Saturated Salt Slurry Research Articles

Modelling desorption isotherm for durable meat products

The desorption isotherms of two durable meat products (sample 1 - durable fermented meat product and sample 2 - unheated durable meat product) by Dynamic Dewpoint Isotherm (DDI) at 20, 25, and 30 °C and Saturated Salt Slurry (SSS) method at 20 °C has been studied. The data acquired from these measurements for 7 models (GAB, DLP, Henderson, Chin, Smith, Oswin, Halsey) were used and statistically evaluated. Based on our collected data, the most suitable model for these types of durable meat products is the DLP model. For the DDI method, DLP model (20–30 °C) reached the R2 = 0.999, P value 3.48–4.22 of sample 1 and R2 = 0.999, P value 1.51–3.24 of sample 2. For SSS method DLP model (20 °C) reached R2 = 0.999, P value 4.23 of sample 1 and R2 = 0.998, P value 3.68 of sample 2. The most commonly used GAB model according to statistical treatment was very accurate only for the DDI method, GAB model (20–30 °C) reached R2 ≥ 0.994, P value 1.93–7.12 of sample 1 and R2 = 0.999, P value 1.76–5.54 of sample 2. In general, for DDI method for both samples have models (DLP, GAB, Halsey, Henderson, and Oswin) a P value of less than 10% for all three measured temperatures. For the SSS method, only the DLP and Henderson models are below 10% for both samples. It has been verified that the DDI method is a suitable and accurate method for measuring desorption isotherms for durable meat products.

Thermophysical properties of frozen parsley: A state diagram representation

AbstractSorption behavior and glass transition of frozen parsley were investigated in order to study the physical modifications, represented as state diagram to figure out information about product behavior for storage and supply chain handling. Frozen products may be located in the state diagram in all the possible freezing temperatures to understand the structure state and study feasible corrective actions mainly focused on temperature and solid content. Parsley was totally dehydrated and equilibrated at selected relative humidity. Sorption behavior was evaluated by saturated salt slurry method and sorption isotherm fitting, while solid components in terms of mass fraction were investigated by using differential scanning calorimetry. Brunauer–Emmet–Teller (BET) model well fitted with moisture and water activity data (R2 = 0.995, p‐level < 0.05). The characteristic ranges of stability, in terms of system mobility and physical modification, are the monolayer values (0.240 water activity; 0.052 kg/kg dry basis) and the critical water activity range (0.424 water activity; 0.078 kg/kg dry basis). Glass transition and melting temperature were used to define parsley state diagram. Different zones figure out a specific physical behavior: depending on solid content and temperature. Unfrozen water was estimated as monolayer BET value 0.84 kg/kg wet basis and extrapolated from state diagram 0.984 kg/kg wet basis.Practical applicationsFrozen high‐quality product and energy efficiency can be obtained by a correct temperature management. Thermophysical properties of parsley represented in a state diagram are reported in the typical solute and temperature range of freezing process and storage. These data can relate physical structure and temperature, allowing different possible conditions management.

Moisture sorption isotherms of raw and extruded wholemeal sorghum flours studied by the dynamic and salt slurry methods

Abstract The saturated salt slurry method has been a standard method for many years, but there are several drawbacks, including long equilibration times, extensive labour and mould growth at high water activity (aw) values. The validity of the dynamic method (automated sorption instrument) was investigated by comparing it with the equilibrium isotherms obtained using the saturated salt slurry method for two food materials (whole sorghum raw flour and whole grain sorghum extrudates), as well as their diffusion coefficients. The sorption isotherms ranged between 11.3% and 84.3%. The equilibration time for the highest water activity (0.843) was about 30 days using the saturated salts method, considerably longer than using the dynamic method (300 min). For raw sorghum flour, the dynamic method values were consistent with the data obtained using the traditional method, which can be confirmed by the similar curves and monolayer values obtained (0.038 and 0.040 g water / g solids for the salt slurry and dynamic methods, respectively). For the sorghum extrudates, the equilibrium moisture values were higher using the dynamic method, which could be related to the low diffusion coefficient of the material (order of 10 -10). The authors suggest the use of the dynamic method as a better alternative to the saturated salt method in order to determine the sorption isotherms of whole grain sorghum-based food materials.

Measurement of Moisture Sorption Isotherm by DVS Hydrosorb

Artificial rice made from corn flour, sago, glycerol monostearate, vegetable oil, water and jelly powder was developed by extrusion method through the process stages of material mixing, extrusion, drying, packaging and storage. Sorption isotherm pattern information on food ingredients used to design and optimize the drying process, packaging, storage. Sorption isotherm of water of artificial rice was measured using humidity generating method with Dynamic Vapor Sorption device that has an advantage of equilibration time is about 10 to 100 times faster than saturated salt slurry method. Relative humidity modification technique are controlled automatically by adjusting the proportion of mixture of dry air and water saturated air. This paper aims to develop moisture sorption isotherm using the Hydrosorb 1000 Water Vapor Sorption Analyzer. Sample preparation was conducted by degassing sample in a heating mantle of 65°C. Analysis parameters need to be fulfilled were determination of Po, sample data, selection of water activity points, and equilibrium conditions. The selected analytical temperatures were 30°C and 45°C. Analysis lasted for 45 hours and curves of adsorption and desorption were obtained. Selected bottom point of water activity 0.05 at 30°C and 45°C yielded adsorbed mass of 0.1466 mg/g and 0.3455 mg/g, respectively, whereas selected top water activity point 0.95 at 30°C and 45°C yielded adsorbed mass of 190.8734 mg/g and 242.4161mg/g, respectively. Moisture sorption isotherm measurements of articial rice made from corn flour at temperature of 30°C and 45°C using Hydrosorb showed that the moisture sorption curve approximates sigmoid-shaped type II curve commonly found in corn-based foodstuffs (high- carbohydrate).

Methods for measuring water activity (a w ) of foods and its applications to moisture sorption isotherm studies

ABSTRACT Moisture sorption isotherm is commonly determined by saturated salt slurry method, which has defects of long time cost, cumbersome labor, and microbial deterioration of samples. Thus, a novel method, aw measurement (AWM) method, has been developed to overcome these drawbacks. Fundamentals and applications of this fast method have been introduced with respects to its typical operational steps, a variety of equipment set-ups and applied samples. The resultant rapidness and reliability have been evaluated by comparing with conventional methods. This review also discussed factors impairing measurement precision and accuracy, including inappropriate choice of predryingwetting techniques and unachieved moisture uniformity in samples due to inadequate time. This analysis and corresponding suggestions can facilitate improved AWM method with more satisfying accuracy and time cost.

Determining the mechanism and parameters of hydrate formation and loss in glucose.

Water-solid interactions are known to play a major role in the chemical and physical stability of food materials. Despite its extensive use throughout the food industry, the mechanism and parameters of hydrate formation and loss in glucose are not well characterized. Hydrate formation in alpha-anhydrous glucose (α-AG) and hydrate loss in glucose monohydrate (GM) were studied under equilibrium conditions at various relative humidity (RH) values using saturated salt slurries for 1 y. The mechanism of hydrate formation and hydrate loss were determined through mathematical modeling of Dynamic Vapor Sorption data and Raman spectroscopy was used to confirm the mechanisms. The critical temperature for hydrate loss in GM was determined using thermogravimetric analysis (TGA). The moisture sorption profiles of α-AG and GM were also studied under dynamic conditions using an AquaSorp Isotherm Generator. Hydrate formation was observed at and above 68% RH at 25 °C and the conversion of α-AG to GM can best be described as following a nucleation mechanism, however, diffusion and/or geometric contraction mechanisms were also observed by Raman spectroscopy subsequent to the coalescence of initial nucleation sites. Hydrate loss was observed to occur at and below 11% RH at 25 °C during RH storage and at 70 °C during TGA. The conversion of GM to α-AG follows nucleation and diffusion mechanisms. Hydrate formation was evident under dynamic conditions in α-AG and GM prior to deliquescence. This research is the first to report hydrate formation and loss parameters for crystalline α-AG and GM during extended storage at 25 ˚C.

Different analytical approaches for the study of water features in green and roasted coffee beans

Water mobility and availability in coffee play an important role in the roasting and storage process, depending on the interactions between the aqueous phase and the biopolymeric matrix.The aim of this research was to deepen the understanding of these aspects in green and roasted coffee, by means of the joint application of traditional saturated salt slurry (DES) and innovative dynamic dewpoint (DDI) methods for adsorption isotherm generation. In addition, on green and roasted samples at different hydration levels, the assessment of proton transverse relaxation time by TD-NMR and dielectric properties through waveguide spectroscopy in the spectral ranges 2–3, 5–6GHz and 17–18GHz have been performed.Green coffee exhibited above the critical aw a different behavior if observed by means of DES or DDI, demonstrating that its hydration is strictly time dependent because of its heterogeneous structure; this phenomenon was not detectable for roasted coffee, that showed very similar results with the two different techniques.The measurement of T2 by using TD-NMR permitted to study the mobility of different proton pools with a high level of details, allowing the quantitative assessment of exchange/interaction phenomena occurring along matrix re-hydration and the consequent increase of water proton mobility.At low frequencies, the described dielectric technique showed high potentiality for the non-destructive estimation of water content of green and roasted coffee. At higher frequencies, the obtained signal seems to be more related to water/solid matrix interactions and water activity.

Determining the physical stability and water–solid interactions responsible for caking during storage of glucose monohydrate

A free flowing crystalline powder can develop severe caking if held under humid and/or high temperature storage. In addition, a crystalline hydrate material can experience compositional changes due to hydrate formation or loss if held at too high or low of a storage RH, respectively. Thus, the critical RH values for caking and compositional changes of glucose monohydrate (GM) and GM partitioned into three particle sizes were assessed using saturated salt slurries ranging from 0 to 84 % RH at 25 °C for 20 weeks. Caking was measured using a five-point visual physical stability scale, from free flowing to fully caked, and sample composition was determined using X-ray powder diffraction. Caking was observed in GM during storage at 53–84 % RH at 25 °C and fine particle GM caked at lower RH values than medium and large particle GM. For all GM samples, hydrate loss (via conversion of GM to alpha-anhydrous glucose) occurred at 0 and 11 % RH and hydrate formation (via mutarotation of beta-anhydrous glucose to alpha-anhydrous glucose and conversion to GM) occurred at 53–84 % RH at 25 °C. Particle size did not affect compositional changes during GM storage, but greatly affected caking. Neither deliquescence nor amorphous content were detected in this study and hydrate formation and β-AG content did not cause caking in GM, therefore, decreased flowability was the result of capillary condensation caking. At 25 °C, GM should be stored above 11 % RH to avoid hydrate loss and below 53 % RH to avoid caking.

Determining the physical stability and water–solid interactions responsible for caking during storage of alpha-anhydrous glucose

Typically, a crystalline powder is considered reasonably stable below it deliquescence point (RH0), however, caking has been reported for some materials below their RH0. The critical relative humidity (RH) values for caking and hydrate formation in alpha-anhydrous glucose (α-AG) and α-AG partitioned into three particle sizes were assessed using saturated salt slurries ranging from 0 to 84 % RH at 25 °C for 20 weeks. The degree of caking was determined by a five-point visual physical stability scale, from free flowing with minimal clumping (1) to fully caked (5), and X-ray powder diffraction was used to determine the composition of the samples. Caking was observed in α-AG during storage at 68 % RH at 25 °C and the severity of caking increased with increasing RH. Fine particle α-AG caked during storage at 64 % RH, whereas medium and large particle α-AG caked at 68 and 75 % RH, respectively, at 25 °C. Caking was observed in the absence of deliquescence, amorphous content, and hydrate formation; therefore, it is proposed that capillary condensation leads to caking in α-AG below its RH0. Capillary condensation caking occurs at a specific RH (termed RHcc) where direct condensation of moisture into confined spaces, such as particle contact points or surface defects, causes the formation of liquid bridges, which may solidify over time without changes in RH or temperature. To avoid caking, α-AG should be stored below its RHcc, which is highly dependent on particle size; and to avoid conversion to glucose monohydrate, α-AG, regardless of particle size, should be stored below 64 % RH at 25 °C.

Comparison between moisture sorption isotherms obtained using the new Vapor Sorption Analyzer and those obtained using the standard saturated salt slurry method

The moisture sorption isotherm is an important tool, useful for both processing and product stability applications. The saturated salt slurry method has been a standard method of generating isotherms for many years. Recently, the Vapor Sorption Analyzer (VSA) has been introduced as a new type of isotherm generating instrument and is the first instrument specifically designed to produce both equilibrium and non-equilibrium isotherms. This research compared the equilibrium isotherms generated by these two methods for five food materials and found no significant differences, demonstrating that the VSA can obtain saturated salt slurry equivalent isotherms in much less time and without visible mold growth.

Comparison Between Water Vapor Sorption Isotherms Obtained Using The New Dynamic Dewpoint Isotherm Method and those Obtained Using The Standard Saturated Salt Slurry Method

The Dynamic Dewpoint isotherm method directly determines sample aw using chilled-mirror technology, while changes in sample weight are tracked gravimetrically. The objective of this research was to compare the Dynamic Dewpoint isotherms to saturated salt slurry isotherms for five materials: dent corn starch, isolated soy protein, microcrystalline cellulose, crystalline sucrose, and corn flakes. The Dynamic Dewpoint isotherms were obtained using the AquaSorp Isotherm Generator between 0.10 and 0.95 aw at 25°C. Comparison working isotherms were obtained using 12 saturated salt slurries, between 0.064 and 0.973 aw in desiccators and proximity equilibration cells at 25°C. The Dynamic Dewpoint isotherms exhibited similar sorption behavior to the saturated salt slurry isotherms, except for corn flakes, where there was a marked decrease in moisture content compared to the saturated salt slurry isotherms between 0.40 and 0.70 aw. This difference was attributed to the slow diffusion of water into the very dense laminated corn flake matrix, highlighting the rate of sorption (time) dependency of the Dynamic Dewpoint isotherm method. The Dynamic Dewpoint isotherm method offers the opportunity for real-time investigation of water sorption-related material properties, such as the glass to rubbery transition, recrystallization, hydrate formation, and deliquescence.

Use of Ramping and Equilibrium Water Vapor Sorption Methods to Determine the Critical Relative Humidity at which the Glassy to Rubbery Transition Occurs in Polydextrose

Recent research has demonstrated that the critical relative humidity (RHc) values, obtained using automatic water vapor sorption instruments, can be used to detect the glassy to rubbery transition. However, reported time dependency of these RHc values suggests that additional research be carried out using equilibrium water vapor sorption methods. Thus, the objectives of this study were to: (1) determine the RHc for amorphous polydextrose at various temperatures using both instrumental (Dynamic Vapor Sorption [DVS] ramping and equilibrium) and saturated salt slurry methods, and (2) compare the RHc values obtained via sorption methods to the glass transition temperature (Tg) values obtained via differential scanning calorimetry (DSC). When plotted as a "glass curve" on a state diagram, the RHc values (plotted as a function of temperature) were found to be similar to the Tg values (plotted as a function of relative humidity). Of the 3 sorption methods employed, at 25 °C, the saturated salt slurry exhibited the lowest RHc value (34.3%), followed by the DVS equilibrium method (41.7%), and the DVS ramping method (49.9%). The RHc DVS equilibrium method was closest to the calculated DSC Tg onset RHc value (41.6% at 25 °C). These water sorption methods show promise as practical tools for predicting the quality and stability attributes of amorphous materials by being able to routinely determine the location of the glassy to rubbery transition. Future research applying these sorption methods to more complex amorphous food systems is suggested. Practical Application: Despite its extreme usefulness, the Tg, a key element of the Food Polymer Science approach, remains a challenging parameter to routinely measure in amorphous food materials. Recent research has demonstrated that the RHc values can be used to detect the glassy to rubbery transition. However, reported time dependency of these RHc values suggests that additional research be carried out using equilibrium water vapor sorption methods. Therefore, in this research 2 instrumental (DVS ramping and equilibrium) methods and the traditional saturated salt slurry method were used to obtain RHc values, comparing them to DSC obtained Tg values. The water sorption methods show promise as practical tools for predicting the quality and stability attributes of amorphous materials by being able to routinely determine the location of the glassy to rubbery transition. Future research applying these sorption methods to more complex amorphous food systems is suggested.

Uncertainty analysis of hygrometer-obtained water activity measurements of saturated salt slurries and food materials

Water activity is a critical food stability parameter. Thus, assessment of the uncertainty associated with the instruments and measurement procedures used to obtain a w data is critical and can be accomplished using uncertainty analysis. Uncertainty analysis was applied to a w data obtained for two saturated salt slurries (potassium acetate and potassium chloride) and two food materials (corn flakes and grape jam) at 25 °C using a commercially available dew point hygrometer, the AquaLab 3TE. Sources of uncertainty investigated included sample and dew point temperatures, sample lot, cup volume, and sample preparation (“as is” or ground), and day to day changes. Uncertainty analysis revealed that the magnitude of the different sources of uncertainty depended on material type, but that the dew point hygrometer instrument uncertainty was always significantly smaller than each of the other sources of uncertainty investigated, except for jam cup volume, which was exceeding small. Uncertainty analysis also revealed that dew point hygrometer accuracy was better than the ±0.003 a w value reported by the manufacturer. Measurement procedures were identified that could be implemented to reduce a w measurement uncertainty for corn flake and jam food materials. The uncertainty analysis used herein can also be applied to investigate other food materials and/or instruments.

Exploring the Problem of Mold Growth and the Efficacy of Various Mold Inhibitor Methods during Moisture Sorption Isotherm Measurements

Mold growth is a common problem during the equilibration of food materials at high relative humidity values using the standard saturated salt slurry method. Exposing samples to toluene vapor and mixing samples with mold inhibitor chemicals are suggested methods for preventing mold growth while obtaining isotherms. However, no published research was found that examined the effect of mold growth on isotherm performance or the efficacy of various mold inhibitor methods, including their possible effect on the physicochemical properties of food materials. Therefore, the objectives of this study were to (1) explore the effect of mold growth on isotherm performance in a range of food materials, (2) investigate the effectiveness of 4 mold inhibitor methods, irradiation, 2 chemical inhibitors (potassium sorbate and sodium acetate), and toluene vapor, on mold growth on dent corn starch inoculated with A. niger, and (3) examine the effect of mold inhibitor methods on the physicochemical properties of dent corn starch, including isotherm performance, pasting properties, gelatinization temperature, and enthalpy. Mold growth was found to affect starch isotherm performance by contributing to weight changes during sample equilibration. Among the 4 mold inhibitor methods tested, irradiation and toluene vapor were found to be the most effective for inhibiting growth of A. niger on dent cornstarch. However, both methods exhibited a significant impact on the starches' physiochemical properties, suggesting the need to probe the efficacy of other mold inhibitor methods and explore the use of new rapid isotherm instruments, which hamper mold growth by significantly decreasing measurement time.

Modeling the Growth Boundary of Staphylococcus aureus for Risk Assessment Purposes

Knowing the precise boundary for growth of Staphylococcus aureus is critical for food safety risk assessment, especially in the formulation of safe, shelf-stable foods with intermediate relative humidity (RH) values. To date, most studies and resulting models have led to the presumption that S. aureus is osmotolerant. However, most studies and resulting models have focused on growth kinetics using NaCl as the humectant. In this study, glycerol was used to investigate the effects of a glass-forming nonionic humectant to avoid specific metabolic aspects of membrane ion transport. The experiments were designed to produce a growth boundary model as a tool for risk assessment. The statistical effects and interactions of RH (84 to 95% adjusted by glycerol), initial pH (4.5 to 7.0 adjusted by HCl), and potassium sorbate (0, 500, or 1,000 ppm) or calcium propionate (0, 500, or 1,000 ppm) on the aerobic growth of a five-strain S. aureus cocktail in brain heart infusion broth were explored. Inoculated broths were distributed into microtiter plates and incubated at 37°C over appropriate saturated salt slurries to maintain RH. Growth was monitored by turbidity during a 24-week period. Toxin production was explored by enterotoxin assay. The 1,280 generated data points were analyzed by SAS LIFEREG procedures, which showed all studied parameters significantly affected the growth responses of S. aureus with interactions between RH and pH. The resulting growth/no growth boundary is presented.

Measuring Water Potential (Activity) from Free Water to Oven Dryness

Water activities (potentials) in plant materials were measured over the range from free water to oven dryness with a Spanner thermocouple psychrometer. In a two-step procedure, water was first condensed on the thermocouple junction for several minutes. The sample was then inserted under the wet thermocouple and the maximum psychrometric cooling was measured in about 10 seconds. Calibration was with saturated salt slurries of known water activities. Psychrometric cooling was a nearly linear function of the water activity and of the negative log of the water potential. The psychrometric cooling to water activity relationship agreed with wetbulb temperature depression to relative humidity relationships given in tables. Water activities of wheat grains and leaves decreased sharply in a curvilinear fashion as their water contents decreased. Some problems of the procedure are discussed.

A Rapid Psychrometric Procedure for Water Activity Measurement of Foods in the Intermediate Moisture Range

Commercial vapor pressure thermocouple psychrometers (hygrometers) are now generally accepted for measuring water activity, aw (water potential) in plants and soils, and commercial instruments are available. We have adapted them for aw measurements in the 0.99 to 0.60 range using a two-step procedure. Water is first condensed on the thermocouple; then the sample is inserted in the thermocouple chamber and the psychrometric cooling of the wet thermocouple measured. The procedure is calibrated with a series of saturated salt slurries of known aw values. Typical aw values (with standard deviations) for a variety of foods were: Cheddar cheese, 0.95 ± 0.03; Parmesan cheese, 0.76 ± 0.03; milk powder, 0.75 ± 0.02; milk chocolate, 0.60 ± 0.04; luncheon meat, 0.96 ± 0.03; bread, 0.95 ± 0.03; dried raisins, 0.82 ± 0.02; corn syrup, 0.60 ± 0.02; and orange juice concentrate, 0.80 ± 0.03. The coefficients of variation ranged from 1.9 to 5.8%. When compared with published values obtained by other methods, these figures were within the standard errors of measurement. The thermocouple detector did not foul since it had only vapor contact with the sample. An economical sample chamber and instrument is described. Analysis time is 4 to 8 min. The procedure is accurate, convenient and rapid.

A Proximity Equilibration Cell for Rapid Determination of Sorption Isotherms

ABSTRACTSorption isotherm data are obtained by instrumental determination of water activity at a known moisture content or determination of moisture content after equilibration against a saturated salt solution. The latter method is simpler and the salt solutions are primary standards. However, the equilibration takes a long time, one to ten weeks, depending upon food composition. Thus, the objective of this work was to devise a method that retains the saturated salt solution but accelerates the rate of equilibration. In an equilibration environment between a food product and a saturated salt slurry, the driving force is the difference in vapor pressure; therefore the faster the vapor space reaches equilibrium with the saturated salt slurry, the quicker the maximum driving force for water absorption will be applied to the sample. It was felt that a reduction in the size of the usual large desiccater to a single sample size would provide the necessary area to volume ratio. The vessel chosen was a small plastic chamber (65 mm/53 mm). In this chamber, the surface area to vapor volume ratio was 0.3101 as compared to 0.0335 for the standard desiccator. The sample was contained in a standard aluminum weighing tray modified by removing a 44 mm diameter circular section from the bottom. This was replaced with a 47 mm diameter circle of Whatman No. 1 quantitative filter paper to support the sample and at the same time allow transmission of moisture. This would allow water molecules to travel in a straight line and thus the shortest distance between the saturated salt slurry and the sample. This small vessel with a single sample supported on a filter paper will be referred to as a Proximity Equilibration Cell (PEC). Using this technique, it was found that a 2/mm deep sample of corn starch required only 6 days for complete equilibration, as compared to 21 days for the conventional desiccator. Thus, the PEC satisfied the objective by reducing time by 70%. In making comparisons with the same salts in conventional and the PEC, it was noted that the end point was higher in the latter. Evidently, absorption in case of the conventional desiccator was so slow at the end that no weight gain could be detected in 24 hr but equilibrium had not yet been attained. In contrast, the PEC equilibrated so rapidly that it allowed a closer evaluation of true equilibrium.

The Use of Salt Cement Blends as an Aid to Better Cementing in Formations Containing Fresh Water Sensitive Clays

Abstract The application of salt for primary cementing in Western Canada has been restricted largely to salt cavern storage wells and to the development of potash reserves in south-central Saskatchewan. The value of salt cement blendsin cementing through fresh water sensitive formations has recently broughtabout wide usage of this technique in certain areas of the United States, andthere is good reason to believe that there are several areas in Canada wherethe success of primary cementing could be improved by the use of saltcements. There has been considerable work done on the applicability of salt cement, with emphasis on improved cement-formation bonding and the minimization offormation deterioration by water contact. Field results have shown that saltcements have improved the success of primary and squeeze cementing jobs. Laboratory work has been done to evaluate the change in slurry properties with the addition of varying concentrations of salt to commonly used cementing blends. Introduction The use of salt cements in Canada has been quite limited and, as a result, the primary purpose of the information presented here is to illustrate theadvantage of salt for primary cementing of oil and gas wells where the formations encountered contain fresh water sensitive clays and shales. The first known use of salt cements in Western Canada occurred within thepast ten years. Initially, salt cements came into use because of the failure toset fresh water cement abandonment plugs in the salt and potash zonesencountered in potash test holes. Earlier experience in the U.S.A. proved that a good cement-formation bond through a salt section could only be achieved byusing a salt cement. Figure 1 illustrates the bonding of cement to rocksalt. The illustration shows how a fresh water slurry will dissolve a portionof the salt, with the result that there is no bond between the salt and cement, while the saturated salt slurry does not dissolve any portion of the salt, resulting in good contact and bonding between the salt and the cement. Operators in Saskatchewan found that casing could be cemented successfully in salt cavern gas storage wells with a sodium chloride slurry; more recentwork has employed a sodium chloride and potassium chloride (potash) saturated slurry (1). Later, casing was set into the potash for a solution mining project, and again salt cements were used to obtain a good primary cement job.