Osmotic Solution Research Articles

Pretreatments, Dehydration Methods and Packaging Materials: Effects on the Nutritional Quality of Tomato Powder- a review

Pretreatments and drying are commonly used before drying tomatoes to inactivate enzymes, improve the drying process, and improve the quality of dried tomato powders. In this review, the effects of different pretreatments (osmotic solutions), dehydration methods and packaging materials on quality attributes of tomato powder were summarized. These include pretreatments and osmotic agent solution (potassium metabisulfite, calcium chloride, sodium metabisulphite, ascorbic acid, citric acid, sodium chloride and sodium benzoate), thermal blanching (steam blanching and hot water) and non-thermal processes like freezing, sulfuring, etc. and drying methods (oven, sun and indirect solar dryer). The tomato powders were dried to preserve, store, and transport them. Drying implies not only physical changes, which the consumer can easily detect through visual inspection, but also chemical modifications. These are responsible for alterations in color, flavor and nutritional value, which compromise the overall quality of the final tomato powder. Maximum lycopene, vitamin A and C contents were found in freeze dried and direct sundried than samples dried using other methods in low drying temperature. Freeze driers showed in keeping the nutritional quality of tomato powder with a combination of different pretreatments. Different pretreatments including osmotic agent solutions have their own merits and demerits for the final tomato powder. To overcome the drawbacks of nutritional quality, non-thermal pretreatment categories may be a better alternative to thermal blanching, and more fundamental research is required for better design and scale-up.

Pretreatments, Dehydration Methods and Packaging Materials: Effects on the Nutritional Quality of Tomato Powder

Pretreatments and drying are commonly used before drying tomatoes to inactivate enzymes, improve the drying process, and improve the quality of dried tomato powders. In this review, the effects of different pretreatments (osmotic solutions), dehydration methods and packaging materials on quality attributes of tomato powder were summarized. They include pretreatments and osmotic agent solution (potassium metabisulphite, calcium chloride, sodium metabisulphite, ascorbic acid, citric acid, sodium chloride and sodium benzoate), thermal blanching (steam blanching and hot water) and non-thermal processes like freezing, sulfuring, etc. and drying methods (oven, sun and indirect solar dryer).Tomato powders have been dried in order to preserve, store, and transport them. Drying implies not only physical changes, which the consumer can easily detect through visual inspection, but also chemical modifications. These are responsible for alterations in color, flavor and nutritional value, which compromise the overall quality of the final tomato powder. Maximum lycopene and vitamins A and C content were found in freeze dried and direct sun dried than samples dried using other methods in low drying temperature, freeze driers showed in keeping the nutritional quality of tomato powder with combination of different pretreatments. Different pretreatments including osmotic agent solutions have their own merits and demerits on the final tomato powder. To overcome nutritional quality drawbacks, non-thermal pretreatment categories may be a better alternative to thermal blanching, and more fundamental research is required for better design and scale up.

Mass transfer kinetics (soluble solids gain and water loss) of ultrasound-assisted osmotic dehydration of apple slices

Ultrasound (sonication) treatment can be used directly for dehydration or pre-treatment before the osmotic dehydration (OD) procedure of fruit or vegetable particles. The combination of this technique with the OD technique can further improve the dehydration process efficiencies by increasing the mass transfer rates and enhancing final product quality. In this study, apple slices were osmotically dehydrated in different hypertonic sucrose solutions and assisted with or without ultrasound. Sucrose concentrations (in three levels of 30, 40, and 50° Brix), sonication power (in three levels of 0, 75, and 150 W), and treatment time (in six time intervals: 10, 20, 30, 40, 50, and 60 min) were the factors investigated concerning weight reduction, soluble solids gain, water loss and rehydration. Also, mass transfer kinetics were modelled according to Page, Newton, Midilli, Logarithmic, Verma, and Two terms equations. Increased sucrose solution concentration resulted in higher weight reduction, soluble solids gain and water loss. Also, increased sonication power levels resulted in higher weight reduction, soluble solids gain and water loss. The average rehydration ratio of apple slices decreased from 237.7 to 177.5%, by increasing osmotic solution concentration from 30 to 50%. The Page equation showed the best fitting for water loss data. The effective moisture diffusivity (Deff) of apple slices during OD calculated using Fick’s second law applied to a slab geometry was found to be in the range of 1.48 × 10–10 and 4.62 × 10–10 m2s−1 for water loss.

Estimation of drought tolerance of spring barley samples in their initial period of development on an osmotic solution

Development of drought-tolerant spring barley varieties is one of the important breeding directions for resistance to abiotic stress factors. In order to solve this problem successfully, it is necessary to use in hybridization the varieties and lines with the highest tolerance. The main purpose of the current study was to estimate the effect of osmotic stress of different concentrations on seed germination and to evaluate the relative drought tolerance of spring barley varieties and lines. The study was carried out in the laboratory for plant physiology in 2018–2020. The estimation of drought tolerance of spring barley samples was carried out on 26 varieties and lines, bred in the ARC “Donskoy”, in the initial period of development. The laboratory experiments on the ability of spring barley seeds to germinate on a sucrose solution (imitation of a lack of moisture in the soil) make it possible to estimate drought tolerance of samples at the early stages of their development. There was studied an effect of a sucrose solution with an osmotic pressure of 3, 8, 10, 12, 14 atmospheres on the ability of seed germination. When increasing a concentration of the solution, there was a seed germination decrease in all genotypes. As a result of the study, there were the largest statistically significant differences (P > 0.95) of the samples under the concentration of the osmotic sucrose solution of 8 atmospheres, in comparison with the options of 3, 10, 12 and 14 atmospheres. There have been obtained the data on the relative drought tolerance of spring barley varieties and lines. The maximum indicators of seed germination under osmotic pressure of 8 atmospheres were registered among the samples ‘Zernogradsky 1716’ (91.1 %), ‘Zernogradsky 1717’ (85.9 %), ‘Zernogradsky 1719’ (84, 1%), ‘12545/18’ (80.2 %), ‘Zernogradsky 1701’ (78.9 %), ‘12551/18’ (72.9%), ‘12487/18’ (72.4%), ‘Zernogradsky 1724’ (70.6 %), ‘Zernogradsky 1721’ (69.8 %), ‘12525/18’ (69.2 %) in comparison with the standard variety ‘Ratnik’ (43.6 %). The identified samples can be used for further study of drought tolerance in the field.

Estimation of drought resistance of rice samples on an osmotic sucrose solution

Drought is a significant abiotic stress factor for agricultural crops, including rice, as freshwater shortage is increasing in the world. The current paper has presented the results of laboratory trials to study the effect of solutions with high osmotic pressure on the ability of seeds to germinate and on the growth of rice sprouts. The purpose of the study was to estimate rice varieties and samples for drought resistance at the initial stages of ontogenesis using osmotic agents. The objects of the study were 67 rice varieties and samples from the VIR, the FRC of Rice and the ARC “Donskoy”. Seeds were germinated in a thermostat on filter paper in Petri dishes in 8, 12, and 16 atm sucrose solutions. As a result of the study, there was found that the best option was rice seeds’ germination in a sucrose solution of 8 atmospheres, in which the samples varied significantly in germination, length of sprouts and roots, both in the trial and in the control. Seed germination on the control was 96.6 %, and in the trial, it significantly decreased to 60.9 %, varying from 20 to 100 %. There were 50.8 % of samples with germination from 60–80 %. At the same time, 4.5 % of the samples were isolated with a germination rate of more than 80 % in the trial. In the trial, a sprout length among the samples varied from 0.2 to 1.4 cm. There were identified 13.5 % of the samples, which had a sprout length more than 1 cm. According to the ratio of a sprout length in the trial to the control, the samples were distributed asymmetri­cally, there were more samples with a low ratio, however, there were identified 4.5% of samples with a maximum O/K ratio (35–40 %). In the trial, aroot length ranged from 0.1 to 4 cm. The frequency distribution was asymmetric, there were 61.2 % samples with a very short root, up to 1 cm. The O/K ratio according to a root was right-sided asymmetric, 74.6 % of the samples had a low ratio from 0 to 15%. There were identified 3 % of samples with the ratio of more than 50 %. They were No. 39 (ZULK 1) and No. 50 (ZULK 12). These samples are used in the breeding process to develop drought-tolerant rice varieties.

Vacuum impregnation of fresh-cut apples with osmotic solutions containing honey

Fresh-cut apples were subjected to mild vacuum impregnation (Vacuum pressure=67.7 mbar). M0: 30 °Brix honey solution (HS); M0.5: HS+0.5% citric acid (CA)+0.5% ascorbic acid (AA); and M1: HS+1% CA+1% AA were used as osmotic solutions. Changes in soluble solids (SS), pH, firmness, color (∆E*ab), total phenolic and vitamin C content, and antioxidant capacity were evaluated on days 0 and 7 of storage at 1.5 °C. Mass transfer parameters were calculated. The best results were obtained with the M1 treatment. Vacuum-impregnated fresh-cut apples gained solids (3.3%) and weight (1.6%) and lost water (1.8%). The following modifications were observed on day 0: an increase of SS (26%), a reduction in firmness (14%), a slight color change (∆E*ab=3.3), a great increase in vitamin C content (31 times higher than in fresh-cut fruits) and increases in total phenolic content and antioxidant capacity (27% and 77%, respectively). On day 7 of storage, an additional reduction of firmness was observed, but the other attributes were maintained or increased. The M1 treatment is an appropriate alternative for processing fresh-cut apples and obtaining improved healthy attributes.

Effect of suction on the mechanical behaviour of unsaturated compacted clay–sand mixtures

Abstract In this work, a series of unconfined compression tests at different water contents were performed to investigate the mechanical behaviour of clay–sand mixtures compacted in standard Proctor conditions. For studying the effect of water content and suction on unconfined compressive strength (UCS) and on strain secant modulus (E50 modulus) of these mixtures, drying–wetting paths were defined by measuring the soil–water characteristic curves (SWCCs) using osmotic and salt solution techniques and filter paper method. The results highlighted that an increase in sand content of the mixture leads to an increase in the maximum dry densities and a decrease in the optimum water content of the materials. However, at the given state, when clay is mixed with 25% of sand, the UCS and E50 modulus increase to 37% and 70%, respectively, compared to those of clayey samples. But when clay is mixed with 50% of sand, the UCS and E50 modulus decrease to 38% and 46%, respectively, compared to those of clayey samples. The results also indicate that the UCS and E50 increase with a decrease in the water content and an increase in suction, irrespective of the sand content.

Anisotropic protein-protein interactions in dilute and concentrated solutions

Interactions between biomolecules are ubiquitous in nature and crucial to many applications including vaccine development; environmentally friendly textile detergents; and food formulation. Using small angle X-ray scattering and structure-based molecular simulations, we explore protein–protein interactions in dilute to semi-concentrated protein solutions. We address the pertinent question, whether interaction models developed at infinite dilution can be extrapolated to concentrated regimes? Our analysis is based on measured and simulated osmotic second virial coefficients and solution structure factors at varying protein concentration and for different variants of the protein Thermomyces Lanuginosus Lipase (TLL). We show that in order to span the dilute and semi-concentrated regime, any model must carefully capture the balance between spatial and orientational correlations as the protein concentration is elevated. This requires consideration of the protein surface morphology, including possible patch interactions. Experimental data for TLL is most accurately described when assuming a patchy interaction, leading to dimer formation. Our analysis supports that the dimeric proteins predominantly exist in their open conformation where the active site is exposed, thereby maximising hydrophobic attractions that promote inter-protein alignment.

The Effect of Selected Fruit (Apple, Bitter Orange and Grape) Juice Concentrates Used as Osmotic Agents on the Osmotic-Dehydration Kinetics and Physico-Chemical Properties of Pomegranate Seeds

This work aimed to study the osmotic-dehydration kinetics of pomegranate seeds (PSs) (Punica granatum L.) using three fruit (apple, bitter orange and grape) juice concentrates as osmotic solutions (OSs) (ratio (1/4) m/v, 55° Brix, at 50 °C). The osmodehydration time, pomegranate-seed water loss, solute gain and weight reduction were determined during the osmodehydration process. The equilibrium time periods of osmodehydration were 20, 60, 80 and 60 min for sucrose solution, and bitter-orange, apple and grape juice concentrates, respectively. The physico-chemical, biological and textural properties of PSs were significantly affected by the changes in OS. At the end of osmodehydration, the dry-matter and the Brix values were higher in all fruit-based OSs compared with sucrose OS. The color of PSs became darker in apple and grape OSs and brighter in bitter-orange OS compared with sucrose OS. On the other hand, all osmodehydrated PSs showed important antioxidant activity, with seeds osmodehydrated in grape-juice OS attaining an IC50 of 49.25 meq GA/100 g DM. All observed changes were attributed to the difference in the composition of the different OS matrices. Moreover, the hedonic analysis showed that consumers preferred osmodehydrated PSs obtained using bitter-orange juice as OS.

Ultrasound assisted osmotic dehydration of dragon fruit slices: Modeling and optimization using integrated artificial neural networks and genetic algorithms

The effect of ultrasonication on osmotic dehydration of dragon fruit (Hylocereus undatus) slices was investigated using a feed forward backpropagation neural network in this study. The four process variables were ultrasonic power ( X UP $$ {X}_{UP} $$ : 100–300 W), ultrasound temperature ( X UT : $$ {X}_{UT}: $$ 30–50°C), osmotic solution concentration ( X SC $$ {X}_{SC} $$ : 40–60°Brix), and liquid to solid ratio ( X LS $$ {X}_{LS} $$ : 8:1–12:1 ml/g). Under different combinations of independent variables, the water loss ( Y WL $$ {Y}_{WL} $$ ), solid gain ( Y SG $$ {Y}_{SG} $$ ), and change in color ( Y ∆ E $$ {Y}_{\Delta E} $$ ) were evaluated. The ANN architecture consists of 4, 9, and 3 neurons in the input, hidden, and output layer, respectively. The three independent variables of ultrasound-assisted osmotic dehydration X UP $$ {X}_{UP} $$ , X UT $$ {X}_{UT} $$ , and X SC $$ {X}_{SC} $$ found to have a positive effect on the three responses water loss, solid gain, and change in color. The liquid to solid ratio was revealed to have a negative effect on color change and a positive impact on response water loss and solid gain. The output parameters of the ANN model (weights and bias) were integrated with genetic algorithm (GA) for the optimization purpose, and the best combination was picked based on the fitness value (FV). The optimal ultrasound-assisted osmotic dehydration condition obtained using integrated ANN-GA was 235 W, 38.74°C, 56°Brix, and 10.5 ml/g. The relative deviation between the experimental and integrated ANN-GA model predicted values for water loss, solid gain, and color change values under optimum conditions was less than 6.880%, suggesting that the predicted values for response were in good agreement with the experimental data. Practical applications The article describes the synergistic influence of sonication power and temperature on the osmotic dehydration of dragon fruit slices. Ultrasound-assisted osmotic dehydration (USOD) prevents enzymatic and oxidative browning, preserving the color. In dragon fruit slices flavor retention increases when sugar syrup is used as an osmotic agent. Furthermore, the fruit pieces absorb sugar and eliminate acid, resulting in a sweeter product than a conventionally dried product. The results showed that ultrasound assisted osmotic dehydration removed water from dragon fruit more rapidly at a lower temperature, keeping color, aroma, nutritional value, and flavor components. The combined impact of ultrasound and temperature also lowered the water activity of fruit and enhanced the product's storage life significantly.

Pulsed Electric Field and Freeze-Thawing Pretreatments for Sugar Uptake Modulation during Osmotic Dehydration of Mango

Osmotic dehydration kinetics depends on food tissue microstructure; thus, modulation of mango porosity could help selectively enhance water removal over sugar gain. In this present study, pretreatments of freeze-thawing (freezing at −36 °C for 2 weeks and thawing at 4 °C for 24 h) and pulsed electric field (1 kV/cm, 10 and 30 pulse numbers), were applied to mango 1 cm-thickness slices prior to osmotic dehydration conducted at 40 °C for 4 h. Three different 60 °Brix agave syrup solutions with or without added polysaccharides (inulin or xanthan gum) were used in the osmotic dehydration operation. Water loss (WL), sugar gain (SG) and microstructure images were used to compare the effects of pretreatments on mango osmotic dehydration efficiency. Results indicated that pulsed electric field (PEF) pretreatment increased slightly WL during osmotic dehydration, contrary to freeze-thawing (F-T), which for most cases led to a decrease. As for solids uptake, due to higher damage induced by F-T to mango tissue, SG was higher than for fresh and PEF pretreated mangoes. Using xanthan gum as additive to agave syrup solution, helped to decrease sugar uptake in frozen-thawed mango due to an increase in solution viscosity. A similar WL/SG ratio was obtained with frozen-thawed mango in solution with xanthan gum. Therefore, in the case of frozen-thawed mango, it is recommended to use an osmotic solution with high viscosity to obtain low sugar uptake in the final product. The novelty of this contribution is twofold: (i) using pretreatments (F-T or PEF) to minimize sugar uptake during osmotic dehydration, and (ii) using agave syrup with added polysaccharides to enrich final product with inulin.

Thin layer modeling of drying kinetics, rehydration kinetics and color changes of osmotic pre-treated pineapple (Ananas comosus) slices during drying: Development of a mechanistic model for mass transfer

This study aimed to develop an effective and safe drying protocol for pineapple fruits. The combination of different osmotic pre-treatments and drying temperatures were used to evolve a novel method that can reduce drying associated changes in pineapple fruits. The pre-treatment was accomplished by soaking fresh pineapple slices in four osmotic solutions (1% trehalose, 2% NaCl, 10% sucrose, and 10% fructose) for 30 min. A hot air convection dryer carried out the drying at 50, 55, and 60 °C temperatures maintaining a constant 30% relative humidity (RH). During the drying experiment, moisture content data were taken and transformed into moisture ratio (MR) and then fitted to the four thin layer models viz. Page, Logarithmic, Newton (Exponential model), and Henderson and Pabi's Model. The impact of pre-treatments and drying temperature on drying kinetics, mass transfer rate, moisture diffusion, rehydration capacity, and color changes of pineapple slices were observed. The drying process was affected by both osmotic pre-treatments and temperature. A satisfactory curve with good fitting as anticipated by the Page and Logarithmic models, with the Logarithmic model fitting best during the drying of pineapple slices. The ideal drying temperature integrated with pre-treatments was 55 °C at 30% RH based on maintaining the color and rehydration. The Page equation provided an excellent statistical fit to experimental rehydration data, with low mean percentage error values of 2.188–7.479%. The pre-treatment of dried pineapples, particularly with trehalose, improved structural retention as seen by increased rehydration capacity and lower color changes after reconstitution. The mechanistic model, which describes activation energy for the increase of moisture diffusion coefficient and mass transfer coefficient, and their correlation to drying conditions (temperature and time), showed a better fit for mass transfer and diffusion. Weibull's distribution model gave a better fit for the water loss model during drying at various temperatures. As a result, the combination of dipping in 1% trehalose solution and hot air drying at 55 °C appears to be a promising procedure for producing high-quality, nutritious dried pineapple products for consumers. This work will assist future researchers in understanding the influence of osmotic pre-treatments on plant foods and improve the existing literature.

Modeling mass transfer during osmodehydration of apple cubes with sucrose or apple juice concentrate solutions: Equilibrium estimation, diffusion model, and state observer‐based approach

AbstractThis article investigates the modeling aspects of mass transfer during osmodehydration of apple cubes. The obtained experimental data were fitted to three mathematical models: Azuara's equilibrium mass‐transfer model (AM), Fick's second law (FSL), and a Luenberger observer (LO). Two scenarios were considered for the mathematical modeling of mass transfer between the osmotic solution and the apple cubes. First, constant apple volume during the osmodehydration process was assumed. Then we included volume shrinkage in the dehydrated product as part of the model. The effect of the osmotic agent in the apple dehydration was also addressed by considering two different osmotic solutions, apple juice concentrate, and sucrose solutions, with different concentrations (40, 50, and 60 °Brix). The equilibrium parameters estimated with the AM model were similar to the parameters determined experimentally (p > .05). The LO model accurately describes the solute mass transfer dynamics during the osmodehydration process (R2 > .950). The overall findings indicate that considering the volume shrinkage as part of the model strongly influences the parameter estimation. When considering volume shrinkage in the FSL model, the estimated diffusivity parameters ranged from 1.26 to 5.05 × 10−10 m2/s for water and 0.68–19.35 × 10−10 m2/s for solutes, respectively. Not considering product shrinkage in the diffusivity model leads to overestimating both water diffusivity (29.9–76.8%) and solute diffusivity (25.3–52.8%).Practical ApplicationsOsmotic dehydration (OD) refers to a mass transfer process where solutes are transported from a hypertonic solution to a food material, while water moves from the food material towards the solution. OD improves the appearance and taste of dehydrated foods, helps inhibit the growth of dangerous microorganisms, and decreases enzymatic browning in some foods. Sucrose solutions are frequently used as osmotic solutions for food treatment in OD. An alternative to sucrose is to treat food with fruit juice concentrates. Fruit juice concentrates have low water activity and can provide bioactive compounds that enrich the dehydrated product. Understanding the effect of different factors on mass transfer during osmotic dehydration is thus critical for the efficient design, optimization, scaling‐up, and operation of OD food treatment processes. Furthermore, the proper selection of osmodehydration conditions allows us to obtain high‐quality food products with specific composition, textural/sensory properties, and microbiological characteristics. Therefore, osmotic dehydration is a food processing alternative that allows us to obtain high‐quality food products with good nutritional attributes.

High pressure impregnation‐assisted drying of abalone ( Haliotis rufescens ) slices: Changes in protein conformation, thermal properties, and microstructure

This study aimed to evaluate the effect of high pressure impregnation (HPI) (pressure: 350, 450, and 500 MPa; time: 5 min; osmotic solution: 15% NaCl) as a pretreatment to the drying process of abalone samples (temperature: 60°C) and subsequent evaluation of physicochemical properties thereof. The protein conformational changes of HPI-dried samples were evaluated by Fourier transform infrared (FT-IR) spectroscopy. The molecular weight profile and amino acid composition were determined. Thermal analysis was performed by differential scanning calorimetry (DSC). Process drying rates were reduced up to 33%, and dried abalones had lower moisture content and water activity as the pressure level increased. In addition, less degradation effects were found in amino acid compositions. In the β-sheet structure, HPI-assisted drying process caused partially folded conformations at 350 and 450 MPa, and aggregation at 500 MPa. A compacted structure was identified as pressure increased (350 ➔ 500 MPa), confirming that the structure of abalone muscle treated with HPI-assisted drying differed significantly from raw material. The results presented in this research could support the potential application of high hydrostatic pressure treatment as combined treatments for other compound impregnation under high pressure. In addition, HPI technology could be used to enhance the quality properties of dried abalones and dried marine products of the aquaculture and fishery industry. Practical applications This research deals with the influence of high-pressure impregnation pretreatment on protein conformational changes of abalone samples subjected to convective air drying. Results showed that applying this combined innovative technology improved abalone slice dehydration rates compared with an atmospheric pressure operation, producing dried abalone with the moisture content required to be used as input material for subsequent processes. The different thermal properties were also determined to assess the importance of the changes in the protein structure that occur during heating and could influence process time. The HPI pretreatment can change the secondary structures of proteins as function the pressure level. The results of this study provide valuable information for the potential application of HPI pretreatment on the development of dried red abalone with high-added value. Thus, the aquaculture and fishery industry when using HPI technology would preserve the quality properties of further dried abalones.

Using derivative products from processing wild berries to enrich pressed sugar

This paper reports a study addressing the issue of enriching pressed sugar in order to improve its biological value. As additives to sugar, the use of derivative products of processing wild berries Hippophaerhamnoides L., Viburnumopulus, Sambucusnigra, Sorbusaucuparia is suggested. The technology of processing wild berries includes their preliminary freezing, partial dehydration by osmotic dehydration, and subsequent drying. The resulting osmotic solution is proposed to be used to moisten sugar before its pressing and drying. An important practical aspect of this technological advancement is the possibility to move away from seasonality at sugar factories. Since it is advisable to process wild berries at the end of the beet processing season. To implement the proposed technology, one can use some available equipment. The chromatographic method was applied to analyze the amino acid spectrum of derivative products from processing wild berries; 17 amino acids were identified in their composition, including essential ones. The highest concentration of amino acids (55.47 mg/100 g) was found in the derivative product of Sambucusnigra processing. The least amount of amino acids passes into the product of processing Viburnumopulus (3.63 mg/100 g). The experiment showed that adding to sugar 10 % of the derivatives of the processed wild berries Hippophaerhamnoides L., Viburnumopulus, Sambucusnigra, Sorbusaucuparia has a positive effect on the organoleptic indicators of the finished product. The highest rating for all organoleptic indicators (appearance, taste and smell, purity of the solution) was given to sugar enriched with a derivative of the Hippophaerhamnoides processing product. It contained only 16 amino acids in the amount of 16.14 mg/100 g. Of the found amino acids, the highest concentration was demonstrated by serine (7.43 mg/100 g). The sugar with the addition of the solution after partial dehydration of Viburnumopulus revealed a slight characteristic smell of the additive. In the sugar with the addition of the derivative product of processing Sorbusaucuparia, a pleasant bitterness was felt, indicating the transition of sorbic acid from the fruit to osmotic solution

Celery Root Phenols Content, Antioxidant Capacities and Their Correlations after Osmotic Dehydration in Molasses.

The osmotic dehydration (OD) of celery root in sugar beet molasses was studied at three temperatures (20, 35, and 50 °C) and three immersion periods (1, 3, and 5 h) in order to examine the changes in antioxidant potential and phenolic profile of celery root throughout the process. The antioxidant capacity (AOC) of dehydrated samples was evaluated by spectrophotometric and polarographic assays, the total phenolic content by the Folin-Ciocalteu method, and the individual phenolic compounds by HPLC-DAD. As a result of OD in molasses, the AOC and phenols content in samples increased proportionally to the augmentation of temperature and the immersion time. Vanillic acid, syringic acid, and catechin were detected in dehydrated samples as a result of transfer from molasses. Compared to fresh celery root, the content of identified phenols in osmodehydrated samples was improved from 1.5 to 6.2 times. Strong correlations between applied assays were obtained, except for the DPPH. Based on the correlation analysis chlorogenic acid, gallic acid, chrysin, catechin, and kaempferol showed the greatest contribution to the overall AOC of osmodehydrated celery root. Molasses, an agro-industrial waste from sugar production, could be valorized as a valuable osmotic solution.

Effects of non-thermal processes on texture, color and sensory properties of Iranian barberry during storage

BACKGROUND: Barberry, is the main agricultural product in South Khorasan province of Iran, after saffron. Fresh fruit is perishable with short storage time. OBJECTIVE: Irradiation is an economical modern technology in food processing which maintains nutritional values and enhance shelf life of raw food without using any additives. METHODS: Barberry fruit was harvested in Birjand city by methods including “cutting branches” and “collecting fallen fruit from the cluster”. Fruit on cut branches was dried at ambient temperature under shadow which is known as “puffy barberry” locally. Fruit has fallen under shrubs was dried on a clean cloth under sunlight and locally is famed as “jewel barberry”. Some of fresh barberries were treated by osmotic solution and then they have been dried. Untreated dried fruit was processed by, freezing pasteurization and gamma irradiation at doses of 0, 3, 5 and 10 kGy. Effects of dried barberry types (puffy and jewel), processes, 6 months of storage at temperature of 4 or 25°C on texture, color and sensory properties of fruit were evaluated. RESULTS: Puffy barberry irradiated at 5 kGy by gamma radiations, after 6 months of storage at 4°C showed an acceptable quality. CONCLUSIONS: Combination of irradiation and refrigerated storage were reported as optimal conditions of processing and storage for barberry fruit.

​Physico-chemical and Organoleptic Properties of Intermediate Moisture (IM) Slices from Pineapple [Ananas comosus (L.) Merr.

Background: Pineapple is produced round the year in the tropics and therefore, market gluts are very common and post harvest losses of around 20-30% are reported. Intermediate Moisture Fruits (IMF) have a water activity ranging between 0.65-0.90 and moisture content of 15-40%. Hence, the present study was undertaken to develop intermediate moisture fruit slices by evaluating the effect of various osmotic agents and pineapple varieties on the physico-chemical and organoleptic qualities of the product. Methods: Pineapple varieties ‘Mauritius’, ‘Kew’ and ‘MD-2’ were selected for the study. Fruit slices were steam blanched, followed by immersion in osmotic solutions (fruit : solution ratio of 1: 4), containing six different osmotic agents viz. sucrose, sucrose+sorbitol, glucose syrup, sucrose+NaCl, palm sugar and honey separately, in combination with 0.5% ascorbic acid and 0.25% potassium metabisulphite, for six hours and were subsequently dehydrated at 50°C in a tray dryer. Result: Moisture content varied between 19.42 and 29.71% and water activity values in between 0.60 and 0.73.Decline in L* and b* values with a corresponding increase in a* value was observed in IM slices. Intermediate moisture pineapple slices had ascorbic acid content in the range of 17.64 to 200 mg 100 g-1.

Impact du couplage de la déshydratation osmotique et du séchage sur la qualité nutritionnelle de la tomate séchée

Le présent travail vise à évaluer l’effet des paramètres opératoires sur la teneur en cendre, la perte en caroténoïdes totaux et la perte en vitamine C de la tomate au cours des procédés de déshydratation et à modéliser ce phénomène en vue d’en déduire les conditions opératoires optimales.
 Des modèles prédictifs ont été proposés pour relier les attributs de qualité du produit fini aux différentes variables opératoires de la déshydratation osmotique combinée au séchage.
 La condition optimale de travail de la combinaison déshydratation osmotique/séchage appliquée aux tomates est donc l’utilisation d’une concentration de chlorure de sodium de 100 g/l, une température de la solution osmotique de 30°C, une durée de la déshydratation osmotique de 60 minutes et une température de séchage de 60 °C pour obtenir un produit final avec une perte en acide ascorbique la plus basse de 2,29%, une teneur minimale en perte en caroténoïdes totaux de 15,17% et une teneur minimale en cendres de 0,84%.

Effect of osmotic agent and vacuum application on mass exchange and qualitative parameters of osmotically dehydrated strawberries

Sucrose is the most commonly used solute in the osmotic dehydration (OD) of fruits. However, there is increasing interest in replacing it with other alternative sugars. Polyols are carbohydrates with low glycemic, insulinemic, and cariogenic indexes. Therefore, this work aimed to study the influence of the type of osmotic agent (sucrose, erythritol, or maltitol) and vacuum application on mass transfer and physical and nutritional changes in 10-mm edge strawberry cubes. OD was performed with or without vacuum application during the first 20 min in a total process time of 300 min. Higher solid gain, water loss and weight reduction, and lower water activity and moisture content were observed by using erythritol solution. The vacuum application strengthened this behavior. The color of the samples was affected by factors. Osmotic processes reduced the total anthocyanin content (TAC), showing that leaching is an important qualitative flow during osmotic processes. Novelty impact statement Polyols showed good potential as an osmotic agent in the osmotic dehydration of strawberries and are a good alternative to the use of sucrose. Osmotic dehydration promoted a satisfactory impregnation of polyols in the strawberry, mainly with the application of vacuum, in which the mass exchange rates were increased. However, leaching was an important flow of anthocyanin loss from strawberries to the osmotic solution.