高速剪切辅助碱法从龙眼核中提取淀粉的研究

以龙眼核为原料,采用高速剪切辅助碱法提取龙眼核淀粉。根据单因素试验和正交试验的结果,结合实际生产情况,确定龙眼核淀粉的最佳提取条件为剪切速率3 000 r/min,溶液p H值9,料液比1∶20,提取时间30 min,淀粉得率可以达到25.12%。与传统碱法相比,高速剪切辅助碱法得率高、提取时间短、对环境相对友好,是一种值得开发的新型淀粉提取方法。     

藕粉红枣酥性饼干的工艺研究

将藕粉取代部分低筋粉并加入保健食材红枣,研制出更为营养美味的藕粉红枣酥性饼干。设置影响饼干品质较大的因素:藕粉添加量、枣浆添加量、糖粉添加量作为试验因子,通过单因素试验和正交试验,得出产品的最佳配方(以低筋粉和藕粉总质量为基准100%)为低筋粉添加量60%,藕粉添加量40%,糖粉添加量30%,枣浆添加量40%,黄油添加量43%,色拉油添加量24%,纯牛奶添加量5%;焙烤条件为上火180℃,下火120℃,烘烤时间10 min。在此条件下制作出的藕粉红枣酥性饼干色泽深红、口感酥脆、口味香甜、后味浓郁、枣香四溢。     

Low soil temperature reducing the yield of drip irrigated rice in arid area by influencing anther development and pollination

Drip irrigation can produce high rice yields with significant water savings; therefore, it is widely used in arid area water-scarce northern China. However, high-frequency irrigation of drip irrigation with low temperature well water leads to low root zone temperature and significantly reduce the rice yield compared to normal temperature water irrigated rice, for example, reservoir water. The main purpose of this paper is to investigate the effects of low soil temperature on the yield reduction of drip irrigated rice in the spike differentiation stage. The experiment set the soil temperatures at 18°C, 24°C and 30°C under two irrigation methods(flood and drip irrigation), respectively. The results showed that, at the 30°C soil temperature, drip irrigation increased total root length by 53% but reduced root water conductivity by 9% compared with flood irrigation. Drip irrigation also increased leaf abscisic acid and proline concentrations by 13% and 5%, respectively. These results indicated that drip irrigated rice was under mild water stress. In the 18°C soil temperature, drip irrigation reduced hydraulic conductivity by 58%, leaf water potential by 40% and leaf net photosynthesis by 25% compared with flood irrigation. The starch concentration in male gametes was also 30% less in the drip irrigation treatment than in the flood irrigation treatment at soil temperature 18°C. Therefore, the main reason for the yield reduction of drip irrigated rice was that the low temperature aggravates the physiological drought of rice and leads to the decrease of starch content in male gametes and low pollination fertilization rate. Low temperature aggravates physiological water deficit in drip irrigated rice and leads to lower starch content in male gametes and low pollination fertilization rate, which is the main reason for the reduced yield of drip irrigated rice. Overall, the results indicated that the low soil temperatures aggravated the water stress that rice was under in the drip irrigated environment, causing declines both in the starch content of male gametes and in pollination rate. Low temperature will ultimately affect the rice yield under drip irrigation.     

Combined mutations in five wheat STARCH BRANCHING ENZYME II genes improve resistant starch but affect grain yield and bread-making quality

Increases in the proportion of amylose in the starch of wheat grains result in higher levels of resistant starch, a fermentable dietary fiber associated with human health benefits. The objective of this study was to assess the effect of combined mutations in five STARCH BRANCHING ENZYME II (SBEII) genes on starch composition, grain yield and bread-making quality in two hexaploid wheat varieties. Significantly higher amylose (∼60%) and resistant starch content (10-fold) was detected in the SBEII mutants than in the wild-type controls. Mutant lines showed a significant decrease in total starch (6%), kernel weight (3%) and total grain yield (6%). Effects of the mutations in bread-making quality included increases in grain hardness, starch damage, water absorption and flour protein content; and reductions in flour extraction, farinograph development and stability times, starch viscosity, and loaf volume. Several traits showed significant interactions between genotypes, varieties, and environments, suggesting that some of the negative impacts of the combined SBEII mutations can be ameliorated by adequate selection of genetic background and growing location. The deployment of wheat varieties with increased resistant starch will likely require economic incentives to compensate growers and millers for the significant reductions detected in grain and flour yields.     

紫花地丁开放花与闭锁花的发育及可溶性糖与淀粉含量的研究

紫花地丁(Viola philippica)为典型的两型花自花受精植物,具有开放花和闭锁花混合繁育系统。通过对开放花和闭锁花花芽形态发育的比较发现:开放花与闭锁花在花芽发育早期形态相似,4轮花器官原基均正常发生。出现明显差异的时期为4轮花器官原基形成以后,小孢子发育时期为产孢细胞阶段,开放花的5个花瓣与5枚雄蕊继续发育,每个雄蕊有4个花药室;而闭锁花只有2枚雄蕊继续发育,每个雄蕊有2个花药室,其余雄蕊与所有的花瓣依然为器官原基状态,不再发育。通过对花芽与叶片可溶性糖与淀粉含量的检测发现,花器官原基形成之后,开放花与闭锁花形态出现明显差异阶段开始,随着花芽的发育,可溶性糖与淀粉含量均呈上升趋势,且开放花花芽中的含量均明显高于对应发育阶段闭锁花花芽;而开放花植株的叶片可溶性糖与淀粉含量均低于闭锁花植株叶片,说明开放花所需要的能量高于闭锁花,推测可溶性糖与淀粉含量的差异与两型花发育有一定的关系。     

可食性液态膜复合保鲜剂对番茄保鲜效果的研究

以番茄为试材,通过壳聚糖、可溶性淀粉、羧甲基纤维素钠配制成不同浓度的复合保鲜液浸泡涂膜处理,研究其对番茄保鲜效果的影响。结果表明,复合保鲜液涂膜可有效地降低番茄果实的失重率、腐烂率、可溶性固形物含量,抑制多酚氧化酶活性,维持番茄VC含量,保持番茄果实较好的感官品质,且以0.5%壳聚糖+0.8%可溶性淀粉+0.3%羧甲基纤维素钠复配的复合保鲜液涂膜对番茄有较好的保鲜效果,15℃环境下其货架期延长到15 d以上。     

灌浆期高温胁迫对不同品种小麦蛋白组分及面团揉混特性的影响

为研究灌浆期高温胁迫对不同品种小麦蛋白组分及面团揉混特性的影响,以济麦22(JM22)和新麦26(XM26)为材料,通过灌浆初期(S1)和灌浆中期(S2)在田间搭棚进行高温胁迫处理,以未进行高温胁迫的大田小麦作对照(CK),收获后对小麦淀粉黏滞谱、蛋白质组分含量和揉混参数等进行分析。结果表明,与各自CK相比,JM22的黏滞谱参数除回复值和糊化温度降低外,其余参数均升高,XM26的黏滞谱参数除峰值时间外均降低。S1和S2使JM22的峰值黏度、低谷黏度、崩解值、最终黏度、峰值时间分别较CK提高2.81%和18.63%、7.71%和19.51%、11.88%和21.15%、1.88%和12.22%、2.45%和4.08%,且S2均大于CK和S1,S1与CK差异不显著;S1和S2使XM26的峰值黏度、低谷黏度、最终黏度、回复值分别较CK降低12.95%和31.21%、1.81%和27.18%、2.50%和22.22%、3.57%和14.39%,其中,S2、S1与CK三者之间的峰值黏度均达显著水平。与CK相比,高温胁迫后JM22的蛋白质含量降低,而XM26升高。两品种各组分蛋白含量均发生改变,S1和S2使JM22谷蛋白含量减少4.52%和6.01%,S1和S2使XM26谷蛋白增加13.66%和17.27%,不可溶蛋白增加28.95%和34.80%,谷醇比也增加。高温处理对两品种面团揉混参数值也有一定影响,S1使JM22和XM26的峰值时间、峰值高度、8 min带宽分别较各自CK显著增加8.50%和42.80%、12.20%和2.80%、26.57%和68.30%,而S2的两品种只有峰值时间同时显著增加,分别增加9.60%和28.50%。本研究结果为优质专用小麦品质提升栽培技术提供了理论基础。     

低温贮藏对猕猴桃果实成熟软化相关基因表达影响

为探究低温对果实采后成熟软化与淀粉降解的影响,以红阳猕猴桃果实为试验材料,研究在低温贮藏期间,猕猴桃果实硬度,可溶性固形物、乙烯、淀粉含量以及淀粉酶相关基因的变化。结果表明,低温贮藏能显著抑制猕猴桃果实采后成熟软化,延缓果实淀粉的降解和可溶性固形物含量的增加,维持贮藏期间果实较高的硬度。低温贮藏抑制乙烯合成关键基因AcACO1和AcACS1的表达,抑制乙烯合成。同时,低温贮藏显著抑制淀粉降解相关基因AcAMY1、AcBAM1/3、AcISA3、AcLDA1和AcDPE1的表达。在低温贮藏后期,淀粉酶相关基因AcAMY1、AcBAM1/3、AcLDA1和AcDPE1的表达与乙烯释放速率有关。综上,低温贮藏延缓猕猴桃采后成熟软化进程与淀粉降解密切相关,可能主要通过抑制乙烯合成,从而影响贮藏后期淀粉降解速率,最终延缓果实软化进程。本研究结果为猕猴桃采后低温贮藏提供了理论依据。     

陇薯系列高淀粉马铃薯品种的淀粉产量及品质性状综合评价

为了评价高淀粉马铃薯品种的综合品质性状,本研究以甘肃省农业科学院育成的15个马铃薯品种(系)为参试材料,2011-2018年连续8年定点田间试验,测定了块茎产量、营养品质(干物质、淀粉、维生素C、粗蛋白)含量和矿物质元素(钾、钙、铁、锌)含量。结果表明,参试材料的块茎产量和营养品质含量均存在显著的基因型、环境及基因型与环境的互作效应,其中块茎产量、淀粉产量、干物质含量、淀粉含量性状的基因型效应大于环境效应,而营养品质中的维生素C、粗蛋白和还原糖含量的环境效应大于基因型效应。参试材料的块茎产量24 549~50 140 kg·hm^-2,淀粉产量4 271~9 298 kg·hm^-2,干物质含量21.07%~30.18%,淀粉含量14.63%~21.83%,维生素C含量12.20~18.95 mg·100g^-1,粗蛋白含量2.17%~2.71%,还原糖含量0.18%~0.43%,钾含量4 316~5 368 mg·kg^-1,钙含量85.10~138.40 mg·kg^-1,铁含量10.17~24.50 mg·kg^-1,锌含量2.45~3.80 mg·kg^-1。大西洋的衍生品种陇薯8号、陇薯9号、陇薯12号、陇薯14号、L0527-2、L08104-12、LZ111和L1149-2淀粉含量均超过18%,其中,L1149-2总体表现优异,其平均块茎产量50 140 kg·hm^-2、淀粉产量9 298 kg·hm^-2、干物质含量26.75%、淀粉含量19.30%、维生素C含量14.62 mg·100g^-1、粗蛋白含量2.52%、还原糖含量0.28%、钾含量5 297 mg·kg^-1、钙含量138.40 mg·kg^-1、铁含量20.40 mg·kg^-1、锌含量3.20 mg·kg^-1;而陇薯5号淀粉产量及营养品质较差。本研究为合理利用陇薯系列高淀粉马铃薯品种提供了科学依据,对改良高淀粉马铃薯品种产量和品质具有指导意义。     

糯性普通小麦的选育及其淀粉品质

普通小麦胚乳淀粉一般由20%~30%的直链淀粉和70%~80%的支链淀粉组成。在自然界,大多数禾谷类作物,如玉米、水稻、高粱等均存在直链淀粉含量几乎为0的糯性类型。普通小麦是异源六倍体,迄今为止尚未发现自然界存在糯性小麦。由于小麦淀粉的构成及品质与面条品质关系密切,在发达国