Resistance to airflow through bulk pistachio nuts (Kalleghochi variety) as affected by moisture content, airflow rate, bed depth and fill method

The prediction of airflow resistance is fundamental to the design of efficient drying and aeration systems for pistachio nuts. Using a laboratory unit, the pressure drop across a column of pistachio nuts (Kalleghochi variety) was investigated to determine the effect of moisture content, airflow rate, bed depth and fill method. Five levels of moisture contents (4.80, 14.50, 23.70, 37.60 and 45.60 w.b.%), four bed depths (25, 50, 75 and 100 cm) and two fill methods (loose and dense) were studied with airflow rates ranging from 0.08-1.00 m³/S m². Results indicated that resistance to airflow through a column of pistachio nuts increased with increasing bed depth, moisture content and airflow rate for both dense and loose fill method. Airflow rate was the most significant factor affecting the pressure drop of pistachio nuts followed by fill method and moisture content. The dense fill of pistachio nuts produced higher resistance to airflow compared with the loose fill. Among the three models (Shedd, Hukill and Ives, and Ergun equation) investigated to describe pressure drop data of pistachio nuts, Ergun equation was found to be the most suitable for describing the pressure drop data of pistachio nuts.     

Sorption Characteristics of Whole Pistachio Nuts (Pistacia Vera L.)

ABSTRACT

Moisture sorption characteristics of whole pistachio nuts were investigated at 10, 20, and 30°C using the static method. The sorption isotherms exhibited hysteresis over the range of 0.10-0.80 water activity which was succesfully interpreted using BET, GAB, Oswin, Smith, Henderson, Chung-Pfost and Halsey mathematical models and from which the BET, GAB and Oswin models were found to give the best fit. Monolayer moisture content of pistachio nuts was determined from BET and GAB equations and the isosteric heat of sorption data were derived using Clausius-Clapeyron equation and presented in graphical form. The information generated can be utilized to optimize the packaging parameters for long term storage of pistachio nuts.     

Effect of Drying Methods on Quality of Pistachio Nuts

The effect of various methods of drying (sun drying, bin drying, vertical continuous drying, vertical cylindrical drying, and funnel cylindrical drying) on moisture content, lipid quality (peroxide value, thiobarbituric acid value, and free fatty acids), sensory attributes (firmness, sweetness, rancidity, roasted flavor, split shell, shell appearance, and overall palatability), and percent split shell of pistachio nuts (Pistacia vera L.) were studied. Sun drying and bin drying resulted in higher split shell percent on pistachio nuts than other drying methods. The different drying methods used in this study did not have any significant influence on the free fatty acids, peroxide value, and thiobarbituric acid of lipids in pistachio nuts. Drying significantly affected shell appearance and split shell. Overall, the bin drying method produced pistachio nuts with the best quality.     

Characteristics of pistachio kernel oils from Iranian cultivars

Ten pistachio samples from various Iranian cultivars were examined for some botanical features of their nuts and oil characteristics of their kernels. The wt of 100 nuts varied from 78.5 to 136.9 g. The nuts contained 44.1–58.9% kernel. Moisture of the kernels was low, 2.5–4.1%, and the kernels contained 55.2–60.5% oil. Unsaponifiable matter (0.72–0.96%), saponification value (189.0–193.6), refractive index (1.4635–1.4643), and iodine value (98.1–100.5) showed little differences in various samples. Fatty acids detectable by gas chromatographic analysis were: traces of myristic; 9.2–13.4%, palmitic; 0.5–1.1%, stearic; traces of arachidic; 0.5–1.0%; palmitoleic; 56.1–64.0%, oleic; 22.6–31.0%, linoleic; and 0.1–0.4%, linolenic. There were no significant differences due to origin and/or cultivar of the samples.     

Polyphenols of Pistachio (Pistacia vera L.) Oil Samples and Geographical Differentiation by Principal Component Analysis

The phenolic compounds of Italian and Turkish pistachio oil samples were investigated by gas chromatography–mass spectrometry (GC–MS) with the aim of identifying substances also present in very low concentration; 21 compounds were identified by means of the mass spectra of the trimethylsilyl (TMS) derivatives. Benzoic acid derivatives (protocatechuic acid, gallic acid, 4‐hydroxybenzoic acid) were the main components; 14 polyphenols were detected in pistachios for the first time. The concentrations of the compounds found were in the range 0.02–5.64 μg/g of fresh pistachio. No appreciable qualitative differences were found between samples of different origin; a multivariate approach was successfully tried to differentiate the samples according to their geographical origin, using Principal Component Analysis (PCA). Finally, Canonical Discriminant Analysis (CDA) was further conducted to classify different pistachio samples.     

Evaluating a Solar Dryer for In-Shell Drying of Split Pistachio Nuts

Abstract

A thin-layer forced air solar dryer was designed to study the feasibility of drying pistachio nuts. The dryer was tested during the 2001 and 2002 drying seasons. The maximum temperature in the solar collector reached 56°C, which was 20°C above the ambient temperature. The required drying time was 36 h. During the first day of drying (0800 to 1700 h) the moisture content dropped to about 21% (wb). The final moisture content of the dried nuts was 6% wb, which was 1% below the recommended storage moisture. The drying constant of the pistachio nuts during solar drying was determined using two mathematical models, a one-term series solution of Fick's diffusion equation and an exponential decaying model. There was no significant difference between the two models (α = 0.05). In general, the quality of solar dried nuts was better than the conventional heated air due to slower drying rates.     

Isolation of two nitrogen-free toxins from tung kernels

Summary A procedure is described for isolating two nitrogen-free toxins from tung kernels and from press cake. Chick-feeding tests were used to determine which fraction was toxic at every separation. Both substances were highly toxic as 10-mg. doses killed 4-day old chicks. These substances were shown by chromatography on glass paper to be different and chromatography homogeneous, but also unstable. The elementary composition, hydroxyl content, saponification value, and specific rotation for the two toxins are given. One of the laboratories of the Southern Utilization Research and Development Division, Agricultural Research Service, U, S. Department of Agriculture.     

Chromatographie analysis of seed oils. Fatty acid composition of castor oil

The fatty acid composition of a number of domestic and foreign castor oils was determined by consecutive column and gas-liquid Chromatographic analysis. After saponification of the oils and removal of the unsaponifiables, the nonhydroxy, monohydroxy, and dihydroxy acids were fractionated by partition chromatography on silicic acid. The amount of acid in each fraction was determined by titration or weighing. Gravimetric data were in good agreement with the titrimetric data. The acids obtained by saponification were converted to methyl esters with diazomethane and similarly subjected to partition chromatography. The methyl esters from various fractions were analyzed by gas-liquid chromatography. Components were tentatively identified by their comparative retention times and confirmed Presented at the AOCS meeting in Chicago, 1961. A laboratory of the Western. Utilization Research and Development Division, Agricultural Research Service, U.S.D.A.     

Fluorescence in pistachio nuts contaminated with aflatoxin

Bright greenish-yellow fluorescence under long wave ultraviolet light was observed on the shells of 7% of the nuts in samples from 46 aflatoxin contaminated commercial lots of Iranian pistachio nuts. Kernels from the fluorescent nuts contained 50% of the aflatoxin in the samples. No aflatoxin was found in any of the shells. When kernels and shells were cultured, toxicogenic fungi grew from only 4% of the shells and 21% of the kernels from fluorescent nuts and from 9% of the shells and 15% of the kernels from nonfluorescent nuts.     

Infrared spectra and gas chromatography of some oxygenated fatty acid derivatives

Infrared spectra of hydroxy-, acetoxy-, oxo-, and unsaturated oxo-stearic acid derivatives were studied, and their purities were checked by gas-liquid chromatography. This investigation was supported by research grant No. A-1671 from the National Institute of Arthritis and Metabolic Diseases, U. S. Public Health Service.     

Hydrogenation of linolenate. II. Hydrazine reduction

Observations by Aylward and Rao that hydrazine is a reducing agent for a number of unsaturated fatty acids were extended. The hydrazine reaction on linolenic acid was followed by periodic sampling until methyl esters prepared from the reduced acids had an iodine value of 162. These esters were shown by countercurrent distribution to consist of 26% triene, 43% diene, 26% monoene, and 5% stearate and by infrared analysis to contain notrans bonds. Oxidation of the separated monoene and diene fractions by permanganate-periodate mixtures and gas chromatography of the dibasic acids showed that the double bonds were in the original 9, 12, and 15 positions and that the double bonds farthest from the carboxyl were reduced at a slightly faster rate. Gas chromatography of the monoene fraction indicated three components that were identified in the order of elution from the column as 9, 12, and 15 monoenes; in the diene fraction three components were identified in the order of elution as 9,12; 9,15; and 12,15 dienes. After alkali isomerization of this diene fraction, the conjugated material was reacted with maleic anhydride; the unreacted 9,15 diene isomer was separated by distillation. Presented at fall meeting, American Oil Chemists’ Society, New York, October 17–19, 1960. This is a laboratory of the Northern Utilization Research and Development Division, Agricultural Research Service, U.S. Department of Agriculture.     

Glycerolysis of marine oils and the preparation of acetylated monoglycerides

Conclusions The glycerolysis reaction was applied to menhaden, tuna, herring, sardine, and salmon-egg oils. Optimum reaction time for the preparation of α-monoglycerides was found to vary, reproducibly, from 45 to 60 min., depending on the particular kind of marine oil employed. The method was suitable for the preparation of kilogram quantities. A laboratory method for the prepagation of kilogram quantities of highly pure acetylated α-mono-glycerides was developed. Both the glycerolysis mixtures from marine oils and their acetylated products were light in color and substantially free of odor. Thin-layer silicic acid chromatography, as described here, was found suitable for the analysis of acetoglycerides from marine oils. The work indicated that the method may have wide use for the separation and identification of other lipid classes as well. This is Contribution No. 497 from the technological laboratories of the Bureau of Commercial Fisheries, Fish and Wildlife Service, U. S. Department of the Interior. This is a laboratory of the Division of Industrial Research and Services, Bureau of Commercial Fisheries, U. S. Fish and Wildlife Service, Department of the Interior.     

Hydrogenation of linolenate. I. Fractionation and characterization studies

Methyl linolenate hydrogenated at 140°C, with 0.5% Ni catalyst and 1.1 mole of hydrogen at atmospheric pressure was separated into octadecenoate, octadecadienoate, and octadecatrienoate fractions by countercurrent distribution. Gas chromatography on a 200-ft. capillary Apiezon L column revealed one component in the triene fraction, four in the diene fraction, and nine in the monoene fraction. These components were partially fractionated by low-temperature crystallization, and their solubilities were correlated with alkali conjugation results, with infrared data forcis andtrans configuration of bonds and with dibasic acids isolated from the fractions after oxidative cleavage. Approximately 45% oftrans acids were present in both the monoene and diene fractions. Considerable migration of double bonds from the original 9, 12, and 15 positions occurred.Cis,cis dienes which could not be conjugated by alkali were formed. Little alteration of the residual methyl linolenate was observed. The results demonstrate the applicability and utility of new techniques of fractionation and analysis to the study of the hydrogenation mechanism. Presented at 51st annual meeting, American Oil Chemists' Society, Dallas, Tex., April 4–6, 1960. This is a laboratory of the Northern Utilization Research and Development Division, Agricultural Research Service, U. S. Department of Agriculture.     

The Effect of Monoglyceride Addition on the Rheological Properties of Pistachio Spread

Pistachio nut (Pistacia vera L.) is one of the most delicious and nutritious nuts in the world. In this study, monoglycerides (0.0–1.5 %) as lipophilic emulsifiers were used to prevent oil separation in pistachio spread A (containing 50.0 % pistachio paste, 30.0 % icing sugar and 20.0 % red palm oil) and B (containing 58.3 % pistachio paste, 25.0 % icing sugar and 16.7 % red palm oil). Changes in rheological behavior of pistachio spreads were investigated. The highest work of shear (which indicates spreadability) was observed in Formulations A and B containing 1.5 % monoglycerides. Addition of emulsifier significantly (P < 0.05) influenced the consistency index (K), thixotropic area (A), yield stress (τ ₀) and coefficient correlation (R) of pistachio spreads. All the pistachio spreads that contained emulsifier exhibited a higher storage modulus (G′) than the loss modulus (G″).     

Effects of intermittent microwave drying on quality characteristics of pistachio nuts

In this research, the effect of intermittent microwave drying (IMD) on drying time and quality characteristics for three varieties of Iranian pistachio nuts was investigated and compared with the sun drying method. The quality parameters, such as chemical characteristics, physical parameters, and sensory evaluation were considered. Three varieties, Kal-Khandan, Kaleh-Bozi, and Ghermez, were dried in an 800-W, 2,450-MHz domestic microwave oven. Experiments were conducted in three material loads of 50, 100, and 150?g under intermittent method at 6?s of power-on and 70?s of power-off with three replications. The total drying time was in the range of 114.03–266.07?min, depending on material loads and varieties. The higher the material load, the longer the drying time. The results showed that the effect of drying method on the shell splitting size was very significant (p?p?相似文献   

孟山都公司聚酯装置简介及放大建议

介绍了目前国内年产量最小的一套从美国孟山都化学公司引进的连续法聚酯生产线的工艺和设备，以及装置的特点，并提出了装置放大建议。     

防老剂BHT的提纯及其纯度检测

为提高防老剂BHT的纯度,采用重结晶和区域熔融法对工业品防老剂BHT进行提纯。用高效液相色谱仪和差示扫描量热仪对样品进行纯度检测,试验结果表明,其方法可靠、准确。提纯品防老剂BHT的纯度为99．09％（高效液相色谱法,相对标准偏差0．08％）和99．16％（差示扫描量热法,相对标准偏差0．14％）,纯度可达到国际同类产品水平。     

Modeling Drying Kinetics of Pistachio Nuts with Multilayer Feed-Forward Neural Network

Drying kinetics of pistachio nuts (Akbari v.) was simulated using a multilayer feed-forward neural network (MFNN). Experiments were performed at five drying air temperatures (ranging from 40 to 80°C) and four input air flow velocities (ranging from 0.5 to 2 m/s) with three replicates in a thin-layer dryer. Initial moisture content in all experiments was held at about 0.3 kg/kg d.b. To find the optimum model, various multilayer perceptron (MLP) topologies, having one and/or two hidden layers of neurons, were investigated and their prediction performances were evaluated. The (3-8-5-1)-MLP, namely, a network having eight neurons in the first hidden layer and five neurons in the second hidden layer resulted in the best-suited model estimating the moisture content of the pistachio nuts at all drying runs. For this topology, R² and MSE values were 0.9989 and 4.20E-06, respectively. A comparative study among MFNN and empirical models was also carried out. Among the empirical models, the logarithmic model, with MSE = 7.29E-6 and R² = 0.9982, gave better predictions than the others. However, the MFNN model performed better than the Lewis, Henderson and Pabis, two-term, and Page models and was marginally better than the logarithmic model.     

人垂体生殖激素(FSH和LH)纯品的研制

本研究用乙醇法从人脑垂体丙酮干粉中提取粗品。用CM-52纤维素离子交换层析法分离促卵泡激素(FSH)和促黄体激素(LH),再用SP-Sephadex-C_(50)离子交换葡聚糖凝胶层析法纯化FSH,用DEAE-52纤维察离子交换层析法纯化LH,用HPLC蛋白A亲和层析法纯化抗LH和抗FSH免疫球蛋白,最后用HPLC抗LH的IgG和抗FSH的IgG精制LH和FSH。精制的FSH放免活性为5406Iu/mg(国际标准品4292),交叉反应(W/W)与LH为1.2％(国际标准品<3.1％)与TSH为0.46％(国际标准品>0.7％)。精制的LH放免活性为7928Iu/mg(国际标准品6640),交叉反应(W/W)与FSH<0.5％(国际标准品<2％)与TSH<0.1％(国际标准品<1％)。本研究制备的人脑垂体FSH和LH纯品达到了国际上同类产品水平,填补了国内空白。     

Phospholipid composition of some fruit-stone oils of Rosaceae species

The phospholipid composition of five types of vegetable oil extracted from the nuts of plum (Prunus domestica L.), peach (Prunus persica L.), apricot (Prunus armeniaca L.), cherry (Prunus aviumL.), and morello-cherry (Prunus cerasus L.) was determined spectrophotometrically after fractionation and separation to individual components by means of two-directional thin-layer chromatography. The content of phospholipids in the oils varied from 0.4% to 1.1%, while in the corresponding nuts it varied from 0.2 to 0.5%. The major components in the phospholipid fraction were phosphatidylcholine (37.1–59.0%), phosphatidylinositol (13.8–31.6%) and phosphatidylethanolamine (12.9–19.5%). The fatty acid composition of the triacylglycerols and of the major phospholipids was determined by capillary gas chromatography. Larger quantities of saturated fatty acids, mainly palmitic and stearic acid, were identified in the phospholipids.