Apparent Viscosity Values Research Articles

Overcoming the rheological performance and density limitations using a novel high density magnesium bromide based completion fluid in oil and gas reservoirs

Commonly used brine-based completion fluids are calcium chloride, sodium chloride, and potassium chloride. Our main objective for this study is to overcome the rheological performance and density limitations of existing brine-based completion fluid for workover and completion in oil and gas reservoirs. Magnesium Bromide-based completion fluid exhibits a high-density 13.41-lb/gal, with a specific gravity of 1.61. Existing, calcium chloride, potassium chloride, and sodium chloride-based completion fluid exhibit a density of 11.64-lb/gal (specific gravity 1.39), 9.6-lb/gal, (specific gravity 1.15), and 10.02-lb/gal (specific gravity 1.20), respectively. Results suggest that a high-density and solid-free novel magnesium bromide-based completion fluid show suitable optimum rheology avoid formation damage, plugging, and eroding of tubular and completion equipment. In this study, we have investigated the rheological properties such as apparent viscosity, plastic viscosity, yield point, and gel strength 10 sec and 10 min of formulated completion fluid at the varying temperature of 84 °F (28.8 °C) to 192 °F (88.8 °C). We have found that magnesium bromide-based completion fluid shows lower apparent viscosity and plastic viscosity as compared to calcium chloride-based completion fluid. A low value of apparent viscosity is desired for the design and development of the completion fluid.

Production and evaluation of microbiological & rheological characteristics of kefir beverages made from nuts

Herein we report the preparation of nut milks followed by kefir production from Almond, peanut, hazelnut, walnut, and cashew. Nut-based milks were used to make kefir from 100% vegetable milk without food additives or sugar. During 30 days of storage at 4 °C, the microbiological (total aerobic mesophilic bacteria, lactobacilli, lactococci, acetic acid bacteria, yeast) and rheological (apparent viscosity, consistency constant, flow behavior index, thixotropy) parameters of kefir samples made from cow's milk and nut-based milk were monitored and compared to examine the effects of different milk types and storage time. The titratable acidity value of nut kefirs was lower than cow kefir. Kefir from walnut milk had the lowest titratable acidity value (0.15%), lowest apparent viscosity (3.3 mPa s) and consistency coefficient (682.1 mPa.sn). Titratable acidity values of the samples increased while apparent viscosity, thixotropy, flow behavior index and consistency coefficient decreased during storage. According to the power-law model, the kefir samples exhibited non-Newtonian pseudoplastic flow behavior. The apparent viscosity values of peanut and almond kefirs were higher among the prepared samples (p < 0.05). The total number of aerobic mesophilic, lactic acid and acetic acid bacteria of kefir samples decreased during storage, while the number of yeasts increased. Kefir made from cow's milk had the highest average total aerobic mesophilic bacteria, lactococci, lactobacilli, and acetic acid bacteria counts, whereas kefir made from peanut milk had the highest yeast count (p < 0.05). During storage the lowest decrease (%) in the counts of microorganism was determined in almond kefir (4.06%), followed by cow (5.16%), walnut (5.73%), peanut (6.72%), cashew (7.78%), and hazelnut kefirs (9.53%).

Optimization of Mixing Parameters on Techno-Functional Properties of Fenugreek Gum-Soy Protein Isolate Dispersion

Fenugreek (Trigonella foenum-graecum L.) gum (FG) has been identified as a hydrocolloid, with promising emulsifying and stabilizing properties. In an emulsion-based food system, these properties dramatically increased when FG was mixed with soy protein isolate (SPI). Nevertheless, it is highly dependent on mixing parameters such as FG:SPI ratio, pH, and temperature, and it is currently not well understood. The objective of this study was to determine the effects of FG:SPI ratio (3:1 - 1:1), pH (3 - 9), and temperature (65 - 85 °C) on techno-functional properties (flow properties, emulsifying properties, and turbidity) of the FG-SPI dispersion, to reveal the optimum mixing parameters. A response surface regression modeling demonstrated that the quadratic effect of the FG:SPI ratio had significantly (p&lt;0.05) increased the flow properties of the dispersion. However, the interaction between FG:SPI ratio and temperature or pH gave the opposite effect. The FG:SPI ratio had the most significant (p&lt;0.05) increasing effect on both emulsifying properties and turbidity. Conversely, the emulsifying properties were determined to decrease with the interaction effect of FG:SPI ratio and pH. The optimized mixing parameters were recorded at FG:SPI ratio of 2.6:1, pH of 3.0, and temperature of 70 °C, with apparent viscosity (0.19 Pa.s), emulsion stability (100%), and turbidity (2.91, Abs600) values were within the predicted ranges. The present findings provide an excellent opportunity to advance the use of FG-SPI dispersion in related to emulsion-based food products.

Effects of different gases on the performance of foams stabilized by Cocamidopropyl betaine surfactant and silica nanoparticles: A comparative experimental study

Application of CO 2 gas in foam enhanced oil recovery (EOR) processes has emerged as a win-win strategy for achieving higher oil recovery factor and reducing greenhouse gas emission, which can significantly help the protection of the ozone layer from depletion. However, lower stability of CO 2 -foam, as compared to the N 2 - and CH 4 -foams, has tempted us to examine combinations of CO 2 with these gases to not only improve the stability of the produced foam but also have CO 2 as the gaseous phase of the foam. In this study, we investigated the effect of different gases and the mixture thereof on the performance of foams in EOR while the aqueous phase of foams is a constant mixture of Cocamidopropyl betaine surfactant (0.03 wt %) and silica nanoparticle (0.1 wt%). To this end, seven different gases, including N 2 , CO 2 , CH 4 , 80% N 2 + 20% CO 2 , 80% CH 4 + 20% CO 2 , 50% CH 4 + 50% CO 2 , 50% N 2 + 50% CO 2 were used as the gases phase for foam generation, and the performance of the produced foams were examined through the following experiments: bulk foam stability tests, apparent foam viscosity measurements, and core flooding tests. The results of foam stability tests showed that half-life time for the CO 2 -, CH 4 -, and N 2 -foams are 13.5, 17.0, and 44.0 min, respectively. Also, as revealed from apparent viscosity measurements, the N 2 - and 80% N 2 +20% CO 2 foams have higher apparent foam viscosity values followed by 50% N 2 +50% CO 2 foam. Furthermore, we showed that a combination of 80% N 2 + 20% CO 2 as the gaseous phase for foam generation could not only improve CO 2 -foam stability, as compared to other foams, but also can substantially increase ultimate oil recovery (56.6 %OOIP), even more than that for N 2 foam (48.6 %OOIP), obtained from core flooding experiments.

Improvement of spreadability of grape molasses with induced crystallization for production of creamed molasses as a novel product

Induced static-crystallization of grape-molasses (GM) was successfully done via adding crystallized honey (CH) to improve the crystallization rate, crystal size and to obtain a homogeneous crystalline structure of the product with the desirable rheological and textural properties. The effect of CH concentration (5, 10, and 15%) as starter and storage time (1st, 7th, 14th, 21st, and 28th day at 14 °C) on the rheological, physicochemical, and crystallization characteristics of GM/CH blends was investigated. Flow behavior of the molasses changed to Ostwalt de Waele model from Newtonian behavior. Apparent viscosity and consistency coefficient values increased and flow behavior index decreased with crystallization. Temperature-dependent apparent viscosity at shear rate 50 s−1 was successfully described by the Arrhenius equation. As storage time increased, activation energy increased from 342.17 to 427.16 (J/mol). All samples showed liquid-like properties because the loss modulus was remarkably higher than the storage modulus. The particle-size ranged between 12.60 and 33.20 μm with the highest value at the 15% sample. Spreadability and firmness values of samples were found to between 0.46 and 5.47 N mm and 0.094–0.195 N, respectively. Spreadability and machinability characteristics of the molasses can be improved by controlled crystallization which can positively affect consumer acceptability of the product.

Physicochemical Evaluation of Personal Care Products Developed with Chondrus crispus Fractions Processed by Ecofriendly Methodologies.

Novel personal care products are necessary to cope with the growing market demand for sustainable green products. In this context, this work deals with the formulation and fundamental physicochemical and rheological characterization of different natural personal care products using bioactive fractions from Chondrus crispus red macroalgae extracted under optimized green conditions. Body milks, body oils and shampoos were supplemented with soluble extracts with antioxidant features recovered after hydrothermal (200 °C) and microwave (170 °C)- and ultrasound (80 °C)-assisted extraction of the red macroalgae used as raw material. Formulated products were also compared with those prepared using (±)-α-tocopherol and butylhydroxytoluene standards. Body scrubs were formulated with the remaining solids (&lt;2.25 %) after microwave hydrodiffusion and gravidity treatment of the macroalgae. Results indicated that selected extracts provided personal care products with similar or even better physicochemical, color and viscous features than those supplemented with (±)-α-tocopherol or butylhydroxytoluene commercial antioxidants. Rheological profiles indicated that it is possible to develop personal care products with adequate viscous behavior (102-105 mPa s, at 1 s-1), comparable with their synthetic counterparts. To conclude, the addition of antioxidant extracts led to lower apparent viscosity values suggesting an advantage from the skin applicability point of view, jointly with the absence of both the hysteresis phenomenon and water syneresis of the proposed formulations.

Improved Flowability and Wettability of Whey Protein-Fortified Skim Milk Powder via Fluidized Bed Agglomeration.

Recently, protein-fortified milk powders are being widely consumed in Korea to prevent sarcopenia, and the demand for high-protein food powders is continuously increasing in the Korean market. However, spray-dried milk proteins have poor flowability and wettability owing to their fine particle sizes and high inter-particle cohesive forces. Fluidized bed agglomeration is widely used to improve the instant properties of food powders. This study investigated the effect of fluidized bed agglomeration on whey protein isolate (WPI)-fortified skim milk powder (SMP) at different SMP/WPI ratios. The fluidized bed process increased the particle size distribution, and agglomerated particles with grape-like structures were observed in the SEM images. As the size increased, the Carr index (CI) and Hausner ratio (HR) values of the agglomerated WPI-fortified SMP particles exhibited excellent flowability (CI: <15) and low cohesiveness (HR: <1.2). In addition, agglomerated WPI-fortified SMP particles exhibited the faster wetting time than the instant criterion (<20 s). As a result, the rheological and physical properties of the WPI-fortified SMP particles were effectively improved by fluidized bed agglomeration. However, the fluidized bed agglomeration process led to a slight change in the color properties. The CIE L* decreased, and the CIE b* increased because of the Maillard reaction. The apparent viscosity (ηa,10) and consistency index (K) values of the rehydrated solutions (60 g/180 mL water) increased with the increasing WPI ratio. These results may be useful for formulating protein-fortified milk powder with better instant properties.

Harnessing the untapped potential of indigenous cow milk in producing set-type yoghurts: case of Thamankaduwa White and Lankan cattle.

This research paper assessed textural, microstructural, sensory and colour properties of set-yoghurts produced using milk from two indigenous cattle types, Thamankaduwa White (TW) and Lankan cattle (LC) compared to two generic cattle breeds, Friesian and Jersey. Instrumental texture profile (firmness, adhesiveness, cohesiveness and springiness), colour space (L* a* b*) and scanning electron micrographs of set-yoghurts during 21 d of storage (4 ± 1°C) were evaluated. Sensory quality attributes were evaluated with 40 untrained panellists using a five-point hedonic scale. Set-yoghurts prepared using indigenous cow milk showed higher (P < 0.05) firmness, cohesiveness and apparent viscosity values compared to those prepared using generic cow milk. As revealed by micrographs, set-yoghurts made from TW milk had lesser and smaller void spaces and a dense protein gel network than gels made from LC and the two generic breeds. The gel network made from Friesian milk showed a comparatively larger porous gel structure and thinner protein strands resulting in a weaker gel than other milk gels. The highest lightness (L*) and yellowness (b*) were observed from set-yoghurt produced from Friesian and LC milk, respectively. Set-yoghurts from TW milk had the highest (P < 0.05) sensory scores for all sensory attributes. The lowest sensory acceptance was recorded in set-yoghurt made from Friesian milk. Thus, milk from TW and LC is likely to be suitable in producing set-yoghurts with superior textural, microstructural and sensory properties, compared to milk from Jersey and Friesian. Our results suggest the merits of using indigenous cow milk in producing set-yoghurts and, thereby, prioritizing the preservation of the genetic pool of these indigenous breeds.

Steady and dynamic rheological properties of cheese dip: Effect of milk proteins, fat and cheddar cheese

The present study was conducted to investigate the effect of milk protein blends, cheddar cheese and milk fat on rheological properties of cheese dip (CD). The 20 samples of CD were prepared using central composite rotatable design of response surface methodology (RSM) and subjected to rheological study using a controlled stress rheometer. The result obtained showed, all samples manifest shear thinning behavior with an increase in frequency. At shear rate 100 s−1, the apparent viscosity value varied from 1.76 to 6.78 Pas for different samples of CD. Storage (G′) and Loss (G′′) modulus increased, while complex viscosity decreased with an increase in the frequency. The G′, G′′ and Tan δ values for CD varies from 45.73 to 845.33, 40.83 to 457.6 and 0.51 to 0.97, respectively. Furthermore, the values of G′ were higher than the G′′ over the entire range of frequency studied. The rheological parameters studied are most significantly affected by the milk fat followed by protein blend and cheddar cheese. The increase in fat level in CD was positively correlated, whereas increased protein blend and cheddar cheese were negatively correlated with apparent viscosity, G′, and G′′ values. Cheese dip behavior was characterized efficiently by correlating Cross, Carreau-Yasuda and Power-law models with flow curve. The Cross and Carreau-Yasuda models were found to be best fitted (R2 = 0.99) than Power-law model (R2 = 0.90). This study demonstrated, the selection of different level of ingredients during the manufacturing CD for controlling its overall quality. This study also aids in the development of machineries for the commercial manufacturing of cheese dip based on its rheological characteristics.

Production and characterization of gum exudate from apricot tree: modeling the rheology of the obtained extract

PurposeThis paper aims to investigate the effect of shear rate, concentration (4–20 kg/m3) and temperature (20°C–60 °C) on the apparent viscosity of apricot gum solutions.Design/methodology/approachApparent viscosity has been measured using a rotational viscometer.FindingsIt has been observed that the shear stress and apparent viscosity values increase at high concentrations in the prepared apricot gum solutions. However, it is understood that the higher the temperature in the operation conditions, the lower the apparent viscosity results. Power-law is found the best-fitting model to illustrate the changes in temperature and concentration. According to the consistency coefficient and flow behavior indices, the apricot gum displayed shear-thinning behavior (pseudoplastic). The apricot gum is a polysaccharide with amino and uronic acids, according to Fouirer Transform Infrared Spektrofotometre spectra.Practical implicationsThe results suggest that power-law model can be used to estimate the viscosity of apricot gum solutions at different temperatures and concentrations for applications for which flow behavior should be taken into account.Originality/valueExudate gums have good rheological properties and, therefore, are widely used in the food industry. Apricot gum is a biodegradable and abundant polysaccharide that enhances viscosity, stabilizes suspension or emulsion and improves the flow properties of foods. Different rheological models are used to investigate rheological properties. However, those models are time-independent to fit the experimental data.

Süt Tozu, Peyniraltı Suyu İzolatı veya İnülin ile Kurumaddesi Arttırılan ve Kalsiyum Klorür Eklenen Sütlerden Üretilen Probiyotik Yoğurtların Bazı Fizikokimyasal, Mikrobiyolojik ve Duyusal Özellikleri

Bu çalışmada, kurumaddesi süt tozu, peyniraltı suyu izolatı veya inülin kullanılarak arttırılan sütler gerek kalsiyum klorür ilave edildikten sonra gerekse ilave edilmeden probiyotik yoğurt üretiminde kullanılmıştır. Üretilen probiyotik yoğurt örnekleri 4°C’de 30 gün süresince depolanmış ve depolamanın 1., 15. ve 30. günlerinde örneklerin fizikokimyasal, duyusal ve mikrobiyolojik özellikleri belirlenmiştir. Kalsiyum klorür ilavesinin sütlerin pH değerlerini düşürdüğü ve inkübasyon süresini arttırdığı tespit edilmiştir. Peyniraltı suyu izolatı ilave edilen sütlerden üretilen probiyotik yoğurt örneklerinin serum ayrılması değerlerinin süt tozu ve inülin ilave edilen sütten üretilen yoğurt örneklerinden düşük; görünür viskozite, kıvam katsayısı ve tiksotropi değerlerinin yüksek olduğu belirlenmiştir. Süte kalsiyum klorür ilavesinin probiyotik yoğurt örneklerinin serum ayrılması değerlerini ve reolojik özelliklerini istatistiksel olarak önemli düzeyde etkilediği saptanmıştır. Peyniraltı suyu izolatı ile kurumadde miktarı arttırılan sütten üretilen probiyotik yoğurt örneklerinde en yüksek granül sayısı, granül çevre uzunluğu ve görsel pürüzlülük değerleri belirlenirken, kalsiyum klorür ilavesinin probiyotik yoğurtların görsel niteliklerini geliştirdiği tespit edilmiştir. Depolama süresince probiyotik yoğurt örneklerinde Lactobacillus paracasei sayısının 7.71-8.98 log kob/g arasında değiştiği ve süte kalsiyum klorür ilavesinin probiyotik bakteri canlılığını etkilemediği belirlenmiştir.

The effect of citric-acid treatment on the physicochemical and gel properties of konjac glucomannan from Amorphophallus bulbifer

The Amorphophallus bulbifer (A. bulbifer) as a newly developed superior konjac variety has the advantages of short growth cycle, high reproductive coefficient, disease resistance and adaptation to humid or hot environments. Because of its good growth characteristics and high konjac glucomannan (KGM) content, A. bulbifer has great potential to be used as KGM resources in food industry. However, KGM from the A. bulbifer flour has very high viscosity even in low concentration, and the gels formed by KGM are easily browning during the alkali-induced process. These shortcomings are key factors that limit its application in the food industry. In order to solve this problem, KGM was modified by citric-acid treatment (CAT), and the effect of CAT on the physicochemical and gel properties of KGM was investigated in this study. The results indicated that the apparent viscosity and ΔE value of the KGM treated with 1.2 M CAT for 2 h were 948.66 Pa·s and 14.55, respectively, which were significantly lower than native KGM in the same variety. Moreover, the CAT did not significantly affect the texture properties of KGM gels. Hence, it will be extremely valuable for developing innovative low-calorie foods favored by consumers and industrial production based on KGM.

Lactobacilli isolates as potential aroma producer starter cultures: Effects on the chemical, physical, microbial, and sensory properties of yogurt

Five lactobacilli isolates from traditional yogurts and a commercial isolate (LB) were utilized for yogurt production and weekly chemical, physical, microbial, and sensory analyzes were performed during the 21-day storage period. All yogurt samples possessed similar gross compositions, and no significant difference was detected between yogurt samples in terms of acidity and syneresis rates, together with lactobacilli and streptococci counts during storage (p > 0.05). All samples exhibited pseudoplastic behavior and solid-like properties. The highest complex and apparent viscosity values were determined in LB, KKC2, and EPSC2 yogurts. The EPSC2 strain has stood out, leaving the commercial culture behind, regarding acetaldehyde and acetone production while CBH4 and CBX have fallen behind others considering sensory and aromatic properties. Except for viscosity, EPSC2 and KKC2 exhibited similar or better characteristics, including sensory properties and flavor profiles, than LB. In conclusion, EPSC2 and KKC2 are recommended as potential yogurt starters.

The effect of pumpkin powder on the physicochemical, emulsification, and textural properties of beef

This study evaluated the physicochemical, emulsification, and textural properties of beef emulsions prepared with four different levels (0.0%, 0.2%, 0.4%, and 0.6%) of pumpkin powder. Some technological properties of beef emulsions such as emulsion capacity (EC), emulsion stability (ES), pH, apparent viscosity, and emulsion color values were determined. The use of pumpkin powder decreased the cooking loss by 17.38%–21.99% (p < 0.01). The highest EC values were determined in samples including 0.4% pumpkin powder (p < 0.01). The pumpkin powder addition increased the ES values compared to control (p < 0.01). All textural properties of beef emulsions were changed when 0.6% of pumpkin powder was added (p < 0.05). The addition of 0.2% and 0.4% pumpkin powder increased the apparent viscosity, while the apparent viscosity was decreased when 0.6% pumpkin powder was used (p < 0.05). The optimal concentration of pumpkin powder for beef emulsions was determined to be 0.4%. Practical applications This study was conducted to evaluate the physicochemical, emulsification, and textural properties of beef emulsions prepared with four different ratios of pumpkin powder. It is a good source of carotenoids, pectin, minerals, vitamins, and various bioactive molecules, so we speculate that it is probable to use the pumpkin powder for enriching meat and meat product formulations with dietary fiber. In this study pumpkin powder improved the color, EC, ES, textural properties and thus increased the quality of emulsified meat products. Therefore, in the preparation of emulsified meat products, the addition of pumpkin powder is thought to provide many advantages for producers and consumers.

Dysphagia thickeners in context of use: Changes in thickened drinks viscosity and thixotropy with temperature and time of consumption.

Dysphagia patients might need to thicken drinks. The viscosity of these thickened drinks varies among commercial thickeners and drinks compromising the ingesta safety. The aim of this study was to investigate how temperature and resting time affect the rheological properties of thickened drinks. Four commercial thickeners were used to thicken water, coffee, orange juice, and milk at two concentration levels used in dysphagia drinks (nectar and pudding). To study the effect of temperature, flow curves of thickened drinks at 10°C and 50°C were obtained and to study the effect of resting time, flow curves of thickened drinks at 25°C were obtained at different times (0, 30, and 60 min). All samples displayed shear‐thinning and time‐dependent behavior (thixotropy or antithixotropy). The effect of temperature on viscosity values and relative thixotropic area (RTA) depended on the thickener and the drink. Overall, apparent viscosity showed higher values at 50°C than 10°C, especially in thickeners containing starch and in drinks with higher soluble solids (milk and orange juice). This was attributed to the water absorption of pregelatinized starch granules favored by temperature. Antithixotropy was mainly observed at pudding concentration for the starch‐containing thickeners, and decreased with temperature. The effect of resting time on apparent viscosity and RTA depended also on the drink and thickener. Mostly, apparent viscosity values increased with resting time and antithixotropic behavior decreased. Both effects, increase in viscosity and decrease of antithixotropy with time, indicated that thickening action was being developed over the resting time.

Orthogonal experimental design for the optimization of four additives in a model liquid infant formula to improve its thermal stability

In this study, kappa-carrageenan (κ-CGN), a thickener, and soybean lecithin (SBL), citric and fatty acid esters of glycerol (CITREM), and mono-and diglycerides (MDGs) emulsifiers were added to a model liquid infant formula (LIF) to enhance its thermal stability. The dosages of the four additives were obtained by comprehensively analyzing the Turbiscan stability index (TSI), apparent viscosity, and volume mean diameter (D (4,3)). The additives decreased the TSI values from 0.761 to 0.272, increased the apparent viscosity values from 6.875 mPa s to 7.887 mPa s, and decreased the (D (4,3)) values from 1.136 μm to 0.706 μm. The optimal additive levels when added separately were determined as follows: 0.025 g/100 mL κ-CGN, 0.150 g/100 mL SBL, 0.600 g/100 mL CITREM, and 0.100 g/100 mL MDGs. Based on the orthogonal experiment L9 (34), which combined range analysis and analysis of variance, the optimal levels of the four additives when combined were 0.025 g/100 mL κ-CGN, 0.125 g/100 mL SBL, 0.450 g/100 mL CITREM, and 0.100 g/100 mL MDGs. Confirmatory experiments involving milk composition, oxidation stability, and △ backscatter demonstrated that the combined addition of additives is more beneficial to the stability of LIF than the separate addition.

Effect of lactose hydrolysis and salt content on the physicochemical, microbiological, and sensory properties of ayran

Ayran is a salty drinkable yoghurt, but lactose in ayran induces lactose intolerance. This can be overcome by production of lactose-free or lactose-reduced ayran. Milk with 50% and 100% lactose hydrolysis by β-galactosidase was therefore used for alternative lactose-reduced or lactose-free ayran production. Physicochemical, microbiological, and sensory analyses were performed during storage at 4 °C for 28 days. Syneresis and flow behaviour index values increased, and apparent viscosity and consistency coefficient values decreased with increasing lactose hydrolysis level, salt content (0.5 and 1%), and storage period. No significant effects of lactose hydrolysis level and salt content on the counts of Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus were found, while counts of these bacteria decreased during the storage period. Sensory evaluation highlighted that the 1% salt-containing ayran samples, which had higher scores of overall liking than 0.5% salt-containing ones, were significantly different from commercial ayran within the storage period.

Rheological and Physicochemical Properties of Oleogel with Esterified Rice Flour and Its Suitability as a Fat Replacer.

The objectives of this study were to produce oleogel using esterified rice flour with citric acid (ERCA), to evaluate physicochemical and rheological properties of oleogels, and to investigate their suitability as a fat replacer. Rice flour was esterified with citric acid (30%, w/w) to produce ERCA. Emulsions and oleogels were prepared with different concentrations (0, 5, 10, and 15%, w/w) of ERCA. In the steady shear rheological analysis, it was found that the values of apparent viscosity (ηa, 100) and consistency index (K) of emulsions were significantly increased by increasing the concentrations of ERCA. Oleogels were prepared with different concentrations (0, 5, 10, and 15%, w/w) of ERCA. All oleogels showed a hydrophobic carbonyl bond in the Fourier transform infrared (FT-IR) spectra. The peaks on new hydrogen bonds and amorphous regions, which did not appear in oleogel prepared with 0% ERCA, were observed at 3300–3400 cm−1 and 1018 cm−1, respectively, in oleogels prepared with ERCA. With the increase in ERCA concentrations in oleogels, oil loss values were significantly decreased. In a time-dependent test, it was found that all oleogels exhibited thixotropic properties. The frequency sweep test revealed that storage modulus (G′), loss modulus (G″), and complex viscosity (η*) values of oleogels were elevated with an increase in the concentration of ERCA. Oleogels prepared with 15% ERCA exhibited the lowest peroxide, p-Anisidine, and Total Oxidation(TOTOX) values. The addition of oleogels to cookies did not considerably affect appearance. However, it increased the content of unsaturated fatty acid. These results indicate that oleogels prepared with ERCA can be used as a fat replacer in food industry.

Rheological properties for determining the interaction of soluble cress seed mucilage and β-lactoglobulin nanocomplexes under sucrose and lactose treatments

Protein-polysaccharide complexes are commonly applied in different food products. Their interaction and their functional properties that arise as a consequence of interactions are remarkably influenced by the presence of co-solutes in the system. In this study, general rheological properties and the aggregation behavior of cress seed mucilage (CSM)-β-lactoglobulin (Blg) complexes were studied in the presence of sucrose (5–20% w/v) and lactose (5–20% w/v). The highest values of apparent viscosity and stability (zeta potential) in CSM-Blg complexes were measured when the medium contained 5% w/v lactose (10.00 Pa.s at 0.1 s−1, −25 ± 0.8 mV) and 20% w/v sucrose (12.89 Pa.s at 0.1 s−1, −35 ± 0.2 mV). The results of oscillatory experiments indicated that the gel-like feature of the complexes improved, parallel to a decrease in frequency, which highlighted the shear-induced gelation phenomenon. The thermal analysis test demonstrated that the thermal stability of Blg (70.5◦C), with its complexation to CSM, improved through denaturation. Also, the association of CSM-Blg (82◦C) nanocomplexes with lactose (96◦C) can enhance the thermal stability more effectively. Considering the widespread use of protein-polysaccharide complexes in diverse sugar-containing food formulations, the results of this study can contribute to the creation of new compounds with special techno-functional features.

Influence of collagen hydrolysate as cocoa butter replacement agent on the chemical, rheological, and sensory properties of reduced‐fat and reduced‐calorie milk chocolate

This study investigates the effect of collagen hydrolysate (CH) as a partial replacement of cocoa butter (CB) on the chemical, rheological, and sensory properties of milk chocolate. Chocolate samples were prepared with different levels of CH (15, 20, 25, and 30% wt/wt) and compared with the control sample, containing 100% CB. The results showed that moisture content increased with increasing replacement levels, but water activity did not show a significant difference with the control sample. The values of hardness, thixotropy, plastic viscosity, and apparent viscosity increased with increasing the percentage of replacement. The values of yield stress had an increasing trend with enhancing replacement percentage. Despite total acceptability reduced with increasing the levels of replacement in sensory evaluation, there was no significant difference with the control sample. In conclusion, samples with 15 and 20% replacement had the least difference from the control sample. Practical applications In recent years, there has been an increased consumer interest and demand for reduced-fat food products because a growing number of people are suffering from overweight or obesity. Chocolate is a product with high fat and calorie content; therefore, the production of reduced-fat and reduced-calorie chocolates is an efficient solution in this way. The result of this article is an effective step toward the development of reduced-fat and reduced-calorie milk chocolates as an alternative to conventional chocolates.