Extraction from Food and Natural Products by Moderate Electric Field: Mechanisms, Benefits, and Potential Industrial Applications

Modern and conventional processing technologies and their impact on the quality of different millets

Millet, the highly sustainable crop for farming and combating hunger, has recently regained a resurgence in popularity as people seek more sustainable and nutrient-dense alternatives. International organizations and research institutions have advocated for increased millet production and consumption by introducing novel technologies and machinery in response to global food security and climate change challenges. This review aims to identify the impact of modern and conventional processing technologies on the quality of different millets. A comprehensive analysis of research reviews reveals that double-stage and tabletop centrifugal dehullers, infrared roasting, pulsed light, ultrasound, high-pressure processing methods, fortification, and encapsulation are optimal for nutrient retention in various millets. Extrusion technology application in millet processing has created a diverse range of value-added products with extended shelf stability. Emphasis is needed to develop robust promotion and distribution channels and establish an export promotion forum involving all stakeholders to promote and diversify millet-based products and technologies.

Electrical Fields in the Processing of Protein-Based Foods

Electric field-based technologies offer interesting perspectives which include controlled heat dissipation (via the ohmic heating effect) and the influence of electrical variables (e.g., electroporation). These factors collectively provide an opportunity to modify the functional and technological properties of numerous food proteins, including ones from emergent plant- and microbial-based sources. Currently, numerous scientific studies are underway, contributing to the emerging body of knowledge about the effects on protein properties. In this review, "Electric Field Processing" acknowledges the broader range of technologies that fall under the umbrella of using the direct passage of electrical current in food material, giving particular focus to the ones that are industrially implemented. The structural and biological effects of electric field processing (thermal and non-thermal) on protein fractions from various sources will be addressed. For a more comprehensive contextualization of the significance of these effects, both conventional and alternative protein sources, along with their respective ingredients, will be introduced initially.

Effect of HHP and UHPH High-Pressure Techniques on the Extraction and Stability of Grape and Other Fruit Anthocyanins

The use of high-pressure technologies is a hot topic in food science because of the potential for a gentle process in which spoilage and pathogenic microorganisms can be eliminated; these technologies also have effects on the extraction, preservation, and modification of some constituents. Whole grapes or bunches can be processed by High Hydrostatic Pressure (HHP), which causes poration of the skin cell walls and rapid diffusion of the anthocyanins into the pulp and seeds in a short treatment time (2-10 min), improving maceration. Grape juice with colloidal skin particles of less than 500 µm processed by Ultra-High Pressure Homogenization (UHPH) is nano-fragmented with high anthocyanin release. Anthocyanins can be rapidly extracted from skins using HHP and cell fragments using UHPH, releasing them and facilitating their diffusion into the liquid quickly. HHP and UHPH techniques are gentle and protective of sensitive molecules such as phenols, terpenes, and vitamins. Both techniques are non-thermal technologies with mild temperatures and residence times. Moreover, UHPH produces an intense inactivation of oxidative enzymes (PPOs), thus preserving the antioxidant activity of grape juices. Both technologies can be applied to juices or concentrates; in addition, HHP can be applied to grapes or bunches. This review provides detailed information on the main features of these novel techniques, their current status in anthocyanin extraction, and their effects on stability and process sustainability.

Perspectives on Novel Technologies of Processing and Monitoring the Safety and Quality of Prepared Food Products

With the changes of lifestyles and rapid growth of prepared food industry, prepared fried rice that meets the consumption patterns of contemporary young people has become popular in China. Although prepared fried rice is convenient and nutritious, it has the following concerns in the supply chain: (1) susceptible to contamination by microorganisms; (2) rich in starch and prone to stall; and (3) vegetables in the ingredients have the issues of water loss and discoloration, and meat substances are vulnerable to oxidation and deterioration. As different ingredients are used in prepared fried rice, their food processing and quality monitoring techniques are also different. This paper reviews the key factors that cause changes in the quality of prepared fried rice, and the advantages and limitations of technologies in the processing and monitoring processes. The processing technologies for prepared fried rice include irradiation, high-voltage electric field, microwave, radio frequency, and ohmic heating, while the quality monitoring technologies include Raman spectral imaging, near-infrared spectral imaging, and low-field nuclear magnetic resonance technology. These technologies will serve as the foundation for enhancing the quality and safety of prepared fried rice and are essential to the further development of prepared fried rice in the emerging market.

Combining high pressure and electric fields towards Nannochloropsis oculata eicosapentaenoic acid-rich extracts

Nannochloropsis oculata is naturally rich in eicosapentaenoic acid (EPA). To turn this microalga into an economically viable source for commercial applications, extraction efficiency must be achieved. Pursuing this goal, emerging technologies such as high hydrostatic pressure (HHP) and moderate electric fields (MEF) were tested, aiming to increase EPA accessibility and subsequent extraction yields. The innovative approach used in this study combined these technologies and associated tailored, less hazardous different solvent mixtures (SM) with distinct polarity indexes. Although the classical Folch SM with chloroform: methanol (PI 4.4) provided the highest yield concerning total lipids (166.4 mg_lipid/g_biomass), diethyl ether: ethanol (PI 3.6) presented statistically higher values in terms of EPA per biomass, corresponding to 1.3-fold increase. When SM were used in HHP and MEF, neither technology independently improved EPA extraction yields, although the sequential combination of technologies did result in 62% increment in EPA extraction. Overall, the SM and extraction methodologies tested (HHP-200 MPa, 21 °C, 15 min, followed by MEF processing at 40 °C, 15 min) enabled increased EPA extraction yields from wet N. oculata biomass. These findings are of high relevance for the food and pharmaceutical industries, providing viable alternatives to the "classical" extraction methodologies and solvents, with increased yields and lower environmental impact. KEY POINTS: • Et₂O: EtOH is a less toxic and more efficient alternative to Folch solvent mixture • HHP or MEF per se was not able to significantly increase EPA extraction yield • Combinations of HHP and MEF technologies increased both lipids and EPA yields.

Food and fruit waste valorisation for pectin recovery: Recent process technologies and future prospects

Pectin possesses a dual property of resistance and flexibility and thus has diverse commercial value which has generated research interest on this versatile biopolymer. Formulated products using pectin could be useful in food, pharma, foam, plasticiser and paper substitute industries. Pectin is structurally tailor-made for greater bioactivity and diverse applications. Sustainable biorefinery leaves greener footprints while producing high-value bioproducts like pectin. The essential oils and polyphenols obtained as byproducts from a pectin-based biorefinery are useful in cosmetics, toiletries and fragrance industries. Pectin can be extracted from organic sources following eco-friendly strategies, and the extraction techniques, structural alterations and the applications are continually being upgraded and standardized. Pectin has great applications in diverse areas, and its green synthesis is a welcome development. In future, growing industrial application of pectin is anticipated as research orients on biopolymers, biotechnologies and renewable source-based processes. As the world is gradually adopting greener strategies in sync with the global sustainable development goal, active involvement of policy makers and public participation are prime. Governance and policy framing are essential in the transition of the world economy towards circularity since green circular bioeconomy is ill-understood among the public in general and within the administrative circles in particular. Concerted efforts by researchers, investors, innovators, and policy and decision makers to integrate biorefinery technologies as loops within loop of biological structures and bioprocesses is suggested. The review focusses on generation of the different nature of food wastes including fruits and vegetables with cauterization of their components. It discusses the innovative extraction and biotransformation approaches for these waste conversions into value-added products at cost-effective and eco-friendly way. This article compiles numerous effective and efficient and green way pectin extraction techniques with their advantages with varying success in an integrated manner.

Roles of physical fields in the extraction of pectin from plant food wastes and byproducts: A systematic review

Pectin is a naturally occurring hydrocolloid found in the cell wall and middle lamella of many plants and has numerous functional applications in food and other related industries. The type of extraction methods used in production has a strong influence on the structural or physicochemical properties of the resultant pectin and the potential application or market value of the produced pectin. Many conventional extraction methods are well-established and commercially well adopted. However, the increased demand for pectin due to limitations of the existing methods in terms of efficiency and influence on end product quality has been renewed in developing novel techniques or procedures that help to alleviate these problems. In this review paper, a series of strategies involving the application of physical fields, such as acoustic, electromagnetic, electric and mechanical one, are reviewed for potential opportunities to improve the yield and quality attributes of pectin extracted from plant food wastes and byproducts. The extraction mechanism, processing equipment, key operating parameters as well as advantages and disadvantages of each method are systematically reviewed, and findings and conclusions on the potential applications of each method are described. Moreover, the challenges and future directions of physical field assisted extraction (PFAE) of pectin are also discussed to facilitate a better understanding of the complex mechanism in PFAE and optimizing operational parameters. This review may also provide specific theoretical information and practical applications to improve the design and scale up PFAE of pectin.

Research Progress on Nutritional Value, Preservation and Processing of Fish-A Review

The global population has rapidly expanded in the last few decades and is continuing to increase at a rapid pace. To meet this growing food demand fish is considered a balanced food source due to their high nutritious value and low cost. Fish are rich in well-balanced nutrients, a good source of polyunsaturated fatty acids and impose various health benefits. Furthermore, the most commonly used preservation technologies including cooling, freezing, super-chilling and chemical preservatives are discussed, which could prolong the shelf life. Non-thermal technologies such as pulsed electric field (PEF), fluorescence spectroscopy, hyperspectral imaging technique (HSI) and high-pressure processing (HPP) are used over thermal techniques in marine food industries for processing of most economical fish products in such a way as to meet consumer demands with minimal quality damage. Many by-products are produced as a result of processing techniques, which have caused serious environmental pollution. Therefore, highly advanced technologies to utilize these by-products for high-value-added product preparation for various applications are required. This review provides updated information on the nutritional value of fish, focusing on their preservation technologies to inhibit spoilage, improve shelf life, retard microbial and oxidative degradation while extending the new applications of non-thermal technologies, as well as reconsidering the values of by-products to obtain bioactive compounds that can be used as functional ingredients in pharmaceutical, cosmetics and food processing industries.

Ohmic Heating Extraction at Different Times, Temperatures, Voltages, and Frequencies: A New Energy-Saving Technique for Pineapple Core Valorization

Pineapple core is considered a processing by-product. This study proposed and evaluated an ohmic heating extraction-based valorization platform to obtain value-added bioactive compounds from pineapple core and studied the effects of four important processing parameters. In this sense, a Taguchi design (L16(4)4) was used to assess the effects of temperature (70, 80, 90, and 100 °C), time (15, 30, 45, and 60 min), voltage (110, 160, 210, and 260 V), and frequency (60, 340, 620, and 900 Hz) on heating rate, come-up time, energy consumption, system performance efficiency, total phenolic compounds (TPC), DPPH, and ABTS. Finally, a side-by-side comparison of optimized ohmic heating (OOH) and conventional extraction was performed, and chemical composition was compared by ultra-performance liquid chromatography equipped with photodiode array detection-mass (UPLC-DAD-ESI-MS-MS). According to the results, increasing temperatures enhanced system performance efficiency but negatively affected TPC and antioxidant values above 90 ℃. Similarly, prolonging the extraction (>30 min) decreased TPC. Further, increasing voltage (from 110 to 260 V) shortened the come-up time (from 35.75 to 5.16 min) and increased the heating rate (from 2.71 to 18.80 °C/min−1). The optimal conditions were 30 min of extraction at 80 °C, 160 V, and 900 Hz. Verification of the optimal conditions revealed that OOH yielded an extract with valuable bioactive compounds and saved 50% of the time and 80% of energy compared to the conventional treatment. The UPLC-DAD-ESI-MS-MS showed that there were similarities between the chemical profiles of the extracts obtained by conventional and OOH methods, while the concentration of major compounds varied depending on the extraction method. This information can help achieve sustainable development goals (SDGs) by maximizing the yield and minimizing energy and time consumption.

Anthocyanins as Key Phytochemicals Acting for the Prevention of Metabolic Diseases: An Overview

Anthocyanins are water-soluble pigments present in fruits and vegetables, which render them an extensive range of colors. They have a wide distribution in the human diet, are innocuous, and, based on numerous studies, have supposed preventive and therapeutical benefits against chronic affections such as inflammatory, neurological, cardiovascular, digestive disorders, diabetes, and cancer, mostly due to their antioxidant action. Despite their great potential as pharmaceutical applications, they have a rather limited use because of their rather low stability to environmental variations. Their absorption was noticed to occur best in the stomach and small intestine, but the pH fluctuation of the digestive system impacts their rapid degradation. Urine excretion and tissue distribution also occur at low rates. The aim of this review is to highlight the chemical characteristics of anthocyanins and emphasize their weaknesses regarding bioavailability. It also targets to deliver an update on the recent advances in the involvement of anthocyanins in different pathologies with a focus on in vivo, in vitro, animal, and human clinical trials.

Application of emerging technologies to obtain legume protein isolates with improved techno-functional properties and health effects

Current demand of consumers for healthy and sustainable food products has led the industry to search for different sources of plant protein isolates and concentrates. Legumes represent an excellent nonanimal protein source with high-protein content. Legume species are distributed in a wide range of ecological conditions, including regions with drought conditions, making them a sustainable crop in a context of global warming. However, their use as human food is limited by the presence of antinutritional factors, such as protease inhibitors, lectins, phytates, and alkaloids, which have adverse nutritional effects. Antitechnological factors, such as fiber, tannins, and lipids, can affect the purity and protein extraction yield. Although most are removed or reduced during alkaline solubilization and isoelectric precipitation processes, some remain in the resulting protein isolates. Selection of appropriate legume genotypes and different emerging and sustainable facilitating technologies, such as high-power ultrasound, pulsed electric fields, high hydrostatic pressure, microwave, and supercritical fluids, can be applied to increase the removal of unwanted compounds. Some technologies can be used to increase protein yield. The technologies can also modify protein structure to improve digestibility, reduce allergenicity, and tune technological properties. This review summarizes recent findings regarding the use of emerging technologies to obtain high-purity protein isolates and the effects on techno-functional properties and health.

Role of Food Hydrocolloids as Antioxidants along with Modern Processing Techniques on the Surimi Protein Gel Textural Properties, Developments, Limitation and Future Perspectives

Texture is an important parameter in determining the quality characteristics and consumer acceptability of seafood and fish protein-based products. The addition of food-based additives as antioxidants (monosaccharides, oilgosaccharides, polysaccharides and protein hydrolysates) in surimi and other seafood products has become a promising trend at an industrial scale. Improvement in gelling, textural and structural attributes of surimi gel could be attained by inhibiting the oxidative changes, protein denaturation and aggregation with these additives along with new emerging processing techniques. Moreover, the intermolecular crosslinking of surimi gel can be improved with the addition of different food hydrocolloid-based antioxidants in combination with modern processing techniques. The high-pressure processing (HPP) technique with polysaccharides can develop surimi gel with better physicochemical, antioxidative, textural attributes and increase the gel matrix than conventional processing methods. The increase in protein oxidation, denaturation, decline in water holding capacity, gel strength and viscoelastic properties of surimi gel can be substantially improved by microwave (MW) processing. The MW, ultrasonication and ultraviolet (UV) treatments can significantly increase the textural properties (hardness, gumminess and cohesiveness) and improve the antioxidative properties of surimi gel produced by different additives. This study will review potential opportunities and primary areas of future exploration for high-quality surimi gel products. Moreover, it also focuses on the influence of different antioxidants as additives and some new production strategies, such as HPP, ultrasonication, UV and MW and ohmic processing. The effects of additives in combination with different modern processing technologies on surimi gel texture are also compared.

Novel Techniques for Microbiological Safety in Meat and Fish Industries

The consumer tendency towards convenient, minimally processed meat items has placed extreme pressure on processors to certify the safety of meat or meat products without compromising the quality of product and to meet consumer’s demand. This has prompted difficulties in creating and carrying out novel processing advancements, as the utilization of more up-to-date innovations may influence customer decisions and assessments of meat and meat products. Novel advances received by the fish and meat industries for controlling food-borne microbes of huge potential general wellbeing concern, gaps in the advancements, and the requirement for improving technologies that have been demonstrated to be effective in research settings or at the pilot scale shall be discussed. Novel preparing advancements in the meat industries warrant microbiological approval before being named as industrially suitable alternatives and authorizing infra-structural changes. This miniature review presents the novel techniques for the microbiological safety of meat products, including both thermal and non-thermal methods. These technologies are being successfully implemented and rationalized in subsisting processing surroundings.

Combinations of emerging technologies with fermentation: Interaction effects for detoxification of mycotoxins?

Consumption of foods containing mycotoxins, as crucial groups of naturally occurring toxic agents, could pose significant health risks. While the extensive scientific literature indicates that prevention of contamination by toxigenic fungi is one of the best ways to reduce mycotoxins, detoxifying strategies are useful for improving the safety of food products. Nowadays, the food and pharmaceutical industries are using the concept of combined technologies to enhance the product yield by implementing emerging techniques, such as ultrasound, ohmic heating, moderate electric field (MEF), pulsed electric field (PEF) and high-pressure processing, during the fermentation process. While the application of emerging technologies in improving the fermentation process is well explained in this literature, there is a lack of scientific texts discussing the possibility of mycotoxin degradation through the interaction effects of emerging technologies and fermentation. Therefore, this study was undertaken to provide deep insight into applying emerging processing technologies in fermentation, mechanisms and the prospects of innovative combinations of physical and biological techniques for mycotoxins' detoxification. Among various emerging technologies, ultrasound, ohmic heating, MEF, PEF, and cold plasma have shown significant positive effects on fermentation and mycotoxins detoxification, highlighting the possibility of interactions from such combinations to degrade mycotoxins in foods.

Rheological Behavior of Glycyrrhiza glabra (Licorice) Extract as a Function of Concentration and Temperature: A Critical Reappraisal

In the present study, rheological properties of twelve different licorice root extracts were evaluated using a rotational viscometer as a function of soluble solids content (15–45 °Bx) and temperature (30–70 °C). Response Surface Methodology was used to understand the relationships between the parameters. The experimental data were then fit into mathematical models. The results, for the first time, revealed that the licorice solutions had non-Newtonian shear-thinning behaviors with flow behavior indexes of 0.24 to 0.91, depending on the licorice extract samples, temperature, and °Bx. These observations were different from those reported in the literature and the present study elaborated on reasons for such observations. Further, the shear-thinning behavior generally increased by increasing the °Bx and decreasing the temperature. In addition, the power-law model was found to be suitable for predicting the experimental data. The newly revealed information can be particularly important in designing the unit operations for licorice extract processing.

Enhanced Antioxidant Capacity of Puffed Turmeric (Curcuma longa L.) by High Hydrostatic Pressure Extraction (HHPE) of Bioactive Compounds

Turmeric (Curcuma longa L.) is known for its health benefits. Several previous studies revealed that curcumin, the main active compound in turmeric, has antioxidant capacity. It has been previously demonstrated that puffing, the physical processing using high heat and pressure, of turmeric increases the antioxidant and anti-inflammatory activities by increasing phenolic compounds in the extract. The current study sought to determine if high hydrostatic pressure extraction (HHPE), a non-thermal extraction at over 100 MPa, aids in the chemical changes and antioxidant functioning of turmeric. 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), and ferric reducing antioxidant power (FRAP) analyses were conducted and assessed the content of total phenol compounds in the extract. The chemical changes of curcuminoids were also determined by high performance liquid chromatography (HPLC). Among the three variables of ethanol concentration, pressure level, and treatment time, ethanol concentration was the most influential factor for the HHPE of turmeric. HHPE at 400 MPa for 20 min with 70% EtOH was the optimal extraction condition for the highest antioxidant activity. Compositional analysis revealed that 2-methoxy-4-vinylphenol was produced by puffing. Vanillic acid and ferulic acid content increased with increasing HHPE time. Synergistic effect was not observed on antioxidant activity when the turmeric was sequentially processed using puffing and HHPE.

Pilot-scale ohmic heating-assisted extraction of wheat bran bioactive compounds: Effects of the extract on corn oil stability

Recent studies introduced ohmic heating-assisted extraction (OHAE) as a promising emerging technology at laboratory-scales. The objectives of the present study were, first, to investigate the applicability of OHAE at pilot-scale for extraction of bioactive compounds from wheat bran immersed in a polar solvent (salted water containing 0.1% NaCl) at the electric field strengths (EFS) of 4.28, 7.90, and 15.71 V/cm and, second, to evaluate the effects of the wheat extracts on the corn oil stability during 30 days of storage at 45 °C. The results showed that OHAE saved 63% of energy consumption compared with the conventional extraction method. Also, the scaled-up OHAE unit yielded extracts with high quantities of bioactive compounds (110-460 ppm total phenolics) and higher antioxidant activities (antioxidant effectiveness of 56-84%) than those of the extract obtained through the conventional extraction method, i.e., 95 ppm total phenolics with antioxidant effectiveness of 51%. Increasing the EFS increased total phenolics and antioxidant effectiveness of extracts. The incorporation of 250 ppm of the extract obtained at the highest EFS effectively postponed the oxidation of corn oil during one month of storage (peroxide value of 7 vs. 19 meq/kg compared with the control sample) and extended the half-life of oil from 11 to 26 days. Besides, mathematical models proposed in this study well-predicted the oxidation stability of the oil samples mixed with the extract.

Smart Food Packaging Designed by Nanotechnological and Drug Delivery Approaches

This paper offers a general view of the solutions that are able to confer bioactivity to the packaging materials, especially antimicrobial and antioxidant activity. These properties can be induced by the nature of the polymers blend or due to the addition of ternary components from natural agents (essential oils or other extracts) to synthetic organic and inorganic agents, including nanoparticles with a broad antimicrobial activity such as metals (e.g., Ag, Au, Cu) or metal oxide (e.g., TiO2, ZnO) nanoparticles, and even bacterial cells such as probiotics. Many times, these components are synergistically used, each of them assuring a specific role or potentiating the role of the other components. The antimicrobial activity can be induced due to the applied coatings or due to the whole bulk material. Along with an increasing food stability which means a longer shelf-life some smart packaging can be exploited in order to highlight the freshness of the food. These act as a sensor (usually pH sensitive but also other mechanisms can be exploited such as aggregation/agglomeration of AuNPs leading to color change or even aldehyde-specific reactions such as the Cannizzaro reaction), and thus, consumers can be confident about the freshness of the food, especially perishable food such as seafood or fish.

Impact of Ohmic Heating and High Pressure Processing on Qualitative Attributes of Ohmic Treated Peach Cubes in Syrup

Stabilization of ohmic pretreated peach cubes (ohm) in syrup, representative of semifinished fruit products, was finalized by ohmic heating (OHM) and high pressure processing (HPP), proposed respectively as thermal and nonthermal pasteurization, in comparison to a conventional pasteurization treatment (DIM). The samples were then studied in terms of histological, physical (dimensional distribution, tenderometry, texture, viscosity of syrup and colour), chemical (total phenolic and ascorbic acid content), and sensorial (triangle test) properties. Severe modifications of the cell walls were observed in ohm-DIM and ohm-OHM samples, with swelling and electroporation, respectively. From chemical analyses, significant reduction of ascorbic acid and simultaneous increase of total phenolics content were observed for ohm-DIM and ohm-OHM, probably in relation to the cell wall damages. ohm-HPP showed the best preservation of the dimensional characteristics and hardness, followed by ohm-OHM and ohm-DIM. In addition, textural and colour parameters evidenced similar results, with ohm-HPP as the less different from ohm. Finally, the sensorial analysis confirmed ohm-HPP and ohm-OHM samples as the most similar to ohm as well as the most appreciated in terms of colour and consistency.

Recent advances in continuous extraction of bioactive ingredients from food-processing wastes by pulsed electric fields

The food processing produces a great amount of wastes that are rich in nutrients. Extraction is the first and most important step in recovery and purification of active ingredients from these wastes. The traditional extraction technologies are known to be laborious and time-consuming, require large volumes of organic solvent, have high temperature and energy costs, and obtain relatively low extraction efficiency. In recent 10 years, a novel, efficient and green extraction method, pulsed electric fields (PEFs) continuous extraction, which is emerging non-thermal food-processing technology, has shown great promise in extracting these food wastes. This work gives an overview of development in the use of PEF continuous extraction for obtaining bioactive ingredients from food-processing wastes. The technology is described in detail with respect to the mechanism, equipment, critical parameters. The protocols and applications of the technology in the extraction of food-processing wastes are comprehensively summarized. Finally, the degradation of bioactive ingredients, industrial applications, problem of novel food, consumer acceptance, and future trends of the technology are discussed. The PEF continuous extraction is considered as the ideal technology of high efficiency and low temperature for natural ingredients extraction. The technology possesses many remarkable potential applications in the food-processing industries compared to the conventional extraction methods.

Impact of ultrasound-assisted extraction and solvent composition on bioactive compounds and in vitro biological activities of thyme and rosemary

Mediterranean herbs, specially thyme and rosemary, are important ingredients in food preparation and more recently have been studied as natural sources of bioactive compounds. This study aimed to study the effect of matrix (thyme vs. rosemary), and extraction protocol (conventional extraction vs. ultrasound assisted extraction) solvent composition (water vs. 50:50 ethanol:water solution) on the extraction of high value compounds (phenolic compounds, flavonoids and carotenoids) and also explore the antioxidant, antimicrobial (Listeria innocua, Staphylococcus aureus, and Salmonella enterica), probiotic (Lactobacillus casei and Bifidobacterium lactis), and anti-inflammatory activities. The phenolic, flavonoid and carotenoid content of extracts was greatly influenced by extraction conditions wherein the ultrasound pre-treatment improved the extraction of carotenoids but induced the opposite effect for polyphenols and flavonoids in both herbs. Only the aqueous extract of thyme obtained from ultrasound pre-treatment was the only extract that inhibited the growth of potentially pathogenic bacteria, stimulated the probiotic bacteria and achieved high anti-inflammatory and antioxidant activity. Moreover, this extract also was rich on phenolic compounds (such as p-coumaric acid 4-O-glucoside, kaempferol 3-O-rutinoside, feruloyl glucose, and 4-vinylguaiacol) and carotenoids. Therefore, ultrasound extraction of bioactive compounds with water as solvent could be explored in food and pharmaceutical applications.

Pulsed electric field and mild heating for milk processing: a review on recent advances

Pulsed electric field (PEF) treatment consists of exposing food to electrical fields between electrodes within a treatment chamber, which can improve the preservation of fresh-like products such as milk. Although several studies support the use of PEF technology to process milk at low temperature, these studies reported microbial reductions of around 3 log₁₀ cycles and also indicated a limited impact of PEF on some endogenous and microbial enzymes. This scenario indicates that increasing the impact of PEF on both enzymes and microorganisms remains a major challenge for this technology in milk processing. More recently, combining PEF with mild heating (below pasteurization condition) has been explored as an alternative processing technology to enhance the safety and to preserve the quality of fresh milk and milk products. Mild heating with PEF enhanced the safety of milk and derived products (3 log₁₀ -6 log₁₀ cycles reduction on microbial load and drastic impact on the activity enzymes related to quality decay). Moreover, with this approach, there was minimal impact on enzymes of technological and safety relevance, proteins, milk fat globules, and nutrients (particularly for vitamins) and improvements in the shelf-life of milk and selected derived products were obtained. Finally, further experiments should consider the use of milk processed by PEF with mild heating on cheese-making. The combined approach of PEF with mild heating to process milk and derived products is very promising. The characteristics of current PEF systems (which is being used at an industrial level in several countries) and their use in the liquid food industry, particularly for milk and some milk products, could advance towards this strategy. © 2019 Society of Chemical Industry.

Ohmic heating as a promising technique for extraction of herbal essential oils: Understanding mechanisms, recent findings, and associated challenges

The applicability of ohmic heating, as a volumetric heating technique, has been explored in various sectors of the food industry. The use of ohmic heating for essential oil extraction is among its emerging applications. This chapter overviews the recent progress in this area of research, discusses the mechanisms involved in ohmic-based essential oil extraction processes, explains the effective process parameters, highlights their benefits, and explains the considerations to address the obstacles to industrial implementation. Ohmic-assisted hydrodistillation (OAHD) and ohmic-accelerated steam distillation (OASD) systems were proposed as alternatives to conventional hydrodistillation and steam distillation, respectively. These techniques have successfully extracted essential oils from several aromatic plants (e.g., thyme, peppermint, citronella, and lavender). Both OAHD and OASD possess a number of benefits, such as reducing the extraction time and energy consumption, compared to classical extraction methods. However, these techniques are in their infancy and further economic and upscaling studies are required for their industrial adaptation.

Application of pulsed electric fields in meat and fish processing industries: An overview

The market demand for new meat and fish products with enhanced physicochemical and nutritional properties attracted the interest of the food industry and academia to investigate innovative processing approaches such as pulsed electric fields (PEF). PEF is an emerging technology based on the application of electrical currents between two electrodes thus inducing electroporation phenomena and enabling a non-invasive modification of the tissues' structure. This review provides an overview of the current knowledge on the use of PEF processing in meat and fish to enhance the physicochemical and nutritional changes, as a preservation method, as well as for improving the extraction of high added-value compounds. PEF treatment had the ability to improve several processes such as preservation, tenderization, and aging. Besides, PEF treatment could be used as a useful strategy to increase water holding properties of fish products as well as for fish drying. Finally, PEF could be also used in both meat and fish foods for by-products valorization, due to its potential to enhance the extraction of high added-value compounds. However, more studies are warranted to completely define specific treatments that can be consistently applied in the industry. This review provides the directions for this purpose in the near future.