Instant Controlled Pressure Drop Research Articles

THE USE OF DIC TECHNOLOGY (INSTANT CONTROLLED PRESSURE DROP) IN FRUIT DESHYDRATATION

Over time, many methods of preserving fruit by drying/dehydration applied at the industrial level (convection, microwave, high frequency currents, infrared radiation, lyophilisation, etc.) have been discovered and perfected to improve the quality of dehydrated products as well as their resistance to storage. The application of many of them is quite expensive, the parameters of the drying process (processing time and energy consumption) having high values. Technological progress in this field involves the development of new dehydration techniques, optimizing existing ones or combining them, aiming to increase energy efficiency, obtain healthy products with high rehydration capacity, reduce costs and negative impact on the environment. The paper presents a brief summary of the basic principles of the DIC (Instant Controlled Pressure Drop) process, as well as the advantages of its uses in industrial fruit dehydration technologies or as pre-treatment.

Trends in quality assessment and drying methods used for fruits and vegetables

Studies on drying of fruits and vegetables by means of different methods are numerous. This review aims at presenting the most usual quality analyses carried out in dried fruits and vegetables over the last five years along with the most used drying methods. It was prepared based on a search on Scopus database with the term ‘drying fruit vegetables’. Results show that color and microstructure can be preserved, apparent density can be reduced, and high rehydration capacity can be achieved by using mild drying methods like freeze-drying and innovative drying methods like conductive multi-flash drying. Shrinkage and water activity can be minimized by using pretreatments like osmotic dehydration, ultrasound, and pulsed electric fields. Such pretreatments also produce crispy texture, which can also be obtained with the use of hot air drying followed by microwave-vacuum drying. Antioxidant activity, phenolic compounds and vitamin C content can be maximized by using innovative pretreatments like immersion in solutions rich in bioactive compounds and short drying time. Microbial counts can be decreased by using pretreatments like immersion in ethanol, and modified atmosphere packaging. High sensory acceptability can also be achieved by using innovative drying methods, like instant controlled pressure drop drying.

In Vivo Evaluation of the Cardiometabolic Potential of Grape Pomace: Effect of Applying Instant Controlled Pressure Drop.

Grape pomace (GP) is a source of polyphenols which may be present as free structures or associated with dietary fiber. Instant controlled pressure drop (DIC) is a technology which can modify the association of polyphenols with food matrixes, but how these modifications affect the health benefits associated with GP remains to be elucidated. In this study, in rats fed a high-fat-fructose diet (HFF), we evaluated the in vivo cardiometabolic effects of the modification of polyphenols in GP caused by DIC at 0.2 MPa for 60 s (DIC1) and 0.4 MPa for 120 s (DIC2). These treatments increased anthocyanin and total flavonoid contents, respectively, while all the supplementations caused significant improvements in insulin resistance and plasma triacylglycerols. Thus, the bioactive compounds present in GP (including a major fraction of non-extractable proanthocyanidins) caused these modifications independently of the specific polyphenol profiles which may have resulted from these DIC treatments. Additionally, only intact GP led to an increase in HDL cholesterol, while only DIC2-treated GP improved hepatic steatosis. In conclusion, GP always improves insulin sensitivity in this animal model of obesity, while the different compositions of GP modified by DIC may be associated with other cardiometabolic parameters.

Recent advances in the extraction, chemical composition, therapeutic potential, and delivery of cardamom phytochemicals.

Dietary phytochemicals including plant-derived alkaloids, carotenoids, organosulfur compounds, phenolics, and phytosterols, are health-promoting bioactive compounds that help in the prevention and mitigation of chronic diseases and microbial infections beyond basic nutrition supply. This article covers recent advances in the extraction, chemical composition, therapeutic potential (nutraceutical and antimicrobial), and delivery of black and green cardamom-derived phytochemicals. In recent years, advance extraction techniques (e.g., enzyme- assisted-, instant controlled pressure drop-, microwave- assisted-, pressurized liquid-, sub- critical-, supercritical fluid-, and ultrasound-assisted extractions) have been applied to obtain phytochemicals from cardamom. The bioactive constituents identification techniques, specifically GC-MS analysis revealed that 1,8-cineole and α-terpinyl acetate were the principle bioactive components in black and green cardamom. Regarding therapeutic potential, research findings have indicated desirable health properties of cardamom phytochemicals, including antioxidant-, anti-hypercholesterolemic, anti-platelet aggregation, anti-hypertensive, and gastro-protective effects. Moreover, antimicrobial investigations revealed that cardamom phytochemicals effectively inhibited growth of pathogenic microorganisms (bacteria and fungi), biofilm formation inhibition (Gram-negative and Gram-positive bacteria) and bacterial quorum sensing inhibition. Encapsulation and delivery vehicles, including microcapsules, nanoparticles, nanostructured lipid carriers, and nanoliposomes were effective strategies to enhance their stability, bioavailability and bioefficacy. In conclusion, cardamom phytochemicals had promising therapeutic potentials (antioxidant and antimicrobial) due to polyphenols, thus could be used as functional additive to increase shelf life, inhibit oxidative rancidity and confer pleasant aroma to commercial edibles as well as mitigate oxidative stress and lifestyle related chronic diseases (e.g., cardiovascular and gastrointestinal diseases). A future perspective concerning the fabrication of functional foods, nutraceuticals and antibiotics to promote cardamom phytochemicals applications as biotherapeutic agents at large-scale requires thorough investigations, e.g., optimum dose and physical form of supplementation to obtain maximum health benefits.

Enhancive effect of instant controlled pressure drop (DIC) pre-treatment on pectin extractability from peach pomace

This study aimed to investigate if instant controlled pressure drop (DIC) processing can enhance pectin extractability from plant material. Peach pomace was treated by 0-, 1-, or 3-cycle of DIC processing at 90 or 105 °C. Pectin fractions including water soluble pectin and insoluble pectin were isolated from dried peach pomace and characterized by degree of methoxylation, neutral sugar composition, and molecular weight distribution. The results demonstrated that the thermomechanical effect of DIC processing induced a strong solubilization of in situ pectic polysaccharides of peach pomace, especially for water insoluble pectin fractions. This solubilization effect resulted in a more than 10% increasing ratio of extractable pectin yield from peach pomace over the maximum yield without the thermomechanical effect of DIC processing. Meanwhile, DIC processing conducted at 90 °C with 1-cycle affected pectin structure and property insignificantly. • DIC process induced solubilization of in situ pectic polysaccharides of peach pomace. • DIC treatment increased the pectin extractive yield of peach pomace by more than 10%. • 1-cycle DIC treatment at 90 °C affected slightly on pectin structure and properties.

Effect of Swell-Drying on Mango (Mangifera indica) Drying Kinetics.

Swell-Drying operation (SD) was applied on mangoes to evaluate its effect on drying kinetics: starting accessibility (δW), apparent drying coefficient (Dapp), and time to obtain a final moisture content of 20% d.b (tf = 20% d.b). Swell-drying consisted of (1) submitting fresh mangoes to a first pre-drying stage under Convective Air Drying (CAD) until a moisture content of 37% d.b; (2) applying Instant Controlled Pressure Drop (DIC) treatments on pre-dried mangoes by following a central composite rotatable design (steam pressure: 0.2–0.6 MPa and treatment time: 5 and 55 s); and (3) apply post-drying of mangoes under CAD. In both cases, CAD was performed at 60 °C and airflow of 1 m/s. Results showed that both the treatment time and the steam pressure impacted the Dapp and the δW. By comparing to the control, SD (0.54 MPa and 48 s) increased the Dapp and δW to 12.2 and 2.7 times, respectively. Moreover, SD triggers a significant reduction in post-drying time (tf = 20% d.b), being this of 2.4 h vs. 30.8 h. These results could be linked to the expansion of the internal pores of mangoes generated by the instant autovaporization of residual water triggered by DIC treatment.

A Preliminary Study on the Effect of the Instant Controlled Pressure Drop Technology (DIC) on Drying and Rehydration Kinetics of Maize Kernels (Zea mays L.).

Maize is one of the three worldwide cereal crops with the most outstanding production; however, its postharvest losses range from 2 to 40% due to inadequate harvesting, drying, and storage technologies. This study focuses on the Instant Controlled Pressure Drop technology (DIC) effect on maize kernels’ drying and rehydration kinetics. In total, 19 different DIC treatments were carried out on maize kernels (~25% d.b.). The DIC parameters studied were steam pressure (0.1 to 0.4 MPa) and treatment time (10 to 90 s). After DIC treatment, drying kinetics were carried out by Convective Air Drying (CAD) at 50 °C and 0.4 ms−1 airflow. Rehydration kinetics and Water Holding Capacity (WHC) were evaluated at 20 °C. In comparison to CAD samples, DIC (0.4 MPa and 90 s) reduced the drying time from 180 min to ~108 min. Additionally, regarding the rehydration and WHC results, DIC achieved the same moisture content in only 3.5 min that controls achieved after 1 h of rehydration (0.40 g H2O/g dry matter). Moreover, DIC (0.4 MPa and nine cycles of 10 s) increased the WHC 2.3 times compared to the control. In this way, DIC could be a postharvest technology to improve maize kernels’ drying operations and functional properties.

Microstructure evolution affecting the rehydration of dried mushrooms during instant controlled pressure drop combined hot air drying (DIC-HA)

This paper presents a study on the microstructure evolution providing good rehydration performance of shiitake mushroom after instant controlled pressure drop combined with hot air drying (DIC-HA). The effect of variations of DIC process parameters on the cell membrane was studied via the electrical conductivity of rehydration liquid as well as transmission electron microscopy (TEM). Microstructural properties of dried products, including porosity and connectivity, were studied by scanning electron microscopy (SEM) and X-ray micro-computed tomography (μCT). The results confirm that DIC pretreatment can facilitate a higher porosity of mushroom tissue, thus preventing collapse during subsequent hot air drying – provided that the product temperature remains below a critical temperature for retaining the integrity of the cell membrane. A new insight into the role of instant controlled pressure drop is to improve the microstructure of the samples. The porous structure implies potential innovative applications in the production of dry foods distinguished by good rehydration behavior.

Effect of the Instant Controlled Pressure Drop Technology in Cardamom (Elettaria cardamomum) Essential Oil Extraction and Antioxidant Activity.

Green cardamom (Elettaria cardamomum) is an outspread spice native to Asia, which is well appreciated for its sensory characteristics, delicate aroma, and unique taste. Currently, the main cardamom extracts are essential oils (EOs), and regarding current market tendencies, this market is in high growth. For this reason, technologies such as the instant controlled pressure drop (DIC) have been applied to reach higher yields and better quality of EO. Then, this study explores the impact of DIC as a pretreatment before hydrodistillation (HD) on the EO yield and their antioxidant activity. Obtained results showed that the coupling of DIC-HD increased the yield of essential oil and also had a positive impact on their antioxidant capacity. The EO yield of DIC-HD (140 °C and 30 s) was 4.43% vs. 2.52% for control; the AOX of DIC-HD (165 °C and 30 s) was 86% inhibition vs. 57.02% for control, and the TEAC of DIC-HD (140 °C and 30 s) was 1.44 uMTE/g EO vs. 13.66 uMTE/g EO.

Hot air‐assisted instant controlled pressure drop drying impact on the Maillard reaction‐related physicochemical properties of apple slices

This research investigated the instant controlled pressure drop-assisted hot air drying (DIC) impact on Maillard reaction related components of apple slices, with freeze drying (FD) and hot air drying (AD) as control. DIC apple slices were significantly (*p<0.05) differentiated from FD and AD apple slices by marked browning, high levels of 5-hydroxymethylfurfural (5-HMF) and fluorescence intermediary compounds (FIC). DIC processing reduced fructose by 18.95%-45.68% and glucose by approximately 50%. While, the free amino acid reduction was 80.7%-95.1% and the reduction of hydrolysable amino acid was 15.1%-65.9% in DIC drying. In multivariate analysis, the DIC apple slices were significantly (*p<0.05) differentiated from fresh, FD, and AD apple slices by three principal components that explained 46.7%, 12.9% and 10.5% variances, respectively. And DIC apple slices were characterized by the FIC, 5-HMF, total free amino acid, and CIE a*, b* values.

Optimisation of Instant Controlled Pressure Drop (DIC)-assisted dehydrofreezing using Response Surface Methodology towards better bioactive compounds retention of quince fruit

Abstract Pre-drying prior to freezing may reduce several freezing drawbacks. Nevertheless, drying may cause nutritional quality losses. Instant Controlled Pressure Drop process has been proposed to intensify pre-drying process. This research is dedicated to study the evolution of the main bioactive compounds (total phenolics, flavonoid, and tannins contents) of quince dehydrofrozen fruits. Fresh samples were subjected to air drying at 40 °C and 3 m s−1 air velocity down to a final water content of 0.3 g g−1 db. Pre-dried samples were Instant Controlled Pressure Drop (DIC) treated under different conditions, i.e. saturated steam pressure (P) and treatment time (t), following a 2-factor/5-level Experimental Design. Treated fruits were frozen at –30 °C then were thawed at 20 °C in order to study the impacts of DIC on phenolic compounds. Response Surface Methodology (RSM) confirmed that pressure was the most influencing parameter in terms of polyphenol, flavonoid, and tannins contents. Finally, DIC pre-treatment allowed the improvement of phenolic content retention compared to untreated DIC samples.

Instant controlled pressure drop (DIC) effect on compositional analysis of olive leaves (Olea europaea L.)

Instant controlled pressure drop (DIC) effect on compositional analysis of olive leaves (Olea europaea L.)

A review on instant controlled pressure drop technology – a strategic tool for extraction of bioactive compounds

SummaryBioactive compounds are the naturally derived extra‐nutritional components with diversified arrangement and functionality, which makes them a promising source for the fabrication of functional foods, nutraceuticals and food additives. Extraction of these compounds by traditional techniques is a cumbersome process, which yields product with compromised quality and poor efficiency besides huge investment in terms of energy and time. This urges an acute need to develop an improved method that ensures the nutritional and organoleptic quality of these bioactive components is better preserved. Instant controlled pressure drop is one such novel and sustainable technique that allows the raw materials to be treated at high pressure and temperature first and latterly followed by an abrupt pressure drop towards a vacuum. The induced thermo‐mechanical effects in the sample ensure boost in availability and extractability of high‐value bioactive compounds. This technique has found numerous applications in food industry such as a pre‐treatment in drying and freezing of food product, enhanced extraction of bioactive compounds and to improve the colour, odour and texture quality of a variety of food products. This review article will emphasise on all these aspects of instant controlled pressure drop technology.

Instant Controlled Pressure Drop as a Strategy To Modify Extractable and Non-extractable Phenolic Compounds: A Study in Different Grape Pomace Materials.

Instant controlled pressure drop (DIC) is a technology able to modify the polyphenol profile in vegetal materials. However, information about how polyphenols are transformed, particularly regarding non-extractable polyphenol (NEPP), as well as the association with the initial content of polyphenols of the material is scarce. Thus, this work aimed to evaluate the DIC effect, modifying the pressure (0.2 and 0.4 MPa), the number of cycles (2 and 4), and grape pomace material (Malbec, Merlot, and Syrah) on extractable polyphenol (EPP) and NEPP contents. The EPP content increased during DIC application, an effect associated with the pressure, cycles, and initial polyphenol content. While for extractable and non-extractable proanthocyanidin contents, the main factors explaining the DIC effect are the pressure and number of cycles. Therefore, changes in polyphenols from grape pomace by DIC treatment are dependent upon experimental conditions, but the origin of the grape pomace also influences the extraction of EPP.

An Overview on Food Applications of the Instant Controlled Pressure-Drop Technology, an Innovative High Pressure-Short Time Process.

Food processing systematically aims at meeting the needs of consumers who are looking for total high quality and perfect food safety. As the various thermal and non-thermal food preservation technologies often affect the natural properties in terms of sensation, flavor, texture, etc., instant controlled pressure drop (DIC) has been conceived as a relevant, innovative process in this field. DIC uses high saturated steam pressure and short duration to provide a new way to expand biological matrices, improve drying, decontaminate, and extract biologically active compounds, among other attributes. Therefore, this review focuses on describing the applications of DIC technology on a wide range of products such as foods and by-products that have been processed both in the laboratory and on an industrial scale. The application of DIC has shown the possibility of a significant leap in quality improvement and cost reduction in the food industry. DIC reduces the drying time of fruits and vegetables, and improves the extraction of essential oils, vegetable oils, and antioxidant components. It also provides strong decontamination, eliminates vegetative microorganisms and spores, and reduces non-nutritional and allergenic components. Over the past 33 years, this technology has continued to expand its food applications and improve its characteristics on an industrial scale. But there are still many food unit operations that can be taken to the next level with DIC.

Expansion of Emmental cheese and tofu using instant controlled pressure drop (DIC) process

Two foods, belonging to different protein sources (dairy vs plant), namely Emmental cheese and tofu, were treated by the instant pressure drop (DIC) process inserted between two drying stages to obtain expanded and crispy snacks. This process consisted of a short heating step (t = 38–52 s) using steam under pressure (p = 0.26–0.62 MPa) and instantaneous pressure drop toward a vacuum. This pressure drop provoked auto-vaporization of the superheated liquid, which resulted in volume expansion, and cooling of the food. The expansion was visualized using a rapid camera at a frequency of 1000 images/s. The pressure and temperature histories were registered simultaneously. Three expansion ratios were evaluated: (i) r the ratio of food volumes after and before DIC process measured using sand pycnometry, (ii) rC calculated from dimensions measured by a caliper, and (iii) rI calculated from dimension reading from images. The shrinkage s = (rI/rC) −1, and the deformation d = (rC/r) −1 of the samples were then evaluated. Using response surface methodology, the optimal processing conditions for maximum expansions r = 2.5 and rC = 4.5 were found for Emmental and tofu, respectively as p = 0.5 and 0.62 MPa, t = 40 and 38 s. The creation of mist, inherent to the pressure drop of steam, made the visual observation impossible at the beginning of pressure drop. The samples were already expanded when the mist disappeared. Taking the mist presence as the upper limit of expansion time, the expansion took dozens of milliseconds at a pressure drop rate of 1.25 MPa/s. The temperature in the reactor decreased at a rate of 750 °C/s.

Solar–geothermal drying/instant controlled pressure drop‐swell drying of mechanically dewatered tomato paste

AbstractThe economic value of many fruits and vegetables is closely related to their suitability for processing and preservation. In the case of tomatoes (about 94% wet basis wb), the manufacture of 1 kg of dry basis (db) powder (5% wb) or concentrate (30% wb) requires the evaporation of 15.9 or 15.7 kg H2O/kg db, respectively. In the current study, mechanical dewatering and geothermal‐assisted solar drying (SD) of tomato paste at 5.8 kg H2O/kg db allowed reaching the required final moisture level of 0.053 ± 0.002 kg H2O/kg wb with low‐cost energy. The instant controlled pressure drop (DIC) was used for texturing the predried tomato paste using the operative parameters of absolute saturated steam‐pressure P = 0.3 MPa and thermal holding‐time t = 30 s. The final hot air‐drying step of tomato paste was carried out at 39, 50, and 70°C with a constant velocity of 3 m s−1. The phenomenological modeling of the drying kinetics allowed identifying the starting accessibility and the effective water diffusivity. DIC texturing reduced drying time from 7 to 1.5 hr and improved the effective water diffusivity from 1.43 × 10−9 to 3.67 × 10−9 m2 s−1 for T = 70°C. The lowest activation energy was recorded for DIC samples with 25.69 kJ mol−1 compared with 41.87 kJ mol−1 for control samples. A comparison of visual quality revealed a huge enhancement for DIC‐samples compared with the control samples (RM). Moreover, the high economic value of dewatered tomato water was noticeable.Practical ApplicationsHigh quality, low energy consumption, and processing time are decisive factors for the industrial drying operations of agro‐products. Solar–geothermal drying combined with innovative treatment technology called instant controlled pressure drop (DIC)‐swell drying can be a good alternative to conventional drying methods such as hot air drying. Mechanical dewatering as a first step followed by solar–geothermal drying/DIC‐swell drying may greatly reduce drying time and improve the quality of the dried product on the one hand, and reduce energy consumption on the other hand. In addition to that, mechanical dewatering and separation allow us to benefit the peels and seeds, in addition to free product juice with less energy.

Modification on the polyphenols and dietary fiber content of grape pomace by instant controlled pressure drop

Instant controlled pressure drop (DIC) has been used as a pre-treatment to increase extractable polyphenols (EPP), mainly attributed to matrix structure expansion. This work aimed to evaluate the effect of DIC on non-extractable polyphenols (NEPP), EPP, and dietary fiber on grape pomace. At 0.2 MPa–60 s was observe an increase of total EPP and total anthocyanins. Despite the increment of EPP, was observe the lowest anthocyanins and non-extractable proanthocyanidins content at 0.4 MPa–120 s. This increase was due to a partial transformation of anthocyanins into phenolic acids and the depolymerization of proanthocyanidins. Also was observe partial solubilization of insoluble dietary fiber. Morphologically, the size of the pores generated by DIC was more significant at higher pressures. Thus, DIC modified the morphology and profile of the polyphenols of grape pomace, producing phenolic compounds of simpler structure and improving their antioxidant capacities.

Recent developments and trends of instant controlled pressure drop drying-a review

Explosion puffing drying (EPD) technology carried out on the expansion of food stuffs can be dated back to 1960s. This technology underwent many modifications with time and developed into instant controlled pressure drop texturing (French for Détente Instantanée Contrôlée, DIC). The principle of DIC is based on a thermomechanical effect induced by an immediate pressure drop from high pressure or ambient pressure to a vacuum, leading to the instant evaporation of water, which results in volume expansion and texture modification. This technology is not only perfectly adapted to produce fruit and vegetable with pleasant texture properties but also applied as a pretreatment to improve the sensory and color characteristics of product. Herein we review the principle of DIC and its current status. Firstly, the principle of DIC, including the basic principle, the mechanism of texture formation and browning reaction during DIC processing were illustrated. Secondly, DIC combined drying technology applied on fruit and vegetable chips were outlined. Then, DIC as a pretreatment for improving the quality properties of foodstuffs was outlined. After that DIC used to extraction, bioethanol production and other applications of DIC were summarized. Finally, future trends of DIC technology were identified and discussed.

Study on the Rehydration Quality Improvement of shiitake Mushroom by Combined Drying Methods.

The aim of study is to improve the rehydration quality of dried shiitake mushrooms for their instant food manufacturers and fast restaurants. Serial combined drying methods were investigated to achieve this objective: either instant controlled pressure drop drying (DIC) or freeze drying (FD) was used as the treatments for microstructure improvement, and they were applied either before or after an additional drying step at low (35 °C) or high (65 °C) temperatures. Dried mushrooms were assessed for quality indicators like relative volume, rehydration rate, dry matter loss and sensory scores. Microstructure properties were inferred to understand the physical mechanisms of quality changes. Principal component analysis (PCA) was used to cluster treatments and to identify combinations of drying techniques, rendering improved quality. Consequently, it was shown that DIC treatment before hot air drying at 35 °C was shown to be the most promising combined drying method to enhance the rehydration quality, leading to a high volume recovery ratio, low dry matter loss after rehydration, and high rehydration rates. This good performance could be explained by the retention of pore interconnectivity resulting from the slight expansion of porous structure during DIC and the retention of cell membrane integrity.