Publications by authors named "Maria Giannakourou"

Article Synopsis
  • The study aimed to evaluate the osmodehydrofreezing (ODF) process for cherry tomatoes by examining various parameters of osmotic dehydration and freezing techniques.* -
  • The optimal conditions for osmotic dehydration were found to be a 61.5% glycerol solution at 36 °C for 72 minutes, which resulted in improved color, firmness, and nutrient retention in the tomatoes.* -
  • Frozen cherry tomatoes treated with ODF showed a significantly extended shelf life and maintained quality during storage at various temperatures, with validated models predicting nutrient degradation and sensory quality loss.*
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Mushroom production and consumption are gaining increased interest due to their unique flavor and nutritional value. However, in the mushroom industry, large amounts of by-products are generated, which have a high negative environmental and economic impact. In this study, an osmotic dehydration process followed by hot-air-drying was applied to mushroom stems to produce dried mushrooms as the end product.

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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.

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Lately, the essential oils industry has been one of the most expanding markets globally. However, the byproducts generated after the distillation of aromatic plants and their transformation to novel high-added value products consist of a major up-to-date challenge. Thus, the scope of the current study is the optimization of ultrasound-assisted extraction (UAE) for the recovery of phenolic compounds from rose () post-distillation side streams using Box-Behnken design.

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Button mushrooms (), one of the most common edible mushroom species, are sensitive to damages because of the absence of a protective skin layer and have a limited shelf life. Osmotic dehydration (OD), mainly used as a pre-processing step of conventional preservation methods, has been proposed as an efficient, mild treatment to preserve mushroom superior quality. In this study, response surface methodology, coupled with a Box-Behnken design, was used to investigate the effect of glycerol concentration (30-50%), temperature (30-50 °C), and duration of osmosis (0-180 min) in order to optimize the process prior to a subsequent freezing step.

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Vitamin C, a water-soluble compound, is a natural antioxidant in many plant-based products, possessing important nutritional benefits for human health. During fruit and vegetable processing, this bioactive compound is prone to various modes of degradation, with temperature and oxygen being recognised as the main factors responsible for this nutritional loss. Consequently, Vitamin C is frequently used as an index of the overall quality deterioration of such products during processing and post-processing storage and handling.

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Multiple factors can directly influence frozen food quality, during processing and post-processing, in the cold chain [...

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This study concerns the implementation of osmotic dehydration (OD) as a pre-treatment of air-drying in fig halves, aiming at drying acceleration, energy savings and product quality improvement. The effect of solid/liquid mass ratio, process temperature (25-45 °C) and duration (up to 300 min) on water activity (a) and transport phenomena during OD, was modelled. The effective diffusion coefficients, drying time and energy consumption, were also calculated during air-drying at 50-70 °C.

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The scope of this work is the study of a combined process including a dipping step into an oregano ( ssp. ) infusion (OV) followed by osmotic treatment of chicken fillets at 15 °C. Chicken fillets were immersed in an osmotic solution consisting of 40% glycerol and 5% NaCl with (OV/OD) and without (OD) prior antioxidant enrichment in a hypotonic oregano solution.

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Determination of inactivation kinetics, associated with thermal processing of foods and obtained from dynamic temperature experiments, requires carefully designed experiments, the primary element being the selection of the appropriate temperature profile along with a carefully planned sampling schedule. In the present work, a number of different dynamic temperature profiles were investigated in terms of their ability to generate accurate kinetic parameters with low confidence intervals (CIs). Although alternative models have been also tested, our work was concentrated on thermal inactivation kinetics that could be described by the classical D-z values.

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Recently, consumers' demand for fresh, nutritious, and convenient food has shown a significant rise. This trend has forced increased sales of minimally processed and/or pre-packed fruit- and vegetable-based products. New product development and the diversification of plant-based foods have supported this growth.

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The osmotic dehydration (OD) of tomatoes in solutions of alternative sweeteners was investigated using Response Surface Methodology (RSM), while selected desirability functions were implemented in order to define the optimum process parameters (temperature/duration of osmotic treatment, osmotic solution composition and concentration). Mass exchange, color and texture were measured during the process. Changes in color occurred rapidly at the beginning of the process, while firmness was significantly increased, indicating that OD processing led to tomato texture improvement.

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Osmodehydrofreezing (ODF), a combined preservation process where osmotic dehydration is applied prior to freezing, achieves several advantages, especially in plant tissues, sensitive to freezing. OD pre-treatment can lead to the selective impregnation of solutes with special characteristics that reduce the freezing time and improve the quality and stability of frozen foods. ODF research has extensively focused on the effect of the osmotic process conditions (e.

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Systematic kinetic modeling is required to predict frozen systems behavior in cold dynamic conditions. A one-step procedure, where all data are used simultaneously in a non-linear algorithm, is implemented to estimate the kinetic parameters of both primary and secondary models. Compared to the traditional two-step methodology, more precise estimates are obtained, and the calculated parameter uncertainty can be introduced in realistic shelf life predictions, as a tool for cold chain optimization.

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The objective of this work is the comparative study of different osmotic treatments at 37 °C on the quality and shelf life of chilled sea bass fillets. Fish fillets were treated using osmotic solutions consisting of oligofructose (40%-50%-60%) and 5% NaCl with (BP/OT) and without (OT) former antioxidant enrichment by using distillation by-products. Water activity decreased to approximately 0.

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The quality and preservation of fresh-cut fruits can be improved by applying mild, non-thermal pre-treatments, such as osmotic dehydration (OD). The aim was to model the effect of OD on mass transfer and quality preservation. Apricot pieces were immersed in multi-component solutions comprising glycerol, erythritol, steviol glucosides and mineral salts, at various time-temperature conditions (25-45 °C for 3-240 min, w/w = 1/5).

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Background: Peach is a perishable fruit of great importance for the Greek food export market which is prone to rapid deterioration after harvesting. Its short shelf life can be substantially prolonged by applying an appropriate osmotic dehydration (OD) pre-treatment, which is a mild, non-thermal procedure. The aim of this study was to describe mass transfer and quality retention induced by the OD process.

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Traditionally, for the determination of the kinetic parameters of thermal inactivation of a heat labile substance, an appropriate index is selected and its change is measured over time at a series of constant temperatures. The rate of this change is described through an appropriate primary model and a secondary model is applied to assess the impact of temperature. By this approach, the confidence intervals of the estimates of the rate constants are not taken into account.

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