Stickiness measurement techniques for food powders: a review (original) (raw)
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Sticky point temperature as a suitable method in evaluation of shelf life of food powders
Bulletin de la Société Royale des Sciences de Liège, 2017
Based on the maintenance of quality of a product in terms of nutritional value, flavor, texture and appearance during storage, the evaluation of shelf life of food is a necessity. The shelf life of food powders depends on the physical changes and their stickiness. This is an importance phenomenon during production, packaging and distribution. Stickiness reduces the quality and efficiency. This study is aimed to evaluate applied methods to control the temperature in which stickiness is occurred. This study evaluates different methods of measuring Sticky point temperature of food powders and the relationship between this temperature and glass transition temperature, storage environmental conditions and quality of food powders can be expressed. The results show the relationship between the increase of environmental moisture and reduction of sticky point temperature. This study aims to evaluate the applied methods to monitor the temperature at which stickiness is occurred. This study ev...
STICKINESS IN FOODS: A REVIEW OF MECHANISMS AND TEST METHODS
International Journal of Food Properties, 2001
Problems associated with the stickiness of food in processing and storage practices along with its causative factors are outlined. Fundamental mechanisms that explain why and how food products become sticky are discussed. Methods currently in use for characterizing and overcoming stickiness problems in food processing and storage operations are described. The use of glass transition temperature-based model, which provides a rational basis for understanding and characterizing the stickiness of many food products, is highlighted.
A modified cyclone stickiness test for characterizing food powders
Journal of Food Engineering, 2009
A cyclone stickiness test device from a preliminary work was modified and used for characterizing stickiness behaviour of food powders. This test device employed the principle of particle dynamics in cyclone section of a spray dryer. The device was more compacted and consisted of temperature-humidity controlled air generator and cyclone test chamber. Characteristic temperature-humidity curves were determined and served as the maximum test conditions. Skim milk powder was used as a model for stickiness testing. The sample was subjected to various air conditions in the cyclone and stickiness conditions were determined. Surface moisture content and glass transition temperature at sticky point were also analysed. It was found that as the particle surface temperature increased humidity at which stickiness occurred decreased. Stickiness curve was drawn to separate between sticky and non-sticky conditions. The curve of glass transition temperature vs equilibrium surface moisture content at sticky points was obtained. It was found that the sticky curve laid at 11.4°C above the glass transition temperature line.
Journal of Food Science, 2010
Plasticization and glass transition of amorphous components in food powders often result in stickiness and caking. The glass transition temperature (T g) of milk powders was measured by differential scanning calorimetry (DSC) and a viscometer method was used to determine sticky-point temperatures. Water sorption isotherms were established for varying solids compositions. Lactose contents were analyzed by high-performance anion exchange chromatography with pulsed amperometric detection (HPAE-PAD) and proteins were identified using SDS-PAGE gel electrophoresis. Solids composition and water affected both the T g and stickiness behavior. Stickiness was governed by carbohydrates and water plasticization. At low protein contents, precrystallization of lactose decreased the sticky point temperature, but increasing protein content in all milk powders decreased stickiness at all water activities. The results showed that glass transition can be used to describe time-dependent stickiness and crystallization phenomena, and it can be used as a parameter to control and reduce stickiness of dairy solids with various compositions.
Analysis of particle-gun-derived dairy powder stickiness curves
International Dairy Journal, 2007
The stickiness curves of a range of dairy powders were measured using a particle-gun rig. The stickiness curves for the powders were shown to run parallel but above the curve of the glass transition temperature (T g) of amorphous lactose. By assuming that the amorphous lactose at the surface of the powder was in equilibrium with the exit conditions of the air from the particle gun, it was found that for any particular dairy powder sample, the amount of powder deposition measured on the particle-gun target disc collapsed into a single function of the temperature difference by which the amorphous lactose T g at the surface was exceeded. The x-axis intercept of these plots was calculated and designated as (TÀT g) crit , characterizing the conditions for initiation of stickiness of the powder. The sensitivity of each powder to stickiness problems when placed in conditions where the critical TÀT g value at the surface is exceeded was quantified with the slope of the plot. These results show that it is the amorphous lactose component that is probably the main cause of stickiness in dairy powders and demonstrates how the particle-gun rig can be used to characterize the stickiness behaviour of powders over a wide range of conditions with two parameters.
Stickiness curves of high fat dairy powders using the particle gun
International Dairy Journal, 2007
High fat (442%) dairy powders are inherently sticky due to their high levels of liquid surface fat. Incorrect operating conditions when spray drying these powders can rapidly lead to blockages. The particle gun was used to characterise the stickiness curves of high fat cream and cheese powders. Stickiness was shown to increase with increasing temperature to a maximum at 50 1C after which it decreased until no stickiness was observed above 68 1C. A dramatic increase in stickiness for the powders was found when the relative humidity of the air was increased past a certain critical point for each temperature. This was attributed to the lactose component of the powder exceeding its glass transition temperature by a critical amount. Best estimates of the (TÀT g) crit. values for White Cheese Powder, Low Fat Cream Powder and High Fat Cream Powder were 28, 37 and 38 1C, respectively.
Journal of Food Engineering, 2003
A stickiness testing device based on the probe tack test has been designed and tested. It was used to perform in situ characterization of drying hemispherical drops with an initial radius 3.5 mm. Tests were carried out in two drying temperatures, 63 and 95°C. Moisture and temperature histories of the drying drops of fructose, honey, sucrose, maltodextrin and sucrose-maltodextrin mixtures were determined. The rates of moisture evaporation of the fructose solution was the fastest while those of the maltodextrin solution was the lowest. A profile reversal was observed when the temperature profiles of these materials were compared. Different modes of failure were observed during the stickiness tests. Pure fructose and honey solutions remained completely sticky and failed cohesively until the end of drying. Pure sucrose solution remained sticky and failed cohesively until complete crystallization occurred. The surface of the maltodextrin drops formed a skin shortly after the start of drying. It exhibited adhesive failure and reached a state of non-adhesion. Addition of maltodextrin significantly altered the stickiness of sucrose solution.
Journal of Food Engineering, 2017
Stickiness is one of the common problems frequently encountered during production, handling and storage of fruit powders with high concentration of low molecular weight sugars. Several techniques and devices were developed in the past to determine the level of stickiness of some of those products. Nevertheless, there is still a need for a simple, more accurate and reliable method. In this study, a new method to quantify and characterize the sticky point temperature (T s) of fruit powder was explored using a rheometer technique. The rheometer system utilized a serrated parallel plate to hold the samples and was operated in dynamic oscillation mode at a frequency of 1 Hz and a constant strain amplitude of 2%. The samples of a model fruit powder (Refractance Window (RW)-dried mango powder) were scanned from 25 to 95 C at an increment of 10 C and a holding time of 180 s for each increment. A crossover between the storage modulus (G 0) and loss modulus (G 00) was established and denoted as sticky point temperature of the model fruit powder. Results showed that the sticky point temperature obtained using the new method agreed well with the published data and can be considered as a suitable technique to characterize the sticky point temperature of sugar-rich materials. The procedure for sample conditioning and rheometric measurements to determine the sticky point temperature are straightforward. This new technique can measure the sticky point temperature of fruit powders with a high degree of repeatability and accuracy (SD ¼ 0.58e1.73 C).
Glass Transition and Sticky Point Temperatures and Stability/Mobility Diagram of Fruit Powders
Food and Bioprocess Technology - FOOD BIOPROCESS TECHNOL, 2009
Principal components present in fruits are low molecular weight sugars and some organic acids. They have low glass transition temperature (T g) and are very hygroscopic in their amorphous state, so the dry product becomes sticky. Water acts as a plasticizer and decreases the glass transition temperature of the product with the increase in moisture content and water activity. To overcome this problem, ingredients having high T g value, such as maltodextrin, and food grade anti-caking agents were added to prepare vacuum dried fruit powders. The relationship between T g and a w provides a simple method for prediction of safe storage temperature at different relative humidities environment. Food powders namely, mango, pineapple, and tomato (3–4% w.b moisture content) were produced by mixing with maltodextrin and tri calcium phosphate at predetermined levels before drying. The relationship among glass transition temperature (T g), sticky point temperature (T s), moisture content and wate...