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141.
超声波技术对醇浸出法大豆浓缩蛋白乳化性的影响 总被引:2,自引:0,他引:2
制取低成本、高蛋白含量的大豆浓缩蛋白时,乙醇产生变性作用,从而降低了大豆浓缩蛋白的功能特性。采用超声波技术对醇浸出法大豆浓缩蛋白进行物理改性。通过对固液比、超声波功率、改性时间的单因素试验,针对乳化性进行研究,然后进行正交试验方差分析,最终得出用超声波技术提高醇浸出法大豆浓缩蛋白乳化性的最佳工艺条件:固液比为1﹕9、功率密度为0.5W.cm-2、时间为3min,可提高乳化能力127.9%,乳化稳定性29.9%。 相似文献
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《Journal of plant nutrition》2013,36(4):789-806
Abstract In this study, the effects of boron (B) and calcium (Ca) supply on Ca fractionation in suspension cells and different tissues of rape (Brassica napus L.) plants of two cultivars with different B efficiency were studied, with a purpose to elucidate the mechanism by which B affects Ca concentration in plants. As Ca supply increased in nutrient solution or culture medium, the relatively easily extractable Ca fractions, that is H2O and 80% ethanol extractable Ca in leaves, 1 mol L?1 NaCl extractable Ca in upper leaves, roots and suspension‐cell were significantly increased. While the recalcitrant Ca fractions extracted by 2% acetic acid, 0.6 mol L?1 HCl and Ca in the residue were not affected by Ca supply. Increasing B supply in nutrient solution or culture media significantly reduced 1 mol L?1NaCl extracted Ca in suspension cell and roots of both cultivars, which were most likely related to the alteration of cell wall metabolism. Calcium extracted by 2% acetic acid, 0.6 mol L?1 HCl and Ca in residue in suspension‐cell and roots of B inefficient cultivar Bakow were easily improved by B deficiency as compared to that of B efficient cultivar Tezao16. Increasing of these relative recalcitrant Ca fractions was related to the different response of cultivars to the B deficiency, which may reflected different extent that Ca deposited in the two cultivars due to impaired membrane integrity under B deficiency. The effects of B on Ca concentration in lower and upper leaves of the two cultivars were quite different and were the integrated effects of B on Ca metabolism, Ca transport in plants and growth of certain organ. Increasing B supply increased total Ca concentration in upper leaves of Bakow and reduced that of Tezao16, which might relate to the different adaptability of the two cultivars to comparatively higher B supply. 相似文献
144.
An experiment was conducted to test the hypothesis that for cows with high levels of milk yield, rotational grazing produces higher milk yields than continuous grazing. The comparison of grazing systems was made at two levels of milk yield (initially 20·3 and 32·5 kg d?1), and interactions with sward height and concentrate level were also examined. The study used 48 multiparous Holstein Friesian cows over a period of 62 d. Mean milk yield, its persistency and composition, live weight, body condition score and liveweight gain were not significantly affected by grazing system at either level of milk yield. There were no significant interactions between grazing system and sward height or concentrate level for any milk production measurement. Mean estimated herbage and total dry matter (DM) intake (P < 0·01), grazing time (P < 0·05) and ruminating time (P < 0·01) were significantly greater on the continuous grazing system. The cows in the higher milk yield group and those grazed at the higher sward height had a significantly (P < 0·05) higher estimated daily herbage DM intake and rate of herbage intake on the continuous grazing system than those on the rotational grazing system. There was no evidence to support the hypothesis that rotational grazing systems support higher levels of milk production than continuous grazing for cows of high milk yield. The shorter grazing time on the rotational grazing system indicated that cows may anticipate the timing of the daily movement of the electric fence, and this reduces their time spent grazing residual herbage. 相似文献
145.
M. J. Hinds L. R. Beuchat M. S. Chinnan 《Plant foods for human nutrition (Dordrecht, Netherlands)》1997,50(4):269-277
A low-fat beverage with roasted peanut flavor was developed from peanuts. The potential milk substitute contained 11.8% total
solids, 2.0% fat and 3.7% protein, and was whitish orange-yellow in color. The effects of stabilizing additives and homogenization
pressure (13.8×106 Pa or 41.4×106 Pa) on selected physical characteristics were determined. Suspension stability was improved by addition of carrageenan [Benlacta
CM61-B (CM), 0.02–0.04%] or a hydrogenated mono- and diglyceride [Emuldan HV52K (HV, 0.2–0.4%)]. Homogenizing at 41.4×106 Pa increased viscosity of all samples except that of the controls but did not improve the suspension stability (top:bottom
solids) of the beverage. The most viscous formulations (17.5±0.95 cps) were those containing 0.04% CM. Treatments yielding
the best combination, compared to cow's milk values, of high suspension stability (0.5±0.03, where 1.0=maximum stability)
and low viscosity (3.7±0.89 cps) were those containing 0.2% HV which were homogenized at 13.8×106 Pa. 相似文献
146.
Two factorial design experiments were carried out in the spring of 1994 and 1995, each of 6 weeks, to quantify the effects of sward height (SH), concentrate level (CL) and initial milk yield (IMY) on milk production and grazing behaviour of continuously stocked dairy cows. In Experiment 1, forty‐five Holstein Friesian cows were in five groups with initial milk yields of 16·9, 21·1, 28·0, 31·5 and 35·5 kg d–1, grazed sward heights were 3–5, 5–7 and 7–9 cm (LSH, MSH and HSH respectively), and concentrates were fed at rates of 0, 3 and 6 kg d–1. In Experiment 2, 48 cows were in two groups with IMY of 21·3 and 35·5 kg d–1, grazed sward heights were 3–5 and 7–9 cm (LSH and HSH), and concentrates were fed at 0 and 6 kg d–1 and ad libitum. Multiple regression models were used to quantify the effects of the three variables on milk yield persistency (MYP), estimated herbage dry‐matter (DM) intake (HDMI), grazing time (GT) and rate of DM intake (RI). The partial regression coefficients showed that increased SH led to increased MYP (Experiment 1 P < 0·001, Experiment 2 P < 0·05), increased HDMI (P < 0·01, P < 0·01), increased GT (P < 0·001, P < 0·05) and increased RI (P < 0·001, P < 0·05). Increasing CL led to increased MYP (NS, P < 0·001), decreased HDMI (P < 0·001, P < 0·001), decreased GT (NS, P < 0·001) and decreased RI (P < 0·001, P < 0·001). Higher IMY level of cows decreased MYP (P < 0·001, P < 0·001), increased HDMI (P < 0·001, P < 0·001), increased GT (P < 0·001, P < 0·05) and increased RI (P < 0·05, P < 0·01). The models were highly significant (P < 0·001), and accounted for 0·48–0·87 of the total variance. The partial regression coefficients quantified the extent to which GT and RI by cows respond positively to higher IMY, and negatively to increased CL, but respond differently (GT declines in response to a higher RI) with increasing SH. 相似文献
147.
重金属元素在湿地生态系统中的迁移与分配 总被引:1,自引:0,他引:1
为了解重金属元素在湿地生态系统中的迁移和分配特征,于2011年夏季采集了大庆市龙凤湿地土壤、水、芦苇、鱼等4种样品,采用原子吸收分光光度法测定其中Cu,Cd,Zn,Pb,As和Hg这6种重金属元素的含量水平,应用统计学方法分析了彼此之间的相关关系。结果显示,龙凤湿地环境质量状况良好,土壤重金属含量低于松嫩平原的平均值,水体环境质量低于地表水环境质量Ⅱ级标准;湿地中生存的动、植物对重金属的累积情况各不相同,鱼体重金属的富集情况为:Zn>Cd>Cu>As>Hg>Pb,而芦苇重金属的富集情况则为:Cd>Hg>Zn>Cu>As>Pb。分析表明,土壤重金属含量与植物、鱼体重金属含量之间均存在明显的正相关关系,而水、植物、鱼三者之间虽然也存在一定的正相关关系,但均未达到显著水平。 相似文献
148.
酪蛋白胶束粉的陶瓷膜分离生产工艺 总被引:1,自引:1,他引:0
为尽快建立酪蛋白胶束粉(micellar casein concentrate, MCC)的中试生产线,实现MCC在国内的工业化生产,该研究通过测定牛乳蛋白粒径,选取孔径40和100 nm的中空纤维陶瓷膜进行膜分离效果的对比,并选用膜分离效果较佳的陶瓷膜进行最佳操作参数的确定及稀释过滤工艺的研究,最后将自制MCC和进口MCC进行品质特性对比并分析其工业化生产的可能性.结果表明:孔径40 nm中空纤维陶瓷膜与孔径100 nm中空纤维陶瓷膜相比,渗透液中不含酪蛋白,能够减少酪蛋白损失,更适合于酪蛋白和乳清蛋白的分离,孔径40nm中空纤维陶瓷膜的最佳操作参数为操作压力2×105 Pa,料液温度50℃;采用四段式的连续稀释过滤工艺,可使料液中酪蛋白占真蛋白的比例从69.39%提升至93.34%,真蛋白占干物质的比例从38.45%提升至88.15%;稀释过滤完毕后膜的纯水通量衰减了39.98%,经生物酶清洗液清洗后膜的纯水通量恢复至初始的98.02%;自制MCC在成分组成上与加拿大Proteinco公司生产的MCC相比差异不显著(p<0.05),但在溶解度和粉粒的微观形态上优于Proteinco MCC;生产1 kg MCC需要原料乳46.24 L,成本为244.58元,可实现其国内工业化生产.研究结果为实现MCC在国内工业化生产及其应用性研究提供参考. 相似文献
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