不同烘烤工艺下烟叶在醇化过程中外观质量和内在成分变化规律研究

[目的]找出烟叶在醇化过程中外观质量和烟叶内总植物碱、总糖、总氮和钾离子等化学成分变化规律。[方法]采用不同的烘烤工艺对烟叶进行烘烤,烘烤结束后取样进行醇化试验研究,探索烟叶在醇化过程中外观质量和内在成分的变化。[结果]在醇化过程中,中温中湿烘烤工艺对烟叶颜色和油分稍有影响,对成熟度、身份和色度等外观质量影响较小,其他烘烤工艺对其外观质量均影响较小;3种烘烤工艺对烟叶总植物碱和总糖含量变化影响较小;T2烘烤工艺下烟叶还原糖含量变化呈上升趋势,3种烘烤工艺下烟叶总氮含量变化呈上升趋势;T3烘烤工艺对烟叶钾离子含量影响较大;T2和T3烘烤工艺对烟叶氯离子含量影响较大。[结论]应针对不同的卷烟配方需求,选取适宜的烘烤工艺,使烟叶有较好的外观质量和较优的内在成分,提升全国烟叶卷烟上水平。     

Effects of a late N fertiliser dose on storage protein composition and bread volume of two wheat varieties differing in quality

Wheat is an important source of energy and protein for humans all over the world and is mainly consumed in form of baked goods, for which a high baking quality is required. The main parameter for bread-making quality predictions of wheat flours is the grain protein concentration (GPC). Therefore, the GPC determines the value of the harvested wheat. Unfortunately, the GPC appears to be no longer an appropriate parameter for baking quality evaluation, given that, especially for high protein varieties, the correlation between GPC and bread volume is poor. A late N application is commonly used to increase GPC and enhance the bread-making quality of wheat flours. To minimise the environmental problems involved in the late use of N fertilisers, it is important to know how much N is necessary to achieve the desired effects. Therefore, in this study, the effects of two different doses of late N application on the GPC, as well as storage protein composition and bread volume were tested in two wheat varieties from different quality groups under field conditions in Germany. The findings of this experiment demonstrate that a low late N application appears to be sufficient to achieve a good baking quality of wheat flours. These results confirm the presumption that GPC is not a suitable parameter for bread-making quality predictions. As the relationships between the single storage protein fractions and bread volume were poor, it can be concluded that only the combined alterations within all gluten protein fractions explain the rise in bread volume.     

高分子量麦谷蛋白亚基的SDS-PAGE图谱在小麦品质研究中的应用

本实验应用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE),分析了河南72个小麦品种(品系)的高分子量(HMW)麦谷蛋白亚基组成,并测定其蛋白质含量、面筋含量、沉淀值、流变学特性和面包烘烤品质。发现含有 Glu—1 D 5+10亚基的品种一般有好的面粉品质和面包烘烤品质,含有 Glu—1 B 7+8或 Glu—1 A 2~*或 Glu—1 B 7亚基的品种有     

定色后期稳温点对烟叶常规化学成分和致香物质的影响

以普洱市景东县烟区烟叶为研究对象,通过对不同部位最佳采收成熟度烟叶定色阶段后期稳温点的研究,分析了定色后期不同稳温处理与烟叶化学成分、致香物质的关系,结果表明:变黄期采用"低温慢变黄"处理,上部成熟烟叶54℃稳温16 h、中部成熟烟叶稳温8 h、下部适熟烟叶稳温16 h的烟叶常规化学成分含量在较适宜范围,糖碱比、氮碱比较为适宜,钾氯比均大于4,接近或符合优质烟叶的特征;烟叶致香物质总量及各类中性致香物质总量明显高于其他处理,由此表明通过优化烟叶烘烤工艺能使各部位烟叶品质向有利的方向转化。     

黔东南州烤房群烟草粉螟监测动态研究

为进一步找到黔东南州烟草粉螟在烘烤阶段的发生规律,对镇远、施秉、岑巩和麻江4个烤烟县烤房群烟草粉螟发生情况进行了监测调查。根据实际调查数据,分析各县烤房群烟草粉螟实时发生和累计发生情况。结果表明,施秉县烤房群烟草粉螟发生最严重,其次分别为镇远县、麻江县和岑巩县。从始发期、暴发期、终发期及周期来看,各县各烤房群发生情况不同,防治时应根据各自发生情况进行针对性、重点性的监测和防治。该结果对加强黔东南烟草粉螟防治工作有一定的指导作用。     

Comparison of protein quality and mineral element concentrations in grain of spelt (Triticum spelta L.) and common wheat (Triticum aestivum L.)

The cultivation of Triticum spelta (spelt) has no tradition in Hungary. In recent years the interest towards this old species renewed in many countries. This high‐nutritional cereal, which has a high ash and fibre content, can be used in many health‐oriented grain‐based food products. Therefore, field experiments have been conducted for some years to test the performance of this species under home growing conditions. Here we report the results of analyses for some important quality parameters of grain samples from the 1996/97 season in comparison with those of older and new home‐grown bread wheat cultivars. Three common wheat cultivars and one advanced spelt line were grown on small plots fertilised with an NPK dose necessary to reach the highest yield and quality. Spikes were sampled weekly from the time of 70–77% grain moisture to full ripening. The grains were analysed for ash, N, P and K content and amino acid composition. Concentrations of 16 other macro + micro elements and in the ripe grains, baking quality parameters were also assessed. The grain development of spelt showed a remarkable time‐lag compared to that of the common wheat cultivars. However, the highest thousand‐grain‐masses, ash, N, and P concentrations were measured in this cultivar after milk ripening. The grains of spelt contained the macro‐nutrient Mg and four micro‐nutrients (Zn, Mn, Fe, Cu) in higher concentrations compared to those of the common wheat varieties. The total and essential amino acid concentrations measured in the ripe grains of spelt were also remarkably higher.

Although its wet gluten content (47.5%) was considerably higher than that of the bread wheat cultivars, its breadmaking quality was poor.     

烘烤方式对‘云烟87’烟叶质量的影响

为进一步提升烟叶烘烤水平,提高出烤烟叶质量,以‘云烟87’为材料,连续多年对当地散叶烘烤和挂杆烘烤的烤后烟叶进行对比。结果表明,随着散叶烘烤工艺的逐年改进,散叶烘烤与挂杆烘烤在烟叶外观质量上的差距逐年缩小;散叶烘烤在烟叶化学品质上明显优于挂杆烘烤,化学成分更加协调;综合来看,散叶烘烤烟叶的综合品质在逐年提升,并优于挂杆烘烤。     

Evaluation of partial-vacuum baking for gluten-free bread: Effects on quality attributes and storage properties

The purpose of this study was to evaluate the impact of partial-vacuum baking on the quality and storage properties of gluten-free bread (GFB). Conventional (180°C-30 min at atmospheric pressure) and partial-vacuum (180°C-15 min at atmospheric pressure and at 180°C-15 min at 60 kPa vacuum pressure) methods were conducted to bake GFB. Quality attributes (specific volume, colour, texture, total water loss) were assessed, DSC and SEM analyses were carried out to understand the effect on the bread's microstructure when using vacuum during baking. No significant differences (p > 0.05) were observed in the hardness and specific volume of the partial-vacuum baked GFB; however, changes in the total water loss and in the total colour change were statistically significant (p < 0.05). The DSC, SEM and XRD results showed that more crystalline structure and different starch crystal types formed after partial-vacuum baking. Storage properties were also investigated over a 3-day period. Partial-vacuum baking significantly affected the total water loss and the texture parameters (p < 0.05) during storage. Partial-vacuum baked samples were softer and had a tendency to become stale more slowly than the control. The findings indicate that the partial-vacuum baking method increases the shelf life of gluten-free products by modifying the microstructure of the bread.     

The comparison of the effect of added amaranth,buckwheat, chickpea,corn, millet and quinoa flour on rice dough rheological characteristics,textural and sensory quality of bread

Gluten free (GF) flour (amaranth, buckwheat, chickpea, corn, millet and quinoa) was blended with rice flour to compare their impact on dough rheological characteristics and bread quality. The potential of some GF-rice blends in breadmaking has already been studied on blends with prevailing content of rice flour. The impact of added flour may be expected to rise with increasing amount of flour; therefore blends containing 30 g/100 g, 50 g/100 g and 70 g/100 g of GF flour in 100 g of GF-rice blend were tested. Under uniaxial deformation, peak strain was not impacted by the addition of GF flour; stress (12.3 kPa) was, however, significantly (P < 0.05) decreased (2.9–6.2 kPa). The reduction initiated by the presence of buckwheat, chickpea, quinoa and partly amaranth, together with thermally-induced dough weakening initiated by buckwheat and quinoa flour, may be related to significantly better crumb porosity. Overall acceptability of composite breads containing amaranth, chickpea and quinoa was negatively impacted by the aroma and taste of these flours. Higher potential to improve rice dough behavior and bread quality was found in the blend containing buckwheat flour (30 g/100 g; 50 g/100 g). Millet and corn flour deteriorated dough and bread quality.     

面筋蛋白对小麦粉理化性质及面包烘焙品质的影响

为明确不同类型小麦的面粉改良方案,为我国优质面包专用粉的生产提供理论与技术支持,以三个筋力不同的小麦品种宁麦13、扬麦16和郑麦9023为材料,通过洗面筋法提取各供试材料的湿面筋,将其冷冻干燥后按照7%、8%、9%、10%、11%的添加比例与各自面粉进行配比,对配粉的面包烘焙品质、面粉理化性质和面团流变学特性进行了测定分析。结果发现,随着面筋蛋白添加量的提高,配粉的蛋白质、湿面筋、谷蛋白大聚体(GMP)含量和沉降值逐步上升;粘度参数和面团弱化度有所下降;糊化温度和糊化时间呈上升趋势。在同一添加量下,强筋小麦的烘焙品质和面粉理化性质始终优于中筋小麦和弱筋小麦。随着面筋蛋白添加量的提高,面包体积、弹性、回复性、内聚力增大,而硬度、咀嚼性减小,感官品质得到改善。面筋蛋白添加量超过一定范围(宁麦13、扬麦16添加9%,郑麦9023添加8%),面包品质改良效果变缓,且色泽不断加深。综上所述,适量添加面筋蛋白可改变面粉的理化性质,提高其面包烘焙品质;配粉的蛋白质含量为18%左右是最经济的面包烘焙品质改良方案。