Compression characteristics of agglomerated food powders: Effect of agglomerate size and water activity Características de la compresión de alimentos en polvo: Efecto del tamaño del aglomerado y del contenido de humedad

The stability of food agglomerates is very important for keeping optimal instant properties as well as flow characteristics. Compression tests have been proven not only to be useful tools in char acterizing attrition, but also excellent descriptors for powder flowability. The purpose of this work was to study the effects of particle size and water activity ( a w) on the compression characteristics of selected agglomerated food powders, and then to identify suitable mathematical models by using a non-linear regression program for predicting the compression characteristics of food agglomerates when partial attrition takes place. Three agglomerated food powders - non-fat milk, low fat milk and instant coffee - were classified by size into five or six fractions with a set of RX-29 sieve screens. Each fraction was conditioned at three aw levels, placed in a cylindrical compression cell, and compressed with a piston attached to the crosshead of a TA-XT2 texture analyser. The crosshead speed was 1 mm/s in all tests and the maximum force applied was 245 N. Particle size was found to play a significant role in compression tests in that the greater the particle size, the greater the volume reduction. It was easier to compress the low aw samples, but in all tests changing aw did not significantly affect compression characteristics. Sone's two- parameter model accurately described the combination of compaction and attrition when compres sion pressure did not exceed a certain level, while Peleg's double-exponential model with four parameters best fitted the compression data.

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EFFECT OF DIFFERENT GUM TYPES ON STABILITY OF ANTIOXIDANT COMPONENTS AND PHYSICAL PROPERTIES OF SPRAY DRIED POUZOLZIA ZEYLANICA POWDER

Vietnam Journal of Science and Technology ◽

10.15625/2525-2518/55/5a/12173 ◽

2018 ◽

Vol 55 (5A) ◽

pp. 10

Author(s):

Nguyen Duy Tan

Keyword(s):

Particle Size ◽

Moisture Content ◽

Physical Properties ◽

Water Activity ◽

Antioxidant Activities ◽

Radical Scavenging ◽

Gum Arabic ◽

Color Difference ◽

Antioxidant Power ◽

The Stability

The objective of this study was to investigate effect of blending three types of different gum (arabic, carrageenan and xanthan) in Pouzolzia zeylanica extract together with maltodextrin as well as encapsulated material during spray-drying process on the stability of antioxidant components (anthocyanin, flavonoid, polyphenol, tannin and antioxidant activities through DPPH radical scavenging capacity, ferrous reducing/antioxidant power FRAP and antioxidant ability index AAI); and physical properties (moisture content, water activity, particle size and morphology as well as the color, nonenzymatic browning) of products. The results showed that the sample which was blended with arabic gum and maltodextrin maintained well bioactive compounds and obtained powder had better quality characteristics than others. In this optimal sample, the content of anthocyanin, flavonoid, polyphenol and tannin were determined as 7.56 ± 0.106 mgCE/100 g, 31.15 ± 1.035 mgQE/g, 27.96 ± 0.380 mgGAE/g, 25.79 ± 0.530 mgTAE/g. The antioxidant activity through DPPH, FRAP and AAI were determined as 75.55 ± 0.65%, 102.87 ± 3.85 mM FeSO4/g and 38.17 ± 11.24. The moisture content, water activity, particle size, the color value of (L, a, b), total color difference (DE) and non enzyme browning (NEB) were determined as 6.42 ± 0.085 %, 0.5142 ± 0.0076, 6.26 ± 0.110 µm, 78.43 ± 0.189, 7.55 ± 0.065, 6.96 ± 0.180, 18.85 ± 0.580 and 0.298 ± 0.015, respectively.

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The Effect of Padding Foam on the Compression Characteristics of Some Agglomerated Food Powders

Food Science and Technology International ◽

10.1106/wc69-qfnv-vn6e-lh00 ◽

2001 ◽

Vol 7 (5) ◽

pp. 417-423 ◽

Cited By ~ 1

Author(s):

H. Yan ◽

G. V. Barbosa-Cánovas

Keyword(s):

Deformation Behavior ◽

Fruits And Vegetables ◽

Impact Damage ◽

Compression Tests ◽

Compression Process ◽

Powder Bed ◽

Instant Coffee ◽

Plastic Foams ◽

Food Powders ◽

Compression Characteristics

Selected padding foam was used to reduce attrition in agglomerated food powders. This is a widely used strategy in fruits and vegetables during harvesting and processing to minimize impact damage. The objective of this research was to determine the padding effect on some agglomerated food powders when plastic foams of different thicknesses were added in the powder bed at different positions while conducting confined uniaxial compression tests. The padding effect was evaluated by two proposed indices: padding index and padding efficiency. The former index was based on the force-deformation behavior of the compression process, while the latter was based on weight comparisons of agglomerates retaining their original particle size with or without the use of padding foams. The padding thickness and positions significantly affect the force-deformation relationships for both agglomerates: instant coffee and instant milk. The padding effect, in terms of padding efficiency and padding index, was more obvious when the padding material was put at the top of the powder bed. The padding efficient index is more useful, in the cases under consideration, than the other index, because it should be more sensitive in depicting attrition.

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Determination of the cohesion, powder flow speed dependency and caking tendency of cocoa powders

Academic Perspective Procedia ◽

10.33793/acperpro.02.03.38 ◽

2019 ◽

Vol 2 (3) ◽

pp. 483-491

Author(s):

Mahmut Dogan ◽

Duygu Aslan Türker

Keyword(s):

Flow Characteristics ◽

Fat Content ◽

Flow Speed ◽

Solid Particles ◽

Powder Flow ◽

Food Powders ◽

Three Samples ◽

Powder Flowability ◽

The Mean

Cocoa is one of the most popular foodstuffs known for centuries and cocoa powders are particularly exposed to caking, a phenomenon of agglomeration of solid particles that disrupt powder functionality. This study aimed to identify the main powder flow characteristics such as caking, cohesion and powder flow speed dependency of cocoa powders, according to their fat content. The loose and tapped bulk density, as well as Carr ratio of cocoa powders, was determined as bulking properties for comparing and interpreting the flowability. The caking was observed in all three samples. With increasing fat content, a decrease in the powder flowability was detected. The mean cake strength of the low fat, reduced fat and full-fat cocoa powders was recorded as 110.42&plusmn;1.71; 164.175&plusmn;1.75 and 207.96&plusmn;0.93, respectively. These results suggest that the fat contents of the food powders may be a useful parameter to describe the powder flowability.

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Time-Dependent Strength Behavior, Expansion, Microstructural Properties, and Environmental Impact of Basic Oxygen Furnace Slag-Treated Marine-Dredged Clay in South Korea

Sustainability ◽

10.3390/su13095026 ◽

2021 ◽

Vol 13 (9) ◽

pp. 5026

Author(s):

Gyeong-o Kang ◽

Jung-goo Kang ◽

Jin-young Kim ◽

Young-sang Kim

Keyword(s):

Particle Size ◽

Environmental Impact ◽

South Korea ◽

Mechanical Characteristics ◽

Basic Oxygen Furnace ◽

Microstructural Properties ◽

Compression Tests ◽

Basic Oxygen ◽

Strength Behavior ◽

Bof Slag

The aim of this study was to investigate the mechanical characteristics, microstructural properties, and environmental impact of basic oxygen furnace (BOF) slag-treated clay in South Korea. Mechanical characteristics were determined via the expansion, vane shear, and unconfined compression tests according to various curing times. Scanning electron microscopy was conducted to analyze microstructural properties. Furthermore, environmental impacts were evaluated by the leaching test and pH measurements. According to the results, at the early curing stage (within 15 h), the free lime (F-CaO) content of the BOF slag is a significant factor for developing the strength of the adopted sample. However, the particle size of the BOF slag influences the increase in the strength at subsequent curing times. It was inferred that the strength behavior of the sample exhibits three phases depending on various incremental strength ratios. The expansion magnitude of the adopted samples is influenced by the F-CaO content and also the particle size of the BOF slag. Regarding the microstructural properties, the presence of reticulation structures in the amorphous gels with intergrowths of rod-like ettringite formation was verified inside the sample. Finally, the pH values and heavy metal leachates of the samples were determined within the compatible ranges of the threshold effect levels in the marine sediments of the marine environment standard of the Republic of Korea.

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Surface Activity of Humic Acid and Its Sub-Fractions from Forest Soil

Sustainability ◽

10.3390/su13158122 ◽

2021 ◽

Vol 13 (15) ◽

pp. 8122

Author(s):

Shijie Tian ◽

Weiqiang Tan ◽

Xinyuan Wang ◽

Tingting Li ◽

Fanhao Song ◽

...

Keyword(s):

Surface Tension ◽

Particle Size ◽

Humic Acid ◽

Forest Soil ◽

Surface Activity ◽

Self Assembly ◽

Average Particle Size ◽

Gaussian Model ◽

Exponential Model ◽

Average Particle

Surface activity of humic acid (HA) and its six sub-fractions isolated from forest soil were characterized by surface tension measurements, dynamic light scattering, and laser doppler electrophoresis. The surface tension of HA and its sub-fractions reduced from 72.4 mN·m−1 to 36.8 mN·m−1 in exponential model with the increasing concentration from 0 to 2000 mg·L−1. The critical micelle concentration (CMC) and Z-average particle size ranged from 216–1024 mg·L−1 and 108.2–186.9 nm for HA and its sub-fractions, respectively. The CMC have related with alkyl C, O-alkyl C, aromatic C, and carbonyl C (p < 0.05), respectively, and could be predicted with the multiple linear regression equation of CMC, CMC = 18896 − 6.9 × C-296 × alkyl C-331 × aromatic C-17019 × H/C + 4054 × HB/HI (p < 0.05). The maximum particle size was 5000 nm after filtered by a membrane with pore size of 450 nm, indicating HA and its sub-fractions could progressed self-assembly at pH 6.86. The aggregate sizes of number-base particle size distributions were mainly in six clusters including 2 ± 1 nm, 5 ± 2 nm, 10 ± 3 nm, 21 ± 8 nm, 40 ± 10 nm, and >50 nm analyzed by Gaussian model that maybe due to the inconsistency of the components and structures of the HA sub-fractions, requiring further study. It is significance to explore the surface activity of HA and its sub-fractions, which is helpful to clarify the environmental behavior of HA.

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Wormhole Solutions in Symmetric Teleparallel Gravity with Noncommutative Geometry

Symmetry ◽

10.3390/sym13071260 ◽

2021 ◽

Vol 13 (7) ◽

pp. 1260

Author(s):

Zinnat Hassan ◽

Ghulam Mustafa ◽

Pradyumn Kumar Sahoo

Keyword(s):

Linear Model ◽

Noncommutative Geometry ◽

Teleparallel Gravity ◽

Exponential Model ◽

Model Parameter ◽

Exponential Models ◽

Feasible Solutions ◽

The Stability ◽

Tov Equation

This article describes the study of wormhole solutions in f(Q) gravity with noncommutative geometry. Here, we considered two different f(Q) models—a linear model f(Q)=αQ and an exponential model f(Q)=Q−α1−e−Q, where Q is the non-metricity and α is the model parameter. In addition, we discussed the existence of wormhole solutions with the help of the Gaussian and Lorentzian distributions of these linear and exponential models. We investigated the feasible solutions and graphically analyzed the different properties of these models by taking appropriate values for the parameter. Moreover, we used the Tolman–Oppenheimer–Volkov (TOV) equation to check the stability of the wormhole solutions that we obtained. Hence, we found that the wormhole solutions obtained with our models are physically capable and stable.

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Stability of a Binary Colloidal Suspension and its effect on Colloidal Processing

MRS Proceedings ◽

10.1557/proc-155-73 ◽

1989 ◽

Vol 155 ◽

Author(s):

Wan V. Shih ◽

Wei-Heng Shih ◽

Jun Liu ◽

Ilhan A. Aksay

Keyword(s):

Particle Size ◽

Hard Sphere ◽

Colloidal Particles ◽

Colloidal Suspension ◽

Fluid Phase ◽

Ceramic Processing ◽

Colloidal Processing ◽

Interparticle Interactions ◽

The Stability ◽

Binary Suspension

The stability of a colloidal suspension plays an important role in colloidal processing of materials. The stability of the colloidal fluid phase is especially vital in achieving high green densities. By colloidal fluid phase, we refer to a phase in which colloidal particles are well separated and free to move about by Brownian motion, By controlling parameters such as pH, salt concentration, and surfactants, one can achieve high packing (green) densities in the repulsive regime where the suspension is well dispersed as a colloidal fluid, and low green densities in the attractive regime where the suspensions are flocculated [1,2]. While there is increasing interest in using bimodal suspensions to improve green densities, neither the stability of a binary suspension as a colloidal fluid nor the stability effects on the green densities have been studied in depth as yet. Traditionally, the effect of using bimodal-particle-size distribution has only been considered in terms of geometrical packing developed by Furnas and others [3,4]. This model is a simple packing concept and is used and useful for hard sphere-like repulsive interparticle interactions. With the advances in powder technology, smaller and smaller particles are available for ceramic processing. Thus, the traditional consideration of geometrial packing for the green densities of bimodal suspensions may not be enough. The interaction between particles must be taken into account.

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CURVAS DE SECAGEM E AVALIAÇÃO DA ATIVIDADE DE ÁGUA DA BANANA PASSA

Boletim do Centro de Pesquisa de Processamento de Alimentos ◽

10.5380/cep.v22i1.1184 ◽

2004 ◽

Vol 22 (1) ◽

Cited By ~ 3

Author(s):

MILTON CANO-CHAUCA ◽

AFONSO M. RAMOS ◽

PAULO C. STRINGHETA ◽

JOSÉ ANTONIO MARQUES ◽

POLLYANNA IBRAHIM SILVA

Keyword(s):

Experimental Data ◽

Linear Regression ◽

Moisture Content ◽

Water Activity ◽

Linear Regression Analysis ◽

Sorption Isotherms ◽

Exponential Model ◽

Drying Time ◽

Non Linear ◽

Drying Curves

Curvas de secagem de banana passa foram determinadas, utilizando-se três temperaturas do ar de secagem. Os resultados indicaram que para reduzir o teor de umidade do produto até 23,5% foram necessários tempos de secagem de 51, 36 e 30 horas paras as temperaturas de 50, 60 e 70ºC, respectivamente. O modelo exponencial U/Uo = exp(-kt) foi ajustado para os dados experimentais mediante análise de regressão não-linear, encontrandose alto coeficiente de regressão linear. Determinou-se a atividade de água do produto ao longo do processo de secagem para as três temperaturas testadas. Estudou-se a correlação entre a atividade de água e o teor de umidade do produto, determinando-se as isotermas de dessorção da banana passa a 25ºC. Observou-se que a atividade de água diminuiu em função do tempo de secagem e do teor de umidade para as três temperaturas de secagem. Os dados experimentais foram ajustados mediante regressão não-linear ao modelo polinomial e a seguinte equação foi obtida: U = -1844,93 + 7293,53Aa 9515,52Aa2 + 4157,196Aa3. O ajuste mostrou-se satisfatório (R2 > 0,90). DRYING CURVES AND WATER ACTIVITY EVALUATION OF THE BANANA-PASSES Abstract Banana drying curves were determined by utilizing three drying air temperatures. The results indicated that to reduce the moisture content of the product until 23.5% it were necessary drying times of 51, 36 and 30 hours for temperatures of 50, 60 and 70ºC, respectively. The exponential model U/Uo = exp(-kt) was adjusted for the experimental data by means of non linear regression analysis, and a high coefficient of linear regression was found. The water activity of the product was determined throughout the drying process for the three tested temperatures. The correlation between the water activity and moisture content of the product was studied, and the sorption isotherms were determined at 25º C. It was observed that the water activity decreased in function to the drying time and moisture content for the three drying temperatures. The experimental data were adjusted by means of non linear regression to the polynomial model and the following equation was obtained: U = - 1844.93 + 7293.53A a 9515.52 Aa 2 + 4157.196A a 3. The final adjust was satisfactory (R2 > 0.90).

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