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In this study, the effect of ultrasonic sound (at 20- and 40-kHz frequency for 15 min) and drying (at 60 °C for 15 min) pretreatments on the moisture content and oil uptake of potato slices (cultivar Satina) during deep frying were studied. The potato slices were fried at temperatures of 170 and 190 °C for 5, 7 and 10 min. Samples pretreated with ultrasound at 20 kHz had higher moisture contents than those receiving the 40-kHz pretreatment. The highest moisture content was obtained at 20 kHz and frying at 170 °C for 5 min. On the other hand, samples pretreated with ultrasound at 40 kHz had higher effective water diffusivity coefficient and activation energy than those pretreated at 20 kHz. The highest effective water diffusivity coefficient was obtained at 40 kHz and frying at 190 °C for 5 min, whereas the highest activation energy belonged to pretreatment with 40 kHz and frying at 170 °C for 10 min. The range for effective water diffusivity coefficient was 6.95?×?10?8 to 8.80?×?10?8 m2 s?1 and that for activation energy was 13.161 to 16.307 kJ mol?1. In addition, samples pretreated at 40 kHz had a lower oil uptake than those pretreated at 20 kHz. The highest oil uptake took place at 20 kHz, with frying at 170 °C for 10 min. Regression analysis revealed that an exponential model was best for predicting variations in moisture content and oil uptake of potato slices. 相似文献
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《Journal of Cereal Science》2006,43(2):144-151
Water sorption isotherms and effective moisture diffusivities were determined at 20 °C for sponge cakes at high water activity as a function of their initial porosity, in the range 86 and 52% (0 g/g dry basis fat content), and of their fat content, ranging between 0 and 0.30 g/g dry basis (67% initial porosity). The equilibrium moisture values were not affected by food structure and decreased with increasing fat content. The effective moisture diffusivity decreased from 7.5 to 0.3×10−10 m2/s with increasing moisture content from 0.30 to 2.20 g/g dry basis. Decreasing initial porosity from 86 to 52% decreased effective moisture diffusivity by more than four orders of magnitude. This behaviour was related to differences of water transfer mechanisms, with the contribution from liquid water diffusion in the solid matrix and from vapour water diffusion in pores. Increasing fat content of 0.30 g/g dry basis in sponge cake, independently of porosity, decreased effective moisture diffusivity by more than five orders of magnitude. A predictive mathematical model was used to simulate moisture intake in two-composite food systems: sponge cakes with varying initial porosities and fat contents and an agar gel as a model of a non-rate limiting water source. Increasing the density of the structure or addition of fat in the cereal-based phase could increase shelf life of composite foods. 相似文献
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C.W. Foong K. Krishnaiah J. Janaun D. Subbarao A. Prabhakar 《Industrial Crops and Products》2009,30(2):227-234
Solid state fermentation (SSF) which involves the growth of microorganism on moist solid substrates in the absence of free flowing water, has gained renewed attention over submerged fermentation for specific applications. During the SSF process in fermenter, there are three main engineering problems encountered such as the removal of metabolic heat from the substrate, diffusion of O2 and moisture through the substrate, and heterogeneity of the substrate and inoculum. A fluidized bed fermenter in which the particles move independently like a fluid was proposed to conduct the study. Throughout the study, rapid heat transfer from PKC to air was experimentally observed within the first 150 s with a temperature drop of 30 °C. This indicated that the excellent heat transfer between palm kernel cake and air allows solid state fermentation of PKC without accumulation of metabolic heat in the fermenter. Apart from heat removal, water adsorption study on PKC from air to bed was carried out. It showed that the increase of adsorbed water in PKC was proportional to air relative humidity and inversely proportional to superficial air velocity. The maximum moisture content adsorbed by PKC under fluidization conditions was around 10% (on dry basis). Finally, mathematical models for heat and mass transfer were proposed which can predict the experimental data quite satisfactorily. 相似文献
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Fei Shen 《Industrial Crops and Products》2011,34(3):1588-1594
The chopped sweet sorghum stalk was thin-layer-dried for long-term storage and ethanol production. The drying kinetics and the effects of drying temperature on the qualities of sweet sorghum stalk were investigated in this work. The results showed that the drying process could be simulated well by Wang and Singh's model. The diffusivity constant (D0) and active energy (Ea) were estimated as 4.4 × 10−5 m2/s and 21.4 kJ/(mol K) for drying the chopped fresh stalk. According to the sugar composition, browning degree, and fermentability of the dried stalk obtained at various temperatures, the approximate drying temperature could be suggested as 50-60 °C for application. In this range, the moisture of the chopped fresh stalk could drop below the safe moisture for storage in 7-5.5 h with 12.1-9.7% total sugar loss during the drying process. 相似文献
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以有性杂交不亲和的抗虫、抗晚疫病的野生二倍体马铃薯Solanum pinnatisecta(2 n=2x=24)和抗晚疫病的二倍体材料DY4-5-10(2n=2x=24)的无菌苗叶片为原生质体来源,进行了电融合的研究,以优化马铃薯高效融合的参数。研究结果表明:其最佳的电融合参数为预融合电压1.0×105V/m,时间60 s,脉冲强度1.8×106V/m,脉冲宽幅20μs,脉冲次数1次。其有效融合率为28.89%,破损率为13.33%。 相似文献
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Switchgrass is an important biomass that can be hydrolyzed to yield fermentable sugars through pretreatment, which is the primary and expensive step in conversion of biomass to bio-ethanol. Most of the pretreatment operates in batch mode, which is energy intensive, requires high capital, results in decomposition of hemicellulose, and formation of inhibitors. Considering these shortcomings, a novel biomass pretreatment method using a high shear bioreactor could be a viable continuous one. The current study was undertaken to determine the effect of biomass parameters such as moisture content (10, 20, 30, 40, and 50% wb) and particle size (2, 4, 6, 8, and 10 mm) over a range of barrel temperature and screw speed (45-225 °C and 20-200 rpm). Statistical analyses revealed that among the independent variables considered temperature, screw speed, and moisture content had significant effect on sugar recoveries. Proposed quadratic model to predict glucose, xylose, and combined sugar recoveries from switchgrass had a high F and R2 values indicating that the model has the ability to represent the relationship among the independent variables studied. The optimum pretreatment condition of barrel temperature 176 °C, screw speed 155 rpm, moisture content 20% wb, and particle size 8 mm resulted in maximum glucose, xylose, and combined sugar recoveries of 41.4, 62.2 and 47.4%, respectively. The optimum pretreated switchgrass had 50% higher surface area than that of the control. 相似文献
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为给我国大豆生产及进口提供决策参考信息,运用ARIMA(自回归单整移动平均)模型预测分析了2021年前世界大豆收获面积、平均单产及总产。结果表明:2018、2019、2020和2021年世界大豆收获面积分别为1.23×10~8,1.27×10~8,1.31×10~8和1.34×10~8 hm^2,平均单产分别为2 767,2 811,2 855和2 900 kg·hm-2,总产分别为3.40×10~8,3.57×10~8,3.74×10~8和3.89×10~8 t;同期中国大豆收获面积分别为6.77×10~6,6.72×10~6,6.68×10~6和6.63×10~6 hm^2,平均单产分别为1 866,1 887,1 908和1 930 kg·hm-2,总产分别为1.26×10~7,1.27×10~7,1.27×10~7和1.28×10~7 t;同期美国大豆收获面积分别为3.49×10~7,3.56×10~7,3.64×10~7和3.71×10~7 hm^2,平均单产分别为3 287,3 329,3 372和3 415 kg·hm-2,总产分别为1.15×10~8,1.18×10~8,1.23×10~8和1.27×10~8 t。该结果意味着:世界大豆的收获面积在扩大、单产在提高、总产在增加,中国大豆收获面积在缓慢缩小、单产在提高、2004年后总产在减少,美国大豆收获面积在扩大、单产在提高、总产在增加。 相似文献
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A novel serine protease inhibitor (serpin) gene designated as Spi1C was cloned via the sequenced-based screening of a metagenomic library from uncultured marine microorganisms. The gene had an open reading frame of 642 base pairs, and encoded a 214-amino acid polypeptide with a predicted molecular mass of about 28.7 kDa. The deduced amino acid sequence comparison and phylogenetic analysis indicated that Spi1C and some partial proteinase inhibitor I4 serpins were closely related. Functional characterization demonstrated that the recombinant Spi1C protein could inhibit a series of serine proteases. The Spi1C protein exhibited inhibitory activity against α-chymotrypsin and trypsin with K(i) values of around 1.79 × 10(-8) and 1.52 × 10(-8) M, respectively. No inhibition activity was exhibited against elastase. Using H-d-Phe-Pip-Arg-pNA as the chromogenic substrate, the optimum pH and temperature of the inhibition activity against trypsin were 7.0-8.0 and 25 °C, respectively. The identification of a novel serpin gene underscores the potential of marine metagenome screening for novel biomolecules. 相似文献
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The rates of drying of herbage, cut from perennial ryegrass (Lolium perenne L.) – dominant swards and subjected to different treatments, were investigated under field conditions by changes in weight of herbage in wire mesh trays in 1995 and 1996. A series of replicated factorial experiments studied the effects, in different combinations, of intensity of conditioning achieved by passing the cut herbage through a laboratory‐scale macerator zero (0C), once (1C), three (3C) or six (6C) times; weight of herbage per unit area equivalent to 450, 675 and 900 g dry matter (DM) m?2. In one experiment, pressing the herbage to form a mat was incorporated into the experimental design. A further experiment investigated the effect of varying the proportion of conditioned herbage in the herbage mass from 0·00, 0·25, 0·50, 0·75 and 1·00 on drying rate. On each occasion the trays plus herbage were weighed at hourly intervals over an ≈6‐h period and the DM content of the herbage estimated from the change in weight. On all occasions, conditioning and weight of herbage per unit area significantly (P < 0·001) influenced herbage drying rate. Lowering the weight per unit area of both unconditioned and conditioned herbage increased the rate of moisture loss. Unconditioned herbage at the equivalent of a herbage mass of 450 g DM m?2 had a total moisture loss that was on average 1·5–1·8 times greater than unconditioned herbage at the equivalent of a herbage mass of 900 g DM m?2. Similarly, conditioned herbage at the equivalent of a herbage mass of 450 g DM m?2 had a total moisture loss that was 1·8–2·3 times greater than unconditioned herbage at the equivalent of a herbage mass of 900 g DM m?2. Increasing the level of conditioning produced a non‐linear response in rate of moisture loss, consequently 3 passes through the macerator produced >0·95 of the total moisture loss that was produced by 6 passes through the macerator. Increasing the proportion of conditioned herbage in the herbage mass increased rate of moisture loss and consequently final DM content (P < 0·001) although there was little effect from increasing the proportion of conditioned herbage above 0·75. The effects of conditioning and weight of herbage per unit area treatments on total nitrogen , water‐soluble carbohydrate and acid‐detergent fibre concentration of the herbage were small. 相似文献
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作物的生物量与产量的形成密切相关,建立生物量预测模型可实时分析植株的生长情况,有利于进行科学管理、合理施肥。本试验通过测定3个品种火龙果3个不同时期的部分形态指标对火龙果的生物量进行拟合。结果表明：火龙果植株结果枝的干物质积累量与其叶肉的长、宽、厚等指标显著相关,其预测模型为W（结果枝干重）= -43.5430+ 0.7100×叶肉长+0.5919×叶肉宽+2.7955×叶肉厚,验证系数R=0.8760;火龙果花的干物质积累量与花长、基部直径等指标密切相关,其预测模型为W（花干重）=-14.8919+0.4499×花长+4.5402×基部直径,验证系数R=0.8815;果的干物质积累量与果横径、横纵比显著相关,其预测模型为W（果干重）=-35.7435+16.3456×果横径-62.6395×横纵比,验证系数R=0.8782;地上部的干物质的积累量与分枝数、主茎的叶肉厚、节点个数、髓部直径、髓部厚度等指标显著相关,其预测模型为W（地上部干重）=0.058707+0.1337955×分枝数+0.0153781×主茎叶肉厚-0.041053×节点个数-0.083695×髓部直径+0.2397029×髓壁厚度,验证系数R=0.8864。本研究通过对红心火龙果植株的多个形态指标进行观测分析,建立红心火龙果生物量预测模型,可以对火龙果植株结果枝、花、果以及地上部分的生物量进行估算,具有一定的应用价值。 相似文献
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大田直播条件下,研究了壮芽灵浸种对三系杂交水稻德香4103群体结构和产量的影响。结果表明：（1）壮芽灵浸种可以显著提高稻种的发芽势,但发芽率提高不显著;（2）壮芽灵浸种可以缩短从始苗到全苗的时间2 d,在播种量相同的条件下,基本苗和出苗率得到显著提高,基本苗从56.67万株/hm^2提高到68.89万株/hm^2,出苗率从75％提高到91％;（3）壮芽灵浸种可以显著提高群体最高苗数和成穗率,最高苗从573.33万/hm^2提高到612.22万/hm^2,成穗率从44％提高到47％;（4）壮芽灵浸种后有效穗数、结实率、千粒重显著提高,增产达7.70％。 相似文献
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加拿大玉米群体与黑龙江省部分早熟骨干系杂种优势分析 总被引：1，自引：1，他引：0
采用NCⅡ设计,以8个黑龙江省常用早熟骨干自交系为测验种,对20个加拿大玉米群体的产量配合力及杂种优势进行分析。结果表明,群体EP8、EP17、EP7、EP13和EP15产量一般配合力(GCA)较高,利用这些群体较易组配出高产杂交组合。以产量特殊配合力(SCA)为指标,发现K10与EP6、EP11、EP12、EP14,L105与EP18、EP19、EP20、EP22、EP23,甸11A与EP7、EP8、EP9,东237与EP1、EP16、EP17,合344与EP3、EP13,龙抗11与EP15,熊掌与EP10、EP21遗传关系较近。从产量平均优势分析可见,部分群体杂种优势组合模式为EP7×K10、EP18×K10、EP1×龙抗11、EP12×龙抗11、EP17×熊掌、EP14×甸11A、EP23×甸11A、EP3×东237、EP21×东237。 相似文献
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甘蓝型油菜主花序有效角果数QTL定位 总被引：3，自引：0，他引：3
为分析甘蓝型油菜主花序有效角果数的遗传标记,以ZY036×51070杂交构建的双单倍体(DH)为材料,采用2010-2012年在武汉、阳逻、青海和襄阳三年四点五个试验的检测数据,运用WinQTL Cartographer 2.5软件进行主花序有效角果数QTL定位分析。研究共检测到10个与主花序有效角果数相关的QTL,表型变异是9.33%～31.60%,LOD(极大似然函数比的常用对数)值是2.51～5.37,加性效应是2.71～8.09。而且在染色体A1、A5、C1和C9上的4个QTL都可以在2个不同的试验中重复检测到。试验还得到QTL区间的16个连锁标记,其中有8个距离QTL的最大峰值不足1cM。 相似文献
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对杂交粳稻甬优8号进行不同播期、基本苗、施氮量和水分4因素3水平的正交试验,筛选其最佳栽培因子组合。结果表明:播期(x)对其全生育期(y)影响显著(F=82.71F0.05),呈显著负相关,y=-0.4x+149.67,(R=0.997 4);基本苗对有效穗影响显著(F=52.74F0.05),随着基本苗的增加有效穗呈递增趋势,结实率和千粒重呈下降趋势;播期和施氮量对产量影响极显著,密度对产量影响显著,甬优8号最佳栽培组合为播期(5月5日)、密度(5.46万/667 m2)、施氮量(20 kg/667 m2)和水分(表层无明水)。 相似文献
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O. Giayetto G. A. Cerioni M.S. Amín 《花生学报》2005,34(2):5-13
研究在本农艺学院开展,对每日平均气温、降水和光照均作记录。处理设六种不同株行距(0 .70×0 .12 ,0 .50×0 .12 ,0 .70×0 .06 ,0 .30×0 .12 ,0 .50×0 .06和0 .30×0 .06 m) ,对应密度是12 ,18 ,24 ,28 ,33和55株/ m2。测定0~100cm土壤样品水分含量,用于计算作物水分蒸发蒸腾量(ET)、作物光截获量(α)、土壤蒸发量(Es)、作物水分利用率( WUE)和蒸腾率(Te)。最低密度(0 .70×0 .12 m)单株生长最好,最高密度处理则导致最低的单株干物质产量,其余4个处理单株干物质产量居于二者之间。两个品种的不同间距处理同样对单株荚果饱果数、荚果和种子产量有显著影响,高密度下使其均降低,但单位面积荚果和种子产量提高,但Florman的产量要好于Colorado。种植处理显著影响作物水分蒸发蒸腾量。行距0 .30 m和0 .50 m下,两个品种都达到46和60 DAS;行距0 .70 m下,Colorado是66DAS而Florman是87DAS。两个品种的蒸腾率都受到行距的影响,两个品种的WUE都受到间距影响,0 .70 m行距下WUE最低,Colorado在0 .50 m和0 .30 m行距下,Florman在0 .30 m下WUE最高。行距对Te的影响因品种而异,Colorado在不同行距下无显著差异,而Florman的Te则随行距减少而增加。不同间距和品种对光合效率都没有很大影响(Colorado是3 .1×10-2Kcal/ha ,Florman是3 .0×10-2Kcal/ha)。 相似文献
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为优化亚麻栽培技术,提高亚麻原茎产量,试验通过二次正交旋转设计分析了有效播种密度、氮肥、磷肥、钾肥对冬播亚麻原茎产量的影响。发现供试条件下,各因素对亚麻原茎产量的影响大小顺序为有效播种密度（X1）〉氮肥（X2）〉钾肥（X4）〉磷肥（X3）,不同肥料间互作不显著。并得到优化后的亚麻高产栽培方案：有效播种密度在3454.8-3502.3万粒/hm2,N263.2-337.7kg/hm^2,P2O5用量75.5-99.7kg/hm^2,K2O用量242.5-316.8kg/hm^2。 相似文献