Effect of Irradiation on Total Glycoalkaloids in Kennebec and Russet Burbank Potatoes

Effect of irradiation and storage conditions following irradiation on total glycoalkaloids (TGA) of Russet Burbank and Kennebec potatoes stored 4 and 12 wk was investigated. TGA increased significantly (p < 0.005) immediately following irradiation in both cultivars, but decreased upon storage. TGA was higher in Kennebec than Russet Burbank often exceeding levels considered safe for human consumption. At 5°C TGA was higher in tubers stored in paper as compared to polyethylene, while at 20°C this was reversed.     

Sugars and Free Amino Acids in Stored Russet Burbank Potatoes Treated with CIPC and Alternative Sprout Inhibitors

Glucose, fructose, sucrose and free amino acids were measured in stored Russet Burbank potatoes treated with sprout inhibitors isopropyl-N-(3-chlorophenyl) carbamate (CIPC), 1,4-dimethylnaphthalene (DMN), cineole and salicylaldehyde. Storage effects on sugar and amino acid contents were dependent on the specific sprout inhibitor. Salicylaldehyde treatment (200 ppm) produced a rapid increase of reducing sugar content and a greater amount of free amino acids than other treatments. A smaller amount of tyrosine was found in DMN (40 ppm) treated tubers compared to all other treatments. After 16 wk at 7°C, all potatoes treated with inhibitors had 10.5–11.8 mg/g dry weight reducing sugar content which would be considered acceptable for French fry processing.     

Diffusion Coefficients of Glucose, Potassium, and Magnesium in Maine Russet Burbank and Maine Katahdin Potatoes from 45 to 90°C

Experimental data for the leaching of glucose, potassium and magnesium from French fry cut Maine Russet Burbank and Maine Katahdin potatoes were modeled over the temperature range 45–90°C., using a one-parameter diffusion equation based on Fick's second law. Correlations for the dependence of the resulting effective diffusion coefficients on temperature were determined. At temperatures greater than 60°C., plots of the diffusion coefficients as a function of temperature showed a change in slope or a discontinuity in the slope of the curve. This reflected the change in the diffusion matrix which occurred when the starch began to gelatinize. The effect of cultivar differences on values of the diffusion coefficients might be linked to the concentrations of starch and electrolytes in the potato.     

Influence of heating conditions and starch on the storage modulus of Russet Burbank and Yukon Gold potatoes

The storage modulus of Russet Burbank (RB) and Yukon Gold (YG) potato discs (13.3 mm × 4.5 mm) was measured continuously during heating in water at temperatures ranging from 40 to 80 °C for 120 min using a dynamic mechanical analyser with a heating stage. The starch content of YG potatoes was higher than that of RB potatoes, but the raw starch granule size distribution of both varieties was similar. RB samples had the highest storage modulus values (25% higher than raw tissue) when heated in 60 °C water for 35 min. Image analysis revealed that the perimeters of starch granules in the potato samples increased by about 50% during heating for 30 min at 60 °C. Heating temperature and time and starch content influenced the storage modulus. © 2001 Society of Chemical Industry     

薯类加工与利用新技术新趋势

论述了我国薯类生产的资源优势 ,提出了要对薯类资源进行精深加工利用 ,发展我国薯类淀粉产业的观点。分析了我国薯类淀粉生产的技术现状及存在的问题 ,并提出一些有益的建议来大力促进国产薯类淀粉产业及生产设备的技术进步。     

Integrated Starch Plant for Alternative Processing of Maize and Potatoes

The emphasis of this paper is on the starch plant, in order to indicate how a great portion of the wet-milling equipment and all the dryers are used for two raw materials. The flowsheet for maize is the standard Dorr Oliver flowsheet. The primary separation of starch and gluten takes place in a merco separator. The same machine is applied for the separation of the effluent from the crude potato starch milk. The maize gluten concentration takes place in a gluten concentrator. The same machine is used for the recovery of the starch from the overflow of the first stage of starch washing when producing potato starch. The 7-stage fibre washing system is used for both maize starch and potato starch. The starch washing systems is used for both starches too.     

Amino Acid Composition and Its Change in Raw and Granulated Potatoes During Processing

Total amino acids and composition of raw and cooked tubers were determined by gas-liquid and ion-exchange column chromatography. Peeled raw potato, after reaching the end product state, lost 40% of its free amino acid pool. Processing into dehydrated granules by the freeze-thaw process caused only small losses in total amino acids and little change in their composition. There was only a 4.5% destruction of essential amino acids and a total loss of 2.1% of non-essential amino acids, excluding aspartic and glutamic acids which comprised 48% of peeled and sliced potatoes.     

Effects of Processing on Zinc Levels in Spinach, Beef, and Potatoes

Spinach, beef, and potatoes were subjected to combinations of cooking, freezing, retorting, and storage and analyzed for total zinc and water soluble zinc, before and after acid-enzyme digestion. Zinc and its complexes that were soluble were membrane filtered to exclude the passage of substances larger than 5,000 daltons. Approximately 30–50% of the total zinc in spinach systems and about 70–100% of the zinc in potato systems was water soluble. Practically none of the endogenous zinc in beef was water soluble. Regardless of processing method, essentially all zinc in spinach and potatoes and about half of the zinc in beef was released after acid-enzyme digestion. All of the spinach and potato zinc and at least a third of the beef zinc following digestion passed through the 5,000 dalton membrane.     

Studies on Sweet Potatoes. Part I: Changes in the Carbohydrates During Processing

The qualitative and quantitative changes in the nature of different carbohydrate fractions of sweet potatoes (hard and soft cooking types), after dry (baking and toasting) and wet (steaming) processing have been studied. Maltose, glucose and fructose were the predominant sugars in the ethanol soluble fraction. The total sugar and amylose contents significantly decreased in the ethanol insoluble residues. This was supported by the decrease in blue value and the absorption maxima of the iodine complex.     

Optimizing Processing Conditions for Chemical Peeling of Potatoes using Response Surface Methodology

Using Response Surface Methodology the effects of NaOH concentration (4–20%), process temperature (55–95°C) and time (1–7 min) was determined on the yield, peeling quality, unpeeled skin and total usage of NaOH. Also evaluated were titratable NaOH in the potato tissue, NaOH penetration and “heat ring” depths during one stage chemical peeling of potatoes (Huincul variety). The best peeling quality, maximum yield and minimum total usage of NaOH was obtained for the following ranges: concentration, 11–13%, time 5–5.70 min and temperature, 90–95°C. The maximum temperature for which the “heat ring” and NaOH penetration depths were equal was 72°C where, at 20% NaOH and 7 min, peeling quality was very good and “heat ring” was absent.     

响应面法优化包装型马铃薯泥营养餐的加工工艺

以马铃薯泥为主要原材料,制做包装型马铃薯泥营养餐。以感官评分和菌落总数为指标,在单因素试验的基础上,采用响应面试验对包装型马铃薯泥营养餐的加工工艺进行优化。结果表明,包装型马铃薯泥营养餐的最佳加工工艺为:蒸煮时间10 min、灭菌温度117℃、灭菌时间8 min。在该工艺条件下制得的包装型马铃薯泥易于储藏、消费者接受程度高,菌落总数为2 CFU/g。     

高效液相色谱法分析饲料中VK_3

在Ｃ８柱和ＮＮ２柱上分别用反相离子对色谱法和离子交换法建立了预混料和配合饲料中ＶＫ３（亚硫酸氢钠甲萘醌）的ＨＰＬＣ分析方法，并对ＶＫ３在这两种分离模式中的保留值与流动相组成的关系作了较系统的研究。     

A Dynamic Test for Kinetic Models of Chemical Changes During Processing: Ascorbic Acid Degradation in Dehydration of Potatoes

A method was developed for kinetic-model parameter estimation using data obtained from processes with known dynamic stress paths. The utility of the method was demonstrated for the case of modeling of ascorbic acid degradation during air drying of potatoes. Potato discs were dried under a variety of conditions using a laboratory-scale tray-dryer with wet- and dry-bulb temperature control. Ascorbic acid concentration was monitored as a function of time along with average moisture content and temperature. These data obtained under dynamic conditions were used to estimate optimal parameters in a kinetic model describing the rate of degradation of ascorbic acid as a function of temperature, moisture content, time, and ascorbic acid concentration.     

Effect of Bisulfite on Lobster Shell Phenoloxidase

The role of bisulfite inhibition on the phenoloxidase (PO) catalyzed melanosis reaction in lobster was investigated. Bisulfite appears to inhibit melanosis by two mechanisms: (1) by reacting with intermediate quinones in the melanosis reaction, forming sulfoquinones, and (2) by irreversibly reacting with PO causing complete inactivation. The first mechanism is important because intermediate quinones (do-pachrome) are the chroma for spectrophotometric analysis of PO activity.     

低浓亚硫酸氢盐法蒸煮竹浆

本文介绍了用低浓亚硫酸氢盐法蒸煮竹子制浆的蒸煮试验,包括实验室的不同蒸煮条件下的蒸煮结果比较,优化出大型生产工艺条件,试验结果表明,经优化的工艺条件在生产试验中,制浆质量比混合蒸煮的稳定,操作控制较容易,药耗、蒸汽消耗基本相当。     

红麻亚硫酸氢镁法制浆工艺

对红麻酸法制浆生产文化用纸进行了研究。通过对红麻的全秆 芯秆和韧皮部进行化学成分分析及正交试验确定出红麻全秆亚硫酸氢镁法蒸煮的最佳工艺条件 :总酸 5 .6 % ,最高温度 16 0℃ ,保温时间 12 0min ,酸比 1.5 ,液比 1∶5。在此条件下蒸煮所得浆料的细浆得率 4 8.3% ,卡伯值 4 2 .1,粘度 94 8.6mL/g ,原浆白度为5 1.4 %ISO     

优良的马铃薯品种

<正> 理想的栽种温度、肥沃的土壤,再加上现代化的加工处理设备,是生产优质马铃薯产品的先决条件。美国马铃薯产品出类拔萃,产量全年无缺,种植者为加工商供应高品质的马铃薯,包括早期收成的Norkitahs与Shepodys品种,以及晚期收成的Russet Burbanks品种。     

应用亚硫酸氢钠作为羊绒漂白的清洗助剂

本文研究了在羊绒漂白的清洗阶段采用亚硫酸氢钠、亚磷酸、醋酸和纯水等不同试剂的效果。对于漂白 ,采用亚硫酸氢钠所得的白度比其他试剂高。实验显示 ,即使是在获得最大白度的触媒处理条件 ,铁以三价铁形式沉积在纤维上 ,也未观察到肉眼可察觉的色变。亚硫酸氢钠清洗 ,通过将铁离子还原成二价铁形式 ,有效地将铁从纤维上去除 ,使白度提高。在传统的清洗条件下 ,使用亚硫酸氢钠对纤维的损伤比纯水要小。有色纤维漂白由三个步骤组成 :亚铁盐触媒处理 ,清洗和在碱性条件下过氧化氢处理。我们以前的工作研究了驼毛漂白中不同触媒助剂的处理效果…