embryo fibroblast (DEF) (MOI=0.1) for 1 to 2 h, the purified plasmid pT-UL56-RFP was transfected according to Lipofectamine 2000 instructions, and then purified by plaque. A 3513-bp deletion mutant, DEVΔ3513-RFP, was generated by targeted homologous recombination, in which red fluorescent protein (RFP) as a reporter replaced the 3 513 bp. The RFP was then removed to generate DEV△3513. A rescue mutant, DEVΔ3513(R), was constructed by reinserting the 3 513 bp into the genome of DEVΔ3513-RFP. The recombinant virus and its parent virus were inoculated in DEF (MOI =0.01), the virus titer was measured and the growth curve was plotted. The recombinant virus and its parent virus were diluted properly and inoculated into monolayers DEF, covered with M199 agarose and cultured 5-7 days. Twenty plaques were selected randomly and the area of plaques was assayed. Six-week old susceptible ducks were inoculated with 10 ^5.0TCID₅₀ of the 3513-bp deletion mutant, rescue mutant and its parental virus, respectively. After 10 days, all the surviving ducks were euthanized. The liver tissues were taken from all the animals and fixed to 4% poly Formaldehyde Solution; the pathological sections were prepared by routine procedures and stained with HE. The recombinant virus and the Duck Plague Live Vaccine (CVCC AV1222) were injected with 10 ^3.0TCID₅₀ in muscles for 6 weeks of age susceptible ducks to be tested for immunogenicity. After 14 days, all vaccinated ducks were challenged with 10 ^3.0MLD of lethal DEV (CVCC AV1221).【Result】The recombinant viruses, DEVΔ3513 and DEVΔ3513(R), and their parental virus possessed similar growth kinetics, and their titer peaked at 72 hours with the peak titer 10 ^6.2-6.5TCID₅₀/0.1mL. Their average plaques sizes were not significantly different; DEVΔ3513 was avirulent in 6-week ducks; the ducks vaccinated with 10 ³TCID₅₀ were protected against subsequent challenge with lethal DEV.【Conclusion】We successfully constructed a DEV mutant with 3 513 bp deletion, and firstly confirmed that the deletion of the 3 513 bp had no effect on virus replication in cells and immunogenicity in ducks. Moreover, the 3 513 bp was associated with DEV virulence.  相似文献   

硼缓释型高吸水性树脂对油菜基质育苗的影响研究     

李雪嫄  王宇欣  王平智  封玲 《中国农业大学学报》2020,25(7):39-50

以自制羟丙基甲基纤维素含硼高吸水性树脂为试验材料,通过油菜育苗试验,采用单因素和正交试验方法,探究不同添加量下,含硼高吸水性树脂是否可以有效改善育苗基质理化性质、提高保水性能和促进油菜幼苗的生长。结果表明:随着含硼高吸水性树脂添加量的增加,各处理组的基质容重逐渐减小、总孔隙度和持水孔隙度逐渐增大、通气孔隙度先增大后减小、pH逐渐增大、EC值逐渐增大、有效硼含量逐渐升高;同时,随着育苗时间的延长,不同处理组基质相对含水率与含硼高吸水性树脂添加量呈正相关关系。因此,在适宜添加量范围内,含硼高吸水性树脂施用量的增加,能够促进油菜幼苗生长,而当施用量过大时将阻碍油菜幼苗正常生长。含硼高吸水性树脂适宜添加量范围为育苗基质质量的0.3%左右。  相似文献   

Effects of Preharvest Sprouting on Flour Pasting Viscosity in Common Buckwheat (Fagopyrum esculentum Moench)     

《Plant Production Science》2013,16(3):361-366

Abstract

Rain before harvest often causes buckwheat to sprout. Preharvest sprouting reduces the processing suitability of buckwheat flour. We examined the effects of preharvest sprouting on buckwheat flour quality by rapid visco-analysis (RVA) of milled sprouting grains of six buckwheat cultivars. Both artificial and natural rainfall increased the frequency of sprouting and decreased pasting viscosity. The difference in pasting viscosity between sprouting and non-sprouting buckwheat grains was not decreased by adding wheat flour. These results suggest that the mechanical characteristics of dough and boiled noodle may be affected by flour made from sprouting grains. Differing responses of the cultivars to rainfall indicate that higher pasting viscosity could be achieved by using cultivars that are resistant to preharvest sprouting caused by rain.  相似文献   

膳食纤维的理化功能特性及甘薯膳食纤维在动物生产中的应用     

《中国畜牧杂志》2019,(10)

甘薯渣是生产甘薯淀粉的副产品,富含膳食纤维。目前甘薯渣除极少部分用于动物饲喂外,几乎全部废弃,造成环境污染和资源浪费。本文综述了膳食纤维的理化特性、生理功能及甘薯膳食纤维在动物生产中的应用,为甘薯膳食纤维的研究和应用提供参考。  相似文献   

MUF树脂浸注改性橡胶木初步研究     

秦韶山  李家宁  李晓文  李民 《热带作物学报》2013,33(7):68-73

采用水溶性三聚氰胺-尿素-甲醛(MUF)共聚树脂浸注处理人工林橡胶树(Hevea brasiliensis)木材，分析树脂浓度对各项物理力学性能指标的影响。结果表明：MUF树脂对橡胶木有良好的浸注性，随着浸注树脂浓度的升高，木材的增重率逐渐增加4.51%～31.73%；气干密度明显提高3.57%～25.62%；明度指数下降7.39%～11.85%；吸湿率下降12.81%～23.68%，吸水率降低12.73%～29.51%，尺寸稳定性明显改善；抗弯弹性模量增加1.01%～18.15%，抗弯强度提高3.38%  相似文献   

Long-Term No-Tillage Direct Seeding Mode for Water-Saving and Drought-Resistance Rice Production in Rice-Rapeseed Rotation System     

Du Xing-bin  ;CHEN Chen  ;LUO Li-jun  ;XIA Long-ping  ;LIU Kang  ;CHEN Yin-hua  ;Yu Xin-qiao 《水稻科学》2014,21(4):210-216

To study the effects of long-term no-tillage direct seeding mode on rice yield and the soil physiochemical property in a rice-rapeseed rotation system,a comparative experiment with a water-saving and drought-resistance rice(WDR)variety and a double low rapeseed variety as materials was conducted under no-tillage direct seeding(NTDS)mode and conventional tillage direct seeding(CTDS)mode for four years,using the CTDS mode as the control.Compared with the CTDS mode,the actual rice yield of WDR decreased by 8.10%at the first year,whereas the plant height,spikelet number per panicle,spikelet fertility,1000-grain weight,grain yield,actual yield,and harvest index increased with no-tillage years,which led to the actual yield increase by 6.49%at the fourth year.Correlation analysis showed that the panicle length was significantly related to the actual yield of WDR.Compared with the CTDS mode in terms of the soil properties,the pH value of the NTDS mode decreased every year,whereas the contents of soil organic matter and total N of the NTDS mode increased.In the 0–5 cm layer of the NTDS mode,the soil bulk decreased,whereas the contents of soil organic matter,total N,and available N increased.In the 5–20 cm layer of the NTDS mode,the available N and K decreased,whereas the soil bulk,contents of soil organic matter,and total N increased.In summary,the NTDS mode increased the rice yield,and could improve the paddy soil fertility of the top layer.  相似文献   

43～63日龄黄羽肉公鸡铜需要量   总被引：1，自引：0，他引：1  

李龙  蒋守群  郑春田  苟钟勇  陈芳  阮栋  林厦菁 《动物营养学报》2014,(11):3266-3275

本研究旨在通过研究饲粮铜添加水平对黄羽肉公鸡生长性能、抗氧化性能、肝脏和血清铜含量等的影响,以探讨43~63日龄黄羽肉公鸡铜的需要量。选用43日龄健康、发育良好的快大型岭南黄羽肉公鸡900只,根据体重随机分为6个组,每组6个重复,每个重复25只鸡,组1(对照组)为基础饲粮组(铜水平为2.74 mg/kg),组2~6饲粮在基础饲粮中分别添加4、8、16、32、64 mg/kg铜。结果表明:1)与对照组相比,16和32 mg/kg铜组显著提高试鸡末重、平均日增重和平均日采食量(P<0.05),饲粮中铜添加水平对料重比无显著影响(P>0.05)。2)与对照组相比,16和32 mg/kg铜组血清铜锌-超氧化物歧化酶(Cu Zn-SOD)活性显著升高(P<0.05),32和64 mg/kg铜组肝脏Cu Zn-SOD活性显著升高(P<0.05),饲粮铜添加水平对胸肌中Cu ZnSOD活性无显著影响(P>0.05);饲粮添加32和64 mg/kg铜显著降低了胸肌丙二醛(M DA)含量(P<0.05),各组间血清和肝脏MDA含量均无显著差异(P>0.05);添加16、32、64 mg/kg铜显著降低了血清铜蓝蛋白活性(P<0.05)。3)与对照组相比,8、16 mg/kg铜组肝脏铜含量显著降低(P<0.05),铜添加水平对血清铜含量和肝脏金属硫蛋白含量影响不显著(P>0.05)。综合考虑各项指标,为获得较好生长性能和抗氧化性能,43~63日龄黄羽肉公鸡饲粮铜适宜添加水平分别为16和32 mg/kg,加上基础饲粮铜水平为2.74 mg/kg,则该阶段黄羽肉公鸡铜需要量分别为18.74和34.74 mg/kg;以生长性能和肝脏Cu Zn-SOD活性为依据,通过折线回归分析估测得到43~63日龄黄羽肉公鸡铜需要量分别为19.94和38.34 mg/kg。  相似文献   

特异腐质酶Humicola insolens Y1耐热型木聚糖酶基因的克隆及酶学性质分析     

李雅楠  余利红  李昀楷  马文康  张伟 《中国农业科技导报》2013,15(4):121-128

利用简并PCR和TAIL PCR从嗜热特异腐质霉Humicola insolens Y1中克隆得到一个新的耐热型木聚糖酶基因xynD。该基因全长1 104 bp, 共编码367个氨基酸，不含有内含子，N端的22个氨基酸为信号肽。成熟蛋白在毕赤酵母中进行了重组表达，重组蛋白经超滤和离子交换柱纯化后达到电泳纯。对其酶学性质分析表明，XynD的最适pH为6.0，在pH 4.0～7.0可以保持80%以上的酶活性，在pH 5.0～10.0具有良好的pH稳定性。最适作用温度为70℃，在60℃条件下保持稳定。多数金属离子对XynD酶活力没有明显的影响。麦芽汁降解实验表明，XynD与商用β 葡聚糖共同作用可以提高麦芽的过滤速率(45.7％)并降低粘度(81％)。因此XynD在酿酒业，特别是啤酒制造业具有潜在的应用价值。  相似文献