Instant Pressure Drop Research Articles

Effect of continuous instant pressure drop treatment on the rheological properties and volatile flavor compounds of whole highland barley flour

Continuous instant pressure drop (CIPD) treatment effectively reduces microbial contamination in whole highland barley flour (WHBF). Base on it, this study further investigated its effects on flour properties (especially rheological properties) and volatile compounds (VOCs) profile of WHBF, and compared it with that of ultraviolet-C (UV-C), ozone and hot air (HA) treatments. The results showed that the damaged starch content (6.0%) of CIPD-treated WHBF was increased, leading to a rough surface and partial aggregation of starch particle, thereby increasing the particle size (18.06 μm of D10, 261.46 μm of D50 and 534.44 μm of D90). Besides, CIPD treatment exerted a positive influence on the structure and rheological properties of WHBF, including an elevation in pasting temperature and viscosity. Notably, CIPD-treated WHBF exhibited higher storage modulus and loss modulus compared to the other three groups of sterilization treatments, contributing to the formulation of a better-defined and stable gel strength (tan δ = 0.38). UV-C and ozone, as cold sterilization techniques, also induced alterations in specific characteristics of WHBF. UV-C treatment led to changes in WHBF's crystallinity, while ozone treatment caused modifications in the secondary protein structure of WHBF. A total of 68 VOCs were identified in raw WHBF (including 3 acids, 19 alcohols, 25 aldehydes, 1 alkene, 8 esters, 2 ethers, 3 furans, and 7 ketones). The maximum flavor-contributing VOC in CIPD-treated WHBF remained dimethyl sulfide monomer (cabbage aroma), consistent with the raw WHBF. Conversely, in HA-treated WHBF, the maximum flavor-contributing VOC shifted to 2-furanmethanethiol monomer (roasted coffee aroma), altering the initial flavor presentation. These findings will provide strong support for the application of CIPD technology in the powdery foods industry.

Study on the microbial inactivation of whole hulless barley flour using a continuous instant pressure drop sterilizer

AbstractThis work evaluated the microbial reduction and quality change of the whole hulless barley flour (WHBF) treated by a continuous instant pressure drop (CIPD) sterilizer. The microbial reduction of WHBF was proportional to steam‐material ratio under the conditions of 165°C, 0.2 MPa steam, and 0.2 MPa Laval nozzle, and the microbial reduction was 3.87 ± 0.09 log cfu/g with the steam‐material ratio of 3.0:1. The work was followed‐up with the quality testing of CIPD, UV‐C, hot air, and ozone treated WHBF. The microbial reduction of hot air, UV‐C, and ozone treated WHBF was 3.98 ± 0.09, 3.33 ± 0.04, and 3.68 ± 0.12 log cfu/g, respectively, while the CIPD treatment achieved similar bactericidal effect at a unit treatment time of 22 s. Moreover, there is no measurable quality degradation in CIPD treated WHBF compared with the untreated WHBF. These results showed CIPD sterilizer had a great potential for microbial inactivation of powdery foods industry.

Deodorization process of vegetal soybean oil using Thermomechanical Multi-Flash Autovaporization (MFA)

Conventional deodorization for refining vegetable oil involves evaporating volatile molecules by applying high temperatures (240–260 °C) for 2–3 h. It inevitably leads to a degradation of the refined oil quality.The chief volatile compounds from the conventional deodorization process were hydrocarbons, which are not the odor source of the oil. Particularly in the case of crude soybean oil, the main compounds responsible odor were Nonanal, Decanal, E-2-hexenal, and 2-Undecenal.The present study adopts the innovative technology of Multi-Flash Autovaporization “MFA” to effectively remove the compounds mainly responsible for the smell and taste while preserving the oil quality. It eradicates the concerned volatile molecules present in crude soybean oil. Based on experimental studies, we used phenomenological mathematical models to describe the deodorization, estimate the reaction efficiency, and optimize the correlation between thermodynamical data (volatility) and the evolution of these molecules during deodorization process.By optimizing the processing parameters, we experimentally estimated the MFA processing parameters at 800 kPa of saturated steam for 60 s, followed by an instant pressure-drop towards a vacuum of 5 kPa. The volatile ratio became 92% lower. Preserving tocopherol levels and the profile of the principal fatty acids significantly reveals the preservation of the oil quality.

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.

Controlled Instant Pressure Drop (DIC) Pretreatment to Enhance Fractionation and Enzymatic Saccharification of Poppy Capsule Waste

Controlled Instant Pressure Drop (DIC) Pretreatment to Enhance Fractionation and Enzymatic Saccharification of Poppy Capsule Waste

Cactus pear peel snacks prepared by instant pressure drop texturing: Effect of process variables on bioactive compounds and functional properties

Cactus pear (Opuntia ficus-indica) has a growing interest from both food manufacturers and consumers due to its medicinal and functional traits. Peel is a major waste from cactus pear juice industry accounting for about 38 % of the fruit weight. New concept of snacks preparation has been developed using instant controlled pressure drop (Detente instantanee controlee, DIC) techniques that provide a texturing stage between initial and final hot air drying stages. In this study, the application of DIC of cactus pear peel (CPP) was performed to be used as starch-free snacks with functional attributes. DIC resulted in high crispness CPP snacks with improved structural and nutritional attributes as well as high relative expansion ratio (up to 21 times). DIC expanded CPP snacks exhibited cutting force (3.34 N) that was much lower than untreated CPP (19.41 N). It is worth noting that optimized DIC treatment (P = 0.6 MPa for t = 15 s) allowed more availability of phenolic compounds and β-carotene by 83 and 551 %, respectively. In addition, antioxidant activity was increased up to 53 %. Results showed that steam pressure had significant effect on fat and alcohol insoluble solids (AIS) contents, wherein the correlation coefficients revealed critical relationships between structural and biochemical availabilities. Therefore, DIC could be used as an innovative technology to value this by-product leading to manufacture of crispy CPP snacks with high nutritious quality. There was a significant difference among the DIC treated and untreated CPP in respect to sensory properties, DIC treated CPP at operation conditions of saturated steam pressure = 0.6 MPa and processing time = 15 had the highest acceptability.

A review of the thermal pretreatment of lignocellulosic biomass towards glucose production: Autohydrolysis with DIC technology

There is increasing demand for the production of biofuels from lignocellulosic biomass. Lignocellulosic biomass consists mainly of three polymeric components: cellulose, hemicelluloses, and lignin. The separation of these components requires an effective pretreatment process to ensure high quality glucose production, and is highly influenced by several factors, including moisture content, cellulose crystallinity, lignin content, and available surface area. Over time, numerous pretreatment methods have been utilized to change the lignocellulosic fiber structure and to enhance the enzymatic saccharification of cellulose to polysaccharides. This article reviews thermal-based pretreatment of lignocellulosic fiber used for glucose production. Based on the reviewed studies, autohydrolysis of lignocellusic biomass, followed by the “Instant pressure drop (DIC),” method can be regarded as an effective pretreatment process of lignocellusic biomass.

Rice Husk Ash to Stabilize Heavy Metals Contained in Municipal Solid Waste Incineration Fly Ash: First Results by Applying New Pre-treatment Technology.

A new technology was recently developed for municipal solid waste incineration (MSWI) fly ash stabilization, based on the employment of all waste and byproduct materials. In particular, the proposed method is based on the use of amorphous silica contained in rice husk ash (RHA), an agricultural byproduct material (COSMOS-RICE project). The obtained final inert can be applied in several applications to produce “green composites”. In this work, for the first time, a process for pre-treatment of rice husk, before its use in the stabilization of heavy metals, based on the employment of Instant Pressure Drop technology (DIC) was tested. The aim of this work is to verify the influence of the pre-treatment on the efficiency on heavy metals stabilization in the COSMOS-RICE technology. DIC technique is based on a thermomechanical effect induced by an abrupt transition from high steam pressure to a vacuum, to produce changes in the material. Two different DIC pre-treatments were selected and thermal annealing at different temperatures were performed on rice husk. The resulting RHAs were employed to obtain COSMOS-RICE samples, and the stabilization procedure was tested on the MSWI fly ash. In the frame of this work, some thermal treatments were also realized in O2-limiting conditions, to test the effect of charcoal obtained from RHA on the stabilization procedure. The results of this work show that the application of DIC technology into existing treatment cycles of some waste materials should be investigated in more details to offer the possibility to stabilize and reuse waste.

Instant Pressure Drop Evaluation during Saturated Steam Puffing of Carrots

Vapor instant release and superheated liquid flash evaporation in foods are the two main factors in steam-puffing. The condensed water produced by saturated steam is absorbed by the food material, thereby increasing moisture content. A model, which incorporated moisture content, radius, mechanical properties of un-puffed materials, properties of saturated steam, was generated. Spherical carrots (diameter: 10±1 mm) were used. The results revealed that the puffing power model can be used to predict the relationship between puffing ratio (R2 >0.95) and moisture content (20–32%), and the relationship between puffing ratio (R2 >0.99) and saturated steam temperature (390–430 K). Sufficient moisture content was the basis for producing superheated liquid for puffing; superheated steam at high temperatures was necessary for the formation of superheated liquid and high vapor pressure values in food materials.

Effects of Instant Pressure Drop Puffing with Super‐Heated Vapor on the Physical Properties of Granny Smith Apple Chips

AbstractA central composite rotatable design of three factors was used to optimize instant pressure drop puffing with super‐heated vapor (IPDPSV) for Granny Smith apple slices. The physical properties of the chips processed by hot‐air drying after IPDPSV, hot‐air drying or freeze drying were analyzed and compared. The results revealed that moisture content, puffing temperature and heating time had significant effects on puffing ratio and color differences. The optimum conditions were 23% moisture content for pre‐dried samples, 122C puffing temperature and 41 s heating time. In these conditions, the puffed slices had a large puffing ratio of 45.137% and a relative small color differences of 4.642. Compared with the chips processed by hot‐air drying or freeze drying, chips processed by hot‐air drying after IPDPSV were brighter in color and had porous structures and suitable hardness. Therefore, IPDPSV is an effective method to improve chips quality.Practical ApplicationsInstant pressure drop puffing with super‐heated vapor (IPDPSV) could increase the pore volume in Granny Smith apple tissue. The effects of puffing parameters, including moisture content in sample, puffing temperature and heating time, on puffing ratio and color difference were studied. On optimized conditions, Granny Smith apple could be effectively puffed with less color change. IPDPSV combined with hot‐air drying gave the best physical qualities for Granny Smith apple chips, such as color and hardness, compared with traditional hot‐air drying and freeze drying. This processing method spent shorter time than hot‐air drying and consumed less energy than freeze drying. We may reasonably infer that IPDPSV has the advantages of productivity and economy. IPDPSV will be a helpful technology to produce high‐quality Granny Smith apple chips.

Improving the Drying of Onion Using the Instant Controlled Pressure Drop Technology

In the present article, a new manner to use the instant controlled pressure drop (DIC) was adopted in the drying of onion. Instead of using it as a texturing treatment inserted in the second stage of hot air swell-drying operation and performed when water content is less than 30 g H2O/100 g dry matter, here the DIC was performed as a blanching–steaming pretreatment of fresh cut onion, with a steam pressure of 0.2–0.5 MPa, for 5–15 s, and an instant pressure drop (with a rate > 5 MPa s−1) toward a vacuum of 5 kPa. Afterward, drying was carried out with 40°C, 1 m s−1, and 267 Pa partially pressure humidity hot air. Although this DIC treatment aimed to avoid notable expansion, it could intensify mass transfer, reducing the total drying time, which reached 700 min instead of 3200 min for untreated samples; the effective diffusivity and the initial starting accessibility dramatically increased. Consequently, sensorial and nutritional attributes could be preserved with a perfect decontaminated end product.

Modeling of fluid flow, stress state and seismicity induced in rock by an instant pressure drop in a hydrofracture

The paper presents a methodology and results of simulations of fluid flow, stress state, and seismicity induced in rock by instant pressure drop in a hydrofracture.

Impact of texturing using instant pressure drop treatment prior to solvent extraction of anthocyanins from Malaysian Roselle (Hibiscus sabdariffa)

Because of the natural structure of plants, which oppose resistance to penetration by any liquid, solvent extraction is very slow. The kinetics involves multiple serial steps and generally internal diffusion is the limiting process. To improve the technological aptitude, and intensify solvent extraction, we propose to submit plants to a treatment by thermo-mechanical Instant Controlled Pressure Drop (DIC), in order to ensure the expansion of the plant structure. In this paper, we present the results of a study concerning the effect of DIC treatment on the extraction of Roselle anthocyanins. By identifying the effect of various operative parameters, we found that an appropriate DIC treatment improved both the kinetics and yield of extraction of anthocyanins from Roselle calyces. By studying extraction kinetics, we identified and quantified the effective diffusivity, which ranged from 4.62 to 6.11 × 10−11 m2 s−1 for DIC treated material compared with 4.19 × 10−11 m2 s−1 for raw material.