Fermentation of Corn for Nigerian Agidi

Agidi, a Nigerian food made from corn, was prepared by the traditional Nigerian method and by a modified procedure in which fermented corn was used. The fermented agidi (with or without pH adjustment of the corn) was significantly higher (P < 0.05) in tryptophan and lysine than the nonfermented agidi. Sensory analyses indicated that flavor for the fermented (either pH adjusted or not) had a score greater than average (scale of 1 to 5, with 5 being the highest on the desired scale). However, since total sensory score (total points for color, firmness, acidity and flavor) was less than the traditional agidi, blending of the two is indicated for best acceptance and nutrition.     

产酸性蛋白酶微生物的筛选及其在玉米淀粉生产中的应用

分别从土壤和泡菜中筛选到适合玉米淀粉湿法加工浸泡条件(50℃,pH值3.5～5)的微生物,经形态学及分子生物学鉴定,初步确定该菌株为烟曲霉(Aspergillas fumigates);提取发酵液中的酸性蛋白酶粗酶进行酶学性质研究,发现该酶在50℃,pH值3.5～5下仍保持较高的稳定性;将发酵液应用于玉米淀粉湿法浸泡工艺中,优化的玉米浸泡条件为:浸泡温度50℃、乳酸含量0.5%、SO2含量0.08%,初次浸泡12 h,然后添加12%发酵液浸泡10 h。新工艺减少了环境污染,浸泡时间缩短了26 h,更有利于生产。     

化学成分对普通玉米微波膨化的影响

通过测定３种普通玉米的蛋白质、淀粉、水分含量,探讨其对微波膨化效果的影响,同时对乙醇浸渍玉米后微波膨化效果的变化进行了初步研究。结果表明,普通玉米的微波膨化率随其淀粉含量的增加而提高;含支链淀粉多的玉米,微波膨化率也较高;乙醇处理后,蛋白质量减少,微波膨化率提高。     

杨木自催化乙醇制浆废液中有机酸的分析

针对杨木自催化乙醇法蒸煮废液成分复杂、副产物价值高等特点,对废液中的有机酸进行分析。首先制取杨木自催化乙醇制浆废液,对分离出木素的废液用乙醚萃取,将萃取物用气相色谱-质谱联用检测仪进行定性分析。结果表明,废液中的各成分复杂而且都很微量,主要是一些酸、酯、低分子木素等,约25种,其中乙酸和甲酸含量较高。其次对杨木自催化乙醇法蒸煮废液减压蒸馏至无液体来分离木素,对全部馏分采用容量分析的方法测得总酸含量为0.043 mol/L,同时用气相色谱定量测得乙酸含量为1.864 g/L、甲酸含量为0.665 g/L。     

Exploring economically and environmentally viable northeastern US dairy farm strategies for coping with rising corn grain prices

In 2008, corn grain prices rose $115/t of DM above the 2005 average. Such an increase creates tight marginal profits for small (<100) and medium-sized (100 to 199) dairy farms in the northeastern United States importing corn grain as animal feed supplement. Particularly in New York State, dairy farmers are attempting to avoid or minimize profit losses by growing more corn silage and reducing corn grain purchases. This study applies the Integrated Farm Systems Model to 1 small and 1 medium-sized New York State dairy farm to predict 1) sediment and P loss impacts from expanding corn fields, 2) benefits of no-till or cover cropping on corn fields, and 3) alternatives to the economic challenge of the current farming system as the price ratio of milk to corn grain continues to decline. Based on the simulation results, expanding corn silage production by 3% of the cultivated farm area increased sediment and sediment-bound P losses by 41 and 18%, respectively. Implementing no-till controlled about 84% of the erosion and about 75% of the sediment-bound P that would have occurred from the conventionally tilled, expanded corn production scenario. Implementing a conventionally tilled cover crop with the conventionally tilled, expanded corn production scenario controlled both erosion and sediment-bound P, but to a lesser extent than no-till corn with no cover crop. However, annual farm net return using cover crops was slightly less than when using no-till. Increasing on-farm grass productivity while feeding cows a high-quality, high-forage diet and precise dietary P levels offered dual benefits: 1) improved farm profitability from reduced purchases of dietary protein and P supplements, and 2) decreased runoff P losses from reduced P-levels in applied manure. Moreover, alternatives such as growing additional small grains on marginal lands and increasing milk production levels demonstrated great potential in increasing farm profitability. Overall, it is crucial that conservation measures such as no-till and cover cropping be implemented on new or existing corn lands as these areas often pose the highest threat for P losses through runoff. Although alternatives that would likely provide the largest net profit were evaluated one at a time to better quantify their individual impacts, combinations of these strategies, such as no-till corn plus a minimum-till cover crop, are recommended whenever feasible.     

Kinetics of Protein Quality Loss in Enriched Pasta Stored in a Sine Wave Temperature Condition

The rate of loss of protein quality in enriched pasta was studied at constant temperature (30, 37 and 45°C) and under a continuous sine wave temperature fluctuation (25/45°C with a 24-hr period). Both loss of lysine by the fluoro-dinitro benzene (FDNB) method and a bioassay (Tetrahymena thermophila growth) for protein quality were employed. Significant loss of protein quality occurs in about 1 yr at temperatures above 30°C. The bioassay method showed that nutrient losses other than lysine could be occurring. Data from the constant temperature studies were used to predict the losses that occurred for the sine wave condition using the Hicks-Schwimmer model as modified with an Arrhenius approach. The prediction model gave about 15% error in comparison to actual losses. In addition, the rate of loss for the sine wave (25/45°C) was greater as predicted than the rate of loss at a constant mean temperature of 35°C.     

Enrichment of macaroni with cellulose-derivative protein complex from whey and corn steep liquor

Macaroni was prepared from semolina fortified with 3, 6 and 9% CMC-protein (CMC — carboxymethyl cellulose) or HEC-protein (HEC — hydroxyethyl cellulose) complexes from whey and corn steep liquor to increase the protein quality and quantity. Fortification increased the protein content up to 14.2% in DM (vs. 12.1% in control) for macaroni. Water absorption, dough weakening and mixing tolerance index were decreased, while dough development time and dough stability were increased when the amount of precipitated cellulose-protein complex from whey and corn steep liquor in the blends increased. Addition of both tested cellulose-protein complexes improved cooking quality by increasing the weight and volume of cooked macaroni, but cooking losses were greater. Sensory evaluation of the colour, flavour and appearance of macaroni were improved as a result of adding cellulose-protein complex from whey. Macaroni samples prepared from dough mixtures with 6 and 9% of cellulose-protein complex from corn steep liquor were less acceptable than those prepared from 100% semolina.     

Impact of Dry-milled Germ Processing on Aqueous Protein and Oil Extraction

Reduced petroleum cost and public objection to using corn for bioenergy rather than food have challenged grain ethanol producers to come up with new bioprocess and coproducts that can add value but maintain ethanol cost competitiveness. Novel dry and wet milling fractionation processes of corn that could generate higher value coproducts and improve coproduct economics, long-term outlook, and economic stability of corn processing plants have been being recently proposed. Germ Wet Milling? is such novel aqueous processing method designed to increase germ protein and oil concentration by water soaking and wet fractionation of dry-milled corn germ. The goal of this study was to investigate the sequential oil and protein extraction after Germ Wet Milling and to develop economically viable processes for producing protein concentrates. Corn protein concentrates were prepared after aqueous processing of dry-milled germ using membrane filtration or isoelectric precipitation. The amount of protein recovered was a function of the protein dispersibility index of the starting material, which depended on soak temperature and time. Extracts prepared after Germ Wet Milling? contained 59.1 to 64.7 % protein (db), while concentrates had 64.9 to 82.4 % protein. The technique used for protein recovery also influenced the mass and protein yield and composition. For all treatments, membrane filtration was a more effective method than isoelectric precipitation for recovering protein from extract. Aqueous enzymatic oil extraction (AEOE) was used to evaluate the oil recovery potential after Germ Wet Milling. The effect of enzyme dosages and/or elimination of the acidic protease on oil extraction from high protein, high protein dispersibility index (PDI) corn germ and high protein, low PDI corn germ were evaluated. AEOE using a combination of cellulases and xylanase (Optimash XL®), an acidic protease (Fermgen®), and a basic protease (Optimase®) resulted in oil recoveries as high as 71.9 % of the initial oil content. A twofold reduction in enzyme dosages was possible with little or no effect on oil recoveries for both types of germ.     

Effects of processing on the thiamin, riboflavin and protein contents of cowpeas (Vigna unguiculata (L) Walp). I. Soaking, cooking and wet milling processes

The effects of soaking, cooking and decortication and conversion to a paste product (moin-moin) on the thiamin, riboflavin and protein contents of six cowpea varieties were investigated. The effect of soaking was not significant but cooking resulted in considerable losses of the two B-vitamins; some of the lost vitamins, especially riboflavin, were detected in the cooking water. Decortication resulted in high losses of the vitamins for the brown varieties of cowpea. The retention of the vitamins in moin-moin was good. Changes in the protein content of the cowpea products as a result of processing were not significant.     

Preparation of improved quick cooking rice

Quick-cookig rice was produced by soaking milled short grain rice in water and water containing 1% and 3% of a 1:1 mixture of sodium citrate and calcium chloride with two soaking periods (15 and 30 min at room temperature). The soaked samples were cooked in an autoclave at 121 °C and 0.147 MPa pressure for 3, 5 and 8 min. Final moisture content of 12% was obtained by using two different drying methods (freeze-drying and convective air drying). After steaming the salt treated samples (1 and 3%) showed lower water absorption ratios than the untreated controls. The end product of the cooked rice, which was freeze dried, had a normal appearance. 1% salt treating (for 15 min) and freeze drying reduced the protein losses. Processing resulted in slight decrease in carbohydrate and amylose content of the product. Treatment with salt solution (1%) and freeze drying improved the rehydration ratio of this sample.     

Effect of processing on available carbohydrate content and starch digestibility of kidney beans (Phaseolus vulgaris L.)

The effects of different soaking and cooking methods were investigated on available carbohydrate content and starch digestibility of red and white kidney beans. Total soluble sugars, reducing sugars, non-reducing sugars and starch contents of red and white kidney beans were 9.95 and 11.3%, 0.82 and 0.96%, 9.13 and 10.3%, and 44.4 and 47.8%, respectively. All these available carbohydrate components decreased to various extents as a result of soaking and cooking. From 2.51 to 13.6% and 7.03 to 28.0% of total soluble sugars were lost on soaking kidney beans in tap water and sodium bicarbonate solution, respectively. However, losses in total soluble sugars were maximum (19.9–60.9%) on cooking pre-soaked kidney beans. Losses in starch contents were 4.27 to 24.7% and 30.4 to 70.7% as a result of the soaking and cooking processes, respectively. Besides these losses, starch digestibility of kidney beans was also markedly improved as a result of cooking. However, no appreciable improvement in starch digestibility was observed after soaking kidney beans in water or alkaline solution.     

玉米淀粉制备中挤压联用亚硫酸浸泡预处理工艺优化

为解决传统玉米湿磨工艺浸泡时间长、淀粉提取率低的问题,展开了挤压技术对玉米淀粉提取预处理的可行性研究。以淀粉提取率和淀粉纯度为考察指标,分别研究挤压温度、挤压水分、螺杆转速、H₂SO₃浸泡时间对玉米淀粉提取率和淀粉纯度的影响。在单因素实验的基础上,采用四因素三水平的响应面分析法确定玉米淀粉提取工艺。结果表明,玉米淀粉提取的最佳工艺为:挤压温度40 ℃、挤压水分53%、螺杆转速194 r/min、H₂SO₃浸泡时间14 h。在此条件下玉米淀粉提取率达到了93.25%,相比传统湿磨工艺提高了1.79%,生产时间缩短34 h。通过红外光谱（FT-IR）分析发现,采用挤压预处理并未导致淀粉化学结构的改变;扫描电镜（SEM）图像表明挤压制备的淀粉颗粒表面出现轻微褶皱和凹陷,但颗粒形状依旧保持完整。故挤压技术应用于玉米淀粉的分离提取是有效可行的。     

Starch and protein digestibility of newly released moth bean cultivars: Effect of soaking, dehulling, germination and pressure cooking

Effect of soaking (12 h), soaking (12 h) dehulling, germination (60 h) and pressure cooking on starch and protein digestibility of four varieties of moth bean, one Local commonly used by the farmers of the area and three newly released high yielding varieties, Jwala, RMO 225 and RMO 257, was studied. The starch digestibility of raw unprocessed moth bean cultivars differed significantly (P < 0.05) from 25.4-28.2 mg maltose released/g flour being the highest and lowest in RMO 257 and RMO 225, respectively. The protein digestibility differed significantly from 70.3-74.6 per cent among all the unprocessed varieties of moth bean. All the processing treatments namely soaking, dehulling, germination and pressure cooking brought about appreciable enhancement in protein digestibility (1-19%) over the control and starch digestibility (19-115%) of all the four moth bean cultivars. However, out of all the processing treatments, germination (60 h) of soaked seeds (12 h) was the most effective in bringing about improvement in digestibility of starch and protein followed by dehulling and soaking (12 h).     

Effect of radiation and soaking on trypsin inhibitor and protein content of chickpea (Cicer arientinum L.)

Composition of Ascochyta-blight resistant chickpea for proximate components, vitamins, energy and trypsin inhibitor, was determined. The influence of irradiation and soaking at ambient temperatures (25–35°C) on trypsin inhibitor activity (TIA) and protein content of chickpea, was investigated. A significant linear relation (r = ?0.960 to ?0.987) was found between the loss of TIA and soaking time of irradiated and unirradiated seeds (p < 0.05) and the rate of loss increased with increasing radiation dose (0.25–1.00 kGy). However, effect of radiation alone was negligible. Maximum decrease (30.7%) in TIA (from 330.0 to 228.6 TIU/g) occurred during soaking for 12 h of 1.00 kGy sample. The protein contents increased from an initial value of 21.7% to 23.4% and 22.7% as a result of soaking for 12 h in tap and distilled waters respectively. Radiation treatment exhibited little or no effect.     

紫玉米中黄曲霉毒素B1和富马毒素B1的脱毒研究

为脱除紫玉米中富马毒素B1(FB1)和黄曲霉毒素B1(AFB1),分别采用紫外、超高压、微波和NaCl处理,利用高效液相色谱方法进行检测。结果表明：紫外和超高压处理对两种毒素含量无影响,微波处理12min能去除90%以上的毒素,而30%以上NaCl浸泡10min即可去除99%的毒素。结论：NaCl浸泡是一种简单经济的脱毒方法。     

Pretreating Dent Corn Grits for Puffing in a Rice Cake Machine

The best operational conditions for puffing dent corn grits with a rice cake machine were 14% grit moisture, 215°C and 9 sec. Salting and steaming, low pH soaking medium, larger corn grit sizes, 2% glycerin, and 2% corn oil tended to increase puffed volume of the corn cakes. Smaller grit sizes, 3% alcohol and high pH soaking medium had negative effects on corn cake volume. Acid-modification of corn starch, 1% or 3% corn oil, and up to 10% sugar had no effect.     

Utilization of Alfalfa Hay and Alfalfa Silage. 1. Protein Sources in Corn Silage-Based Diets

Different amounts of alfalfa as hay or silage were compared with soybean meal or urea as protein sources for steers fed corn silage-based diets. Source of alfalfa and source by amount interactions were not significant when alfalfa was fed as hay or silage at 32, 63, or 100% of dry matter in trial 1. A highly significant linear response in average daily gain and gain to feed ratio was observed to alfalfa amounts. Daily gain (.90 vs. .87 kg) and gain to feed ratio (.139 vs. .136) were very similar when diets were formulated to meet protein requirements with 32% alfalfa as either hay or silage.In trial 2, supplemental protein for steers fed corn silage was provided by alfalfa hay or silage at 12 or 50% of diet dry matter or by soybean meal or urea. The 12% alfalfa diet contained equal parts of supplemental protein from alfalfa and from urea. Regression analyses indicated that supplementation of either alfalfa hay or silage with urea did not improve utilization of corn silage. Differences in fiber and protein fractions resulting from harvesting and storage of alfalfa as hay or silage do not change the value of alfalfa as a protein source when used in corn silage-based diets.     

Whole linted cottonseed as a forage substitute fed with ground or steam-flaked corn: digestibility and performance

Six ruminally and duodenally cannulated Holstein cows were used in a 6 x 6 Latin square design. The objective was to evaluate any potential interactions in site of nutrient digestion when neutral detergent fiber (NDF) from cottonseed was incrementally substituted for forage NDF (FNDF) from alfalfa silage and when starch availability was varied by feeding ground (G) or steam-flaked (SF) corn. Iso-NDF diets were forage control with G corn (21% FNDF), 5% whole cottonseed (WCS) with G or SF corn (18% FNDF), 10% WCS with G or SF corn (15% FNDF), and 15% WCS with G corn (12% FNDF). Ruminal or total tract digestibilities of organic matter (OM) or nonstructural carbohydrate (NSC) were unaffected, but efficiency of microbial protein synthesis decreased as WCS increased. Ruminal NDF digestibility was not affected despite a linear decrease in pH, but postruminal NDF digestibility decreased with increasing WCS. Ruminal digestibilities of OM and NSC were higher for SF than G corn but did not affect efficiency of microbial N synthesis. Dry matter intake increased quadratically with increasing level of WCS but decreased when SF replaced G corn. Milk yield did not differ across treatments. Milk fat percentage was affected quadratically and milk protein increased linearly with increasing WCS. Milk fat percentage decreased but milk protein was not affected when SF replaced G corn. Lack of an interaction between corn source and level of WCS substitution suggests that WCS was equally effective in maintaining ruminal fermentation and digestibility in diets varying in ruminal starch availability.     

Effectiveness of density segregation and sodium carbonate treatment on the detoxification of Fusarium-contaminated corn fed to growing pigs

The effectiveness of using rinsing, density segregation or 0.1 M sodium carbonate treatments of Fusarium-contaminated corn containing deoxynivalenol (DON) and zearalenone were tested both chemically and by feeding the material to growing pigs. Uninfected and Fusarium graminearum-inoculated corn (containing 40.3 mg DON and 0.94 mg zearalenone kg^?1cor) were subjected to various treatments: no treatment (control), rinsed, rinsed and all floating material removed, soaked in 0.1 M sodium carbonate for 24 h or soaked in 0.1 M sodium carbonate for 24 h after removal of the floating material. All corn samples were analysed for DON and zearalenone. Rinsing the contaminated corn reduced the concentrations of both mycotoxins by 44% while soaking in 0.1 M sodium carbonate reduced the toxin concentrations an additional 35%. In both cases, removal of the floating material decreased concentrations another 8 and 4%, respectively. In the feeding study, 10-week-old barrows were fed diets containing 17.5% of the treated corn samples over a 21 day period. Daily feed consumption and weight gains were significantly improved in pigs fed the rinsed-minus-floating corn and the sodium carbonate-soaked corn with and without floating material compared to the untreated contaminated corn. The chemical and biological data demonstrated that rinsing combined with the removal of floating material or soaking in 0.1 M sodium carbonate with or without removal of floating material were effective in reducing the toxicity of the contaminated corn. Due to a higher energy requirement needed to dry the corn soaked in sodium carbonate, the combination of rinsing and removal of the floating material is recommended as a more general and practical method of detoxification of contaminated grain.     

Studies on Bovine Natural Actomyosin 1. Relationship of ATPase and Contractility to Tenderness of Muscle

SUMMARY: The effects of muscle tenderness classification and of aging muscle postmortem on ATPase activity and superprecipitation of natural actomyosin were studied. Actomyosin from muscle 12- and 24-hr postmortem had higher ATPase activity than that from 0-hr, 5-day aged or 10-day aged muscle. However, ATPase activity did not usually return to the 0-hr level. No consistent differences were found in actomyosin ATPase activity after the various periods of aging for actomyosins from tough and tender muscle. Superprecipitation of actomyosin was used as a measure of contractility. Actmyosin from 12- and 24-hr postmortem muscle superprecipitated faster than that from 0-hr muscle. However, actomyosin from 5 and 10-day aged muscle superprecipitated less rapidly than that from 12- and 24-hr postmortem muscle. Superprecipitation was more rapid in actomyosin from tough muscle than tender muscle at low KCI concentrations, but this was not true at high KCI concentrations. This observation suggested that actomyosin from tough muscle had a stronger interaction or higher amounts of some protein factor such as α-actinin than did tender muscle.