Super sweet corn hybrid sh2 adaptability for industrial canning process

The super sweet corns Krispy king, Victor and 324 (sh2 hybrids) were evaluated to determine their adaptabilities to the industrial canning process as whole kernels. All these hybrids and Bonanza (control) were sown in San Joaquín (Carabobo, Venezuela), harvested and canned. After 110 days storage at room temperature they were analyzed to be compared physically, chemically and sensorially with Bonanza hybrid. Results did not show significant differences among most of the physical characteristics, except for percentage of broken kernels which was higher in 324 hybrid. Chemical parameters showed significant differences (P < 0.05) comparing each super sweet hybrid with Bonanza. The super sweet hybrids presented a higher sugar content and soluble solid of the brine than Bonanza, also a lower pH. The super sweet whole kernel presented a lower soluble solids content than Bonanza but they were not significant (Krispy king and 324). Appearance, odor and overall quality were the same for super sweet hybrids and Bonanza (su). Color, flavor and sweetness were better for 324 than all the other hybrids. Super sweet hybrids presented a very good adaptation to the canning process, having as an advantage that doesn't require sugar addition in the brine and a very good texture (firm and crispy).     

某速冻食品厂废水处理工艺设计

食品工业废水的特点是有机物质和悬浮物含量高,易腐败,会使水体富营养化。本设计采用水解酸化—接触氧化法处理食品废水,处理效果良好,各项指标均达到《废水综合排放标准》(GB8978-1996)的一级标准。     

几种浮选机对胶磷矿直接浮选工艺的适应性

根据胶磷矿对浮选机的特殊要求 ,通过对几种在王集磷矿选厂使用、试验过的浮选机的结构性能及其运行、试验情况论述 ,提出了胶磷矿浮选机应具备的结构性能。     

Super sweet corn hybrids adaptability for industrial processing. I freezing

With the purpose of evaluating adaptability to the freezing process of super sweet corn sh2 hybrids Krispy King, Victor and 324, 100 cobs of each type were frozen at -18 degrees C. After 120 days of storage, their chemical, microbiological and sensorial characteristics were compared with a sweet corn su. Industrial quality of the process of freezing and length and number of rows in cobs were also determined. Results revealed yields above 60% in frozen corns. Length and number of rows in cobs were acceptable. Most of the chemical characteristics of super sweet hybrids were not different from the sweet corn assayed at the 5% significance level. Moisture content and soluble solids of hybrid Victor, as well as total sugars of hybrid 324 were statistically different. All sh2 corns had higher pH values. During freezing, soluble solids concentration, sugars and acids decreased whereas pH increased. Frozen cobs exhibited acceptable microbiological rank, with low activities of mesophiles and total coliforms, absence of psychrophiles and fecal coliforms, and an appreciable amount of molds. In conclusion, sh2 hybrids adapted with no problems to the freezing process, they had lower contents of soluble solids and higher contents of total sugars, which almost doubled the amount of su corn; flavor, texture, sweetness and appearance of kernels were also better. Hybrid Victor was preferred by the evaluating panel and had an outstanding performance due to its yield and sensorial characteristics.     

红薯淀粉浆在水解过程中的黏度

淀粉是由直链结构与支链结构构成结晶与非结晶的颗粒结构.在淀粉水解过程中的水链与链链的能量结构具有一定的变化规律.本文对红薯淀粉浆水解过程中的黏度进行了研究,找到了黏度与直链、支链淀粉的关系,发现了糊化过程的黏度急剧增加,并用特定的复合水解酶实现了常温水解的低黏度过程.     

玉米淀粉氧化工艺的研究

研究了玉米淀粉的氧化工艺。通过次氯酸钠、过氧化氢、高锰酸钾二次氧化、高碘酸钠氧化的比较,优选了高锰酸钾二次氧化作正交实验。直观分析及方差分析结果表明,最佳的氧化工艺为:氢氧化钠0.6 g,硫酸3 g,淀粉乳浓度40%,高锰酸钾1.2 g。     

玉米秸秆高浓度厌氧发酵的启动过程特性

高浓度厌氧发酵具有单位体积产气率高、原料处理量大、需水量小、能耗低等优点,同时存在启动难和易酸化的问题。以玉米秸秆为原料,研究秸秆高浓度发酵过程接种物、分批进料结合渗滤液回流对启动的影响。结果表明,分批进料结合渗滤液回流工艺可有效实现高浓度厌氧发酵系统的稳定启动,反应器启动运行22 d,以污泥为接种物的秸秆累积产沼气量为43.54 ml·（g TS）^-1,以湿法发酵的沼液为接种物的秸秆累积产沼气量为115.15 ml·（g TS）^-1。与以厌氧污泥为接种物的发酵系统相比,以湿式发酵沼液为接种物的高浓度厌氧发酵系统秸秆微观结构变化更明显,主要表现为半纤维的溶解;荧光原位杂交技术（FISH）结果也表明两种接种物系统的甲烷菌形态存在明显差异。     

水泥对外加剂的适应性

配制流态化混凝土所使用的外加剂主要有萘磺酸盐甲醛缩合物、多环芳烃磺酸盐甲醛缩合物、三聚氰胺磺酸盐甲醛缩合物、改性木质素磺酸盐、多元醇系等，单一外加剂不能满足流态混凝土的流化效果、强度、干缩、抗冻性、耐久性及运输过程中的经时损失要求，为达到综合效果，视混凝土的特性要求．需加入。     

Ultrasound-assisted osmotic process on quality of microwave vacuum drying sweet potato

The effects of pretreatment before microwave vacuum drying (MVD) on texture, color, expansion, rehydration, drying rate, microstructure, sensory evaluation, and other properties of sweet potato were investigated in this study. The pretreatment consisted in five processing conditions, using blanching; osmotic dehydration at 35°Brix of sucrose (OD); ultrasound in distilled water (US); ultrasound in distilled water before osmotic dehydration (US?+?OD), and ultrasound-assisted osmotic dehydration (USOD). Pretreatments of sweet potato before MVD have shown success in reducing drying time with US treatment relatively more effective regarding drying time than other treatments. Compared with other treatments, US showed the highest rehydration ratio values. The osmotic group pretreatment exhibited a pronounced effect on water loss and solid gain, improved the color, aroma, and taste of dried sweet potato, whereas sucrose impregnation resulted in a hard texture observed with OD sample. USOD samples had a higher expansion ratio, lower hardness and color difference values, appeared less cell damaged, and recorded better overall quality than the other samples. There was a slight difference between USOD and US?+?OD samples. Combining osmotic dehydration with ultrasound as a pretreatment can significantly accelerate the heat transfer rate, reducing the dried time accordingly and increasing energy efficiency.     

Diffuse interface model of the freeze-drying process of individually frozen products

Abstract

Vacuum freeze-drying (VFD) is a dehydration method based on the sublimation of the liquid phase contained in a certain product, previously frozen, at low pressure and temperature. Since it is a time and energy consuming process, it is crucial to select the best processing conditions to minimize drying duration, thus reducing the energy requirement. Additionally, product temperature must be monitored since it plays an important role in preserving product quality. The aim of this study was to develop a Diffuse Interface Model (DIM) for in-silico simulation of the freeze-drying process of individually frozen products. Due to the geometrical features of the samples, and to the role of radiation in the heat transfer to the product, the usual one-dimensional approach is inappropriate. Using a DIM, each cell of the computational domain can be described as a porous solid matrix filled by ice and vapor with a time-varying composition, thus allowing the use of a fixed computational grid and making the computation effort less demanding in comparison to moving interface-based models. Drying of eggplant cubic samples was considered as case study: model parameters were estimated by fitting the experimentally measured product temperature and drying time to the calculated ones. The model was proven to be reliable in providing an accurate estimate of both the drying time and the product temperature. Therefore, it can be used for off-line process design and optimization, minimizing the experimental effort required to design and optimize the process.     

以玉米为原料的乙醇发酵工艺优化

以糖化醪液及发酵醪液为研究对象,通过响应面实验对ρ(糖)、营养成分及发酵工艺进行优化,达到提高酵母活性,实现高ρ(乙醇)发酵技术的突破。利用Placket-Burman(PB)实验证明磷酸氢二铵对乙醇发酵有促进作用,而磷酸氢二钾和硫酸钾对乙醇发酵无显著促进作用。利用响应面实验对ρ(糖化醪糖)及ρ(磷酸氢二铵)进行优化,当发酵醪与高质量浓度糖化醪[ρ(葡萄糖)=316 g/L]按体积比1∶1混合后,补加2 g/L磷酸氢二铵,并在30℃条件下发酵48 h,实现醪液ρ(乙醇)=137 g/L[φ(乙醇)=17%],醪液ρ(葡萄糖)1.7 g/L。     

Use of sweet sorghum juice for lactic acid fermentation: preliminary steps in a process optimization

BACKGROUND: Lactic acid has many applications in the chemical industries and it can be produced economically by microorganisms using biomass raw materials of different origins. Sweet sorghum juice is a high sugar content raw material with potential for lactic acid production because after hydrolysis of its sucrose content the remaining glucose and fructose can supply the carbon demand of most lactic acid bacteria. However, satisfying the nitrogen and B‐vitamin needs of the bacteria by supplementation with yeast extract and/or other alternative nitrogen‐containing supplements can make the process too expensive. RESULTS: Using a statistical optimization process much of the yeast extract can be replaced by a cheaper alternative nitrogen source, namely wheat gluten. This resulted in a fermentation with 99% lactic acid yield and 3.04 g L^?1 h^?1 volumetric productivity. CONCLUSION: Using response surface methodology (RSM) media optimization was performed for lactic acid fermentation with an industrially acceptable result, reducing the costs of raw materials by half, replacing yeast extract by an alternative nitrogen source and applying yeast extract only as a source of micro‐elements (vitamins, salts, etc.) Copyright © 2010 Society of Chemical Industry     

Management of Gliricidia (Gliricidia sepium) residues for improved sweet corn yield in an ultisol

The nitrogen contribution from Gliricidia (G. sepium) leaves and roots in a Gliricidia alley cropping with sweet corn was quantified by the 15N isotope dilution technique over 3 cropping seasons. Below-ground competition in the third crop was assessed using ³²P radioisotope. Leaf prunings, roots and their mixture were compared in the presence or absence of hedgerows in a randomized complete block design. The combination of leaf prunings and roots resulted in highest N uptake, plant N concentration, and dry matter yield of corn. The Gliricidia leaf prunings decomposed fast and provided nutrients to the corn crop when applied at 21 and 45 days after planting. By contrast, roots decomposed slowly and did not become an important nutrient source to the corn crop. Below-ground competition was observed between hedgerows and corn at 1.7 m distance under conditions of low nutrient availability. However, the competition was masked when the supply of plant available nutrient increased.     

新型玉米淀粉胶粘剂合成工艺对比研究

通过因子轮换实验和正交设计实验研究了淀粉胶粘剂的合成工艺。分别以高锰酸钾、过氧化氢和次氯酸钠为氧化剂,探讨了氧化剂、糊化剂和交联剂3种原料用量对胶粘剂性能的影响,并分别确定了其最佳合成工艺。对高锰酸钾、过氧化氢和次氯酸钠3种氧化剂进行了对比研究,发现以次氯酸钠作氧化剂得到的产品性能好,工艺简单,合成成本低。     

高效协同酶解中性汽爆玉米秸秆的工艺优化

玉米秸秆是我国主要的农业废弃物之一,在木质纤维素乙醇领域具有广阔的应用前景。而玉米秸秆预处理和酶法糖化成本过高是目前工艺中的重点和难点之一。从4种纤维素降解酶制剂中优选出对中性汽爆玉米秸秆有最佳协同效果的木霉和黑曲霉纤维素酶制剂（6∶4体积比混合）。在此基础上,评估了木聚糖酶、β-葡萄糖苷酶、β-葡聚糖酶、漆酶、锰过氧化物酶等酶制剂,聚乙二醇-4000、吐温-80、牛血清白蛋白等非酶因子对糖化效率的影响,得到了一组高效协同降解汽爆玉米秸秆的复合酶体系,并获得了适宜的糖化工艺。结果表明,以每克中性汽爆预处理的玉米秸秆为底物,加入10FPU木霉/曲霉混合酶液,并添加1000IU的木聚糖酶和0.05 g PEG4000,于50℃/150 r·min^-1相似文献   

Composition and nutritive value of the Pajimaca sweet corn and Pajimaca Opaque-2, grown in Venezuela

The chemical composition and nutritive value of the sweet corn variety known as Pajimaca, and of the Pajimaca with the Opaque-2 gen, is herein presented. Evidence revealed that they contained similar levels of vitamins and minerals, with the exception of niacin, which was found to be higher in the latter. Lysine and tryptophan values for the Pajimaca Opaque-2 almost doubled those determined in the normal variety Pajimaca. As expected, compared with common corn, these varieties showed lower amounts of starch and higher amounts of sucrose and of total sugars. Biological evaluation assays in rats demonstrated a higher PER, weight gain and food efficiency index values for the Pajimaca Opaque-2, thus confirming its better protein quality.     

Nitrogen dynamics and yields of fresh bean and sweet corn with different cover crops and planting dates

Cover crops are recommended to mitigate N losses but effects on crop productivity have been variable and often negative. A better understanding of management-specific cover crop systems may lead to yield improvements. In 2011–2014, a split–split-plot factorial field experiment, with four replicates assessed the impact of cover crop (five species and no cover crop controls) and planting date (August vs. September) on crop yield and N dynamics. Fresh bean (Phaseolus vulgaris L.) and sweet corn (Zea mays L. var. rugosa) were grown with 45 and 101 kg N ha^?1 fertilizer, respectively, except for the no cover crop without fertilizer control (Nocc-NoN). Although there was a cover crop by planting date interaction (P < 0.05) for cover crop biomass and N accumulation in the fall and spring, this interaction was not observed in main crop yield nor N concentration and accumulation, suggesting that simply growing a cover crop and below-ground effects may be more influential than the quantity and quality of above-ground biomass. Based on greater yields (6.9%) than the no cover crop with fertilizer (Nocc+N) control, all cover crops tested were recommended before corn but only the oat cover crop increased fresh bean yield (by 10.5%), which suggests crop-specific recommendations are needed. Yield improvements could not be attributed to N fertility alone, suggesting another mechanism was involved. The increased productivity with cover crops while minimizing potential for N losses in the non-growing season has important implications for sustainable agroecosystems and food security.     

A neural network-based production process modeling and variable importance analysis approach in corn to sugar factory

Corn to sugar process has long faced the risks of high energy consumption and thin profits. However, it’s hard to upgrade or optimize the process based on mechanism unit operation models due to the high complexity of the related processes. Big data technology provides a promising solution as its ability to turn huge amounts of data into insights for operational decisions. In this paper, a neural network-based production process modeling and variable importance analysis approach is proposed for corn to sugar processes, which contains data preprocessing, dimensionality reduction, multilayer perceptron/convolutional neural network/recurrent neural network based modeling and extended weights connection method. In the established model, dextrose equivalent value is selected as the output, and 654 sites from the DCS system are selected as the inputs. LASSO analysis is first applied to reduce the data dimension to 155, then the inputs are dimensionalized to 50 by means of genetic algorithm optimization. Ultimately, variable importance analysis is carried out by the extended weight connection method, and 20 of the most important sites are selected for each neural network. The results indicate that the multilayer perceptron and recurrent neural network models have a relative error of less than 0.1%, which have a better prediction result than other models, and the 20 most important sites selected have better explicable performance. The major contributions derived from this work are of significant aid in process simulation model with high accuracy and process optimization based on the selected most important sites to maintain high quality and stable production for corn to sugar processes.     

Rheological and viscoelastic properties of corn starch suspension modified by hydrothermal process: Impacts of process intensification

Rheological properties of starch suspension and particle size distribution of treated starch granules under the same conditions (2 bar and 20 min) by direct vapour-heat moisture treatment (DV-HMT), Reduced-Pressurized Heat Moisture Treatment (RP-HMT) and Instantaneous Controlled Pressure Drop Process (DIC) were investigated. DV-HMT and RP-HMT were compared to DIC process in order to determine the role of the vacuum pressure steps before and after injection of live steam on the starch powder. For all treated starches an increase of the particle size of granules was observed, a reduction of the consistency index and of the conservative modulus, compared to the untreated one. This difference becomes so important with increasing of process intensification. Relaxation spectra evaluated from the generalized Maxwell model implied a drift to shorter relaxation time for treated starch suspension than the native one. A decrease in peak intensity H(λ) of relaxation spectra with increase of intensification of processes was observed which conclude that the modified starch suspension moving away from a stable state like gel according to the following order DV-HMT < RP-HMT < DIC. The effect of DIC process seems to be more intense than the two other treatments. This difference can be attributed to the mechanical effect induced by the abrupt decompression towards vacuum after treatment.     

玉米油酶法合成甘油二酯工艺优化研究

以玉米油、甘油为原料,在无溶剂体系中用固定化脂肪酶Lipozyme TL IM催化合成甘油二酯,通过单因素试验和响应面试验研究底物摩尔比(亚油酸/甘油)、反应温度、反应时间、酶质量分数和初始水质量分数等因素对亚油酸转化率的影响。得出:反应温度、底物摩尔比、反应时间、酶质量分数对亚油酸转化率影响较大;影响酯化反应中亚油酸转化率的主次因素依次为反应温度、底物摩尔比、反应时间、酶质量分数;最佳工艺条件为亚油酸和甘油的摩尔比为2.10∶1,反应温度为61.16℃,反应时间为12.17 h,酶质量分数为20.09%,亚油酸转化率达到75.69%。Lipozyme TL IM连续反应3批次,其相对酶活仍有65.7%。