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In this study, benchmarking of methods used for assessing freeze damage in potatoes was carried out. Initially, the samples were frozen by subjecting them to three different temperatures (i.e. at – 18 °C, − 30 °C, and at − 74 °C). Then, different analytical techniques comprising of focused methods (i.e. cryo-Scanning elctron microscopy-cryo-SEM, confocal laser scanning microscopy-CLSM) and global methods (i.e. texture analysis, low field nuclear magnetic resonance (NMR), exudate loss and colour change) were used to assess the impact of the freezing treatment from the different point of view addressed by each method. As a result, each of these methods were able to distinguish significantly fresh samples from the frozen-thawed samples. Focused methods like cryo-SEM and CLSM methods could differentiate the impact of all three different protocols. Meanwhile, texture analysis (including conventional method and novel method based on a touchless laser puff firmness tester), NMR and exudate loss could only determine the quality difference between − 18 °C and − 74 °C freezing conditions. Colour analysis was found as an inappropriate parameter for comparing the three freezing protocols. Among all analytical techniques, cryo-SEM provides the most authentic information about the product as the analysis is performed in frozen state, while for other techniques the product is thawed prior to analysis.

Although freezing is known as the best method of food preservation, physical and chemical changes that occur to the cellular structure during processing and storage may damage the quality of food products. Most freeze damages are associated with ice crystal morphology (size, number, shape and distribution) which in turn affects the microstructure of the frozen food. Therefore, the evaluation of frozen food microstructure provides opportunities for monitoring the ice crystal morphology and also identifies freeze damage at cellular level which can be linked with the final quality of frozen food products. In this review, the most important physical damages that occur during freezing and storage of food matrices are described. In addition, methods for evaluating and observing the morphology of ice crystals and microstructure of frozen food stuffs are comprehensively discussed. An understanding of the freeze damage and their relationship with ice crystal morphology can contribute to the improvement of the freezing process as well as to the frozen product quality.

This paper investigated the effects of heat treatment (75 °C × 18 s and 100 °C × 18 s) and wet-mix total solids level (TS: 50 and 60%, w/w) on the physicochemical and techno-functional properties of model infant milk formula (IMF) powders. IMF produced from wet-mixes with 50% TS preheated at 75 °C (50%-75°C) exhibited the longest wettability time (55 ± 2 s) and the poorest flowability, explained by the small particle size (D [4;3]= 16.5 ± 2.29 μm) and low poured bulk density (0.27 ± 0.02 g/cm3). Larger particles were obtained by increasing both pasteurization temperature and TS. Further, powders from 60% TS wet-mixes showed less particle size uniformity, leading to better packing and higher bulk densities. 50%-75°C powders also showed the lowest onset glass transition temperature, which may affect its storage stability. Wettability time was reduced by increasing TS from 50 to 60% or by increasing pre-heating temperature from 75 to 100 °C. However, as observed by low-field nuclear magnetic resonance, the increase in the pasteurization temperature slowed down the global rehydration process. The flowing properties of the powders improved by increasing TS level of the wet-mix. In conclusion, the pre-spray drying wet-mix processing variables, pasteurization temperature and TS level, had a major effect on the physicochemical and functional properties of the IMF powders. It is crucial to understand how variations in the process parameters affect these powder characteristics, due to their functional, technological and economic importance.

The present study aimed to characterize wastewater fractions obtained after the wet extraction of proteins from legumes. In addition, the suitability of wastewater fractions for the potential recovery of high value-added compounds was also examined, and consequently, the prevention of the environmental impact of these wastes was explored. Similar to the industrial production of proteins, wet alkaline and acidic extractions of proteins from faba bean and pea flours were performed in two stages of extraction. The different wastewater fractions were characterized by measuring their organic matter content, total solids (TS), total dissolved solids (TDS), electrical conductivity (EC), pH, and turbidity. The value-added compounds from these wastewater fractions were quantified, which included the protein content, carbohydrate content, phenolic content, and antioxidant activity. In addition, the phenolic compounds in these factions were identified and quantified. It was observed that the fractions obtained in the first extraction stage had 60%–90% higher organic matter content, measured as the chemical oxygen demand (COD), compared to the second fractions, indicating a higher environmental impact of the former in case of disposal. The results obtained for COD, TS, TDS, EC, pH, and turbidity demonstrated that microfiltration reduced only the turbidity (85%), and consequently, a decrease was observed in the particulate matter, while there was a practically negligible reduction in the soluble matter. Wastewater from faba exhibited the highest polyphenol content and antioxidant activity, and was, therefore, considered the most valuable fraction for potential valorization.

Preparation of a bolus is a complex process with both food comminution and degree of lubrication with saliva playing an important role in a safe swallow. Swallowing disorders i.e. dysphagia, are especially present among the elderly population and often lead to choking and further health complications. The aim of this research was to investigate the relationship between the perception of ease of swallowing in the elderly and the rheological parameters of particulated foods, using broccoli purees as a model system. Particulated foods can be described as a concentrated dispersion of plant particles in a fluid phase. The effect of the fluid phase (Newtonian vs. shear thinning) and dispersed phase (plant particles with different size distribution and morphology) on the rheological properties of simulated boli was studied by characterising shear viscosity, viscoelasticity, yield stress, extensional viscosity and cohesiveness. Ease of swallowing and mouthfeel were evaluated by a semi trained healthy elderly panel (n = 19, aged 61 to 81). Ease of swallowing was correlated with the presence of yield stress and extensional viscosity in the bolus, characteristic of boli with xanthan gum as the fluid phase. Although the properties of the fluid phase played a dominant role in the ease of swallowing, compared to the dispersed phase, both components played a role in the rheological properties of the bolus and the perception of ease of swallowing by the elderly panel. These results provide insights into the design of personalised foods for populations with specific needs such as those suffering from swallowing disorders.

This study considered the effect of low energy microwave assisted freezing (MAF) on freezing time and quality attributes (microstructure, texture, drip loss and colour) of apple and potato. MAF of apples and potatoes was performed by applying constant microwave (MW) power (167 W/kg) and pulsed MW power (500 and 667 W/kg with 10 s pulse width and 20 s pulse interval resulting in an average power of 167 and 222 W/kg) during the freezing process. The temperature profile was monitored during the freezing process, and the microstructure was examined using X-ray micro-tomography and cryo-SEM. Other quality parameters such as texture, drip loss and colour were evaluated with thawed samples. It appeared that the freezing time was not affected by the MAF process. It is the first time that a MAF process is used for freezing plant-based products and showed that the application of microwaves during freezing process caused less freeze damage than the control condition.

The process optimization and biological characterization of marshmallow root polysaccharides (MRPs) obtained from the microwave-assisted extraction (MAE) were studied. The highest MAE-yield (14.47%) was optimized at 457.32 W and 75 °C for 26 min. The extracted crude polysaccharides were purified using ion-exchange and gel-filtration chromatographies and eluted a single symmetrical narrow peak, showing a homogenous fraction (MRP-P1) with a molecular weight of 4.87 × 104 Da. The surface morphology of polysaccharides and functional groups of MRP-P1 were determined by employing scanning electron microscopy and Fourier-transform infrared spectroscopy, respectively. The major monosaccharide composition of MRPs were the three monomers of rhamnose, galactose, and glucose. The antioxidant, antimicrobial, and antitumor activities were increased in a concentration-dependent manner (1.0-10.0 mg/mL). MRP-P1 exhibited a strong in vitro antiproliferative activity against lung (A549), liver (HepG2), and breast (MCF-7) cancer cells. The anticancer activity of polysaccharides extracted under optimal MAE conditions was highly associated with their antioxidant and antibacterial functions.

Within a few weeks the world has changed, at the time this text is written (May 2020) more than 3.5 million people have been confirmed cases of COVID-19 and estimations propose up to a hundred times the number of actually infected. A third of the global population is on lockdown and a large part of our global economic activity has stopped. Food and access to food has played a visual role in portraying the impact of the outbreak on our society, with images of empty supermarket shelves appearing in mainstream media. In some countries closed schools resulted in many children not having access to free meals and mobilised a number of charities. While parts of the world are now exiting lockdown and measures start relaxing the near future remains uncertain with more waves of the pandemic expected. Given that there is currently no evidence to show that transmission of COVID-19 could occur through food or food packaging there has been limited discussion on the issue, implications and potential future scenarios within the wider food science community., peer-reviewed

International audience; Food freezing is a complex process, involving heat transfer and a series of physical and chemical changes which may profoundly affect the product quality. Several novel freezing methods have been developed in recent times taking into account the energy saving and/or quality preservation to a greater extent upon thawing. Electro-freezing technique, especially electric field assisted freezing is gaining momentum among them; it offers less energy intensive freezing conditions (higher set point ambient temperature, lower air velocity), and allows better quality retention. In the present short review article, a focused overview of the main findings and the latest studies regarding the applications of electro-freezing in food is given.

Although Arctic charr side streams contain limited amounts of fish flesh, they are a rich fish oil source (46.3 ± 0.6%). The aim of the study was to investigate the potential for valorization of Arctic charr filleting side streams through the extraction of oil by supercritical CO2 technology. The effect of temperature (40 °C and 80 °C) and pressure (20, 35 and 45 MPa) on the final extract after supercritical fluid extraction (SFE) was evaluated. Temperature increase enhanced the yield but decreased the antioxidant activity at 45 MPa, did not affect the yield and the antioxidant activity at 35 MPa, whereas yield was limited at 20 MPa and 80 °C. Extracts were rich in monounsaturated fatty acids (56.7–58.3%, especially oleic acid 37.2–38.0%), and polyunsaturated fatty acids (20.2–26.1%, especially DHA 7.3–11.4%). The presence of astaxanthin significantly preserved the extracts from oxidation. Industrial relevance Supercritical carbon dioxide extraction is a green technology appropriate for the recovery of non-polar and heat sensitive compounds. The extracted Arctic charr oils were rich in polyunsaturated fatty acids and astaxanthin which inhibited oxidation in combination with the absence of oxygen and light during the process. This technology could be an excellent alternative for more sustainable valorization of fish processing side streams.

Within the context of circular economy, there is an increasing interest to utilise agrifood by-products. However, extensive extraction and purification steps make the valorisation of side streams not always cost effective. Therefore, an increased knowledge of the functionality of unrefined side streams could increase their utilisation in food products. We investigated the thermal gelation of mixed legume systems containing a commercial pea protein isolate (Pisum sativum) and the unrefined fraction remaining after protein extraction from lentils (Lens culinaris). The unrefined lentil fraction contained mainly starch (similar to 45 g/100 g) and insoluble cell wall polysaccharides (similar to 50 g/100 g) with minor amounts of soluble protein (4 g/100 g) and polyphenols (

Freezing is an efficient and widely used method of food preservation. However, it can also cause irreversible damages at cellular level which in turn degrade the overall quality of the frozen food products. Therefore, qualitative and quantitative methods and technologies that will be able to evaluate with accuracy the freeze damage are of great importance. This review paper provides a comprehensive study of the methods that have been used to evaluate the freeze damage in fruits and vegetables. Further than the principles and the applications of those methods, the advantages and the limitations are also being discussed.

The effect of microwave assisted and conventional water blanching of mango (Mangifera indica) under two different blanching scenarios, High Temperature Short Time (HTST) and Low Temperature Long Time (LTLT) on ascorbic acid oxidase (AAO) inactivation and on vitamin C (L-ascorbic acid & dehydroascorbic acid) retention were comparatively studied. The impact of alternative blanching processes and subsequent frozen storage on enzymatic inactivation and vitamin C was kinetically modelled. Both water and microwave HTST as well as LTLT microwave treatments of mango pieces showed high degree of AAO inactivation. An approximately 30% residual AAO activity was observed and was described through a first order fractional conversion model. Microwave assisted blanching led to higher retention of total vitamin C in both LTLT and HTST treatments. In LTLT water blanching, vitamin C loss was mainly caused by mass transfer phenomena rather than temperature degradation, while after HTST treatments the decrease of total vitamin C content seemed to be mainly related to thermal degradation than due to the leakage of the nutrients in the blanching medium. Further inactivation of the thermostable fraction of AAO and degradation of total vitamin C were observed after frozen storage for 130 days at −18.63 ± 0.48 °C. Funding details: 660067, MSCA, H2020 Marie Skłodowska-Curie Actions; Funding text: This research work and the contribution of Dr. Epameinondas Xanthakis is part of COLDμWAVE project that has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 660067 .

Several techniques have been developed during the 20th century in order to preserve foods. These innovative technologies vary considerably and embrace physical technologies (e.g., high hydrostatic pressure and high-pressure homogenization), electromagnetic technologies (e.g., pulsed electric fields, ohmic heating, microwaves, radio-frequency, and UV-light), acoustic technologies (e.g., ultrasound and shockwaves), and others such as membrane filtration and dense phase CO 2 . In this chapter, the theoretical background and definition of the technologies are explained together with a description of the equipment, main technological/processing parameters, and some advantages and limitations from a technological point of view.

Due to the importance of powder flow properties and the variety of available measuring methods, several studies were published regarding the comparison of different flow properties testers. Within this work, a ring shear tester from Dr. Dietmar Schulze and a powder flow tester from Brookfield Engineering Laboratories Inc. were compared for cumin (Cuminum cyminum L.), oregano (Origanum vulgare), and onion (Allium cepa) powder and granules. The spices showed similar flow behavior from both methods. Flow function plots and effective angle of internal friction measurements indicated contiguous trends and showed that the methods were comparable.

This work studied the effect of composition of powders and water content on mixture quality (MQ) of three binary powder mixtures with good (salt/paprika or salt/sugar) or poor mixing (salt/oregano) behaviour. The mixing behaviour was assessed using coefficient of variation. Results showed that mixture composition did not influence the MQ of sugar/salt and paprika/salt within 20–80% salt content range but it did influence the MQ of oregano/salt with a progressive dis-improvement in MQ with higher oregano content and also for low concentrations of 1% salt. Water content did have an effect on mixing behaviour. When paprika with high water activity ( a w ) was mixed with salt, the time required to reach good MQ was longer because of the increased cohesiveness and when oregano with high a w was mixed with salt it displayed improved MQ because salt particles were able to stick onto the larger oregano particles and reduced segregation.

Ice nucleation is a stochastic process and it is very difficult to be controlled. Freezing technologies and more specifically crystallisation assisted by magnetic, electric and electromagnetic fields have the capability to interact with nucleation. Static magnetic field (SMF) may affect matter crystallisation; however, this is still under debate in the literature. Static electric field (SEF) has a significant effect on crystallisation; this has been evidenced experimentally and confirmed by the theory. Oscillating magnetic field induces an oscillating electric field and is also expected to interact with water crystallisation. Oscillating electromagnetic fields interact with water, perturb and even disrupt hydrogen bonds, which in turn are thought to increase the degree of supercooling and to generate numerous fine ice crystals. Based on the literature, it seems that the frequency has an influence on the above-mentioned phenomena. This review article summarizes the fundamentals of freezing under magnetic, electric and electromagnetic fields, as well as their applicability and potentials within the food industry.

Dielectric properties of a variety of foodstuffs were measured during freezing and thawing conditions, and are presented here as functions of temperature. Measurements were done with the Agilent 85070 high temperature dielectric probe. The differences in characteristics of the graphs resulting from cooling and thawing are discussed. A specific model accommodating the amount of frozen water in the food sample as a function of temperature is used and compared to experimental results. The mass fraction of each component is coupled to the dielectric properties of each fraction to evaluate the effective dielectric properties based on a two phases Maxwell-Wagner model considering ice as a dispersed fraction and food as a continuous fraction. The unknown dielectric properties of dry matter and an adjusting coefficient are used to optimize the fitting between experimental data and calculated data.

Freezing is the most popular and widely used food preservation method of the modern times. The freezing process of food matrices is related to their high water content and its metamorphoses into ice on cooling. The final quality of the frozen product is highly depended on the ice crystal morphology because it can cause irreversible damage on the microstructure of the food matrix. Supercooling and ice nucleation temperature need to be controlled both in suppressing and inducing the solidification to improve technological processes such as freeze drying, freeze concentration, cryopreservation, ice formation and cold-energy storage both in food industry and domestic preservation. However, the mechanism of freezing is not yet well known and it is affected by several factors. Several emerging technologies have been recently proposed for ice nucleation control during freezing. This review article is focused on the alternative freezing methods such as ultrasound waves, magnetic, electric, and electromagnetic field assisted freezing. In addition, the properties, mechanism of action and possible applications of electrofreezing are extensively discussed.

Report on ice crystal properties and vegetable microstructure after microwave assisted freezing

Design and description of the prototype MW blanching laboratory equipment

E. Xanthakis, V. Valdramidis. “Impact of heating operations on the microbial ecology of foods”. In Anderson de Souza Sant'Ana (Eds.), Modeling the Microbial Ecology of Foods: Quantitative Microbiology in Food Processing, Chapter: 5, Publisher: John Wiley & Sons, Ltd., pp.117-142 (2017).

Report on ice crystal growth computer modelling and simulations during freezing of food model systems

Modelling and computer simulations of microwave blanching of fruits

There are several drawbacks of heat processes as their application may also lead to nutritional and quality deterioration of the food product. The chapter presents basic information regarding the heating processes and unit operations and covers the impact of these operations on food-borne microorganisms. It describes the main cooking methods, such as grilling, broiling, and roasting. Quantitative methodologies are the main tools to describe the impact of a process as well as the storage conditions post-processing on the food stability. In order to assess the efficacy of a specific processing technology, the estimation of the time to achieve a certain number of log reductions can be applied. The most common process in the food industry is the thermal process. The chapter reviews a number of different thermal processes and outlines critical issues in relation to their efficacy and to their impact on the microbial inactivation.

International audience; Food processing is a major part of the modern global industry and it will certainly be an important sector of the industry in the future. Several processes for different purposes are involved in food processing aiming at the development of new products by combining and/or transforming raw materials, to the extension of food shelf-life, recovery, exploitation and further use of valuable compounds and many others. During the last century several new food processes have arisen and most of the traditional ones have evolved. The future food factory will require innovative approaches food processing which can combine increased sustainability, efficiency and quality. Herein, the objective of this review is to explore the multiple applications of high voltage electric field (HVEF) and its potentials within the food industry. These applications include processes such as drying, refrigeration, freezing, thawing, extending food shelf- life, and extraction of biocompounds. In addition, the principles, mechanism of action and influence of specific parameters have been discussed comprehensively.

The applications of nanopowders are increasing significantly over the last years. In most of these applications, the flow behavior of the nanopowders seems to be a complicated, multiparametric but critical issue for the proper design of the processes. We have investigated, classified and compared several different metal oxide nanoparticles with respect to their flow properties. The flow properties of titania, silica and alumina hydrophilic nanopowders as well as their corresponding hydrophobic counterparts were determined by means of an annular shear cell powder flow tester (PFT). All the tested powders showed difficulties in flow while the titania nanopowders showed the highest difficulty among them. The results acquired regarding the compressibility, the flow functions and the effective angle of internal friction revealed that in all the cases the hydrophobic nanopowder seemed to be more cohesive than its hydrophilic counterpart. Moreover, the nanoparticles, no matter their polarity, showed negligible hygroscopicity while in the case of the alumina nanopowders the flow properties can be significantly influenced by ca. 1% (w/w) of moisture content.

The monoterpene perillyl alcohol (POH), an intermediate in the plant terpenoid biosynthetic pathway, has well-established tumor chemopreventive and chemotherapeutic potential. We have previously shown that the primary hydroxyl group of POH is essential for its antitumor and anti-angiogenic activities. In the current study we present the enzymatic synthesis of two POH derivatives with different polar and hydrophobic characteristics, namely perillyl glucoside and perillyl glucoside fatty ester, through a two-step modification. Initial glucosylation of POH on its active hydroxyl group with D-(+)-glucose and subsequent esterification of the perillyl glucoside product with vinyl laurate were carried out using almond beta-glucosidase and lipase B from Candida antarctica, respectively, in a low-water system. Optimization of enzymatic reactions was performed to achieve the highest possible conversion yields. The antitumor cell proliferation activity against mouse Lewis lung carcinoma cells was retained in both derivatives, although the perillyl glucoside ester showed greater inhibition than perillyl glucoside. Our results underline the feasibility of enzymatically producing novel bioactive analogs of phytochemicals displaying useful physicochemical properties. Biocatalysis and Biotransformation

In this study, a novel experimental setup was developed and an innovative process was implemented aiming at the application of microwave radiation during freezing of a food matrix. The results acquired from the present study are considered as remarkable and promising. The developed freezing process was applied on pork tenderloin samples. The application of microwaves during cooling the samples caused oscillated decrease of temperature and had a significant impact on the crystallization process as the degree of supercooling was decreased circa 92% under the tested conditions. The meat microstructure evaluation showed a 62% decrease in the average ice crystal size when samples were frozen under a microwave field as compared to the conventional freezing process. These results indicate that the application of microwave radiation during freezing may reduce the damage of the meat tissue and in turn to retain better texture in the frozen meat. Industrial relevance The reduction of freeze damage exerted to any tissue undergoing freezing remains a challenge. The mechanical and biochemical stress caused by the ice crystals to the cellular membranes results in irreversible tissue damage. The application of electric and/or magnetic disturbances has been identified as a possible means to reduce the size of ice crystals during freezing of biological tissues. In the present study microwaves were applied during freezing of pork meat. Our results indicate that the size of the formed ice crystals was significantly reduced during microwave assisted freezing leading to a lower damage on the microstructure of meat. This paper describes an innovative and novel freezing process that could be used in order for higher quality frozen products to be produced.

In this chapter, novel freezing methods involving the application of electrical and magnetic disturbances are covered. Freezing is one of the most popular and widely used food preservation methods. The freezing process of food matrices is based on their dominant constituent, which is water. The phase transition of liquid water into ice during the crystallization stage is closely related to the final quality of the frozen product. For this reason, several emerging technologies have been developed to control the crystallization process and to improve the formation as well as the growth of ice crystals. This chapter contains an overview of the theoretical and experimental methods available for the application of static electric, oscillating electric, and magnetic fields related to the freezing process. Understanding the importance of these techniques for improving freezing processes requires analyzing the mechanisms that arise from the findings of these studies.

The objective of this research was to evaluate the influence of static electric field (SEF) on the freezing of pork meat (pork tenderloin muscle) with respect to the size of ice crystal formulation. The results showed that by increasing the strength of the static electric field, the degree of supercooling was reduced. The measured degree of supercooling varied from 3.93 ± 1.3 °C to 1.92 ± 1.45 °C for the control and the frozen sample under 12 kV SEF, respectively. Meat microstructure was investigated after Carnoy fixation of the frozen tissues. The overall relative surface of the ice crystals was unchanged. The average equivalent circular diameter of the ice crystals was significantly reduced with increasing SEF; values from 32.79 ± 4.04 μm for the control to 14.55 ± 8.20 μm for the sample frozen at the maximum magnitude electric field which was tested were observed respectively. These findings demonstrate clearly the advantage of freezing under SEF which appears as a promising and innovative freezing process for food systems. Industrial relevance The reduction of freeze damage exerted to any tissue undergoing freezing remains a challenge. The mechanical and biochemical stress caused by the ice crystals to the cellular membranes results in irreversible tissue damage. Freezing under static electric field (SEF) has been identified as a possible means to reduce the size of ice crystals during freezing of biological tissues. In the present study SEF was applied during freezing of pork meat. Our results indicate that the size of the formed ice crystals was significantly reduced under SEF freezing leading to a lower damage on the microstructure of meat. This paper describes an innovative freezing process that could be used in order for higher quality frozen products to be produced.

Flavonoids and terpenoids are promising candidates for use as functional foods and novel therapeutics due to their prominent biological activities. However, the use of several bioactive plant compounds is limited by low stability and solubility problems. This review underlines the feasibility of enzymatic synthesis of novel bioactive analogs of selected flavonoids (silybin, rutin) and terpenoids (perillyl alcohol, POH) in nonconventional reaction systems. The effect of various parameters on the enzymatic acylation and/or glucosylation of these phytochemicals was studied. Also, the role of the structure of the novel Molecules in relation to their biological function was investigated in various cancer cell lines. Pure and Applied Chemistry

A comparative study was performed in the enzymic resolution of the isomers of 2-(4-methoxybenzyl)cyclohexyl acetates 1 and 2. The investigation consisted in application of three commercially available lipases (Novozyme 435, Lipozyme IM and non-immobilized powdered lipase from Candida antarctica), two ionic liquids (1-butyl-4-methylpyridinium chloride and 1,3-dimethylimidazolinium methyl sulfate), three modifications of the reaction conditions and two respective isomers of the racemic substrate (1 and 2), and resulted in our finding the appropriate conditions to get both of the products, stereoisomers of 2-(4-methoxybenzyl)cyclohexanol (3; 1S,2S) or (5; 1S,2R), and (in some cases) also the stereoisomers of the deracemized substrate (4; 1R,2R) or (6; 1R,2S) with high or acceptable enantiomeric purity.

Presented in 13th International Biotechnology Symposium and Exhibition, 2008, 12–17 October, Dalian, China Phytochemicals, plant compounds with low toxicity and prominent biological actions, are promising candidates for use as functional foods and novel therapeutics. Flavonoids and terpenoids comprise two very interesting classes of phytochemicals as they have been proved effective in prevention and therapy of several cancer types both in vitro and in vivo (Surh, 2003) As chemical heterogeneity among phytochemicals, even within the same class, justifies differences in their action mechanisms, bioavailability and pharmacokinetic profiles, there is a necessity to investigate the structural characteristics that are essential for their biological function. Furthermore, because the use of several bioactive plant compounds is limited by low stability and solubility problems, there is a requirement of improving their physicochemical properties by introducing selective modifications thus extending their application in pharmaceutical and food industry (Srivastava et al., 2005). In these studies, by using enzymatic acylation and/or glucosidation of selected flavonoids (silybin, naringin, rutin) and monoterpenes (perillyl alcohol) in non-conventional reaction systems (Kontogianni et al., 2001) we attempted to investigate their structure-biological activity relationship and also to improve their stability and solubility. We synthesized several novel derivatives which showed compared to parental compounds similar or even increased anti-tumor activities while their physicochemical properties were improved. Our results underline the feasibility of enzymatically producing novel bioactive analogues of phytochemicals displaying desired physicochemical properties. Finally, current research in our laboratory using systemic approaches (genomics, metabolomics) would provide a more global understanding of the mechanisms linked to the anti-tumor actions of the examined phytochemicals and their derivatives.

Graphical abstract, The paper aims at optimising and validating possible routes toward the full valorisation of grape agrowaste to produce bioactive molecules and new materials. Starting from Merlot red pomace, phenol complex mixtures were successfully extracted by using two different approaches. Extracts obtained by solvent-based (SE) technique contained up to 46.9 gGAeq/kgDW of total phenols. Depending on the used solvent, the prevalence of compounds belonging to different phenol families was achieved. Pressurized liquid extraction (PLE) gave higher total phenol yields (up to 79 gGAeq/kgDW) but a lower range of extracted compounds. All liquid extracts exerted strong antioxidant properties. Moreover, both SE and PLE extraction solid residues were directly exploited (between 5 and 20% w/w) to prepare biocomposite materials by direct mixing via an eco-friendly approach with PHBV polymer. The final composites showed mechanical characteristics similar to PHVB matrix. The use of pomace residues in biocomposites could therefore bring both to the reduction of the cost of the final material, as a lower amount of costly PHBV is used. The present research demonstrated the full valorisation of grape pomace, an agrowaste produced every year in large amounts and having a significant environmental impact.

Enzyme inactivation, the nutritional value during microwave blanching of vegetables and the efficiency of the developed MW blanching process

Freezing is the most popular and widely used food preservation method of the modern times. The freezing process of food matrices is related to their high water content and its metamorphoses into ice on cooling. The final quality of the frozen product is highly depended on the ice crystal morphology because it can cause irreversible damage on the microstructure of the food matrix. Supercooling and ice nucleation temperature need to be controlled both in suppressing and inducing the solidification to improve technological processes such as freeze drying, freeze concentration, cryopreservation, ice formation and cold-energy storage both in food industry and domestic preservation. However, the mechanism of freezing is not yet well known and it is affected by several factors. Several emerging technologies have been recently proposed for ice nucleation control during freezing. This review article is focused on the alternative freezing methods such as ultrasound waves, magnetic, electric, and electromagnetic field assisted freezing. In addition, the properties, mechanism of action and possible applications of electrofreezing are extensively discussed.

Freezing is the most popular and widely used food preservation method of the modern times. The freezing process of food matrices is related to their high water content and its metamorphoses into ice on cooling. The final quality of the frozen product is highly depended on the ice crystal morphology because it can cause irreversible damage on the microstructure of the food matrix. Supercooling and ice nucleation temperature need to be controlled both in suppressing and inducing the solidification to improve technological processes such as freeze drying, freeze concentration, cryopreservation, ice formation and cold-energy storage both in food industry and domestic preservation. However, the mechanism of freezing is not yet well known and it is affected by several factors. Several emerging technologies have been recently proposed for ice nucleation control during freezing. This review article is focused on the alternative freezing methods such as ultrasound waves, magnetic, electric, and electromagnetic field assisted freezing. In addition, the properties, mechanism of action and possible applications of electrofreezing are extensively discussed.

Enzyme inactivation, the nutritional value during microwave blanching of vegetables and the efficiency of the developed MW blanching process

Agro-waste reduction and reuse are among the current main social challenges. In this perspective, the present research was aimed at the complete valorisation of Garganega grape pomace by recovering bioactive phenol extracts and by testing the solid fibre extract residues in composite formulation for packaging applications. The pomace was derived from white wine production, therefore, respect to red pomace, it was promptly removed from must after pressing, and its exploitation can be particularly interesting and valuable as still rich in active compounds. Phenol extracts were obtained both via solvent-based and pressurised liquid extractions and their phytochemical compositions were compared in terms of total amount of phenols, flavonoids, flavanols, anthocyanins, hydroxycinnamic acids, and reducing sugars. Antioxidant activity and detailed phenol profiles were also achieved. The highest phenol yield was obtained via solvent-based extraction with 75% acetone (v/v), solid/liquid ratio 1:5, 2h incubation at 50°C (77.9 gGAeq/kgDW). The fibrous solid residue of the extraction was characterized via thermogravimetric analysis and used for composite preparation by melt mixing with the renewable and biodegradable PHBV polymer through a green approach (solvent-less process). The composites resulted thermally stable at high temperatures, showing initial degradation processes only at temperatures higher than 250°C. Differential scanning calorimetry analyses were carried out to study melting and crystallization phenomena, while mechanical properties were investigated by tensile tests. The materials finally showed properties similar to those of the matrix. The bio-composites can be considered as an alternative to plain PHBV, since they are less expensive and eco-friendlier thanks to a reduced polymeric content, and they could represent a suitable way for full agro-waste exploitation.