A comparison study between ultrasound-assisted and enzyme-assisted extraction of anthocyanins from blackcurrant (Ribes nigrum L.)

Artificial neural networks (ANN)-genetic algorithm (GA) optimization on thermosonicated achocha juice: kinetic and thermodynamic perspectives of retained phytocompounds

The extraction of phytocompounds from Achocha (Cyclanthera pedata) vegetable juice using traditional methods often results in suboptimal yields and efficiency. This study aimed to enhance the extraction process through the application of thermosonication (TS). To achieve this, an artificial neural network (ANN) and a genetic algorithm (GA) were utilized to simulate and optimize the process parameters. The study investigated the influence of ultrasonic amplitude (30%-50%), temperature (30 °C-50 °C), and sonication duration (15-60 min) on total polyphenolic content (TPC), total flavonoid content (TFC), antioxidant activity (AOA), and ascorbic acid content (AA). Remarkably, the ANN-GA optimization resulted in optimal TS conditions: an ultrasonic amplitude of 40%, a temperature of 40 °C, and a sonication duration of 30 min. Subsequent analysis of extraction kinetics and thermodynamics across various temperatures (30 °C-50 °C) and extraction times (0-30 min) demonstrated R2 (0.98821) and χ2 (1.74773) for TPC with activation energy (Ea) 26.0456, R2 (0.99906) and χ2 (0.07215) for TFC with Ea 26.2336, R2 (0.99867) and χ2 (0.03003) for AOA with Ea 26.0987, R2 (0.99731) and χ2 (0.13719) for AA with Ea 26.0984, validating the pseudo second-order kinetic model. These findings indicate that increased temperature enhances the saturation concentration and rate constant of phytochemical extraction.

Enhancing anthocyanin extraction efficiency in vegetables and fruits: a high-speed shear homogenization technology

BACKGROUND

To extract anthocyanins with high efficiency, a hypothesis for high-speed shear homogenization extraction (HSHE) method was established through a combination of solvent and ultrasonic-assisted extractions. The efficacy of this hypothesis was demonstrated by performing qualitative and quantitative analyses of 16 anthocyanins extracted from five northern vegetables, and five berry fruits using ultra-high-performance Q-Exactive Orbitrap tandem mass spectrometry. Single-factor experiments were conducted by varying ethanol concentration, temperature, pH and extraction cycles to determine the optimal conditions for this method.

RESULTS

Optimal extraction conditions (ethanol 70-80%, 40-50 °C, pH 3-4, performed twice) were determined using an HSHE (5 min, 10 000 rpm, 25 °C) assisted shaker (60 min) and ultrasonication (40 kHz, 160 W cm-2, 30 min, 25 °C) procedure. Compared to the traditional non-HSHE method, the total anthocyanin content obtained through HSHE extraction showed a significant increase, ranging from 1.0 to 3.9 times higher, with purple cabbage exhibiting the most pronounced enhancement in content. More types of anthocyanins were detected in blueberry (9), black bean (7) and raspberry (5), of which malvidin was the major anthocyanin (0.426 g kg-1) in blueberry, having an amount five times than previously obtained.

CONCLUSION

The established HSHE method has been proven to be a superior technique for anthocyanin extraction, with higher extraction efficiency and concentrations. This technique also provides a new avenue for extracting bioactive compounds from diverse food sources, with potential applications in improving the functional properties of food products. © 2024 Society of Chemical Industry.

Metabolomic analysis, extraction, purification and stability of the anthocyanins from colored potatoes

Colored potatoes have many health benefits because they are rich in anthocyanins. However, the constituent and property of anthocyanins in colored potatoes have not been systematically studied yet. Herein, metabolomic analysis was carried out to investigate the chemical composition of anthocyanins in the four different colored potatoes. After that, the extract and purification conditions, and the stability of the anthocyanins were further studied. The results indicated that the four colored potatoes contained abundant of polyphenols, flavonoids, and anthocyanins. Cyanidin, delphinidin, and malvidin were identified as the major anthocyanidins in purple potatoes, whereas red potatoes were mainly consisted of pelargonidin and its derivatives. 84.47 mg C3GE/100 g DW of anthocyanins was obtained at the optimal conditions, which could be effectively purified macroporous resin of D101. Moreover, the anthocyanins were sensitive to pH, temperature, light, redox agents, and divalent or trivalent metal ions, but stable to sugars and univalent metal ions.

Extraction of Bioactive Compounds from Wine Lees: A Systematic and Bibliometric Review

The extraction of bioactive compounds from wine lees involves a variety of methods, the selection of which is crucial to ensure optimal yields. This systematic review, following PRISMA guidelines and utilizing the Web of Science database, aimed to examine the current state of this field, providing insights for future investigations. The search employed strategies with truncation techniques and Boolean operators, followed by a three-step screening using well-defined eligibility criteria. A bibliometric analysis was conducted to identify authors, affiliations, countries/regions, and research trends. Thirty references were selected for analysis, with Spain standing out as the main source of research on the topic. The majority of studies (66%) focused on the extraction of bioactive compounds from alcoholic fermentation lees, while 33% were directed towards malolactic fermentation lees. Binary mixtures (ethanol-water) were the predominant solvents, with ultrasound being the most used extraction method (31.3%), providing the highest average yields (288.6%) for the various evaluated compounds, especially flavonoids. The potential of wine lees as a source of bioactive compounds is highlighted, along with the need for further research exploring alternative extraction technologies and the combination of methods. Additionally, the importance of "in vitro" and "in vivo" tests to assess the bioactive potential of lees, as well as the use of computational tools to optimize extraction and identify the molecules responsible for bioactive activity, is emphasized.

Effects of Thermosonication on the Antioxidant Capacity and Physicochemical, Bioactive, Microbiological, and Sensory Qualities of Blackcurrant Juice

This study investigated the effects of thermosonication (TS) on the quality of blackcurrant juice, along with its physicochemical properties, bioactive compounds, antioxidant capacity, and microbiological and sensory qualities. The treatments included raw juice (RJ), pasteurized juice (90 °C, 1 min, PJ), and thermosonicated juice (480 W, 40 kHz at 40, 50, or 60 °C, for 10, 20, 30, or 40 min, TJ). The results indicated that the effects of pasteurization and thermosonication on the pH, total soluble solids, and titratable acidity of the juice were not significant (p > 0.05). However, the cloudiness, browning index, and viscosity were significantly increased (p < 0.05), and the color properties of the blackcurrant juice were improved. The total phenolic, flavonoid, and anthocyanin contents of TJ (treated at 50 °C for 30 min) were increased by 12.6%, 20.9%, and 40.4%, respectively, and there was a notable decline in ascorbic acid content after the pasteurization treatment, while the loss was minor in all TJ samples compared with RJ. The scavenging ability of 1,1-diphenyl-2-pyridyl and hydroxyl radicals increased to 52.77% and 50.52%, respectively, which were significantly (p < 0.05) higher than those in the RJ and PJ samples. In addition, both pasteurization and thermosonication resulted in a significant (p < 0.05) reduction in microbial counts, while there were no significant (p > 0.05) differences in the sensory parameters compared with the RJ samples. In conclusion, this study suggests that TS is an effective method that can be used as an alternative to pasteurization to improve the quality of blackcurrant juice.

Enhancing Anthocyanin Extraction from Wine Lees: A Comprehensive Ultrasound-Assisted Optimization Study

Wine lees, an important by-product of the wine industry, pose a major environmental problem due to the enormous quantities of solid-liquid waste that are discarded annually without defined applications. In this study, the optimization of a method based on a Box-Behnken design with surface response has been carried out to obtain extracts with high anthocyanin content and potent antioxidant activity. Six variables have been considered: %EtOH, temperature, amplitude, cycle, pH, and ratio. The developed method exhibited important repeatability properties and intermediate precision, with less than 5% CV being achieved. Furthermore, these novel methods were successfully applied to diverse wine lees samples sourced from Cabernet Sauvignon and Syrah varieties (Vitis vinifera), resulting in extracts enriched with significant anthocyanin content and noteworthy antioxidant activity. Additionally, this study evaluated the influence of grape variety, fermentation type (alcoholic or malolactic), and sample treatment on anthocyanin content and antioxidant activity, providing valuable insights for further research and application in various sectors. The potential applications of these high-quality extracts extend beyond the winemaking industry, holding promise for fields like medicine, pharmaceuticals, and nutraceuticals, thus promoting a circular economy and mitigating environmental contamination.

Natural Sources of Food Colorants as Potential Substitutes for Artificial Additives

In recent years, the demand of healthier food products and products made with natural ingredients has increased overwhelmingly, led by the awareness of human beings of the influence of food on their health, as well as by the evidence of side effects generated by different ingredients such as some additives. This is the case for several artificial colorants, especially azo colorants, which have been related to the development of allergic reactions, attention deficit and hyperactivity disorder. All the above has focused the attention of researchers on obtaining colorants from natural sources that do not present a risk for consumption and, on the contrary, show biological activity. The most representative compounds that present colorant capacity found in nature are anthocyanins, anthraquinones, betalains, carotenoids and chlorophylls. Therefore, the present review summarizes research published in the last 15 years (2008-2023) in different databases (PubMed, Scopus, Web of Science and ScienceDirect) encompassing various natural sources of these colorant compounds, referring to their obtention, identification, some of the efforts made for improvements in their stability and their incorporation in different food matrices. In this way, this review evidences the promising path of development of natural colorants for the replacement of their artificial counterparts.

On the Valorization of Arbutus unedo L. Pomace: Polyphenol Extraction and Development of Novel Functional Cookies

The fruits of Arbutus unedo L. have a crimson colour and are enriched with remarkable concentrations of bioactive compounds such as anthocyanins and polyphenols. These fruits are commonly used in the production of a Portuguese Protected Geographical Indication distillate called "Aguardente de Medronho". During this process, a solid pomace is generated and presently discarded without valuable applications. In this work, two strategies have been developed for the valorisation of A. unedo pomace. The first approach considers the extraction of polyphenols from this by-product through the optimization of an ultrasound-assisted method using a Box-Behnken design coupled with response surface methodology. The results indicate that the temperature and the percentage of methanol, along with their interaction, significantly influence the total concentration of polyphenols and the antioxidant activity of the extracts obtained. The optimal conditions identified consider the extraction of 0.5 g of sample with 20 mL of a solvent containing 74% MeOH (aq), at a pH of 4.8, maintained at 70 °C for 15 min. On the other hand, the second valorisation strategy considered the use of A. unedo pomace in the development of functional cookies. The incorporation of 15-20% pomace in the cookie formulation was well-received by consumers. This incorporation results in an intake of ca. 6.55 mg of polyphenols per gram of cookie consumed, accompanied by an antioxidant activity of 4.54 mg Trolox equivalents per gram of cookie consumed. Overall, these results encourage the employment of A. unedo pomace either as a reliable source of extracts enriched in polyphenols or as a nutraceutical active ingredient in functional cookies, thereby positively impacting human health.

Ultrasound-Assisted Anthocyanins Extraction from Pigmented Corn: Optimization Using Response Surface Methodology

This study aimed to determine the optimal UAE conditions for extracting anthocyanins from pigmented corn using the Box-Behnken design (BBD). Six anthocyanins were identified in the samples and were used as response variables to evaluate the effects of the following working variables: extraction solvent pH (2-7), temperature (10-70 °C), solvent composition (0-50% methanol in water), and ultrasound power (20-80%). The extraction time (5-25 min) was evaluated for complete recovery. Response surface methodology suggested optimal conditions, specifically 36% methanol in water with pH 7 at 70 °C using 73% ultrasound power for 10 min. The method was validated with a high level of accuracy (>90% of recovery) and high precision (CV < 5% for both repeatability and intermediate precision). Finally, the proposed analytical extraction method was successfully applied to determine anthocyanins that covered a wide concentration range (36.47-551.92 mg kg-1) in several pigmented corn samples revealing potential varieties providing more health benefits.

Cavitation-Effect-Based Treatments and Extractions for Superior Fruit and Milk Valorisation

Ultrasound generates cavities in liquids with high-energy behaviour due to large pressure variations, leading to (bio)chemical effects and material modification. Numerous cavity-based treatments in food processes have been reported, but the transition from research to industrial applications is hampered by specific engineering factors, such as the combination of several ultrasound sources, more powerful wave generators or tank geometry. The challenges and development of cavity-based treatments developed for the food industry are reviewed with examples limited to two representative raw materials (fruit and milk) with significantly different properties. Both active compound extraction and food processing techniques based on ultrasound are taken into consideration.

Effect of hot water, ultrasound, microwave, and pectinase-assisted extraction of anthocyanins from black goji berry for food application

Lycium ruthenicum, commonly known as black goji berry, is a rich anthocyanin source containing a high amount of monoacylated anthocyanins. This study investigates the effect of different extraction methods to extract anthocyanins from black goji berry for food application. Different hot water extraction conditions were applied to investigate the effect of specific substrate: solvent ratio (1:15 and 1:20 (w/v)), extraction time (30 and 60 min) and extraction temperature (40, 50 and 60 °C) on the extraction yield, total anthocyanin content (TAC) and the total phenolic content (TPC) of the anthocyanin extracts. Best hot water extraction conditions for obtaining an anthocyanin extract with high TAC (13.8 ± 1.14 mg CGE/g), TPC (69.7 ± 2.50 mg of GAE/g), and extraction yield (48.3 ± 3.25%) consuming less solvent, time and heat were substrate: solvent ratio of 1: 15 (w/v), extraction temperature of 50 °C, and extraction time of 30 min. The effect of pectinase, ultrasound, and microwave on hot water extraction of anthocyanins from black goji berry was investigated using the best conditions for hot water extraction. Pectinase-assisted extraction [1.5% (w/v) pectinase, substrate: solvent ratio of 1:15 (w/v) at 50 °C for 30 min] was the best extraction method to extract black goji berry anthocyanins demonstrating higher extraction yield, TAC, TPC, and the highest percentage of petunidin-3-O-(trans-p-coumaroyl)-rutinoside-5-O-glucoside.

Optimization of enzyme-assisted extraction of anthocyanins from eggplant (Solanum melongena L.) peel

Enzyme-assisted extraction (EAE) of total yield (TY), total anthocyanin content (TA), antioxidant activity (AOA) and total phenolic content (TPC) from eggplant peel was optimized using response surface methodology. Enzyme concentration (5-15 %), extraction temperature (35-60 °C) and maceration time (1-4.5 hrs) were used to optimize the process of extraction using a Central-Composite design. Optimum values of TY (71.45 %), TAC (578.66 mg C3G L^-1), TPC (2040.87 mg GAE L^-1), DPPH (79.92 %) and FRAP (29.90 mmol AAE/100 g) were obtained for the optimized extraction parameters viz., temperature (37.32 °C), enzyme concentration (5%) and extraction time (1 h). Further, a comparative study was also done between conventional extraction and enzyme-assisted extraction of eggplant peel. It was observed that the responses of the extract obtained by conventional method showed significant variation from that obtained by EAE indicating the superiority of latter.

Effects of single-, dual-, and multi-frequency ultrasound-assisted freezing on the muscle quality and myofibrillar protein structure in large yellow croaker (Larimichthys crocea)

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MUAF significantly promoted the freezing process of large yellow croakers.

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MUAF enhanced the quality of large yellow croakers.

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MUAF better maintained the stability of fish protein.

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The mechanisms of single-, dual-, and multi-frequency UAF were analyzed.

Ultrasound-assisted freezing (UAF) has been proved to be a new technology to improve the quality of frozen foods. Frequency is an important parameter affecting UAF result. This study was to investigate the effects of single-, dual- and multi-frequency UAF on muscle quality and myofibrillar protein structure in large yellow croaker (Larimichthys crocea), providing reference for the application of multi-frequency UAF in frozen foods. Multi-frequency UAF increased the freezing rate and had lower thawing loss, thiobarbituric acid reactive substances (TBARS) value, total volatile basic nitrogen (TVB-N) value, and higher immobilized water content. Multi-frequency UAF had lower carbonyl, higher sulfhydryl content, and more stable myofibrillar protein secondary and tertiary structures. Confocal laser scanning microscopy (CLSM) indicated that the filamentous polymer in muscle fibrin solution with multi-frequency UAF was transformed into more evenly distributed units. In general, multi-frequency UAF significantly improved the freezing rate, reduced lipid oxidation, and maintained the myofibrillar structure.

Ultrasound-Assisted Extraction and the Encapsulation of Bioactive Components for Food Applications

Various potential sources of bioactive components exist in nature which are fairly underutilized due to the lack of a scientific approach that can be sustainable as well as practically feasible. The recovery of bioactive compounds is a big challenge and its use in food industry to develop functional foods is a promising area of research. Various techniques are available for the extraction of these bioactives but due to their thermolabile nature, there is demand for nonthermal or green technologies which can lower the cost of operation and decrease operational time and energy consumption as compared to conventional methods. Ultrasound-assisted extraction (UAE) is gaining popularity due to its relative advantages over solvent extraction. Thereafter, ultrasonication as an encapsulating tool helps in protecting the core components against adverse food environmental conditions during processing and storage. The review mainly aims to discuss ultrasound technology, its applications, the fundamental principles of ultrasonic-assisted extraction and encapsulation, the parameters affecting them, and applications of ultrasound-assisted extraction and encapsulation in food systems. Additionally, future research areas are highlighted with an emphasis on the energy sustainability of the whole process.

The Biochemical Alteration of Enzymatically Hydrolysed and Spontaneously Fermented Oat Flour and Its Impact on Pathogenic Bacteria

Avena sativa (A. sativa) oats have recently made a comeback as suitable alternative raw materials for dairy substitutes due to their functional properties. Amylolytic and cellulolytic enzyme-assisted modifications of oats produce new products that are more appealing to consumers. However, the biochemical and functional alteration of products and extracts requires careful selection of raw materials, enzyme cocktails, and technological aspects. This study compares the biochemical composition of different A. sativa enzyme-assisted water extracts and evaluates their microbial growth using spontaneous fermentation and the antimicrobial properties of the ferment extracts. Fibre content, total phenolic content, and antioxidant activity were evaluated using traditional methodologies. The degradation of A. sativa flour was captured using scanning electron microscopy (SEM); moreover, sugar and oligosaccharide alteration were identified using HPLC and HPLC-SEC after INFOGEST in vitro digestion (IVD). Additionally, taste differentiation was performed using an electronic tongue with principal component analysis. The oat liquid extracts were continuously fermented using two ancient fermentation starters, birch sap and Tibetan kefir grains. Both starters contain lactic acid bacteria (LAB), which has major potential for use in bio-preservation. In fermented extracts, antimicrobial properties against Gram-positive Staphylococcus aureus and group A streptococci as well as Gram-negative opportunistic bacteria such as Escherichia coli and Pseudomonas aeruginosa were also determined. SEM images confirmed the successful incorporation of enzymes into the oat flour. The results indicate that using enzyme-assisted extraction significantly increased TPC and antioxidant activity in both the extract and residues. Additionally, carbohydrates with a molecular mass (MM) of over 70,000 kDa were reduced to 7000 kDa and lower after the incorporation of amylolytic and cellulolytic enzymes. The MM impacted the variation in microbial fermentation, which demonstrated favourable antimicrobial properties. The results demonstrated promising applications for developing functional products and components using bioprocessing as an innovative tool.

Enzyme-assisted extraction of anthocyanins and other phenolic compounds from blackcurrant (Ribes nigrum L.) press cake: From processing to bioactivities

The effects of commercial enzymes (pectinases, cellulases, beta-1-3-glucanases, and pectin lyases) on the recovery of anthocyanins and polyphenols from blackcurrant press cake were studied considering two solid:solvent ratios (1:10 and 1:4 w/v). β-glucanase enabled the recovery of the highest total phenolic content - 1142 mg/100 g, and the extraction of anthocyanins was similar using all enzymes (∼400 mg/100 g). The use of cellulases and pectinases enhanced the extraction of antioxidants (DPPH - 1080 mg/100 g; CUPRAC - 3697 mg/100 g). The freeze-dried extracts presented antioxidant potential (CUPRAC, DPPH), which was associated with their biological effects in different systems: antiviral activity against both non-enveloped viruses (enterovirus coxsackievirus A-9) and enveloped coronaviruses (HCoV-OC43), and cytotoxicity towards cancer cells (A549 and HCT8). No cytotoxic effects on normal human lung fibroblast (IMR90) were observed, and no anti-inflammatory activity was detected in lipopolysaccharides-treated murine immortalised microglial cells.

Enzymes-Assisted Extraction of Plants for Sustainable and Functional Applications

The scientific community and industrial companies have discovered significant enzyme applications to plant material. This rise imparts to changing consumers’ demands while searching for ‘clean label’ food products, boosting the immune system, uprising resistance to bacterial and fungal diseases, and climate change challenges. First, enzymes were used for enhancing production yield with mild and not hazardous applications. However, enzyme specificity, activity, plant origin and characteristics, ratio, and extraction conditions differ depending on the goal. As a result, researchers have gained interest in enzymes’ ability to cleave specific bonds of macroelements and release bioactive compounds by enhancing value and creating novel derivatives in plant extracts. The extract is enriched with reducing sugars, phenolic content, and peptides by disrupting lignocellulose and releasing compounds from the cell wall and cytosolic. Nonetheless, depolymerizing carbohydrates and using specific enzymes form and release various saccharides lengths. The latest studies show that oligosaccharides released and formed by enzymes have a high potential to be slowly digestible starches (SDS) and possibly be labeled as prebiotics. Additionally, they excel in new technological, organoleptic, and physicochemical properties. Released novel derivatives and phenolic compounds have a significant role in human and animal health and gut-microbiota interactions, affecting many metabolic pathways. The latest studies have contributed to enzyme-modified extracts and products used for functional, fermented products development and sustainable processes: in particular, nanocellulose, nanocrystals, nanoparticles green synthesis with drug delivery, wound healing, and antimicrobial properties. Even so, enzymes’ incorporation into processes has limitations and is regulated by national and international levels.