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

Exploring Osmotic Dehydration for Food Preservation: Methods, Modelling, and Modern Applications

This study summarizes the most recent findings on osmotic dehydration, a crucial step in food preservation. The many benefits of osmotic dehydration are listed, including longer shelf life and preserved nutritional value. Mass transfer dynamics, which are critical to understanding osmotic dehydration, are explored alongside mathematical models essential for comprehending this process. The effect of osmotic agents and process parameters on efficacy, such as temperature, agitation and osmotic agent concentration, is closely examined. Pre-treatment techniques are emphasized in order to improve process effectiveness and product quality. The increasing demand for sustainability is a critical factor driving research into eco-friendly osmotic agents, waste valorization, and energy-efficient methods. The review also provides practical insights into process optimization and discusses the energy consumption and viability of osmotic dehydration compared to other drying methods. Future applications and improvements are highlighted, making it an invaluable tool for the food industry.

Investigating intermittent immersion during osmotic dehydration of mango (Mangifera indica L. Moench). Part A: Determination of optimal conditions for mango (Mangifera indica L. Moench) dehydration impregnation by immersion (D2I) and intermittent immersion (D3I)

This work aimed to determine the optimum conditions for dehydration impregnation by immersion (D2I) and by intermittent immersion (D3I) of mango (Mangifera indica) slices measuring 4 × 1 × 1 cm3. To this end, the Doehlert response surface plan was used, with the following factors for D2I: the volume of D2I solution/fruit mass ratio (6/1-13/1 mL/g), the process time (120-360 min) and the Brix degree of the solution (45-65 °Brix) and with the following factors for D3I: immersion time (20-60 min), process time (60-300 min) and de-immersion time (7-25 min). The temperature was fixed according to literature at 35 °C. The optimum responses obtained for the D2I process were (47.63 ± 1.79) g/100 g (w-b) for water loss, and (6.67 ± 1.04) g/100 g (w-b) for solute gain, for optimum operating conditions of 6/1 mL/g; 245 min and 61.6°Brix respectively for the immersion ratio, process time and solute concentration of the hypertonic solution. The optimum responses obtained for D3I process were (47.98 ± 2.12) g/100 g (w-b) for water loss, and (4.31 ± 0.052) g/100 g (w-b) for solute gain (SG), for operating conditions of 21; 270; and 9 min, respectively for immersion time, process time and de-immersion time. The Student's t-test on the predicted and experimental optima of WL and SG revealed valuable insights for comparing these two processes. The present study will undoubtedly introduce a new dynamic to the osmotic dehydration systems for fruits and vegetables.

Effect of freeze-thaw and PEF pretreatments on the kinetics and microstructure of convective and ultrasound-assisted drying of orange peel

The main waste generated by juice industry comprises orange peels, which have a great upcycling potential once stabilized. Drying is the most used method for this purpose, but the high energy consumption prompts interest in its intensification. This study assessed the influence of freeze-thaw and pulsed electric field (PEF) pretreatments in conventional and airborne ultrasound-assisted drying (50 °C) of orange peels. None of these pretreatments alone got to reduce processing times significantly, but combined with ultrasound-assisted drying produced a significant shortening of the process. This was particularly important in the lower intensity PEF pretreatment tested (0.33 kJ/kg), indicating the existence of optimum conditions to carry out the pretreatments. Microstructure analysis revealed that the application of ultrasound during drying led to better preservation of the sample structure. Thus, the integration of pretreatment techniques to ultrasound-assisted drying may not only shorten the process but also help to preserve the original structure.

Review of osmotic dehydration: Promising technologies for enhancing products' attributes, opportunities, and challenges for the food industries

Osmotic dehydration (OD) is an efficient preservation technology in that water is removed by immersing the food in a solution with a higher concentration of solutes. The application of OD in food processing offers more benefits than conventional drying technologies. Notably, OD can effectively remove a significant amount of water without a phase change, which reduces the energy demand associated with latent heat and high temperatures. A specific feature of OD is its ability to introduce solutes from the hypertonic solution into the food matrix, thereby influencing the attributes of the final product. This review comprehensively discusses the fundamental principles governing OD, emphasizing the role of chemical potential differences as the driving force behind the molecular diffusion occurring between the food and the osmotic solution. The kinetics of OD are described using mathematical models and the Biot number. The critical factors essential for optimizing OD efficiency are discussed, including product characteristics, osmotic solution properties, and process conditions. In addition, several promising technologies are introduced to enhance OD performance, such as coating, skin treatments, freeze-thawing, ultrasound, high hydrostatic pressure, centrifugation, and pulsed electric field. Reusing osmotic solutions to produce innovative products offers an opportunity to reduce food wastes. This review explores the prospects of valorizing food wastes from various food industries when formulating osmotic solutions for enhancing the quality and nutritional value of osmotically dehydrated foods while mitigating environmental impacts.

Shelf-Life Enhancement Applying Pulsed Electric Field and High-Pressure Treatments Prior to Osmotic Dehydration of Fresh-Cut Potatoes

From a quality standpoint, it is desirable to preserve the characteristics of fresh-cut potatoes at their peak. However, due to the mechanical tissue damage during the cutting process, potatoes are susceptible to enzymatic browning. This study pertains to the selection of the appropriate osmotic dehydration (OD), high pressure (HP), and pulsed electric fields (PEF) processing conditions leading to effective quality retention of potato cuts. PEF (0.5 kV/cm, 200 pulses) or HP (400 MPa, 1 min) treatments prior to OD (35 °C, 120 min) were found to promote the retention of the overall quality (texture and color) of the samples. The incorporation of anti-browning agents (ascorbic acid and papain) into the osmotic solution improved the color retention, especially when combined with PEF or HP due to increased solid uptake (during OD) as indicated by DEI index (2.30, 1.93, and 2.10 for OD treated 120 min, non-pre-treated, HP pre-treated, and PEF pre-treated samples, respectively). PEF and HP combined with OD and anti-browning agent enrichment are sought to improve the quality and microbial stability of fresh-cut potatoes during refrigerator storage. Untreated fresh-cut potatoes were characterized by color degradation from the 2nd day of storage at 4 °C, and presented microbial growth (total viable counts: 6 log (CFU)/g) at day 6, whereas pre-treated potato samples retained their color and microbiologically stability after 6 days of cold storage (total viable counts, <4 log(CFU)/g).

Advances in Postharvest Preservation and Quality of Fruits and Vegetables

Numerous agricultural regions face the daunting task of providing high-quality fresh fruits and vegetables to increasingly competitive markets [...].