研究型大学中《淀粉化学及工艺学》课程的教学模式探索

针对《淀粉化学及工艺学》课程的特点,提出了课程研究型教学的模式,以及实施课程教学的几个方面的工作:课堂教学提高理论深度、教学过程加强引导与互动、课外教学侧重于研究与生产实践、实验教学强化自主设计与协作、课程考核重在激发思维与鼓励创新。通过各个教学环节培养学生的"开放式思维",使学生具有综合应用、举一反三的能力。

Chemical Constituents of Pu-erh Tea and Its Inhibition Effect on α-amylase in vitro

[Objective]The aim was to clarify the chemical substance basis of hypoglycemic and lipid-lowering effects of Pu-erh Tea. [Method]Pu-erh Tea was extracted with 95% ethanol,followed by petroleum ether,chloroform,ethyl acetate and n-butanol extraction,after the further purification and through the NKA-9 macroporous resin and many times of Sephadex column chromatography,two compounds were isolated,in the same time,the effect of Uracil and Gallic acid on α-amylase was studied. [Result]The Uracil and Gallic acid were isolated and identified respectively from Pu-erh Tea and the Uracil was firstly isolated from Pu-erh Tea; Gallic acid had strong inhibition on α-amylase. [Conclusion]It could provide some theories on the hypoglycemic and lipid-lowering effects of Pu-erh Tea.

Effect of degree of substitution of carboxymethyl starch on diaspore depression in reverse flotation

Carboxymethyl starchs（CMS） with low and high degrees of substitution（CMSL and CMSH in short,respectively） were employed as depressants of diaspore in cationic reverse flotation using dodecylamine（DDA） as collector.The effect of degree of substitution of CMS on its depression performance was examined and the interaction mode and behavior were investigated in a comparative manner.Micro-flotation test showed that CMSL exhibited better performance in depressing diaspore than CMSH in a broad pH range.The adsorption of CMS on diaspore was studied by adsorption test,zeta potential measurement,and atomic force microscopy.It was found that CMSH corresponds to lower adsorption amount,thinner adsorption layer,and more negative charge than CMSL,resulting from the more chelating sites brought by the high degree of substitution.The surface tension measurement and DDA adsorption test further revealed that CMSL/DDA system gives a better depressing performance benefiting from the trapping effect by enveloping some DDA molecules inside the loop chains,while CMSH/DDA system is likely considered a quasi-surfactant.

Flotation of low-grade bauxite using organosilicon cationic collector and starch depressant

The flotation of diaspore and three kinds of silicate minerals, including kaolinite, illite and pyrophyllite, using an organosilicon cationic surfactant (TAS101) as collector and starch as depressant was investigated. The results show that both diaspore and aluminosilicate minerals float readily with organosilicon cationic collector TAS101 at pH values of 4 to 10. Starch has a strong depression effect for diaspore in the alkaline pH region but has little influence on the flotation of aluminosilicate minerals. It is possible to separate diaspore from aluminosilicate minerals using the organosilicon cationic collector and starch depressant. Further studies of bauxite ore flotation were also conducted, and the reverse flotation separation process was adopted. The concentrates with the mass ratio of Al2O3 to SiO2 of 9.58 and Al2O3 recovery of 83.34% are obtained from natural bauxite ore with the mass ratio of Al2O3 to SiO2 of 6.1 at pH value of 11 using the organosilicon cationic collector and starch depressant.

Starch RVA Profile Properties for Cold Tolerant and Sensitive Cultivars of Japonica Rice at Different Altitudes

[Objective] By investigating of change rule rice starch RVA profile properties and the influence of cold tolerance on rice quality,the aim was to provide scientific references to the breeding of new cold-tolerant japonica rice varieties with high quality in the Yunnan plateau.[Method] Four cold-tolerant and five cold-sensitive japonica rice cultivars were grown at three locations with different altitudes in Yunnan plateau to investigate rice starch RVA profile characteristics.[Result] The results showed that with increasing altitude,the setback viscosity in cold-sensitive cultivars increased significantly,while the peak viscosity and breakdown viscosity decreased significantly.However,the peak viscosity and breakdown viscosity in cold-tolerant cultivars initially decreased and then gradually increased with rising altitude,whereas the setback viscosity initially increased and then decreased.[Conclusion] The starch RVA parameters of cold-tolerant cultivars were less sensitive to different environments than those of cold-sensitive cultivars.Cooking and eating quality of cold-tolerant cultivars had relatively stable trends with rising altitude,whereas cooking and eating quality of cold-sensitive cultivars had a trend toward inferior.

Effects of Different Storage Temperature on Nutritional Quality of Potato Cultivar Kexin No.1

Objective] This study almed to investigate the effects of different storage temperature on nutritional quality of potato cuItivar Kexin No.1 and expIore the opti-mal storage temperature and time for Kexin No.1 with different uses. [Method] After storage at different temperature （1, 4, 10 and 16 ℃）, changes in dry matter, starch, reducing sugar and protein contents, amyIase activity and germination rate of potato cuItivar Kexin No.1 were observed and analyzed. [Result] Reducing sugar content of Kexin No.1 stored at 1 and 4 ℃ increased significantIy compared with that of Kexin No.1 stored at 10 and 16 ℃. Kexin No.1 stored at 1 ℃ exhibited no chiI ing injury. After storage at 16 ℃, Kexin No.1 began to germinate at 30 d, and the Iength and number of germinated buds increased significantIy with the extension of storage time, dispIaying a significant reduction in moisture content. Kexin No.1 potato couId be stored at 1 and 4 ℃ for more than 120 d without any changes in various indi-cators. Therefore, 1-4 ℃ was the optimal storage temperature for potato cuItivar Kexin No.1. [Conclusion] This study provided theoretical basis and technical support for the optimization of post-harvest storage conditions of potatoes.

Research on Laws of Starch Accumulation in Micro-endosperm Maize Kernel

[Objective] The experiment aimed to study laws of accumulation of starch in micro-endosperm maize kernel. [Method] The laws of accumulation of starch in maize embryo and OSK(the other section of a kernel except embryo) of MEM(micro-endosperm maize) were studied in this experiment by taking Gaoyou 115 maize as control. [Result] The starch accumulation speed of MEM embryo was slightly lower than that of Gaoyou115 and the starch accumulation speed of MEM OSK was far lower than that of Gaoyou 115, so the starch content of the whole kernel of Gaoyou 115 was 3.4 to 4.5 times as high as that of MEM during harvesting. The embryo starch weight ration of Gaoyou 115 maize during harvesting was only 3% to 4% while that of MEM was 16% to 22%. Moreover, starch accumulation speeds of different MEM materials were different and there were significant differences in starch content during harvesting among different MEM materials. [Conclusion] The starch accumulation in MEM was slow, and MEM has widely variation on starch accumulation.

Effects of Different Sowing Dates and Sites on Starch RVA Profile Characteristics of Different Ecotypes of Rice (Oryza sativa, L. japonica)

[Objective] This study aimed to investigate the effects of different sowing dates and sites on starch RVA profile characteristics of different ecotypes of japonica rice. [Method] Five different ecotypes of japonica rice were sown at seven different dates in four rice planting regions in Jiangsu Province to analyze the differences in starch RVA profile parameters among different rice varieties. [Result] Among eight parameters of rice starch RVA profile, peak time exhibited no significant differences among different sites, while other seven parameters varied significantly or extremely significantly among different sites, sowing dates and varieties. Specifically, rice variety exerted the most significant effects on rice starch RVA profile parameters. Starch RVA profile characteristics varied significantly among different ecological conditions but exhibited no significant differences among different latitudes. To be specific, in different sites, peak viscosity （PKV）, hot paste viscosity （HPV） and breakdown viscosity （BDV） demonstrated a descending order of Huai＇an 〉 Suzhou 〉 Lianyungang 〉 Yangzhou. Cool paste viscosity （CPV） and consistence viscosity （CSV） were higher in the north than in the south; specifically, CPV and CSV were significantly higher in Lianyungang and Huai＇an than in Yangzhou and Suzhou. Setback viscosity （SBV） showed an increasing trend with increasing latitude; specifically, SBV was significantly lower in Suzhou than in other three sites. Pasting temperature （PAT） and peak time （PET） changed slightly among different latitudes. With the postponing of sowing date, peak viscosity （PKV）, hot paste viscosity （HPV）, cool paste viscosity （CPV） and peak time （PET） showed a decreasing trend, setback viscosity （SBV） and consistence viscosity （CSV） increased, breakdown viscosity （BDV） increased first and then decreased, whereas pasting temperature （PAT） decreased first and then increased. Furthermore, rice starch RVA profile parameters showed the same variation trend with sowing date in different sites; early sowing within suitable sowing dates could effectively improve the parameters of rice starch RVA profile. However, different parameters exerted different variations among different sites and most parameters were higher in the north than in the south, which indicated that starch RVA profile parameters were significantly affected by sowing date in the north of Jiangsu Province. Among eight starch RVA profile parameters, setback viscosity exhibited the maximum variation coefficient, while peak time exhibited the minimum variation coefficient. Among five rice varieties, Nanjing 46 exhibited the highest peak viscosity and breakdown viscosity and the lowest setback viscosity and consistence viscosity, suggesting that Nanjing 46 had the most appropriate starch RVA profile characteristics and the best cooking and eating quality. Lianjing 4 exhibited relatively high peak viscosity and breakdown viscosity, and relatively low setback viscosity and consistence viscosity, suggesting that Lianjing 4 had good starch RVA profile characteristics. Different sowing dates and sites exerted significant effects on starch RVA profiles of different eco- types of japonica rice. Rice starch RVA profile characteristics varied significantly among different sites but exhibited no significant variations among different latitudes. In addition, starch RVA profile characteristics varied significantly among different sowing dates. Therefore, early sowing of the same variety was conducive to improving starch RVA profile characteristics in appropriate planting regions. [Conclusion] This study provided a theoretical basis for producing high-quality rice and improving the eating quality of rice in Jiangsu Province.

Analysis of the Conditional Correlations from Different Genetic Systems Between the Protein Content and the Appearance Quality Traits of Indica Rice

A factorial mating design in two environments was conducted using 7 cytoplasmic male sterile lines （A） and 5 restorer lines （R） along with their F1 （A × R） and F2 populations. The unconditional and conditional analyses of genetic models and the corresponding statistic methods, including endospermic, cytoplasmic, and maternal plant genetic systems, were used to analyze the genetic relationships between protein content （PC） and the appearance quality traits of indica rice （Oryza sativa L.）. The results from unconditional analysis indicated that PC was significantly correlated with the appearance quality traits of rice, except for the brown rice thickness （BRT）. Only the genetic covariance between PC and the brown rice width （BRW） was positively correlative, whereas all the other pairwise traits were negatively correlative. The results from conditional analysis revealed that the weight of brown rice （WBR） or the amylose content （AC） could significantly affect the relationships between PC and the appearance quality traits of indica rice. The conditional analysis showed that WBR might negatively affect the relationships between PC and the brown rice length （BRL）, BRW, or BRT through the geuotype x environmental （GE） interaction effects, but positively affected the relationships between PC and the ratio of brown rice length to width （RLW） or the ratio of brown rice length to thickness （RLT）. The amylase content could positively affect the relationships between PC and BRL, RLW, RLT through the cytoplasmic effects and maternal additive effects, but negatively affected the relationships between PC and BRW.

Correlation of Simple Sequence Repeat (SSR) Variants in the Leader Sequence of the waxy Gene with Amylose Content of the Grain in Rice

Variation of two simple sequence repeats (SSRs) in the leader region of the waxy gene was analyzed in a sample of 74 accessions, including Oryza sativa L. ssp. indica, japonica and wild rice (O.rufipogon) representing a wide distribution range of amylose content (AC) in cultivated rice. Eight alleles were detected in the (CT) n motif and two alleles were resolved in the (AATT) n motif. The distribution of the alleles of the two SSRs was quite uneven as detected by the (CT) n motif. The repeat numbers of the two SSR motifs, (CT) n and (AATT) n, appeared to be inversely related such that the total length of this region was maintained. AC of the varieties was highly correlated with the length of SSRs. Differences in AC among the various SSR genotypes were statistically highly significant as analyzed using genotypes of both SSR motifs. Although the SSR variation did not seem to have obvious function in the synthesis of the starch synthase encoded by the waxy gene, the almost perfect correlation between the two SSRs and AC level could be used for quality improvement in rice breeding programs.

Screening and Identification of Amylase-producing Strain from Arctic Ocean and Optimization of Enzyme Producing Conditions

[Objective] The aims were to investigate the screening and identification of amylase-producing marine bacteria from Arctic sea and the optimization of the amylase producing conditions. [Method] A high-yield strain for producing amylase named ArcB84A was isolated from a total of 156 marine bacteria of Arctic sea. Then,the morphological identification of the strain,molecular identification of 16S rRNA and optimization of fermentation conditions were conducted. [Result] ArcB84A strain was a member of Pseudoalteromonas genus. The optimum conditions for enzyme production of B84A strain included that,the initial pH value of the medium was 7.0-8.0,and the best carbon and nitrogen sources respectively were 5‰ glucose and peptone. Surfactants including TritonX-100,Tween20 and Tween80 could increase amylase activity of the strain,in which,the effect of 10‰ Tween80 was the most obvious.

Effects of Bacillus amyloliquefaciens Biofertilizer on Brassica juncea var. multiceps Growth and N_2O Emission from Soil

In this study, Bacil us amyloliquefaciens A3 was continual y incubated in shake fIasks contalning wastewater from sweet potato starch production as an ef-fective biofertiIizer for cuItivation of Brassica juncea var. multiceps（XueIihong）. Based on pot experiments in the greenhouse, the effects of chemical fertiIizers （CN）, biofertiIizer （BF）, inactivated broth （BI）, starch wastewater （SW） and the combination of biofertiIizer and chemical fertiIizer （BC） on the yield, NO3- content and NO2- con-tent of XueIihong, soiI physicochemical properties and N2O emission were investi-gated. The resuIts showed that the yield of XueIihong in BC and CN treatments was improved by five times compared with CK; BF and SW treatments had insignifi-cant impact on the yield of XueIihong. Compared with CN treatment, BCL treatment exhibited simiIar improving effects on the yield of XueIihong, in which NO3- content of XueIihong and soiI was reduced by 16.4%-73.6% and 22%-29%, which reduced the risk of nitrogen eIuviations in soiI; average N2O fIux （FPV30） in BCL treatment was reduced by 58.3%-73.1% compared with CN treatment. In concIusion, B. amy-loliquefaciens is a feasibIe Iow-cost biofertiIizer for sustalnabIe vegetabIe farming with a great potential for starch wastewater utiIization.

Construction of Vectors to Express Foreign Protein within Potato Starch Grains

[Objective] The aim is to study the construction of vectors expressing foreign protein in potato starch grains specifically, and provide some reference for solving industrialized core problem of high cost and low expression level of foreign protein. [Method] By using molecular biological techniques of RT-PCR and nested PCR, plant expression vector for the foreign protein locating in the potato starch grains was constructed. [ Result] Coding sequence （ GC20 ） of potato starch grains that was located and expressed by GBSSI promoter was cloned. Plant expression vector was screened out through connection, transformation and enzyme digestion identification. [ Conclusion] This result laid a foundation for further screening the foreign protein on the potato starch grains.

Analysis of α-amylase Inhibitor Content Change in Pu-erh Tea During Pile-fermentation Process

The study was to investigate the changes of α-amylase inhibitor content in Pu-erh tea during pile-fermentation process. Pu-erh tea samples from two regions of Shuangjiang County and Jinggu Dai and Yi Autonomous County of Yunnan Province at various fermentation stages were used as experimental materials to investigate the effect of different fermentation stages on the inhibitory effect to α-amylase; and the change law of the inhibitory effect of c-amylase inhibitor during processing was meanwhile studied by determining the contents of tea polyphenol and amino acid. The results showed that crude meterial of Pu-erh tea presented strong inhibitory effect to α-amylase; this inhibitory effect assumed a de： creasing trend to the minimum at the middle stage of fermentation, whereafter it increased to some extent. Made tea also showed a strong inhibitory effect to α-amylase. During whole processing period, contents of tea polyphenol and amino acid generally assumed a remarkably decreasing trend. Our results provided references for further isolating co-amylase inhibitor from Pu-erh tea and discussing the mechanism of its health care function.

Quality Analysis and Evaluation of Maize Cultivars Approved by Shanxi Province

[Objective] This study aimed to provide a theoretical basis for the genetic improvement of maize quality in Shanxi Province. [Method] The variations in unit weight, crude starch content, crude protein content, crude fat content and lysine content of maize cultivars approved by Shanxi Province during 2003-2012 were analyzed. [Result] In Shanxi Province, the average unit weight and crude starch content of maize cultivars approved during 2003-2012 were trended to be increased;the crude fat contents of maize cultivars approved during 2003-2012 showed no significant changes; the lysine contents of maize cultivars approved during 2003-2008 were essentially unchanged; the crude protein contents of maize cultivars approved during 2003-2012 declined slightly. [Conclusion] The crude starch content and unit weight of maize increased with the increased yield; the crude protein content, crude fat content and lysine content showed certain stability, and they were mainly controlled by genes. Therefore, the breeding of particular maize should be strengthened.

Correlation analysis between major nutritional components and resistant starch content in wheat

With 94 spring wheat cultivars as experimental materials, the correlations between the content of resistant starch （RS） in uncooked flour and cooked flour, and the apparent amylose content （AAC）, protein, lipid were investigated. The results showed that RS contents in both the uncooked flour and cooked flour assumed significantly positive correlation with AAC, and significantly negative cor- relation with protein content; and they were proved to be not significantly correlated with lipid content. RS content in uncooked flour was significantly correlated with that in cooked flour. These results provided references for the genetic improvement of wheat cultivars.

Effects of Curing Techniques on Starch Contents of Leaves in Different Tobacco Parts with Varying Maturity Degrees

[Objective] The aim was to explore effects of different curing techniques on starch contents of tobaccos from different growth parts and with varying maturity degrees in order to reduce starch content of Yunnan tobacco. [Method] Compar- isons were conducted on tobaccos from upper, middle and down parts （immature, premature, mature and excessive mature） by low temperature and low humidity cur- ing technique, moderate temperature and moderate humidity curing technique, mod- erate temperature and high humidity curing technique to measure starch contents before and after curing. [Result] The results showed starch content of tobacco was increasing upon growth part. Low temperature and low humidity curing technique has poor effects on reduction of starch content; moderate temperature and moderate humidity curing technique improves starch content; moderate temperature and high humidity curing technique dramatically reduces starch content of tobaccos. [Conclu- sion] With consideration of tobacco appearance, inner quality and characters, moder- ate temperature and moderate humidity curing technique is recommended for tobac- co production.