Submit to Applied Sciences Review for Applied Sciences Propose a Special Issue

Journal Browser

Drying Technologies in Food Processing

Print Special Issue Flyer
Special Issue Editors
Special Issue Information
Keywords
Published Papers

A special issue of Applied Sciences (ISSN 2076-3417). This special issue belongs to the section "Food Science and Technology".

Deadline for manuscript submissions: closed (10 January 2023) | Viewed by 39718

Share This Special Issue

Special Issue Editors

Dr. Malgorzata Nowacka

E-Mail Website
Guest Editor

Department of Food Engineering and Process Management, Institute of Food Sciences, Warsaw University of Life Sciences – SGGW, Nowoursynowska 159c, 02-787 Warsaw, Poland
Interests: non-thermal technologies such as ultrasound and pulsed electric field; osmotic dehydration; drying; design new products; sustainable methods of food production
Special Issues, Collections and Topics in MDPI journals

Dr. Urszula Tylewicz

E-Mail Website
Guest Editor

Department of Agricultural and Food Sciences, University of Bologna, 47521 Cesena, Italy
Interests: non-thermal technologies for fruit and vegetable processing (pulsed electric field, ultrasound, vacuum impregnation, osmotic dehydration, high pressure homogenization); waste and byproduct valorization; sustainable food production
Special Issues, Collections and Topics in MDPI journals

Dr. Magdalena Dadan

E-Mail Website
Guest Editor

Department of Food Engineering and Process Management, Institute of Food Sciences, Warsaw University of Life Sciences – SGGW, Nowoursynowska 159c, 02-787 Warsaw, Poland
Interests: non-thermal processing; ultrasound; pulsed electric field; drying; osmotic dehydration; innovative processes; food quality; sustainable food production

Special Issue Information

Dear Colleagues,

The aim of this Special Issue of Applied Sciences is to present current original research articles as well as review articles focused on drying technologies and osmotic dehydration in food processing.

Recently, consumers pay more attention to healthy diet and often seek products with a high amount of bioactive compounds such as fruit and vegetables. Due to the seasonality of raw plants, some fruit and vegetables are available on the market in a fresh state only for a short time during the year. Furthermore, after harvest a surplus of raw material can occur. Drying is one of the most frequently used processing methods that enable surplus to be handled. However, the drying process is used in different processes during food production and has impact on the quality of the final product. Different methods of drying and pretreatments are used to obtain high quality products. Osmotic dehydration could be applied as a pre-treatment before drying process, to partially remove water from tissue by immersion of cellular tissue in hypertonic aqueous solutions, reducing drying time as well as decreasing process costs and improving the taste of final product. However, osmotic dehydration might be also used to obtain minimally processed fruit and vegetable products. To accelerate mass transfer during osmotic dehydration and drying in recent years new techniques such as pulsed-vacuum, high and low pressure, power ultrasound, pulsed electric fields etc.

Therefore, we would like to invite authors to contribute with current original research articles and state-of-the-art review articles regarding drying and osmotic dehydration processes.

Dr. Magdalena Dadan
Dr. Urszula Tylewicz
Dr. Malgorzata Nowacka
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Applied Sciences is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2400 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

drying
osmotic dehydration
traditional and innovative processes
food quality
shelf life
functional products

Published Papers (14 papers)

Download All Papers

Editorial

Jump to: Research, Review

6 pages, 224 KiB

Open AccessEditorial

Drying Technologies in Food Processing

by Małgorzata Nowacka, Magdalena Dadan and Urszula Tylewicz

Appl. Sci. 2023, 13(19), 10597; https://0-doi-org.brum.beds.ac.uk/10.3390/app131910597 - 22 Sep 2023

Viewed by 1991

Abstract

Recently, consumers are paying more attention to healthy diets and often seek products with a high number of bioactive compounds, such as fruit and vegetables [...] Full article

(This article belongs to the Special Issue Drying Technologies in Food Processing)

Research

Jump to: Editorial, Review

21 pages, 2857 KiB

Open AccessArticle

Shaping the Properties of Osmo-Dehydrated Strawberries in Fruit Juice Concentrates

by Hanna Kowalska, Magdalena Trusinska, Katarzyna Rybak, Artur Wiktor, Dorota Witrowa-Rajchert and Malgorzata Nowacka

Appl. Sci. 2023, 13(4), 2728; https://0-doi-org.brum.beds.ac.uk/10.3390/app13042728 - 20 Feb 2023

Cited by 5 | Viewed by 2273

Abstract

The growing interest in high-quality food leads to looking for new solutions in the production of natural fruit snacks. Osmotic dehydration is one of the processes, which can be used to obtain a minimally processed product as well as to give it specific characteristics. Usually, a sucrose solution is used as an osmotic agent; however, the use of chokeberry, strawberry, or cherry juice concentrates can be beneficial in the process of the osmotic dehydration of fruits. The process of the dehydration of strawberries with the use of fruit juice concentrates (chokeberry, strawberry, or cherry) and a sucrose solution as a standard was carried out at a temperature of 30 °C for 3 h. The kinetics of the processes (weight reduction, water loss, and solid gain) were evaluated as well as physical (water activity, color parameters L*, a*, b*, ΔE, texture with maximum force and compression work, and structure) and chemical properties (dry matter content, total polyphenols content, total anthocyanin content, vitamin C, antioxidant activity with DPPH and ABTS radicals, spectral analysis with FTIR method, sucrose, glucose and fructose content, and thermal decomposition with TG analysis). The use of fruit juice concentrates positively influences the enrichment of the final product with bioactive compounds, such as anthocyanin and vitamin C. Strawberry and chokeberry juice concentrates have proven to be good hypertonic media for increasing the antioxidant activity of dehydrated fruit. Moreover, the use of fruit concentrates has a positive effect on the sugar profile of dehydrated strawberries. Full article

(This article belongs to the Special Issue Drying Technologies in Food Processing)

► Show Figures

Figure 1

16 pages, 2230 KiB

Open AccessArticle

Sustainable Approach for Development Dried Snack Based on Actinidia deliciosa Kiwifruit

by Malgorzata Nowacka, Cinzia Mannozzi, Marco Dalla Rosa and Urszula Tylewicz

Appl. Sci. 2023, 13(4), 2189; https://0-doi-org.brum.beds.ac.uk/10.3390/app13042189 - 08 Feb 2023

Cited by 3 | Viewed by 1141

Abstract

The aim of this study was to evaluate the method of producing shelf-stable snacks based on kiwifruit with the objective of obtaining an appealing snack with good taste, color, and nutritional value. Less valuable kiwifruits for size and shape were utilized in order to reduce kiwifruit production waste. To obtain the snacks, two drying methods were used: freeze-drying and hot air drying. Physical and chemical analyses were conducted. Furthermore, a sensory evaluation was undertaken. The results showed that both hot-air and freeze-drying methods are suitable for obtaining a good quality snack, which was attractive to consumers. However, the freeze-dried snack was better assessed than hot-air dried. Moreover, consumers preferred snacks with additional sucrose or trehalose to those without it. It was observed that products produced using the freeze-drying process had lower water content, and lower water activity, were brighter, had a more saturated color, and had similar or higher antioxidant activity, especially for samples made from kiwi, fennel, and spinach. The drying process allows for obtaining a snack that can be stored at room temperature. Freeze drying better preserved bioactive compounds compared to air drying. The freeze-dried samples were more appreciated by consumers than the air-dried and those containing sweetener. Full article

(This article belongs to the Special Issue Drying Technologies in Food Processing)

► Show Figures

Figure 1

20 pages, 11544 KiB

Open AccessArticle

Experimental Research to Determine the Effect of Ultrasound in Drying Bo Chinh Ginseng by Ultrasound-Assisted Heat Pump Drying Method

by Hay Nguyen, Quang-Huy Le, Thanh-Dat Le and Van-Kien Pham

Appl. Sci. 2022, 12(22), 11525; https://0-doi-org.brum.beds.ac.uk/10.3390/app122211525 - 13 Nov 2022

Cited by 2 | Viewed by 1664

Abstract

This study focused on the experimental drying of Bo Chinh ginseng by the ultrasound-assisted heat pump drying method, in which the effects of drying air temperature (T), ultrasonic power (P), intermittency ratio of ultrasound generator (A) on the moisture effective diffusion coefficient (Deff), saponin content (Sp) and color change (dE) during the drying process were determined. The results showed that the drying time was reduced from 12.5 h at 35 °C to 8.9 h at 40 °C and greatly reduced to 5.8 h at 55 °C. The moisture diffusion coefficient Deff and color change index increased with the increase in drying temperature. Meanwhile, from 35 °C to 45 °C, the saponin content after drying tended to increase gradually, but when the temperature continued to rise from 45 °C to 55 °C, the saponin content decreased. The effect of ultrasonic power in the drying process was in particular as follows. The drying time of 8.8 h at 40 W ultrasonic power reduced to 7.8 h at 80 W ultrasonic power, and reduced to 7 h at 160 W ultrasonic power. The remaining saponin content after drying tended to increase gradually at the power level of 40–120 W (from 89.2% to 95.2%) and decrease when the power increased from 120 to 160 W (from 95.2% to 90.5%). The moisture diffusion coefficient Deff also increased with the increase in ultrasonic power. Meanwhile, the color change of dried products decreased as the ultrasonic power increased in the range of 40–120 W but increased with the ultrasonic power range from 120 to 160 W. Additionally, the experimental method and Box–Behnken design were used for optimizing the drying process with the optimal drying conditions such as drying air temperature of 45.2 °C, ultrasonic power of 127.7 W and intermittency ratio of ultrasound generator of 0.18. Full article

(This article belongs to the Special Issue Drying Technologies in Food Processing)

► Show Figures

Figure 1

19 pages, 1969 KiB

Open AccessArticle

Impact of Vacuum Assisted Oven Drying of Kurut on Product Quality and Drying Characteristics

by Elif Ayse Anli

Appl. Sci. 2022, 12(21), 11228; https://0-doi-org.brum.beds.ac.uk/10.3390/app122111228 - 05 Nov 2022

Cited by 2 | Viewed by 1952

Abstract

Kurut is an ancient flavor of central Asia, produced by sun-drying of yogurt. Kurut is used in preparation of pasta, soup and also in the form of yogurt by mixing with water. Alternative to sun drying, this study was aimed at conducting Kurut production by use of vacuum-oven drying (VOD) and oven drying (OD) techniques at two different temperatures (35 °C and 45 °C). Samples were coded as KV35, KV45 and K35, K45 for VOD and OD techniques, respectively. All samples were concentrated by drying in proximate composition (p > 0.05). Less progress of acidity, lower solubility ratio (p > 0.05) and lower hydroxymethyl furfural (HMF) values were maintained by VOD than OD (p < 0.05) in the 1st day. All Kurut samples were very distinctly different (ΔE ˃ 3), more yellowish (b*) and less bright (L*) than strained yogurt. Redness (a*) was observed only in OD-applied samples (p < 0.05). Yagcioglu, Wang and Singh, Midilli and two-term models were best fitting models for predicting drying behavior of KV35, KV45, K35 and K45, respectively. Drying time for VOD and OD were determined as 2 days and 8 days, respectively. Difference in means of drying temperature was found statistically significant in terms of HMF, L*, a* and b* in the OD technique (p < 0.05). In the industrial aspect use of VOD, especially with the establishment of continuous systems, Kurut production in a shorter time with better preservation of quality is possible. Full article

(This article belongs to the Special Issue Drying Technologies in Food Processing)

► Show Figures

Figure 1

12 pages, 1356 KiB

Open AccessArticle

Effects of Infrared Drying Conditions and Maltodextrin Addition on Some Physicochemical Characteristics of Avocado (Persea americana) Pulp Powder

by Thi-Van-Linh Nguyen, Quoc-Duy Nguyen, Thi-Thuy-Dung Nguyen and Phuoc-Bao-Duy Nguyen

Appl. Sci. 2021, 11(24), 11803; https://0-doi-org.brum.beds.ac.uk/10.3390/app112411803 - 12 Dec 2021

Cited by 5 | Viewed by 2607

Abstract

In this study, avocado pulp with a good nutritional profile and economic value was dehydrated using infrared drying to produce pulp powder, which shows potential application in nutritional supplements. An experimental design with two factors, namely maltodextrin level (0% and 9%) and infrared temperature (ranging from 65 to 80 °C), was used. Responses related to the physicochemical properties of the resulted powder were observed, including peroxide value, total polyphenols, total chlorophylls, antioxidant activity, and color parameters (L*, a*, and b* values). The quality of dried products may be harmed by drying either at a high temperature or for an extended period of time. The coating substance maltodextrin was found to be beneficial in limiting unexpected changes in avocado pulp subjected to infrared drying. The highest quality of dried avocado could be obtained via infrared drying of avocado pulp with 9% maltodextrin at 70 °C, as illustrated by the exceptional retention of total polyphenols, total chlorophylls, and antioxidant activity, being 95.1, 95.2, and 94.4%, respectively. Moreover, the short drying time (35–55 min) led to the minimization of lipid oxidation and the absence of peroxide compounds in all samples. Full article

(This article belongs to the Special Issue Drying Technologies in Food Processing)

► Show Figures

Figure 1

18 pages, 2984 KiB

Open AccessArticle

Drying Kinetics of Wheat (Triticum aestivum L., cv. ‘Pionier’) during Thin-Layer Drying at Low Temperatures

by Iris Ramaj, Steffen Schock and Joachim Müller

Appl. Sci. 2021, 11(20), 9557; https://0-doi-org.brum.beds.ac.uk/10.3390/app11209557 - 14 Oct 2021

Cited by 7 | Viewed by 2145

Abstract

The management of moisture is one of the main challenges in anticipating and averting food decay and food losses during postharvest processing and storage. Hence, it is imperative to reduce the moisture of freshly harvested products to safe-storage limits in order to inhibit the occurrence of diverse biochemical, microbiological and other moisture-related deteriorative reactions which can contribute to quality degradation. A viable alternative to conventional hot-air drying is the application of low temperatures for drying, which has scarcely been investigated. In this regard, experimental-based modeling is a requisite to gain insights into drying processes. Thus, this study focused on investigating the drying kinetics of wheat (Triticum aestivum L.) cv. ‘Pionier’ under a coherent set of drying air temperatures (T = 10–50 °C), relative humidity (RH = 20–60%), and airflow velocity (v = 0.15–1.00 ms⁻¹). A robust and automated measurement system using a high precision balance was utilized as a basis for the real-time and continuous acquisition of drying data. The analysis of the experimental results facilitated the establishment of generalized drying model for low temperatures able to describe at a high accuracy the behavior of moisture ratio X* (R² = 0.997, RMSE = 1.285 × 10⁻², MAPE = 6.5%). An analytical model for predicting the effective diffusion coefficients D (R² = 0.988, RMSE = 4.239 × 10⁻², MAPE = 7.7%) was also developed. In conclusion, the anticipated drying model has demonstrated the capability of modeling the drying behavior of wheat at low temperatures with a high temporal resolution and should be employed in the design, analysis and modeling of cooling, aeration and low-temperature drying processes of wheat bulks. Full article

(This article belongs to the Special Issue Drying Technologies in Food Processing)

► Show Figures

Figure 1

18 pages, 1615 KiB

Open AccessArticle

Effect of Pretreatments on Convective and Infrared Drying Kinetics, Energy Consumption and Quality of Terebinth

by Yousef Abbaspour-Gilandeh, Mohammad Kaveh, Hamideh Fatemi, Esmail Khalife, Dorota Witrowa-Rajchert and Małgorzata Nowacka

Appl. Sci. 2021, 11(16), 7672; https://0-doi-org.brum.beds.ac.uk/10.3390/app11167672 - 20 Aug 2021

Cited by 22 | Viewed by 2417

Abstract

This study is focused on the influence of convective drying (50, 60, and 70 °C) and infrared (IR) power (250, 500, and 750 W) on the drying kinetics, the specific energy consumption of terebinth drying as well as quality and bioactive compounds upon various pretreatments such as ultrasound (US), blanching (BL), and microwave (MW). Compared to convective drying, IR drying decreased more the drying time and energy consumption (SEC). Application of higher IR powers and air temperatures accelerated the drying process at lower energy consumption (SEC) and higher energy efficiency and moisture diffusion. Terebinth dried by a convective dryer at 60 °C with US pretreatment showed a better color compared to other samples. It also exhibited the polyphenol and flavonoid content of 145.35 mg GAE/g d.m. and 49.24 mg QE/g d.m., respectively, with color variations of 14.25 and a rehydration rate of 3.17. The proposed pretreatment methods significantly reduced the drying time and energy consumption, and from the other side it increased energy efficiency, bioactive compounds, and quality of the dried samples (p < 0.01). Among the different pretreatments used, microwave pretreatment led to the best results in terms of the drying time and SEC, and energy efficiency. US pretreatment showed the best results in terms of preserving the bioactive compounds and the general appearance of the terebinth. Full article

(This article belongs to the Special Issue Drying Technologies in Food Processing)

► Show Figures

Figure 1

12 pages, 5810 KiB

Open AccessArticle

Hot Air and Microwave Combined Drying of Potato Monitored by Infrared Thermography

by Juan Angel Tomas-Egea, Maria Victoria Traffano-Schiffo, Marta Castro-Giraldez and Pedro J. Fito

Appl. Sci. 2021, 11(4), 1730; https://0-doi-org.brum.beds.ac.uk/10.3390/app11041730 - 15 Feb 2021

Cited by 6 | Viewed by 1945

Abstract

Hot air drying (HAD) at temperatures below the spontaneous evaporation temperature could be combined with microwave (MW) radiation as a thermal energy source in order to reduce the drying time. A photon flux in the microwave range interacts with dipolar molecules (water) through orientation and induction, producing electrical energy storage and thermal energy accumulation and generating an increase in the internal energy of food. The different mechanisms involved in water transport could change when the microwave penetration depth exceeds the sample characteristic dimension of mass transport. The aim of this paper is to determine the effect of MW in the combined HAD-MW drying of raw potato in order to obtain the real driving forces and mechanisms involved in the water transport, with the purpose of optimizing the MW power used. For this purpose, combined drying was carried out on potato samples (0, 4 and 6 W/g). The sample surface temperature was monitored by infrared thermography, and the sample mass was measured continuously through a precision balance. In parallel with continuous drying, another drying treatment was performed at different times (20, 40, 60, 90, 120, 180, 420 min) and conditions (0, 4 and 6 W/g) to analyze the dielectric properties, mass, moisture, volume and water activity. The results show that it is possible to monitor combined drying by infrared thermography, and it can be concluded that the convection heating is mostly transformed into surface water evaporation, with negligible thermal conduction from the surface, and microwave radiation is mostly transformed into an increase in the potato’s internal energy. Full article

(This article belongs to the Special Issue Drying Technologies in Food Processing)

► Show Figures

Figure 1

19 pages, 2780 KiB

Open AccessArticle

The Assessment of the Possibility of Using Ethanol and Ultrasound to Design the Properties of Dried Carrot Tissue

by Magdalena Dadan and Malgorzata Nowacka

Appl. Sci. 2021, 11(2), 689; https://0-doi-org.brum.beds.ac.uk/10.3390/app11020689 - 12 Jan 2021

Cited by 25 | Viewed by 2536

Abstract

The purpose of this study was to investigate the effect of pre-treatment in ethyl alcohol for 5, 15, 60 and 180 s with the application of ultrasound on the course of convective drying and properties of carrot tissue directly after the treatment and after the drying process. The treatment in ethanol resulted in loss of mass, increase of dry matter, ethanol conductivity, extractivity of carotenoids with a slight effect on the colour of carrot tissue after the treatment. The utilization of ultrasound during immersion in ethanol contributed to additional increase of conductivity of ethanol, and extractivity of carotenoids. The immersion in ethanol virtually did not affect the drying kinetics, which can be explained by the increase of shrinkage of the tissue in relation to the untreated dried tissue. Despite the lack of the influence on the drying course in the ethanol-immersed carrot, an increase of the carotenoid content (up to 135%) and the rehydration ability (up to 19%) was noted with the simultaneously unchanged colour of dried carrot in comparison to untreated dried material, which indicates the possibility to improve the quality of dried carrot after immersion in ethanol. Full article

(This article belongs to the Special Issue Drying Technologies in Food Processing)

► Show Figures

Figure 1

20 pages, 2363 KiB

Open AccessArticle

The Effect of Freeze-Drying on the Properties of Polish Vegetable Soups

by Ewa Jakubczyk and Aleksandra Jaskulska

Appl. Sci. 2021, 11(2), 654; https://0-doi-org.brum.beds.ac.uk/10.3390/app11020654 - 11 Jan 2021

Cited by 13 | Viewed by 4786

Abstract

The aim of this study was to investigate selected physical and biochemical properties of four vegetable freeze-dried soups. The water content, water activity, pH, color parameters, antioxidant activity (EC50), total polyphenolic content of fresh tomato, pumpkin, beetroot, and cucumber, and freeze-dried soups were measured. Sensory analysis was applied to compare sensory attributes of fresh and rehydrated soups. The sorption isotherms of freeze-dried soups were obtained with the application of the static and dynamic vapor sorption (DVS) method. The application of the freeze-drying method enabled the obtaining of dry soups with a low water content of 2–3%. The drying caused a significant change of color of all soups. The redness of soups decreased after drying for the beetroot soups from +39.64 to +21.91. The lower chroma value of 25.98 and the highest total color change ΔE*_ab = 36.74 were noted for freeze-dried beetroot soup. The antioxidation activity and total polyphenolic content were reduced after drying, especially for the cucumber and tomato soups. The Peleg model was selected to describe the sorption isotherms of dried soups. The sorption isotherm of freeze-dried cucumber and beetroot soups had a sigmoidal shape of type II. The shape of the moisture sorption isotherm for freeze-dried tomato and pumpkin soups corresponded more with type III isotherms. The DVS method can be used to characterize the moisture sorption isotherms of freeze-dried products. Full article

(This article belongs to the Special Issue Drying Technologies in Food Processing)

► Show Figures

Figure 1

13 pages, 1326 KiB

Open AccessArticle

The Impact of Vacuum and Convective Drying Parameters on Kinetics, Total Phenolic Content, Carotenoid Content and Antioxidant Capacity of Kiwiberry (Actinidia arguta)

by Michał Bialik, Artur Wiktor, Katarzyna Rybak, Dorota Witrowa-Rajchert, Piotr Latocha and Ewa Gondek

Appl. Sci. 2020, 10(19), 6914; https://0-doi-org.brum.beds.ac.uk/10.3390/app10196914 - 02 Oct 2020

Cited by 9 | Viewed by 2351

Abstract

This study aimed to investigate the impact of convective and vacuum drying performed at different temperatures on the content of bioactive components of kiwiberry. Dried fruits obtained from Geneva and Weiki cultivars were analyzed for total carotenoid content, total phenolic content (TPC), and antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays. The secondary goal was to establish drying kinetics and to find the best-fitting model for the drying process. The results showed that the highest total carotenoid content was found in Geneva fruits dried by vacuum method and was equal to 39.55–90.27 µg/g dry matter (d.m.). Considering free radical scavenging activity, the best results were also achieved for vacuum dried Geneva cultivar. These samples exhibited EC50 equal to 0.16–0.51 mg d.m./mL and 0.05–0.24 mg d.m./mL as evaluated using DPPH and ABTS assays, respectively. Vacuum drying method usually better preserved the phenolic content of kiwiberry—samples dried at 50 °C did not differ significantly from fresh material. Generally, the shortest drying time was observed for the samples dried at 70 °C regardless of the drying method. Changing the temperature during drying from 80 to 50 and 60 °C did not cause expected benefits regarding chemical property preservation. In most cases, the Midilli et al. model represented the best fit to describe obtained drying kinetics. Full article

(This article belongs to the Special Issue Drying Technologies in Food Processing)

► Show Figures

Figure 1

17 pages, 3094 KiB

Open AccessFeature PaperArticle

Osmotic Dehydration for the Production of Novel Pumpkin Cut Products of Enhanced Nutritional Value and Sustainability

by Efimia Dermesonlouoglou, Eleni Paraskevopoulou, Varvara Andreou and Petros Taoukis

Appl. Sci. 2020, 10(18), 6225; https://0-doi-org.brum.beds.ac.uk/10.3390/app10186225 - 08 Sep 2020

Cited by 11 | Viewed by 2618

Abstract

The quality and preservability of fresh-cut fruits can be improved by osmotic dehydration (OD). In this study, the impact of Strained Yoghurt Whey (SY Whey) (along with other osmotic solutes) on mass transfer kinetics (water loss, solid gain, water activity decrease), quality attributes (color, texture, sensory characteristics, vitamin C), and microbial stability during OD and subsequent refrigerated storage (5–15 °C) of OD-processed pumpkin cuts was studied. The effect of temperature (35–55 °C), time (10–240 min), and type of osmotic solvent was evaluated to select the optimal processing conditions (55 °C–120 min; WL: 9-99-10.86 g w./g i.d.m. SG: 1.47–1.79 g s./g i.d.m., a_w: 0.89). The use of SY Whey vs. water as solvent enhanced the mass transfer phenomena increasing the solids uptake diffusion coefficient by 20%. Water and whey osmosed samples were of similar quality (32–38% increase of hardness, total sensory quality score: 7.9–8.2/9.0, vitamin C content: 77–81 mg/100 g). At all studied storage temperatures, OD_{SY Whey} samples presented lower quality degradation rates compared to the respective OD_Water samples (e.g., almost half for hardness change). The shelf life of both OD processed pumpkin cuts exceeded 90 days at 5–15 °C (no microbial growth) supporting the applicability of SY whey as novel osmotic solvent. Full article

(This article belongs to the Special Issue Drying Technologies in Food Processing)

► Show Figures

Figure 1

Review

Jump to: Editorial, Research

22 pages, 3477 KiB

Open AccessEditor’s ChoiceReview

Current Applications of Ultrasound in Fruit and Vegetables Osmotic Dehydration Processes

by Małgorzata Nowacka, Magdalena Dadan and Urszula Tylewicz

Appl. Sci. 2021, 11(3), 1269; https://0-doi-org.brum.beds.ac.uk/10.3390/app11031269 - 30 Jan 2021

Cited by 29 | Viewed by 7587

Abstract

Ultrasound (US) is a promising technology, which can be used to improve the efficacy of the processes in food technology and the quality of final product. US technique is used, e.g., to support mass and heat transfer processes, such as osmotic dehydration, drying and freezing, as well as extraction, crystallization, emulsification, filtration, etc. Osmotic dehydration (OD) is a well-known process applied in food processing; however, improvements are required due to the long duration of the process. Therefore, many recent studies focus on the development of OD combined with sonication as a pretreatment method and support during the OD process. The article describes the mechanism of the OD process as well as those of US and changes in microstructure caused by sonication. Furthermore, it focuses on current applications of US in fruits and vegetables OD processes, comparison of ultrasound-assisted osmotic dehydration to sonication treatment and synergic effect of US and other innovative technics/treatments in OD (such as innovative osmotic solutions, blanching, pulsed electric field, reduced pressure and edible coatings). Additionally, the physical and functional properties of tissue subjected to ultrasound pretreatment before OD as well as ultrasound-assisted osmotic dehydration are described. Full article

(This article belongs to the Special Issue Drying Technologies in Food Processing)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Drying Technologies in Food Processing

Share This Special Issue

Special Issue Editors

Special Issue Information

Keywords

Published Papers (14 papers)

Editorial

Research

Review

Further Information

Guidelines

MDPI Initiatives

Follow MDPI