New technologies to enhance quality and safety of table eggs: ultra-violet treatment and modified atmosphere packaging

In the present study the effect of ultra-violet (UV) treatment alone and in combination with 100% CO2 modified atmosphere packaging (MAP) was evaluated both on the survival of naturally occurring bacteria, as well as on quality parameters of table eggs during 28 days of storage at 21\ub0C. Table eggs were collected from the conveyor belt after the UV module, and placed on carton trays. A representative number of carton trays were packed in a high barrier multilayer pouch filled with 100% CO2. All eggs were stored at 21\ub0C and analysed at 0, 1, 7, 14, 21 and 28 days of storage. Eggs not treated with UV and not packed were also included. On the eggshells total colony count, total coliforms and faecal coliforms counts, as well as the detection of Salmonella spp. were investigated. Moreover, chemical-functional parameters such as weight loss, albumen pH and Haugh Unit (HU) were evaluated. The total colony count on UV treated table eggs was approximately 1 log10 CFU/g lower than untreated eggs (2.27 vs 3.29 log10 CFU/g). During storage, CO2 packed eggs maintained the initial values of HU, whereas the albumen pH decreased up to 1.5-2 points in comparison to unpacked eggs. The UV treatment was effective in reducing the total colony count on the surface of table eggs. MAP showed a great potential in maintaining/enhance the technological properties of egg constituents (higher foam stability of the albumen for meringue preparation) without significantly impacting on the microbial load of table eggs

Modification of Transverse NMR Relaxation Times and Water Diffusion Coefficients of Kiwifruit Pericarp Tissue Subjected to Osmotic Dehydration

The objective of the present study was to evaluate cellular compartment modifications of kiwifruit (Actinidia deliciosa) outer pericarp tissue caused by osmotic treatment in a 61. 5 % sucrose solution, through the quantification of transverse relaxation time (T2) and water self-diffusion coefficient (Dw) obtained by low field nuclear magnetic resonance means. Raw material ripening stage was taken into account as an osmotic dehydration (OD) process variable by analyzing two different kiwifruit groups, low (LB) and high (HB) °Brix. Three T2 values were obtained of about 20, 310, and 1,250 ms, which could be ascribed to the proton populations, located in the cell walls, in the cytoplasm/extracellular space, and in the vacuoles, respectively. According to T2 intensity values, vacuole protons represented between 47 and 60 % of the total kiwifruit protons, for LB and HB kiwifruits, respectively. The leakage of water leading to vacuole shrinkage seemed to cause concentration of solutes, retained by the tonoplast, making the vacuole T2 value decrease along the OD. As expected, the Dw values of raw kiwifruits were lower than the value of the free pure water. The water mobility (and hence Dw), depending on the kiwifruit distinctive cellular structures and solutes, decreased even more during OD due to water loss and sugar gain phenomena. Dw represents an average value of the diffusion coefficient of the whole kiwifruit tissue protons. In order to obtain Dw values specific for each cellular compartment, a multiple component model fitting was also used. According to these results, the vacuole water self-diffusion coefficient (Dw,v) was much higher than Dw.Fil: Santagapita, Patricio Roman. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industrias; Argentina. Università di Bologna; Italia. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Laghi, Luca. Università di Bologna; ItaliaFil: Panarese, Valentina. Università di Bologna; ItaliaFil: Tylewicz, Urszula. Università di Bologna; ItaliaFil: Rocculi, Pietro. Università di Bologna; ItaliaFil: Dalla Rosa, Marco. Università di Bologna; Itali

High-Intensity Ultrasonication as an Innovative Approach for the Softening of Wooden Breast Meat in Broilers

Considering the remarkable implications exerted by the occurrence of wooden breast (WB) abnormality on meat tenderness and marketability, the poultry processing industry demands the implementation of postmortem procedures that can improve the textural traits of chicken breasts affected by this defect. Within this scenario, this study aimed at exploring the effectiveness of high-intensity ultrasonication (HIU) in attenuating the toughness of WB fillets and evaluating its effects on the main technological properties and quality characteristics of chicken breast meat. Overall outcomes showed that HIU significantly reduced (P<0.01) the compression forces of both unaffected and WB raw meat without negatively affecting the main meat quality traits and technological properties, such as color and water holding capacity. The significant (P<0.05) increase in myofibrillar fragmentation index (MFI) observed in unaffected fillets might hint at an alteration of myofibril integrity following the mechanical action of ultrasonic waves. However, despite the effectiveness of HIUin improving the textural traits of raw WB meat, overall outcomes obtained through western blot and MFI analyses suggested that HIU did not remarkably alter the microstructure of myopathic muscles. The myodegenerative lesions typically occurring in WB muscles may have partially disguised the mechanical effects of ultrasonic waves on muscle cells’ structures, making the elucidation of the mechanisms that lead to the softening of WB meat particularly complex

Uticaj osmotske dehidracije na kivi: rezultati multianalitičkog pristupa proučavanja strukture

This paper presents the results of the comparison of different analytical techniques (Differential Scanning Calorimetry - DSC, Low Field Nuclear Magnetic Resonance - LF-NMR, Light Microscopy - LM and Transmission Electron Microscopy – TEM) in order to evaluate the mass transfer, water status and cellular compartment modifications of the kiwifruit outer pericarp tissue during osmotic dehydration treatment (OD). Two kiwifruit species, A. deliciosa and A. chinensis were submitted to OD. OD was performed in a 61.5 % w/v sucrose solution at three different temperatures (25, 35 and 45 °C), with treatment time from 0 to 300 min. Peleg’s model highlighted that the main response differences between the two kiwifruit species occurred during the initial phase of the osmotic treatment. DSC parameters appeared to be sensitive to water and solid exchange between fruits and osmotic solution. LF-NMR proton T2 revealed the consequences of the water-solid exchange on the cell compartments, namely vacuole, cytoplasm plus extracellular space and cell wall. During OD, the reduction of the vacuole proton pool, detected by LF-NMR, suggested a shrinkage of such compartment, confirmed by LM. Cell walls of outer pericarp showed considerable changes in size, structure and stain uptake during OD observed at TEM. The proposed multianalytical approaches should enable better design of combined processing technologies permitting the evaluation of their effects on tissue response.U ovom radu su prikazani rezultati poređenja različitih analitičkih tehnika (Diferencijalna skeniranja Kalorimetrija – DSC, Niska Polje nuklearna magnetna rezonanca - LF-NMR, svetlost mikroskopije - LM i Prenos elektronsku mikroskopiju - TEM), u cilju određivanja prenosa mase, statusa vode i modifikacije ćelija tkiva perikarpa kivija tokom osmotske dehidratacije tretmana (OD). Dve sorte kivija su bile izložene osmotskom tretmanu, A. deliciosa i A. chinensis. Osmotsko sušenje obavljeno je u 61,5% rastvoru saharoze na tri različite temperature (25, 35 i 45°C), sa vremenom trajanja sušenja od 0 do 300 minuta. Pelegovim modelom naglašene su glavne razlike između dve sorte kivija koje se događaju tokom početne faze osmotskog tretmana. DSC parametri osetljivi su na izmenu vode i čvrste materije između voća i osmotskog rastvora. LF-NMR-om otkrivene su posledice razmene vode i čvrste materije na ćeliju, odnosno vakuole, citoplazmu sa vanćelijskim prostorom i ćelijski zid. Tokom OD, smanjenje vakuole protona bazena, otkrivena je LF-NMR, predložio skupljanja takvog odeljka, potvrđeno LM. Ćelijske zidove spoljne perikarpa su pokazali značajne promene u veličini, strukturi i mrlja uzimanja u toku OD posmatrano na sistem. Predloženi multianalitical pristupi treba da omogući bolji dizajn u kombinaciji obrade tehnologija dozvoljava procenu njihovog uticaja na tkivo odgovor.Fil: Dalla Rosa, Marco. Università di Bologna; ItaliaFil: Tylewicz, Urszula. Università di Bologna; ItaliaFil: Panarese, Valentina. Università di Bologna; ItaliaFil: Laghi, Luca. Università di Bologna; ItaliaFil: Pisi, Annamaria. Università di Bologna; ItaliaFil: Santagapita, Patricio Roman. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industrias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rocculi, Pietro. Università di Bologna; Itali

Analysis by non-linear irreversible thermodynamics of compositional and structural changes occurred during air drying of vacuum impregnated apple (cv. Granny smith). Calcium and trehalose effects

[EN] Apple discs were impregnated with isotonic solutions of sucrose and trehalose with and without calcium addition and after air dried. In the vacuum impregnation experiments, the calcium and the replacement of sucrose by trehalose did not have significant effect on the final volumetric deformation of the samples. During air drying two stages of changes were considered. The first one lasted until the saturation of the intracellular liquid phase, and the second one from the saturation of the intracellular liquid phase until the end of the drying process. Mass transfer has been analysed applying nonlinear irreversible thermodynamics. Water flux, water chemical potential and tissue shrinkage have been taken into account in order to accurately describe the mass transfer phenomena during air drying. A precise definition of chemical potential allowed estimating the partial molar energy needed for breakages and the reversible and irreversible deformations of tissue structure coupled with mass transfer during air drying of apple. 2014 Elsevier Ltd. All rights reserved.The authors thank the Spanish Government (Ministerio de Ciencia e Innovacion) for financial support to the project AGL2009-09905. The authors also acknowledge the European Commission for its contribution throughout the FoodSPProcess Project.Betoret Valls, ME.; Betoret Valls, N.; Castagnini, JM.; Rocculi, P.; Dalla Rosa, M.; Fito Maupoey, P. (2015). Analysis by non-linear irreversible thermodynamics of compositional and structural changes occurred during air drying of vacuum impregnated apple (cv. Granny smith). Calcium and trehalose effects. Journal of Food Engineering. 147:95-101. https://doi.org/10.1016/j.jfoodeng.2014.09.028S9510114

Osmotic dehydration of organic kiwifruit pre-treated by pulsed electric fields and monitored by NMR

[EN] Osmotic dehydration (OD) is a widely used preservation technique that consists in the reduction in food water activity by the immersion of the biological tissue in hypertonic solutions. The aim of this work was to analyze the effect of pulsed electric fields (PEF) in mass transfer as a pre-treatment of the OD using NMR. In this sense, PEF pre-treatments were done using three different voltages (100, 250 and 400 V/cm) and 60 number of pulse. The OD of kiwifruit was carried out in 61.5% of sucrose solution at 25 °C, for a contact period from 0 to 120 min. The water distribution into the cellular tissue was studied by NMR relaxometry. In conclusion, NMR is an excellent technique for quantifying water molecules according to their interactions in the fruit tissue, obtaining the adsorbed water and opening the possibility to apply the BET model to fit the adsorbed isotherm over the whole range of water activity.The authors Urszula Tylewicz and Marco Dalla Rosa want to thank for the financial support provided by funding bodies within the FP7 ERA-Net CORE Organic Plus, and with cofounds from the European Commission. The author Maria Victoria Traffano Schiffo wants to thank the FPI Predoctoral Program of the Universidad Politecnica de Valencia for support her PhD studies, ERASMUS PRACTICAS program to finance her mobility to Italy. The authors Pedro J. Fito, Marta Castro-Giraldez and M. Victoria Traffano-Schiffo acknowledge the financial support from the Spanish Ministerio de Economia, Industria y Competitividad, Programa Estatal de I+D+i orientada a los Retos de la Sociedad AGL2016-80643-R.Traffano-Schiffo, MV.; Laghi, L.; Castro Giráldez, M.; Tylewicz, U.; Rocculi, P.; Ragni, L.; Dalla Rosa, M.... (2017). Osmotic dehydration of organic kiwifruit pre-treated by pulsed electric fields and monitored by NMR. Food Chemistry. 236:87-93. https://doi.org/10.1016/j.foodchem.2017.02.046S879323

Effect of pulsed electric field pre-treatment on microstructure and internal transport throughout osmotic treatment of organic kiwifruit.

Plant cellular structure could be considered a complex organized system where flows are carried out by different solutes or solvents transports systems. Passive transports, which is based on the free energy gradients, involve symplastic, apoplastic and aquaporins transmembrane transports. During osmotic dehydration (OD) treatment the semipermeable membranes such as plasma membrane and tonoplast, are forced to separate, due to the water losses from the vacuoles, starting the process known as plasmolysis, characterized by the loss of the turgor pressure. In the last years, OD has been extensively studied for the partial dehydration of fruits and vegetables in order to obtain semi-moist products; however, it presents some limitations such as the low dehydration rate and the high solute content in the final product. Therefore, the use of pre-treatment such as Pulsed Electric Fields (PEF) has been reported to facilitate water removal and to improve the quality of the dried or osmo-dried products. PEF is a non-thermal technology which involves the application of short and repeated voltage pulses to a biological tissue placed between two electrodes; it induces changes and reorganization in the electric conformation of the cell membrane, modifying the normal fluxes during drying process when it is used as a pre-treatment. In present work PEF has been applied as a pre-treatment prior OD of organic kiwifruits (Actinidia deliciosa cv Hayward) in order to evaluate its effect on the internal structure and internal water transport. PEF pre-treatments were performed using the following parameters: E= 100, 250 and 400 V/cm, 60 near-rectangular shape pulses, pulse width of 100 ± 2 μs and a repetition time of 10.0 ± 0.1 ms. The OD was carried out by immersing the samples in 61.5% sucrose solution at 25 °C for different time period (0-120 min). The samples were analyzed in terms of microstructure by Cryo-SEM microscopy and internal water transport by Time Domain Nuclear Magnetic Resonance (TD-NMR). The results showed that the application of a PEF pre-treatment before the OD produces a process of plasmolysis proportional to the electric field strength applied. It is because the PEF removes the mobile charges of the medium, such as electrolytes, organic acids, amino acids; Ca+2 is the major culprit of the plasmolysis because it fixes some of the junctions of the microtubules between the cell wall and the membrane. In addition, the process of plasmolysis induced by the electric field changes the behavior of kiwifruit tissue during the OD process. In a standard OD without any pretratment, the main transport is the symplastic, whereas if previously treated with PEF, the apoplastic transport is as important as the symplastic, considerably increasing the rate of dehydration. Acknowledgements: Financial support for this project is provided by funding bodies within the FP7 ERA-Net CORE Organic Plus, and with cofounds from the European Commission (No 618107)

Quality Changes during Frozen Storage of Mechanical-Separated Flesh Obtained from an Underutilized Crustacean

Despite their high nutritional value, high quantities of fish caught in the Adriatic Sea are underused or discarded for their insignificant economic value. Mechanical separation of flesh represents an opportunity for developing innovative semi-finished products, even if it can promote an increased quality degradation rate. The aim of this study was to evaluate physico-chemical modifications of mechanically separated mantis shrimp flesh during deep-freezing storage. Flesh samples obtained using a belt-drum separator, frozen and vacuum-packed, were stored at 3 temperatures (industrial: -26 \ub0C; domestic: -18 \ub0C and abuse: -10 \ub0C) for 12 months. During storage, qualitative (color, water content, pH, fatty acids (FA) and lipid oxidation) were evaluated. Fish freshness parameters (e.g., trimethylamine (TMA), dimethylamine (DMA) and amino acids) were assessed using nuclear magnetic resonance (1H-NMR). The mechanical separation process accelerated the initial oxidation phenomena, promoting color alterations, compared to manual separation. The main degradation phenomena during storage were significantly affected by temperature and were related to changes in luminosity, oxidation of n-3 polyunsaturated fatty acids (PUFA), increased lipolysis with release of free FA, production of TMA and DMA by residual enzymatic activity, and changes in amino acids due to proteolysis. The inter-disciplinary approach permitted important findings to be made, in terms of the extent of different degradative phenomena, bound to processing and storage conditions of mechanically separated mantis flesh

Potential of Natural Antimicrobials for the Production of Minimally Processed Fresh-Cut Apples

Background: Minimally processed fruit are susceptible to microbial spoilage and loss of sensory quality. In this experimental work, in order to increase the shelf-life and to maintain quality parameter (texture and colour) of sliced apples (Malus communis, var. Golden delicious), the use of natural antimicrobials was proposed. Materials and methods: Natural antimicrobials were purposed to produce fresh-cut apples. Hexanal, citral, and combinations of hexanal+citral, citron essential oil+carvacrol, citral+2-(E)-hexenal, citral+citron essential oil and hexanal+2- (E)-hexenal were used in dipping step. After treatment, sample were stored at 6°C in ordinary atmosphere. During storage, yeast and lactic acid bacteria were monitored. Also volatile and electronic nose profiles, colour and texture analyses were considered. The samples were compared with a control (apples dipped in ascorbic and citric acid solution). Results: Yeast cell loads showed that natural antimicrobials changed naturally occurring yeast growth parameters. The combination of citron+carvacrol prolonged the yeast lag phase of 6 d comparing with control, while citral and hexanal+2-(E)- hexenal decreased the maximum reached yeast cell load and growth rate, respectively. After 8 d, samples with hexanal+2-(E)- hexenal and citral showed equivalent or even better quality attributes compared to the controls, suggesting that this approach is a useful tool for fresh-cut apple production. Highlight: Natural antimicrobial can be useful for the dipping of minimally processed apples Citral and hexanal+2-(E)-hexenal prolonged the apples shelf-life. Apples treated with Citral and hexanal+2-(E)-hexenal had good quality attributes

Effect of cold plasma generated with different gas mixtures on safety, quality and nutritional aspects of fresh sea bream fillets

Cold atmospheric plasma (CAP) is a non-thermal technology, successfully used to decontaminate and extend the shelf-life of various foods. However, since CAP is highly oxidative, it can cause quality deterioration in sensitive matrices, such as fish products. This research aimed to evaluate the effect of CAP treatment with a surface dielectric barrier discharge (SDBD) with different gas mixtures (80% Ar/20% O2, or 80% N2/20% O2) on the decontamination of inoculated pathogens (E.coli and L.innocua; log 4 CFU/g inoculum) and endogenous spoilage microbiota and on the main quality indices of seabream (Spaurus aurata) fillets. For selected appropriate treatments, the impact on the nutritional value of the products was investigated through in vitro digestion, bioaccessibility of fatty acids and the degree of protein hydrolysis. The use of CAP resulted in a decrease in the bacterial load in the fresh sea bream fillets up to 1 log CFU/g obtained with Ar/O2 gas mixture for 20 min, affected by the treatment duration, but not by the gas mixture. Although a slight increase in lipid oxidation was observed (from 0.5 mg MDA/kg to a maximum of 4 mg MDA/kg), the digestibility of the products was not affected. Industrial relevance From an industrial point of view, increasing shelf-life of perishable products such as fish fillets with an environmentally friendly and non-thermal technology could represent a great advantage; however, maintaining quality is of paramount importance for the industrial use of this novel processing technology. The results of the present study show negligible effects on the nutritional quality of seabream fillets, which encourages further research.publishedVersio