食用藕粉辐照杀菌与贮藏效果的研究

 研究结果表明 ,食用藕粉经60 Coγ射线辐照杀菌 ,杀菌效果随剂量增加而显著。辐照对淀粉含量、可溶性糖和脂肪无明显影响 ,氨基酸总量有减少趋势 ,淀粉粘滞性随剂量增加而下降 ,商业化加工辐照杀菌剂量控制在4～ 6kGy为宜。     

不同淀粉对小麦面团流变学特性及馒头品质的影响

向小麦粉中添加马铃薯淀粉、绿豆淀粉和玉米淀粉,研究淀粉种类及添加比例对面团流变学特性及馒头品质的影响。结果表明:添加马铃薯淀粉和绿豆淀粉,面团吸水率随添加量增大呈下降趋势,添加玉米淀粉则吸水率呈上升趋势;面团拉伸能量随淀粉添加量增大而减弱,延伸度先增大后减小。综合来看,添加淀粉使得面团面筋网络结构不同程度弱化,小麦粉中淀粉添加量不宜超过20%。     

不同籼稻米品种米粉加工适应性探究

本实验选用黔优35、贵丰优785、川香优569、协优385几个杂交水稻品种及常规稻桂朝2号5个米粉加工原料大米品种进行米粉加工适应性探究实验,从基础指标、出粉率、质构特性、感官评分几个方面对其加工适应性进行综合评价,探究不同大米在米粉加工中的适应性,以期获得较为适宜的米粉加工大米品种,结果表明：黔优35无论在出粉率还是感官评分上都具有较为明显的优势,是比较具有潜力的米粉加工大米品种。     

冻融循环老化降低竹粉/聚丙烯发泡复合材料性能

竹粉/聚丙烯(polypropylene,PP)发泡复合材料具有密度低、比强度高等优点,为了探讨期老化规律,该文研究冻融循环对不同竹粉含量(0,20%,33%和42%)的发泡复合材料的材色、物理力学性能、热学性能的影响,并结合环境扫描电镜(environmental scanning electronic microscopy,ESEM)和傅里叶红外光谱(fourier transform infrared spectrum,FTIR)对复合材料的表面形貌及化学结构进行分析。结果表明:随着竹粉含量增加,冻融循环老化对复合材料的材色和物理力学性能影响越明显,且随着冻融循环次数的增加,复合材料产生的色差越大,力学性能降低越多。9次冻融循环后,0、20%、33%和42%竹粉/PP发泡复合材料产生的色差ΔE*分别为0.9、2.4、7.0和9.9,弯曲模量、弯曲强度、拉伸强度和缺口冲击强度的保留率分别为95.2%~99.1%、97.3%~98.9%、94.9%~97.5%和92.0%~95.6%。热重分析(thermogravimetric analysis,TG)结果表明,9次冻融循环老化后,0和33%竹粉/PP发泡复合材料的初始热分解温度分别下降了19和8℃。ESEM显示,老化后复合材料表面出现少量的裂纹以及褶皱,且少量的表层高分子层脱落。FITR测试结果发现,冻融循环过程中复合材料的木材指数减少,表明材料表面的竹粉颗粒损失,且基体PP的基团峰强度减弱。该研究可为进一步探索竹塑发泡复合材料的老化规律,制定产品标准提供试验数据和理论参考。     

添加甘薯粉对面包烘焙品质的影响

研究分析了添加不同比例甘薯粉对面包烘焙品质的影响，并对优质一级面包粉和普通面包粉进行了比较。结果表明，对于优质面包粉，甘薯粉添加量可在１０％以内，对于一般面包粉应控制在７．５％以内     

Nixtamalized Flour From Quality Protein Maize (<Emphasis Type="Italic">Zea mays</Emphasis> L). Optimization of Alkaline Processing

Quality of maize proteins is poor, they are deficient in the essential amino acids lysine and tryptophan. Recently, in México were successfully developed nutritionally improved 26 new hybrids and cultivars called quality protein maize (QPM) which contain greater amounts of lysine and tryptophan. Alkaline cooking of maize with lime (nixtamalization) is the first step for producing several maize products (masa, tortillas, flours, snacks). Processors adjust nixtamalization variables based on experience. The objective of this work was to determine the best combination of nixtamalization process variables for producing nixtamalized maize flour (NMF) from QPM V-537 variety. Nixtamalization conditions were selected from factorial combinations of process variables: nixtamalization time (NT, 20–85 min), lime concentration (LC, 3.3–6.7 g Ca(OH)₂/l, in distilled water), and steep time (ST, 8–16 hours). Nixtamalization temperature and ratio of grain to cooking medium were 85 °C and 1:3 (w/v), respectively. At the end of each cooking treatment the steeping started for the required time. Steeping was finished by draining the cooking liquor (nejayote). Nixtamal (alkaline-cooked maize kernels) was washed with running tap water. Wet nixtamal was dried (24 hours, 55 °C) and milled to pass through 80-US mesh screen to obtain NMF. Response surface methodology (RSM) was applied as optimization technique, over four response variables: {In vitro} protein digestibility (PD), total color difference ( E), water absorption index (WAI), and pH. Predictive models for response variables were developed as a function of process variables. Conventional graphical method was applied to obtain maximum PD, WAI and minimum E, pH. Contour plots of each of the response variables were utilized applying superposition surface methodology, to obtain three contour plots for observation and selection of best combination of NT (31 min), LC (5.4 g Ca(OH)₂/l), and ST (8.1 hours) for producing optimized NMF from QPM.     

Formulation,acceptability, chemical composition and in vitro digestibility of novel snack food and meat ball analogue

Potato purée and wheat flour were blended at ratio of 7:1 w/w with 2 parts per weight of soybean protein concentrate (SPC) and/or faba bean-protein micellar mass (PMM). Two snack foods were formulated and deep fried. Spices, onion, parsley and chicken stock were added to the aforementioned two recipes to formulate meat ball analogues. Data revealed good acceptability of all products. Moreover, they can be considered as a good source for some essential amino acids; protein (26%); lipids (20%); carbohydrates (48%) and minerals. The in vitro digestibility ranged between 61.0% and 66.9%.     

Glycemic index of grain amaranth, wheat and rice in NIDDM subjects

Glycemic index of grain amaranth, wheat and rice preparations was studied in noninsulin dependent diabetic subjects. Diets containing 50 g carbohydrate equivalent were given and post-prandial blood glucose estimated at different intervals. Glycemic index calculated for different experimental diets showed that GI of amaranth-wheat composite flour diet (25∶75) was the least (65.6%) followed by wheat diet (65.7%), rice diet (69.2%), amaranth-wheat flour 50∶50 (75.5%), and popped amaranth in milk (97.3%). Therefore 25∶75 combination of amaranth and wheat, wheat and rice can be considered low GI food, 50∶50 grain amaranth and wheat medium GI food and popped amaranth and milk combination high GI food.     

Studies on samh seeds (Mesembryanthemum forsskalei Hochst) growing in Saudi Arabia: 3. Utilization of samh seeds in bakery products

Samh seeds obtained from Al-Jouf area were ground into flour analyzed and used as a replacement for wheat in the ratio of 10, 20 and 30% for bread and 30, 60 100% for cookies. The rheological effect of the Samh flour on Saudi wheat flour was also studied. The bread and cookies obtained were evaluated physically and by sensory evaluation. The results obtained indicated that samh flour has high protein content and could be used as a replacement for wheat flour upto 30% without adversely affecting the bread specific volume much. Samh flour has improved the cookies appearance specially the colour (chocolate colour) and spreading ratio. The results also revealed that it is possible to make cookies from 100% samh flour. Due to the high protein content of the samh seeds the nutritional value of the bread and cookies made with samh flour will be improved. The results of the sensory evaluation of the bread and cookies indicated that the bread made with samh flour upto 30% has similar characters except for the crumb color and the overall acceptability which were rated as significantly inferior. The sensory evaluation of the cookies showed that the cookies made with samh flour upto 100% were significantly superior (p<0.05) to the cookies made with 100% wheat flour (control).     

Effects of raw soy flour feeding in weanling pigs: comparison with rats and monkeys

Feeding of raw and heated soy flour (RSF & HSF) for 4 or 8 weeks to weanling swine was compared with feeding of casein diets. There was essentially no growth in pigs fed RSF, whereas body weight increased 4.5 fold over 8 weeks with either casein or HSF. No change in pancrease weight as percent body weight was found in any group in either experiment. Both total pancreatic RNA and DNA were decreased in RSF groups, although RNA and DNA/mg pancreas were increased by the RSF diets. Total pancreatic protein, as well as protein/mg, were decreased in RSF-fed pigs compared to casein and HSF. Pancreatic trypsin, chymotrypsin, lipase, and amylase, and fecal trypsin were decreased in RSF-fed pigs to varying degrees compared to either HSF or casein. HSF and casein performance was equivalent in all parameters measured. Results of these experiments are compared with results of feeding similar diets to rats and monkeys.