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11 pages, 1938 KiB

Open AccessArticle

Ultrasound-Assisted Extraction of Polyphenols from Olive Pomace: Scale Up from Laboratory to Pilot Scenario

by Óscar Rodríguez, Sergio Bona, Andreas Stäbler and Laura Rodríguez-Turienzo

Processes 2022, 10(12), 2481; https://doi.org/10.3390/pr10122481 - 23 Nov 2022

Cited by 7 | Viewed by 1621

Power ultrasound application has been proven to intensify the extraction of biocompounds from plant materials. In this work, the ultrasound-assisted extraction (UAE) of polyphenols from olive pomace (OP) has been studied at three different scales: laboratory (batch, 400 W, 0 barg), medium (continuous, [...] Read more.

Power ultrasound application has been proven to intensify the extraction of biocompounds from plant materials. In this work, the ultrasound-assisted extraction (UAE) of polyphenols from olive pomace (OP) has been studied at three different scales: laboratory (batch, 400 W, 0 barg), medium (continuous, 1000 W, 1.0 barg), and pilot (continuous, 2000 W, 1.0 barg) taking into consideration the influence of technological parameters: extraction time (s), solvent to solid ratio (mL/g), mixture pH, and acoustic parameters: amplitude (µm), intensity (W/cm²), and applied energy (Wh). A central composite design was used to optimize the UAE at laboratory scale (0.2 kg). The optimal conditions were: time: 490 s; ratio: 2.1 mL H₂O/g OP; pH: 5.6 at an acoustic amplitude of 46 µm for a maximum extraction yield of 3.6 g GAE/L of extract. At medium scale (2.2 kg) the UAE was carried out using amplitudes from 41 to 57 µm. The effect of the pressure (1.0 barg) on the UAE was positive, in terms of higher extraction yield (2.9 g GAE/L) and faster extraction rates compared to the non-pressurized UAE (2.5 g GAE/L), however, the extraction yield was lower than the one observed at laboratory scale. At pilot scale (120 kg), the UAE involved different ultrasound constellations (booster + sonotrode) to deliver the ultrasound energy at different acoustic intensities from 23 to 57 W/cm². The acoustic intensity (W/cm²) exerts an important effect on the extraction yield, and should be tailored to each process scale. The highest yield obtained at pilot-scale was 3.0 g GAE/L, and it was 58% higher than the one observed in the conventional extraction without ultrasound assistance (stirring and heating). In all tests, regardless of the scale, higher yields were observed between 80 and 85 °C. The application of this technology at the industrial scale to evaluate if the improvement of the extraction caused by the application of ultrasound could is still important when other operations like centrifugation, ultrafiltration, and reverse osmosis are included in the system and to evaluate its techno-economic feasibility. Full article

(This article belongs to the Special Issue Non-thermal Technologies in Food Science)

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12 pages, 3231 KiB

Open AccessArticle

Indirect Contact Chamber with Dielectric Layers for Pulsed Electric Field Treatment of Microorganisms

by Si Qin, Zixin Zhang, Jiangang Han, Shihai Huang and Jianzong Meng

Processes 2022, 10(11), 2432; https://doi.org/10.3390/pr10112432 - 17 Nov 2022

Cited by 1 | Viewed by 1207

Abstract

Investigation of pulsed electric field (PEF) treatment of yeast at 20 kV/cm using chambers with BaTiO₃ dielectric layers was conducted in this study. The sterile rate as well as concentrations of metallic ions and hydroxyl radicals were measured to assess the PEF [...] Read more.

Investigation of pulsed electric field (PEF) treatment of yeast at 20 kV/cm using chambers with BaTiO₃ dielectric layers was conducted in this study. The sterile rate as well as concentrations of metallic ions and hydroxyl radicals were measured to assess the PEF performance. The results indicated that generation of metallic ions could be reduced by 90%. However, a much higher field strength would be required for satisfactory sterilization due to the Maxwell-Wagner field relaxation, and reactions between the dielectric barriers and liquid could also occur. It was also proven that the continuous presence of a sufficient electric field is the main factor that inactivates the microorganism. Full article

(This article belongs to the Special Issue Non-thermal Technologies in Food Science)

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12 pages, 1728 KiB

Open AccessFeature PaperArticle

Glow Discharge Plasma Processing for the Improvement of Pasteurized Orange Juice’s Aroma and Off-Flavor

by Sueli Rodrigues and Fabiano Andre Narciso Fernandes

Processes 2022, 10(9), 1812; https://doi.org/10.3390/pr10091812 - 08 Sep 2022

Cited by 7 | Viewed by 1335

Abstract

Orange juice is one of the most popular juices sold in the world. Although very popular, most orange juice sold in the market is pasteurized, presenting off-flavor compounds and aromas different from the freshly squeezed juice. This study investigated how green chemistry, through [...] Read more.

Orange juice is one of the most popular juices sold in the world. Although very popular, most orange juice sold in the market is pasteurized, presenting off-flavor compounds and aromas different from the freshly squeezed juice. This study investigated how green chemistry, through the application of glow discharge plasma, can help improve the aroma and mitigate off-flavors of pasteurized orange juice. Orange juice was processed at different plasma flow rates (10 to 30 mL/min) for 10 to 30 min. Glow discharge plasma processing induced several chemical reactions enabling positive changes in the volatile profile of pasteurized orange juice. Chemical pathways were proposed and correlated to the changes in aroma and mitigation of off-flavor compounds. Glow discharge plasma increased the concentration of terpenoid and aldehyde compounds that give the orange juice its fresh-like characteristics and reduced the off-flavor compound concentration by 61%. Full article

(This article belongs to the Special Issue Non-thermal Technologies in Food Science)

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9 pages, 281 KiB

Open AccessCommunication

Effects of Ultrasound versus Pasteurization on Whey–Oat Beverage Processing: Quality and Antioxidative Properties

by Ana L. Herrera-Ponce, Ivan Salmeron-Ochoa, Jose C. Rodriguez-Figueroa, Eduardo Santellano-Estrada, Ivan A. Garcia-Galicia, Einar Vargas-Bello-Pérez and Alma D. Alarcon-Rojo

Processes 2022, 10(8), 1572; https://doi.org/10.3390/pr10081572 - 11 Aug 2022

Viewed by 1444

Abstract

The consumption of functional beverages is rapidly increasing. The improvement in the functional properties of whey after the application of ultrasound is due to the release of bioactive peptides that have antioxidant properties, among others. Bioactive peptides with antioxidant activity have also been [...] Read more.

The consumption of functional beverages is rapidly increasing. The improvement in the functional properties of whey after the application of ultrasound is due to the release of bioactive peptides that have antioxidant properties, among others. Bioactive peptides with antioxidant activity have also been found in oats, stimulating the study of whey beverages formulated with oats to obtain functional products. The aim of this study was to determine the influence of ultrasound (24 kHz) at 20 °C for 15 min at 23 W and 154 W on the quality and functional properties of whey–oat (50:50 v/v) beverages and compare it with pasteurization at 65 °C for 30 min (LTLT). Non-significant effect (p > 0.05) of ultrasound intensity (23 W and 154 W) was observed on the physicochemical characteristics and the proximal composition of the whey–oat beverages. The sonicated beverages showed a greater tendency to green and yellow color (p < 0.05), higher fat content (p < 0.05), and less ash and carbohydrates (p < 0.05) than the pasteurized beverage. The antioxidant activity of the mM Trolox equivalent/mL of the sonicated beverages was higher (p < 0.05) (4.24 and 4.27 for 23 W and 54 W, respectively) compared to that of the pasteurized beverage (4.12). It is concluded that ultrasound is superior to pasteurization in improving the antioxidant activity of whey–oat beverages without having a detrimental impact on the proximal composition and physicochemical quality. Future studies should evaluate more functional parameters and determine the shelf life of sonicated whey–oat beverages. Full article

(This article belongs to the Special Issue Non-thermal Technologies in Food Science)

14 pages, 1548 KiB

Open AccessArticle

Effect of Three Types of Drying on the Viability of Lactic Acid Bacteria in Foam-Mat Dried Yogurt

by Claudia Gallardo-Rivera, Juan G. Báez-González, Karla G. García-Alanís, Cynthia Torres-Alvarez, Karla Dares-Sánchez, Ana Szymanski, Carlos A. Amaya-Guerra and Sandra Castillo

Processes 2021, 9(12), 2123; https://doi.org/10.3390/pr9122123 - 25 Nov 2021

Cited by 4 | Viewed by 2669

Abstract

In this research, foaming technology was applied to obtain powdered yogurt from commercial yogurt at lower temperatures than the typical temperatures used during the dehydration process; the viability of lactic acid bacteria (LAB) was evaluated after the application of different drying techniques (conventional [...] Read more.

In this research, foaming technology was applied to obtain powdered yogurt from commercial yogurt at lower temperatures than the typical temperatures used during the dehydration process; the viability of lactic acid bacteria (LAB) was evaluated after the application of different drying techniques (conventional drying, freeze drying, and vacuum drying). Three different formulas (F1, F2, and F3) based on a foaming agent (albumen), stabilizers (guar gum), and prebiotics sources (inulin and agave syrup) were developed. Foam stability was evaluated at different pH values through optimum time of foam (OTF), medium drainage time (MDT), and drainage volume (DV). Foam expansion (FE) and foam density (FD) were measured. The OTF ranged from 6 to 10 min. The MDT ranged from 4.3 to 27.3 min, depending on pH, while the DV varied from 14.1 to 16.2 mL only in F1. No drainage was evidenced in F2 and F3, showing the best stability. The F2 and F3 produced the best FE and FD values. The dried yogurt with different techniques showed a survival rate (SR) of up to 85% Log-CFU/mL, even with the conventional drying method. Sensorial trials were carried out in reconstituted product, with the freeze-dried yogurt showing higher scores. The foam formulas developed demonstrate the efficacy of both the dehydration of yogurt and the preservation of LAB. Full article

(This article belongs to the Special Issue Non-thermal Technologies in Food Science)

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16 pages, 1614 KiB

Open AccessFeature PaperArticle

Effects of Spray-Drying Inlet Temperature on the Production of High-Quality Native Rice Starch

by Jamie Boon Jun Tay, Xinying Chua, Cailing Ang, Gomathy Sandhya Subramanian, Sze Yu Tan, Esther Marie Jierong Lin, Wen-Ya Wu, Kelvin Kim Tha Goh and Kaiyang Lim

Processes 2021, 9(9), 1557; https://doi.org/10.3390/pr9091557 - 31 Aug 2021

Cited by 9 | Viewed by 5191

Abstract

Rice starch is a common functional ingredient used in various food applications. The drying regime to obtain dry starch powder is an important processing step, which affects the functional properties of the starch. The application of extreme thermal treatment during the conventional drying [...] Read more.

Rice starch is a common functional ingredient used in various food applications. The drying regime to obtain dry starch powder is an important processing step, which affects the functional properties of the starch. The application of extreme thermal treatment during the conventional drying process tends to elicit irreversible changes to the rice starch, resulting in the loss of desired functionalities. In a previous study, we reported the development of a novel low temperature spray-drying based process which efficiently dries waxy rice starch, while preserving its physicochemical properties and functionalities. This study, a follow-up to the previous report, evaluated the effect of different spray-drying inlet temperatures on the production yield, physicochemical properties, and functionalities of waxy rice starch. Increasing the inlet temperature from 40 °C to 100 °C resulted in an increase in the process yield from 74.83% to 88.66%, respectively. All spray dried waxy rice starches possessed a low moisture content of less than 15%, and a consistent particle size (median ~6.00 μm). Regardless of the inlet temperatures, the physicochemical functionalities, including the pasting characteristics and flowability, were similar to that of the native waxy rice starch. The molecular and A-type crystalline structure of the waxy rice starches were also conserved. An inlet temperature of 60 °C represented the optimum temperature for the spray-drying process, with a good yield (84.55 ± 1.77%) and a low moisture content (10.74 ± 1.08%), while retaining its native physicochemical functionalities and maximizing energy efficacy. Full article

(This article belongs to the Special Issue Non-thermal Technologies in Food Science)

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Review

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23 pages, 14052 KiB

Open AccessFeature PaperReview

Non-Thermal Technologies Combined with Antimicrobial Peptides as Methods for Microbial Inactivation: A Review

by Larissa Andaluz-Mejía, Daniela Ruiz-De Anda and César Ozuna

Processes 2022, 10(5), 995; https://doi.org/10.3390/pr10050995 - 17 May 2022

Cited by 3 | Viewed by 2358

Abstract

Non-thermal technologies allow for the nutritional and sensory properties of foods to be preserved, something that consumers demand. Combining their use with antimicrobial peptides (AMPs) provides potential methods for food preservation that could have advantages over the use of chemical preservatives and thermal [...] Read more.

Non-thermal technologies allow for the nutritional and sensory properties of foods to be preserved, something that consumers demand. Combining their use with antimicrobial peptides (AMPs) provides potential methods for food preservation that could have advantages over the use of chemical preservatives and thermal technologies. The aim of this review was to discuss the advances in the application of non-thermal technologies in combination with AMPs as a method for microbial inactivation. Published papers reporting studies on the combined use of power ultrasound (US), pulsed electrical fields (PEF), and high hydrostatic pressure (HHP) with AMPs were reviewed. All three technologies show a possibility of being combined with AMPs, generally demonstrating higher efficiency than the application of US, PEF, HHP, and AMPs separately. The most studied AMP used in combination with the three technologies was nisin, probably due to the fact that it is already officially regulated. However, the combination of these non-thermal technologies with other AMPs also shows promising results for microbial inactivation, as does the combination of AMPs with other novel non-thermal technologies. The effectiveness of the combined treatment depends on several factors; in particular, the characteristics of the food matrix, the conditions of the non-thermal treatment, and the conditions of AMP application. Full article

(This article belongs to the Special Issue Non-thermal Technologies in Food Science)

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25 pages, 2756 KiB

Open AccessFeature PaperReview

Valorization of Tomato Residues by Supercritical Fluid Extraction

by José P. S. Aniceto, Vítor H. Rodrigues, Inês Portugal and Carlos M. Silva

Processes 2022, 10(1), 28; https://doi.org/10.3390/pr10010028 - 24 Dec 2021

Cited by 13 | Viewed by 3856

Abstract

Tomato processing leads to the production of considerable amounts of residues, mainly in the form of tomato skins, seeds and vascular tissues, which still contain bioactive molecules of interest for food, pharmaceutical and nutraceutical industries. These include carotenoids, such as lycopene and β-carotene, [...] Read more.

Tomato processing leads to the production of considerable amounts of residues, mainly in the form of tomato skins, seeds and vascular tissues, which still contain bioactive molecules of interest for food, pharmaceutical and nutraceutical industries. These include carotenoids, such as lycopene and β-carotene, tocopherols and sitosterols, among others. Supercritical fluid extraction is well positioned for the valorization of tomato residues prior to disposal, because it remains an environmentally safe extraction process, especially when using carbon dioxide as the solvent. In this article, we provide an extensive literature overview of the research on the supercritical fluid extraction of tomato residues. We start by identifying the most relevant extractables present in tomatoes (e.g., lycopene) and their main bioactivities. Then, the main aspects affecting the extraction performance are covered, starting with the differences between tomato matrixes (e.g., seeds, skins and pulp) and possible pretreatments to enhance extraction (e.g., milling, drying and enzymatic digestion). Finally, the effects of extraction conditions, such as pressure, temperature, cosolvent, flow rate and time, are discussed. Full article

(This article belongs to the Special Issue Non-thermal Technologies in Food Science)

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