Application of Ultrasound in Food Science and Technology: A Perspective

Continuous acid-catalyzed esterification using a 3D printed rotor-stator hydrodynamic cavitation reactor reduces free fatty acid content in mixed crude palm oil

Free fatty acid (FFA) content in FFA-rich mixed crude palm oil (MCPO) was reduced through a continuous esterification process. The reaction conditions were optimized, the yield purified esterified oil was determined, and the average total electricity consumption of the entire process was evaluated. The key component of this study was the cost-effective, 3D-printed rotor that was installed in a continuous rotor-stator hydrodynamic reactor. The surface of the rotor was designed with spherical holes where the center-to-center distance between them was fixed. Response surface methodology (RSM) using central composite design (CCD) was employed to analyze the design of experiments (DOE) and optimize FFA-content reduction. The optimized conditions were 17.7 vol% methanol, 2.9 vol% sulfuric acid, a 3000 rpm rotor speed, and surface holes measuring 4 mm in diameter and 6 mm in depth. The experimental results showed that the FFA content in MCPO was reduced from 11.456 to 1.028 wt% upon esterification under these optimal conditions. The maximum yield of esterified oil from the phase separation step was 96.07 vol%, and that of the purified esterified oil was 91.27 vol%. The average total energy consumed by this hydrodynamic cavitation reactor to produce this esterified oil was 0.0264 kW h/L. This 3D printed rotor-stator reactor is a promising, novel reactor technology for producing biodiesel from FFA-rich oils.

The Quality of Wheat Bread With Ultrasonicated and Fermented By-Products From Plant Drinks Production

During plant-based drinks production a significant amount of valuable by-products (BPs) is obtained. The valorization of BPs is beneficial for both the environment and the food industry. The direct incorporation of the fermented and/or ultrasonicated almond, coconut, and oat drinks production BPs in other food products, such as wheat bread (WB) could lead to the better nutritional value as well as quality of WB. Therefore, in this study, various quantities (5, 10, 15, and 20%) of differently treated [ultrasonicated (37 kHz) or fermented with Lacticaseibacillus casei LUHS210] almond, coconut, and oat drinks preparation BPs were used in wheat bread (WB) formulations. Microbiological and other quality parameters (acidity, color, specific volume, porosity, moisture content, overall acceptability) as well as bread texture hardness during the storage and acrylamide content in the WB were evaluated. Among the fermented samples, 12-h-fermented almond and oat, as well as 24-h-fermented coconut drinks preparation BPs (pH values of 2.94, 2.41, and 4.50, respectively; total enterobacteria and mold/yeast were not found) were selected for WB production. In most cases, the dough and bread quality parameters were significantly (p ≤ 0.05) influenced by the BPs used, the treatment of the BPs, and the quantity of the BPs. The highest overall acceptability of the WB prepared with 20% fermented almond drink preparation by-product (AP), 15% fermented oat drink preparation by-product (OP), and 15% ultrasonicated OP was established. After 96 h of storage, the lowest hardness (on average, 1.2 mJ) of the breads prepared with 5% fermented AP, coconut drink preparation by-product (CP), and OP and ultrasonicated CP was found. The lowest content of acrylamide in the WB prepared with OP was found (on average, 14.7 μg/kg). Finally, 15% fermented OP could be safely used for WB preparation because the prepared bread showed high overall acceptability, as well as low acrylamide content.

Physical and Chemical Methods for Reduction in Aflatoxin Content of Feed and Food

Aflatoxins (AFs) are among the most harmful fungal secondary metabolites imposing serious health risks on both household animals and humans. The more frequent occurrence of aflatoxins in the feed and food chain is clearly foreseeable as a consequence of the extreme weather conditions recorded most recently worldwide. Furthermore, production parameters, such as unadjusted variety use and improper cultural practices, can also increase the incidence of contamination. In current aflatoxin control measures, emphasis is put on prevention including a plethora of pre-harvest methods, introduced to control Aspergillus infestations and to avoid the deleterious effects of aflatoxins on public health. Nevertheless, the continuous evaluation and improvement of post-harvest methods to combat these hazardous secondary metabolites are also required. Already in-use and emerging physical methods, such as pulsed electric fields and other nonthermal treatments as well as interventions with chemical agents such as acids, enzymes, gases, and absorbents in animal husbandry have been demonstrated as effective in reducing mycotoxins in feed and food. Although most of them have no disadvantageous effect either on nutritional properties or food safety, further research is needed to ensure the expected efficacy. Nevertheless, we can envisage the rapid spread of these easy-to-use, cost-effective, and safe post-harvest tools during storage and food processing.

Impact of Emerging Technologies on Virgin Olive Oil Processing, Consumer Acceptance, and the Valorization of Olive Mill Wastes

There is a growing consumer preference for high quality extra virgin olive oil (EVOO) with health-promoting and sensory properties that are associated with a higher content of phenolic and volatile compounds. To meet this demand, several novel and emerging technologies are being under study to be applied in EVOO production. This review provides an update of the effect of emerging technologies (pulsed electric fields, high pressure, ultrasound, and microwave treatment), compared to traditional EVOO extraction, on yield, quality, and/or content of some minor compounds and bioactive components, including phenolic compounds, tocopherols, chlorophyll, and carotenoids. In addition, the consumer acceptability of EVOO is discussed. Finally, the application of these emerging technologies in the valorization of olive mill wastes, whose generation is of concern due to its environmental impact, is also addressed.

Review of the beneficial and anti-nutritional qualities of phytic acid, and procedures for removing it from food products

Phytic acid (PA) is the primary phosphorus reserve in cereals and legumes which serves the biosynthesis needs of growing tissues during germination. It is generally considered to be an anti-nutritional factor found in grains because it can bind to minerals, proteins, and starch, limiting their bioavailability. However, this same mineral binding property can also confer a number of health benefits such as reducing the risk of certain cancers, supporting heart health, and managing renal stones. In addition, the ability of PA to bind minerals allows it to be used in certain food quality applications such as stabilizing the green color of vegetables, preventing lipid peroxidation, and reducing enzymatic browning in fruits/vegetables. These beneficial properties create a potential for added-value applications in the utilization of PA in many new areas. Many possible processing techniques for the preparation of raw materials in the food industry can be used to reduce the concentration of PA in foods to mitigate its anti-nutritional effects. In turn, the recovered PA by-products could be available for novel uses. In this review, a general overview of the beneficial and anti-nutritional effects of PA will be discussed and then dephytinization methods will be explained.

Impact of ultrasonic treatment on rice starch and grain functional properties: A review

As a green, nonthermal, and innovative technology, ultrasonication generates acoustic cavitation in an aqueous medium, developing physical forces that affect the starch chemistry and rice grain characteristics. This review describes the current information on the effect of ultrasonication on the morphological, textural, and physicochemical properties of rice starch and grain. In a biphasic system, ultrasonication introduced fissures and cracks, which facilitated higher uptake of water and altered the rice starch characteristics impacting textural properties. In wholegrain rice, ultrasonic treatment stimulated the production of health-related metabolites, facilitated the higher uptake of micronutrient fortificants, and enhanced the palatability by softening the rice texture. This review provides insights into the future direction on the utilization of ultrasonication for the applications towards the improvement of rice functional properties.

High pressure processing combined with selected hurdles: Enhancement in the inactivation of vegetative microorganisms

High pressure processing (HPP) as a nonthermal processing (NTP) technology can ensure microbial safety to some extent without compromising food quality. However, for vegetative microorganisms, the existence of pressure-resistant subpopulations, the revival of sublethal injury (SLI) state cells, and the resuscitation of viable but nonculturable (VBNC) state cells may constitute potential food safety risks and pose challenges for the further development of HPP application. HPP combined with selected hurdles, such as moderately elevated or low temperature, low pH, natural antimicrobials (bacteriocin, lactate, reuterin, endolysin, lactoferrin, lactoperoxidase system, chitosan, essential oils), or other NTP (CO₂ , UV-TiO₂ photocatalysis, ultrasound, pulsed electric field, ultrafiltration), have been highlighted as feasible alternatives to enhance microbial inactivation (synergistic or additive effect). These combinations can effectively eliminate the pressure-resistant subpopulation, reduce the population of SLI or VBNC state cells and inhibit their revival or resuscitation. This review provides an updated overview of the microbial inactivation by the combination of HPP and selected hurdles and restructures the possible inactivation mechanisms.

Inactivation efficacy of atmospheric air plasma and airborne acoustic ultrasound against bacterial biofilms

Biofilms are complex microbial communities that present serious contamination risks to our environment and health. In this study, atmospheric air plasma and airborne acoustic ultrasound technology were applied to inactivate Escherichia coli and Listeria innocua biofilms. Both technologies were efficient in controlling, or completely inactivating, the target bacterial biofilms. Viability and metabolic assays, along with microscopy analysis, revealed that atmospheric air plasma and airborne acoustic ultrasound damaged both the bacterial biofilm cells and its structural integrity. Scanning electron microscopy images highlighted the disruption of the biofilms and pore formation in bacterial cells exposed to both the plasma and acoustic treatments. Elevated reactive oxygen and nitrogen species in bacterial cells treated with atmospheric air plasma, demonstrated their primary role in the observed bacterial inactivation process. Our findings provide potential antimicrobial strategies to combat bacterial biofilms in the food and healthcare sectors.

Non-Thermal Methods for Ensuring the Microbiological Quality and Safety of Seafood

A literature search and systematic review were conducted to present and discuss the most recent research studies for the past twenty years on the application of non-thermal methods for ensuring the microbiological safety and quality of fish and seafood. This review presents the principles and reveals the potential benefits of high hydrostatic pressure processing (HHP), ultrasounds (US), non-thermal atmospheric plasma (NTAP), pulsed electric fields (PEF), and electrolyzed water (EW) as alternative methods to conventional heat treatments. Some of these methods have already been adopted by the seafood industry, while others show promising results in inactivating microbial contaminants or spoilage bacteria from solid or liquid seafood products without affecting the biochemical or sensory quality. The main applications and mechanisms of action for each emerging technology are being discussed. Each of these technologies has a specific mode of microbial inactivation and a specific range of use. Thus, their knowledge is important to design a practical application plan focusing on producing safer, qualitative seafood products with added value following today’s consumers’ needs.

The Effect of Pre-Treatment (Blanching, Ultrasound and Freezing) on Quality of Freeze-Dried Red Beets

This paper presents the influence of blanching, ultrasonic processing and freezing conditions on selected physical properties of freeze-dried red beet, i.e., water activity, structure, porosity and shrinkage. Red beets subjected to a selected pre-treatment using its various parameters were frozen by three methods and then freeze-dried. Ultrasound reduced the water activity of samples. Blanching in water reduced shrinkage and improved porosity. In addition to the type of pre-treatment applied, the quality was also affected by freezing conditions before drying. Combined freezing resulted in the highest shrinkage and the lowest porosity and water activity. Slowly frozen samples were characterized by the best porosity.

Aplicação do ultrassom no processamento de frutas e hortaliças

Resumo Este trabalho objetivou apresentar aspectos relacionados à utilização do ultrassom no processamento de frutas e hortaliças, como o funcionamento do método, os efeitos no alimento, as aplicações, os aspectos sensoriais e a percepção dos consumidores. As mudanças dos hábitos alimentares e a busca do bem-estar refletem no aumento da procura por alimentos naturais, como as frutas e as hortaliças. Estes alimentos podem sofrer alterações microbiológicas ao longo da cadeia produtiva, sendo necessária a aplicação de boas práticas agrícolas e de manipulação, e processos tecnológicos de conservação para a garantia da qualidade do produto. O ultrassom é uma tecnologia emergente aplicada no processamento de frutas e hortaliças que está relacionada a melhorias na qualidade e preservação. O princípio básico do ultrassom é a cavitação acústica, que envolve o crescimento e colapso de bolhas durante períodos de rarefação e compressão, causando alterações químicas, físicas e mecânicas no alimento. Essas alterações estão relacionadas à inativação de micro-organismos e de enzimas, à remoção de resíduos e às melhorias na qualidade físico-química, e à acessibilidade de compostos bioativos. Além disso, a aplicação deste método pode ter boa aceitabilidade pelos consumidores, que procuram alimentos mais naturais e submetidos a processos que não causem impacto ambiental.

Optimization of Ultrasonic Extraction to Obtain Erinacine A and Polyphenols with Antioxidant Activity from the Fungal Biomass of Hericium erinaceus

Hericium erinaceus is a medicinal fungal species that produces the active biological metabolite erinacine A with strong antioxidant activity. The classical extraction techniques used to date to obtain metabolites from this fungal species require high consumption of resources and energy and, in the end, prove to be expensive and inefficient, especially on a biomedical scale. The aim of this research is based on the development of an ultrasonic extraction (UE) method for the identification and extraction of biological compounds with high antioxidant activity from the mycelia of H. erinaceus biomass developed through a solid cultivation process. The extraction process was optimized by varying parameters to determine the best extraction yield of metabolites involved in such antioxidant activity, using the response surface methodology (RSM). The physicochemical analyses were oriented towards the investigation of polyphenols, flavonoids, and the diterpenoid erinacine A. It is highlighted that there is a very good mutual connection between the concentration of polyphenols and flavonoids in the extracts studied and the diterpenoid erinacine A. Also, this study describes an efficient and qualitative extraction method for extracting natural antioxidants from the H. erinaceus mushroom, since toxic solvents were not used in the developed extraction procedure. This biomass can be used both as a food source and as a possible phytotherapeutic tool in the prevention or treatment of various neurodegenerative disorders that require drugs with strong antioxidant activity.

A review on recent advances in plasma-activated water for food safety: current applications and future trends

Plasma-activated water (PAW), the water or solutions treated with atmospheric cold plasma, is an eco-friendly technique with minimal changes in food products, making it a befitting alternative to traditional disinfection methods. Due to its potential microbicidal properties, PAW has been receiving increasing attention for applications in the food, agricultural, and biomedical fields. In this article, we aimed at presenting an overview of recent studies on the generation methods, physicochemical properties, and antimicrobial activity of PAW, as well as its application in the food industry. Specific areas were well discussed including microbial decontamination of food products, reduction of pesticide residues, meat curing, sprouts production, and disinfection of food contact materials. In addition, the factors influencing PAW efficiency were also well illustrated in detail, such as discharge parameters, types and amounts of microorganisms, characteristics of the liquid solution and food products, and treatment time. Moreover, the strategies to improve the efficacy of PAW were also presented in combination with other technologies. Furthermore, the salient drawbacks of this technology were discussed and the important areas for future research were also highlighted. Overall, the present review provides important insights for the application of PAW in the food industry.

Low and High-Intensity Ultrasound in Dairy Products: Applications and Effects on Physicochemical and Microbiological Quality

Milk and dairy products have a major role in human nutrition, as they contribute essential nutrients for child development. The nutritional properties of dairy products are maintained despite applying traditional processing techniques. Nowadays, so-called emerging technologies have also been implemented for food manufacture and preservation purposes. Low- and high-intensity ultrasounds are among these technologies. Low-intensity ultrasounds have been used to determine, analyze and characterize the physical characteristics of foods, while high-intensity ultrasounds are applied to accelerate particular biological, physical and chemical processes during food product handling and transformation. The objective of this review is to explain the phenomenology of ultrasounds and to detail the differences between low and high-intensity ultrasounds, as well as to present the advantages and disadvantages of each one in terms of the processing, quality and preservation of milk and dairy products. Additionally, it reviews the rheological, physicochemical and microbiological applications in dairy products, such as raw milk, cream, yogurt, butter, ice cream and cheese. Finally, it explains some methodologies for the generation of emulsions, homogenates, crystallization, etc. Currently, low and high-intensity ultrasounds are an active field of study, and they might be promising tools in the dairy industry.

Platelet Anti-Aggregant Activity and Bioactive Compounds of Ultrasound-Assisted Extracts from Whole and Seedless Tomato Pomace

Tomato paste production generates a residue known as tomato pomace, which corresponds to peels and seeds separated during tomato processing. Currently, there is an opportunity to use tomato pomace to obtain a functional extract with antithrombotic properties, such as platelet anti-aggregant activity. The aim of this study was to evaluate the yield and inhibitory activity of different extracts of tomato pomace on in vitro platelet aggregation, comparing this activity with commercial cardioprotective products, and quantify bioactive compounds. Aqueous or ethanolic/water (1:1) extracts of whole tomato pomace, seedless tomato pomace, tomato pomace supplemented with seeds (50% and 20%), and only seeds were obtained with different ultrasound-assisted extraction times. The inhibition of platelet aggregation was evaluated using a lumi-aggregometer. The quantification of bioactive compounds was determined by HPLC-MS. From 5 g of each type of tomato pomace sample, 0.023-0.22 g of a dry extract was obtained for the platelet aggregation assay. The time of sonication and extraction solvent had a significant role in platelet anti-aggregant activity of some extracts respect the control. Thus, the most active extracts decreased adenosine diphosphate (ADP)-induced platelet aggregation from 87 ± 6% (control) to values between 26 ± 6% and 34 ± 2% (p < 0.05). Furthermore, different ultrasound-assisted extraction conditions of tomato pomace fractions had varied concentration of flavonoids and nucleosides, and had an effect on extract yield.

Application of ultrasound for quality control of Torta del Casar cheese ripening

This work aimed to establish the ultrasound parameters that can be useful to classify the defects in the soft cheese Torta del Casar during ripening. During ripening by ultrasound, 1 standard and 3 defective cheese batches (anomalous microbial population, inadequate pressing curd, and excessive pressing curd) were evaluated. Ultrasound parameters related to velocity, attenuation, and frequency were calculated and correlated with the physicochemical and rheological properties of the cheeses. Ultrasound data were considered variables in linear discriminant analysis to attempt cheese classification at different periods of the ripening process. Defective soft cheeses could be discriminated from standard ones with good accuracy, mainly at the final stages of ripening. The differentiation of cheese samples from 2 of the defective cheese batches (anomalous microbial population and inadequate pressing curd) from the standard was mainly attributed to different values of the attenuation-related parameters, whereas for samples from the other defective batch (excessive pressing curd), some parameters related to velocity and frequency were responsible for such discrimination.

High-Pressure Carbon Dioxide Used for Pasteurization in Food Industry

The demand for safe, high-quality food has greatly increased, in recent times. As traditional thermal pasteurization can significantly impact the nutritional value and the color of fresh food, an increasing number of nonthermal pasteurization technologies have attracted attention. The bactericidal effect of high-pressure carbon dioxide has been known for many years, and its effect on food-related enzymes has been studied. This novel technology has many merits, owing to its use of relatively low pressures and temperatures, which make it a potentially valuable future method for nonthermal pasteurization. For example, the inactivation of polyphenol oxidase can be achieved with relatively low temperature and pressure, and this can contribute to food quality and better preserve nutrients, such as vitamin C. However, this novel technology has yet to be developed on an industrial scale due to insufficient test data. In order to support the further development of this application, on an industrial scale, we have reviewed the existing information on high-pressure carbon dioxide pasteurization technology. We include its bactericidal effects and its influence on food quality. We also pave the way for future studies, by highlighting key areas.

Ultrasound Treatment of Buckwheat Grains Impacts Important Functional Properties of Resulting Flour

The benefit of not containing the gluten complex protein also provides problems with the achievement of typical and proper texture, especially in bakery products. Ultrasound (US) treatment has been previously studied on buckwheat as assistance treatment facilitating the release of antioxidant compounds. However, there is no study regarding the changes occurring in US-treated buckwheat grains regarding the structure-creating capacity, like water absorption, gelling, and pasting. The aim of this study is to the impact of US-treatment of buckwheat grains at 1:10, 1:5, and 1:2.5 solid: liquid ratio (in water). The particle size distribution, water absorption index (WAI), water solubility index (WSI), swelling power (SP), pasting characteristics, color, soluble, insoluble and total polyphenols content (SPC, IPC, TPC) and antioxidant activity (DPPH) were assessed in resulting flours. US-treatment caused specific agglomeration, resulting in bigger particles for 1:5, and 1:2.5 ratio treated samples, while higher dilution (1:10) increased smaller particle size fractions. The WAI and SP were the highest for the1:5 solid: liquid ratio sample, and the same sample revealed the highest peak viscosity, breakdown, and setback values. The ultrasound treatment increased the WSI, which was positively correlated with insoluble polyphenols content. The soluble polyphenols content decreased, and insoluble polyphenols content increased in all ultrasound treated samples. The DPPH scavenging activity remaining in grain after US treatment was lowered compared to the control sample. The relocation of pigments resulted in a redness and yellowish increase in all treated samples, while lightness was also increased but was most pronounced for a 1:10 ratio treated sample. The results suggest that ultrasound treatment of grain can improve the essential functional properties of buckwheat flour.

Challenges Associated with Byproducts Valorization-Comparison Study of Safety Parameters of Ultrasonicated and Fermented Plant-Based Byproducts

In order to promote the efficient use of byproducts from the production of plant-based beverages, which still contain a large amount of nutritional and functional compounds, microbiological and chemical safety characteristics should be evaluated and, if needed, improved. Many challenges are associated with byproducts valorization, and the most important ones, which should be taken into account at the further steps of valorization, are biological and chemical safety. For safety improving, several technological treatments (biological, physical etc.) can be used. In this study, the influence of low-frequency ultrasonication (US) and fermentation with Lactobacillus casei LUHS210 strain, as physical and biotechnological treatments, on the safety characteristics of the byproducts (BYs) from the processing of rice, soy, almond, coconut, and oat drinks was compared. Ultrasonication, as well as fermentation, effectively improved the microbiological safety of BYs. Ultrasonication and fermentation reduced the concentration of deoxynivalenol, on average, by 24% only in soy BYs. After fermentation, 15-acetyldeoxynivalenol was formed in all samples (<12 µg kg-1), except for soy BYs. The lowest total biogenic amines content was found in fermented rice BYs and ultrasonicated coconut BYs. When comparing untreated and fermented BYs, significant changes in macro- and micro-elements content were found. Ultrasonication at 37 kHz did not significantly influence the concentrations of macro- and micro-elements, while fermentation affected most of the essential micro-elements. Consequently, while ultrasonication and fermentation can enhance the safety of BYs, the specific effects must be taken into account on biogenic amines, mycotoxins, and micro and macro elements.

Latest advances in imaging techniques for characterizing soft, multiphasic food materials

Over the last two decades, the development and production of innovative, customer-tailored food products with enhanced health benefits have seen major advances. However, the manufacture of edible materials with tuned physical and organoleptic properties requires a good knowledge of food microstructure and its relationship to the macroscopic properties of the final food product. Food products are complex materials, often consisting of multiple phases. Furthermore, each phase usually contains a variety of biological macromolecules, such as carbohydrates, proteins and lipids, as well as water droplets and gas bubbles. Micronutrients, such as vitamins and minerals, might also play an important role in determining and engineering food microstructure. Considering this complexity, highly advanced physio-chemical techniques are required for characterizing the microstructure of food systems prior to, during and after processing. Fast, in situ techniques are also essential for industrial applications. Due to the wide variety of instruments and methods, the scope of this paper is focused only on the latest advances of selected food characterization techniques, with emphasis on soft, multi-phasic food materials.

The Effect of High-Intensity Ultrasound on the Physicochemical and Microbiological Properties of Mexican Panela Cheese

High-intensity ultrasound could be an alternative to pasteurization for cheeses made with fresh raw milk, the properties of which must be preserved as part of their intangible cultural heritage, such as Panela cheese in Mexico. This research aimed to study the effect of the amplitude (50% and 100%) and application time (0, 5, and 10 min) of ultrasound treatment of fresh raw milk, on the yield and microbiological and physicochemical qualities of Panela cheese after 24 h of storage at 4 °C. The yield was increased to 24.29% with 10 min of ultrasonication, although the amount of exudate was higher in the ultrasonic product than in the control (20.33%). As the ultrasonication time increased, the yellowness (b*) increased significantly, while the hue angle decreased (with values close to 90°), resulting in evident yellow tones in cheeses made with milk treated for 10 min. The pH significantly increased from 6.6 to 6.74 with 5 min of ultrasound, but decreased to 6.37 with 10 min of ultrasonication. Although no significant differences were found in fat content, the protein significantly increased with 5 min of sonication, but it decreased markedly when ultrasound was applied for 10 min. Ultrasound treatment with amplitudes of 50% effectively decreased the counts of coliform bacteria regardless of ultrasonication time. However, the mesophilic bacteria increased by a 0.9 log with an amplitude of 100% and 10 min treatment. The results showed that ultrasound improved the yield and microbial, nutritional, and physicochemical properties of Panela cheese.

Sonicated extracts from the Quorn fermentation co-product as oil-lowering emulsifiers and foaming agents

Abstract

This study assessed the impact of sonication on the structure and properties of a functional extract (retentate 100 or R100) from the Quorn fermentation co-product (centrate). In a previous study, we reported that the R100 fraction displayed good foaming, emulsifying and rheological properties. Sonication of a R100 solution led to the breakdown of the large hyphal structures characteristic of this extract into smaller fragments. Foams prepared with sonicated R100 displayed a higher foaming ability than with untreated R100 and a high foam stability but lower than untreated R100 ones. Oil-in-water emulsions prepared with sonicated R100 displayed smaller oil droplet size distributions than with untreated R100. Confocal micrographs suggested that small fungal fragments contributed to the stabilisation of oil droplets. 50% oil-reduced R100 emulsions were prepared by mixing R100 emulsions (untreated or sonicated) with a sonicated R100 solution at a 1:1 ratio. Smaller oil droplet size distributions were reported for the oil-reduced emulsions. These results showed that the addition of small hyphal fragments or surface-active molecules and molecular aggregates released during sonication contributed to the formation and stabilisation of smaller oil droplets. This study highlighted the potential to modulate the structure, emulsifying and foaming properties of functional extracts from the Quorn fermentation co-product by sonication and the potential of these extracts as oil-lowering agents in emulsion-based products through the reduction of oil droplet size and their stabilisation.

Graphical abstract

Evidence of the Possible Interaction between Ultrasound and Thiol Precursors

The effect of ultrasound (20 kHz, 153 μm) on the prefermentation extraction mechanisms in Sauvignon Blanc grapes was studied, focusing on 3-mercaptohexan-1-ol (3MH) and 4-mercapto-4-methyl-pentan-2-one (4MMP) precursors linked to glutathione (GSH) and cysteine (Cys). The treatment determined a positive extraction trend between the duration (untreated, 3 and 5 min) and the conductivity or the concentration of catechins and total phenols, significantly differentiated after 5 min. Nevertheless, the concentration of the thiol precursors in grape juice not only remained undifferentiated, but that of 3-S-glutathionyl mercaptohexan-1-ol showed a negative trend with the treatment time applied (168 ± 43, 156 ± 36, and 149 ± 32 μg/L, respectively, for control, 3 and 5 min). The divergence on the effect between families of compounds suggests an interaction between the sonication treatment and thiol precursor molecules. In order to evaluate the possible degradation properly, ultrasound was applied in a model solution spiked with 3MH and 4MMP precursors, reproducing the conditions of grapes. Except for Cys-3MH, the mean concentration (n = 5) for the rest of the precursors was significantly lower in treated samples, predominantly in those linked to glutathione (~-22% and ~18% for GSH-3MH and GSH-4MMP) rather than to cysteine (~-6%~-8% for Cys-3MH and Cys-4MMP). The degradation of precursors was associated with a significant increase of 3MH and 4MMP. The formation of volatile thiols following sonication is interesting from a technological point of view, as they are key aroma compounds of wine and potentially exploitable in the wine industry through specific vinification protocols.

Response surface methodology for optimization of cinnamon essential oil nanoemulsion with improved stability and antifungal activity

The optimum formulation and ultrasonic condition for fabrication of cinnamon essential oil (CEO) nanoemulsion were determined using Response Surface Methodology (RSM). The CEO nanoemulsions were formed using an ultrasonic bath (43 kHz at power output of 210 W) and an ultrasonic probe (24 kHz at power of 400 W). Probe ultrasonication outperformed bath ultrasonication since it produced nanoemulsions with smaller droplet size, narrower size distribution as measured using polydispersity index (PDI), and higher viscosity. The influences of sonication time of 180.23-351.77 s, temperature of 4.82-45.18 °C, and Tween® 80 concentration of 1-3% w/w on the droplet size, PDI, and viscosity were investigated using RSM based on Box-Behnken design (BBD). The RSM revealed that the sonication time of 266 s, temperature of 4.82 °C, and Tween® 80 of 3% w/w produced the optimum CEO nanoemulsion with droplet size of 65.98 nm, PDI of 0.15, and viscosity of 1.67 mPa.s. Moreover, the optimum nanoemulsion had good stability in terms of droplet size and PDI when storing at 4, 30, and 45 °C for 90 days. The antifungal activity of the optimum CEO nanoemulsion was then investigated against Aspergillus niger, Rhizopus arrhizus, Penicillium sp., and Colletotrichum gloeosporioides in comparison to CEO coarse emulsion. The results showed that the CEO nanoemulsion had better antifungal activity than coarse emulsion of CEO.

Innovative Green Technologies of Intensification for Valorization of Seafood and Their by-Products

The activities linked to the fishing sector generate substantial quantities of by-products, which are often discarded or used as low-value ingredients in animal feed. However, these marine by-products are a prominent potential good source of bioactive compounds, with important functional properties that can be isolated or up-concentrated, giving them an added value in higher end markets, as for instance nutraceuticals and cosmetics. This valorization of fish by-products has been boosted by the increasing awareness of consumers regarding the relationship between diet and health, demanding new fish products with enhanced nutritional and functional properties. To obtain fish by-product-derived biocompounds with good, functional and acceptable organoleptic properties, the selection of appropriate extraction methods for each bioactive ingredient is of the outmost importance. In this regard, over the last years, innovative alternative technologies of intensification, such as ultrasound-assisted extraction (UAE) and supercritical fluid extraction (SFE), have become an alternative to the conventional methods in the isolation of valuable compounds from fish and shellfish by-products. Innovative green technologies present great advantages to traditional methods, preserving and even enhancing the quality and the extraction efficiency, as well as minimizing functional properties' losses of the bioactive compounds extracted from marine by-products. Besides their biological activities, bioactive compounds obtained by innovative alternative technologies can enhance several technological properties of food matrices, enabling their use as ingredients in novel foods. This review is focusing on analyzing the principles and the use of UAE and SFE as emerging technologies to valorize seafoods and their by-products.

Rapid Solid-Liquid Dynamic Extraction (RSLDE): A Powerful and Greener Alternative to the Latest Solid-Liquid Extraction Techniques

Traditionally, solid-liquid extractions are performed using organic and/or inorganic liquids and their mixtures as extractant solvents in contact with an insoluble solid matrix (e.g., the Soxhlet method) or using sequential atmospheric pressure systems that require long procedures, such as maceration or percolation. The objective of this procedure is the extraction of any compounds that can be carried out from the inner solid material to the outlet, resulting in a solution containing colorants, bioactive compounds, odorous substances, etc. Over the years, in the extraction techniques sector, there have been many important changes from the points of view of production, quality, and human and environmental safety due to improvements in technology. In more recent times, the interest of the scientific community has been aimed at the study of sustainable processes for the valorization of extracts from vegetables and food by-products, through the use of non-conventional (innovative) technologies that represent a valid alternative to conventional methods, generally through saving time and energy and the formation of fewer by-products. Therefore, with the development of principles based on the prevention of pollution, on a lower risk for human health, and on a low environmental impact, new systems have been implemented to reduce extraction times and solvent consumption, to improve efficiency, and to increase the productivity of the extracts. From this point of view, rapid solid-liquid dynamic extraction (RSLDE), performed using the Naviglio extractor, compared to traditional applications, is a technique that is able to reduce extraction times, generally leads to higher yields, does not require heating of the system, allows one to extract the active ingredients, and avoids their degradation. This technique is based on a new solid-liquid extraction principle named Naviglio’s principle. In this review, after reviewing the latest extraction techniques, an overview of RSLDE applications in various research and production sectors over the past two decades is provided.

New developments on ultrasound-assisted processing and flavor detection of spices: A review

Spices are widely used to add unique flavors to food; such uniqueness may, however, suffer significant loss during processing, which is in many cases needed to preserve or transform spices into food ingredients. Here, the effects of ultrasound-assisted drying, extraction and microencapsulation on flavor of spices along with selected progresses made on ultrasonic detection of the flavor are reviewed. Flavors of some spices, e.g., laurel, onion and peppermint, dried with the aid of ultrasound are noted to be better than those of shade-dried, infrared, microwave and hot-air dried products. Ultrasound-assisted extraction can be effectively used to extract essential oils or oleoresins from spices. Compared with selected extraction methods, the variety of flavor substances obtained via ultrasound-assisted extraction is richer and their concentrations are also higher, making the flavors of the extracts stronger. Ultrasound-assisted microencapsulation has noted to increase the compound embedding and loading ratios, resulting in better maintenance of flavor over a longer period of time. Ultrasound has finally proved to be an efficient, green, economical and sensitive flavor detection technology for spices.