1,720,986 research outputs found
Improving the Extraction of Juice And Bioactive Compounds from Blueberry Fruits and Their By-Products cy Application of Moderate Electric Field (MEF)
No full textThe influence of Moderate Electric Field (MEF) pre-treatment of blueberry fruits on the yield and quality of the
expressed juice as well as the subsequent extraction yield of bioactive compounds from berry by-products
(press cake left after MEF-assisted pressing), was investigated. Thermal MEF pre-treatments were performed
under different combinations of electric field strengths (E=18-55 V.cm-1) and final heating temperature (Tf=25-
80 °C) before applying a pressure of 1.32 bar for 5 min. For the sake of comparison, the effect of conventional
heating (CH) (Tf=25-80 °C), was also investigated. Results showed that the Zp values increased with
increasing the field strength and heating temperature. However, at the same final heating temperature, MEF
treatment achieved higher Zp values (up to 0.66) than CH (up to 0.45). Coherently, thermal MEF pre-treatment
(36.4 V.cm-1, 60 °C) significantly increased the juice yield, which also showed higher TPC, TAC, and AA, as
compared with either untreated or CH-treated samples. Moreover, compared to the untreated and CH-treated
samples, higher amounts of total phenolics, total anthocyanins and antioxidant activity were detected in the
press cake extracts. These results were explained by the combined non-thermal and thermal effect of MEF on
the cell disintegration and extraction efficiency
Electrochemical Reaction in PEF Treatment
No full textPulsed electric fields (PEF) is an innovative non-thermal technology which has attracted considerable interest in the last decades as a valuable and sustainable alternative to conventional techniques in several processes of food industry involving improvement of mass transfer phenomena, liquid food preservation and targeted structural modifications. The first commercial scale applications have been achieved in potato processing industry and fruit juice preservation. However, the full exploitation of PEF technology in food industry requires that the unavoidable electrochemical and chemical reactions accompanying the flow of electric current through the PEF treatment chamber must be minimized, since it may seriously affect food safety and quality, as well as process efficiency, equipment reliability and cost aspects. The occurrence of these reactions is a very complex phenomena, which is affected by several factors, such as circuit topology of the pulse generator, PEF chamber design and electrode material, PEF electrical parameters, as well as composition and chemical-physical properties of the treated products. This chapter describes in detail the electrochemical behavior of a PEF chamber with specific reference to the phenomena that occur at the electrode-solution interface, and explains the main factors controlling the rate and amount of electrochemical reactions. Finally, the main side effects associated to the occurrence of electrochemical and chemical reactions are described, and strategies to eliminate, or at least reduce, the extent of electrochemical phenomena that cause these undesired effects are also suggested
Effect of post-harvest pulsed light treatment on the respiration rate of grapes: modelling and validation
No full textIntroduction. The quality and shelf-life of packed fresh produce is strictly related to the dynamic of the gas composition, namely O2, CO2, and ethylene, in the head space of the packages. Therefore, the challenge is to control the head space composition and, hence the respiration rate of fresh produce during storage. However, several factors can affect the dynamic of the head space gas composition including harvesting time, presence of injury due to handling, microbial infection level, type of sanitization technique, and storage conditions (e.g., temperature, humidity), among others. In this framework, numerical simulation could be applied to predict the dynamic of the head space composition, as well as to select optimal conditions to be adopted during post-harvest treatment, storage, and handling of fresh produce. The aim of this paper was to develop and validate a mathematical model describing the effects of both Pulsed Light (PL) treatment and film permeability on the dynamic of the concentration of O2 and CO2 in the head space of packages during the passive modified atmosphere packaging of fruit.
Materials and Methods. A 2D numerical model describing the mass transport of O2, CO2 in the packages as a function of both diffusivity and film permeability was developed. Simulations were performed on three different films with high (MRX), medium (PPCX) and low (PSF530) permeability. The computation of both O2 and CO2 mass transport equations was performed using an implicit finite difference method (Crank Nicolson) solved with Matlab® (v.R2012b). For the validation of the model, experimental data on the respiration rate of table grape were collected. Samples of grapes were exposed to PL treatments at fluences from 1 to 12 J/cm2 before being packed in passive modified atmosphere packaging, and then stored 10°C for up to 10 days.
Results. Results demonstrated that the model set up is able to predict the dynamic of the head space gas composition of either untreated and PL treated grape during storage in packages with films of different permeability. The concentration of O2 increased with storage time, while that of CO2 decreased accordingly. Changes in the head space composition were, besides the storage time, dependent on the film permeability and PL fluence applied.
Conclusions. The developed model can represent a valuable tool to predict the concentration of O2 and CO2 in the head space of packages during the passive modified atmosphere packaging of fruit. Further work is necessary in order improve the capability of the model to predict the dynamics of the gas composition in more complex systems, where, for example, the influence of the ethylene production is also taken into accout
Economic and Environmental Impact Analysis of Innovative Peeling Methods in the Tomato Processing Industry
Full text linkPeeling is a key step in the industrial production of canned peeled tomatoes, vital for optimizing efficiency, yield, product quality, waste reduction, and environmental impact. This study presents a comparative assessment of the economic and environmental impacts of adopting innovative peeling technologies, including infrared (IR), ohmic heating-assisted lye (OH-lye), and ultrasound-assisted lye (US-lye) peeling, relative to conventional steam and lye peeling methods. Focusing on a medium-sized Italian tomato processor, the impacts of these methods on productivity, water and energy consumption, wastewater generation, and environmental footprint using Life Cycle Assessment (LCA) methodology, were evaluated. Findings indicated that adopting IR, OH-lye, and US-lye methods enhanced peelability (ease of peeling > 4.5) and increased production capacity by 2.6–9.2%, while reducing solid waste by 16–52% compared to conventional steam and lye methods. LCA results showed IR as the most environmentally favorable method, followed by steam, OH-lye, and US-lye, with conventional lye peeling being the least sustainable. OH-lye and IR methods also significantly reduce water and energy use, while US-lye shows higher demands in these areas. Additionally, OH-lye and IR methods require little or no NaOH, minimizing chemical consumption and wastewater production, which offers notable environmental and cost advantages. Overall, this preliminary study underscores economic and environmental potential for novel peeling technologies, encouraging industry consideration for adoption
Effect of PEF and steam blanching treatments on the extraction yield of carotenoids from tomato wastes
No full textIntroduction. Industrial transformation of tomatoes typically include a thermophysical peeling phase of the fruits, which lead to the production of large amount of wastes, namely peels. These wastes are currently used as feed for animal or sent to landfill leading to environmental and economical problems for the industry. However, they represent a cheap and rich source of several carotenoids, particularly lycopene. Therefore, in order to pursue the concept of ―zero waste‖ or ―total use‖ of agri-food residues with increasing industrial profitability, the recovery of these high-added value compounds is a challenge. Traditionally, these compounds are recovered by extraction with solvent which is a time consuming process and requires large quantities of solvents. The aim of this work, which was carried out in the frame of the European project ―FieldFood‖, was to assess the potential of pulsed electric field (PEF) technology alone or in combination with steam blanching, to improve the recovery of carotenoids from tomato peels.
Materials and Methods. PEF treatments of whole tomato fruit were carried out at field strengths in the range 0.25-0.75 kV/cm and energy input between 0.25 and 5 kJ/kg. The evaluation of the cell disintegration index via impedance analysis was used to select optimal PEF treatment conditions. Tomato samples treated under these optimal conditions were then peeled with or without the application of a thermal treatment by steam (50–60–70°C). The achieved peels were subjected to solvent extraction in acetone for 24h, and the extracts were analysed by both spectrophotometric and HPLC analysis in order to evaluate the total carotenoids content and antioxidant activity of the extracts as well as the chemical composition of the extracts.
Results. Results showed that, for each field strength applied, the cell disintegration index increased with increasing the energy input, reaching a saturation value for an energy input of 1 kJ/kg. The application of PEF pretreatment at different field strengths and at 1 kJ/kg at room temperature, allowed to increase the total carotenoids content and antioxidant activity of the extracts up to, respectively, 2.7 and 4.2-fold those detected in the untreated samples. The application of a combined treatment (PEF + steam blanching) significantly increased the carotenoids content and the antioxidant power of the extracts, allowing to save energy with respect to a conventional steam blanching treatment. HPLC analyses revealed that PEF pre-treatment alone or in combination with steam blanching increased lycopene concentration in the extracts with respect to the untreated samples. Moreover, no evidence of selective release or degradation of individual carotenoids due to PEF application was detected.
Conclusions. Results obtained from this study demonstrate the potential of PEF as pre-treatment method to improve the efficiency of industrial processing of tomato fruits
Emerging green techniques for the extraction of antioxidants from agri-food by-products as promising ingredients for the food industry
No full textNowadays, the food industry is heavily involved in searching for green sources of valuable compounds, to be employed as potential food ingredients, to cater to the evolving consumers’ requirements for health-beneficial food ingredients. In this frame, agri-food by-products represent a low-cost source of natural bioactive compounds, including antioxidants. However, to effectively recover these intracellular compounds, it is necessary to reduce the mass transfer resistances represented by the cellular envelope, within which they are localized, to enhance their extractability. To this purpose, emerging extraction technologies, have been proposed, including Supercritical Fluid Extraction, Microwave-Assisted Extraction, Ultrasound-Assisted Extraction, High-Pressure Homogenization, Pulsed Electric Fields, High Voltage Electrical Discharges. These technologies demonstrated to be a sustainable alternative to conventional extraction, showing the potential to increase the extraction yield, decrease the extraction time and solvent consumption. Additionally, in green extraction processes, also the contribution of solvent selection, as well as environmental and economic aspects, represent a key factor. Therefore, this review focused on critically analyzing the main findings on the synergistic effect of low environmental impact technologies and green solvents towards the green extraction of antioxidants from food by-products, by discussing the main associated advantages and drawbacks, and the criteria of selection for process sustainability
Edible Coating and Pulsed Light to Increase the Shelf Life of Food Products
Full text linkThe application of edible coatings (EC) in combination with pulsed light (PL) treatments represents an emerging approach for extending the shelf life of highly perishable but high value-added products, such as fresh-cut fruits and vegetables. The surface of these products would benefit from the protective effects of ECs and the PL decontamination capability. This review describes in detail the fundamentals of both EC and PL, focusing on the food engineering principles in the formulation and application of EC and the delivery of efficient PL treatments and the technological aspects related to the food characterization following these treatments and discussing the implementation of the two technologies, individually or in combination. The advantages of the combination of EC and PL are extensively discussed emphasizing the potential benefits that may be derived from their combination when preserving perishable foods. The downsides of combining EC and PL are also presented, with specific reference to the potential EC degradation when exposed to PL treatments and the screening effect of PL transmittance through the coating layer. Finally, the potential applications of the combined treatments to food products are highlighted, comparatively presenting the treatment conditions and the product shelf-life improvement
Cost, Energy Efficiency, and Environmental Impact Analysis of Orange Juice Pasteurization: Comparing Pulsed Electric Fields with Traditional Thermal Treatment
No full textThis study conducts a comprehensive analysis to assess the feasibility of integrating pulsed electric field technology for pasteurizing orange juice with heat recovery, aiming to offer a sustainable electrical alternative to conventional high-temperature short-time treatment. The evaluation encompasses energy, economic, and sustainability aspects, including cost analysis, energy efficiency, and environmental impact assessment. Despite higher initial costs, the comparison analysis demonstrates significant utility savings and enhanced sustainability with the electric technology compared to the conventional thermal method. An analysis of energetic scenarios identifies the electrical solution with a preheating temperature of 40°C and thermal recovery of 20% as the most energy-efficient and sustainable option, with reduced water consumption and emissions. Overall, the findings suggest that electrical technology holds promise as a viable and environmentally friendly approach to orange juice pasteurization, contributing to the advancement of sustainable food processing practices
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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