High-pressure homogenization treatment to recover bioactive compounds from tomato peels

Potential Use of Tomato Peel, a Rich Source of Lycopene, for Cancer Treatment

Tomatoes are well known for their impressive nutritional value among vegetables. However, the industrial processing of tomatoes generates a significant amount of waste. Specifically, 10% to 18% of the raw materials used in tomato processing become waste. This waste can seriously affect ecosystems, such as freshwater bodies, wetlands, rivers, and other natural environments, if not properly managed. Interestingly, tomato waste, specifically the skin, contains lycopene, a potent antioxidant and antimutagenic that offers a range of health benefits. This makes it a valuable ingredient in industries such as food and cosmetics. In addition, researchers are exploring the potential of lycopene in the treatment of various types of cancer. This systematic review, guided by the PRISMA 2020 methodology, examined studies exploring the possibility of tomato peel as a source of lycopene and carotenoids for cancer treatment. The findings suggest that tomato peel extracts exhibit promising anticancer properties, underscoring the need for further investigation of possible therapeutic applications. The compiled literature reveals significant potential for using tomato peel to create new cancer treatments, which could potentially revolutionize the field of oncology. This underscores the importance of continued research and exploration, emphasizing the urgency and importance of the scientific community's contribution to this promising area of study.

Enhancing Cutin Extraction Efficiency from Industrially Derived Tomato Processing Residues by High-Pressure Homogenization

This study primarily aimed to enhance the extraction of cutin from industrial tomato peel residues. Initially, the conventional extraction process was optimized using response surface methodology (RSM). Subsequently, high-pressure homogenization (HPH) was introduced to improve extraction efficiency and sustainability. The optimization process focused on determining the optimal conditions for conventional extraction via chemical hydrolysis, including temperature (100-130 °C), time (15-120 min), and NaOH concentration (1-3%). The optimized conditions, determined as 130 °C, 120 min, and 3% NaOH solution, yielded a maximum cutin extraction of 32.5%. Furthermore, the results indicated that applying HPH pre-treatment to tomato peels before alkaline hydrolysis significantly increased the cutin extraction yield, reaching 46.1%. This represents an approximately 42% increase compared to the conventional process. Importantly, HPH pre-treatment enabled cutin extraction under milder conditions using a 2% NaOH solution, reducing NaOH usage by 33%, while still achieving a substantial cutin yield of 45.6%. FT-IR analysis confirmed that cutin obtained via both conventional and HPH-assisted extraction exhibited similar chemical structures, indicating that the main chemical groups and structure of cutin remained unaltered by HPH treatment. Furthermore, cutin extracts from both conventional and HPH-assisted extraction demonstrated thermal stability up to approximately 200 °C, with less than 5% weight loss according to TGA analysis. These findings underscore the potential of HPH technology to significantly enhance cutin extraction yield from tomato peel residues while utilizing milder chemical hydrolysis conditions, thereby promoting a more sustainable and efficient cutin extraction process.

Effect of Novel Processing Techniques on the Carotenoid Release during the Production of Red Guava Juice

Red guava, distinguished by its elevated lycopene content, emerges as a promising natural source of carotenoids. This study systematically evaluates the impact of diverse processing techniques on the efficient release of carotenoids. The primary objective is to facilitate the transfer of carotenoids into the juice fraction, yielding carotenoid-enriched juice seamlessly integrable into aqueous-based food matrices. The untreated guava puree exhibited a modest release of carotenoids, with only 66.26% of β-carotene and 57.08% of lycopene reaching the juice. Contrastly, both high-pressure homogenization (HPH) at 25 MPa and enzyme (EM) treatment significantly enhanced carotenoid release efficiency (p < 0.05), while high hydrostatic pressure (HHP) at 400 MPa and pulsed electric field (PEF) of 4 kV/cm did not (p > 0.05). Notably, HPH demonstrated the most substantial release effect, with β-carotene and lycopene reaching 90.78% and 73.85%, respectively. However, the stability of EM-treated samples was relatively poor, evident in a zeta-potential value of -6.51 mV observed in the juice. Correlation analysis highlighted the interactions between pectin and carotenoids likely a key factor influencing the stable dissolution or dispersion of carotenoids in the aqueous phase. The findings underscore HPH as a potent tool for obtaining carotenoid-enriched guava juice, positioning it as a desirable ingredient for clean-label foods.

Leveraging new opportunities and advances in high-pressure homogenization to design non-dairy foods

High-pressure homogenization (HPH) and ultrahigh-pressure homogenization (UHPH) are emerging food processing techniques for stabilizing emulsions and food components under the pressure range from 60 to 400 MPa. Apart from this, they also support increasing nutritional profile, food preservation, and functionality enhancement. Even though the food undergoes the shortest processing operation, the treatment leads to modification of physical, chemical, and techno-functional properties, in addition to the formation of micro-sized particles. This study focuses on recent advances in using HPH/UHPH on plant-based milk sources such as soybeans, almonds, hazelnuts, and peanuts. Overall, this systematic review provides an in-depth analysis of the principles of HPH/UHPH, the mechanism of action, and their applications in other nondairy areas such as fruits and vegetables, meat, fish, and marine species. This work also deciphers the role of HPH/UHPH in modifying food components, their functional quality enhancement, and their provision of oxidative resistance to many foods. HPH is not only perceived as a technique for size reduction and homogenization; however, it does various functions like microbial inactivation, improvement of rheologies like texture and consistency, decreasing of lipid oxidation, and making positive modifications to proteins such as changes to the secondary structure and tertiary structure thereby enhancing the emulsifying properties, hydrophobicity of proteins, and other associated functional properties in many nondairy sources at pressures of 100-300 MPa. Thus, HPH is an emerging technique with a high throughput and commercialization value in food industries.

Comprehensive Update on Carotenoid Colorants from Plants and Microalgae: Challenges and Advances from Research Laboratories to Industry

The substitution of synthetic food dyes with natural colorants continues to be assiduously pursued. The current list of natural carotenoid colorants consists of plant-derived annatto (bixin and norbixin), paprika (capsanthin and capsorubin), saffron (crocin), tomato and gac fruit lycopene, marigold lutein, and red palm oil (α- and β-carotene), along with microalgal Dunaliella β-carotene and Haematococcus astaxanthin and fungal Blakeslea trispora β-carotene and lycopene. Potential microalgal sources are being sought, especially in relation to lutein, for which commercial plant sources are lacking. Research efforts, manifested in numerous reviews and research papers published in the last decade, have been directed to green extraction, microencapsulation/nanoencapsulation, and valorization of processing by-products. Extraction is shifting from conventional extraction with organic solvents to supercritical CO2 extraction and different types of assisted extraction. Initially intended for the stabilization of the highly degradable carotenoids, additional benefits of encapsulation have been demonstrated, especially the improvement of carotenoid solubility and bioavailability. Instead of searching for new higher plant sources, enormous effort has been directed to the utilization of by-products of the fruit and vegetable processing industry, with the application of biorefinery and circular economy concepts. Amidst enormous research activities, however, the gap between research and industrial implementation remains wide.

High-Pressure Homogenization for Enhanced Bioactive Recovery from Tomato Processing By-Products and Improved Lycopene Bioaccessibility during In Vitro Digestion

The principles of industrial ecology have emerged as pivotal drivers of eco-innovation, aiming to realize a "zero-waste" society where waste materials are repurposed as valuable resources. In this context, High-Pressure Homogenization (HPH) presents a promising, easily scalable micronization technology, capable of enhancing the extractability and bioaccessibility of bioactive compounds found in tomato processing by-products, which are notably abundant waste streams in the Mediterranean region. This study focuses on optimizing HPH treatment parameters to intensify the recovery of bioactive compounds from tomato pomace. Additionally, it investigates the multifaceted impacts of HPH on various aspects, including color, particle size distribution, microscopic characteristics, surface properties, bioactivity, and lycopene bioaccessibility through in vitro digestion simulations. The results demonstrate that the application of HPH under optimized conditions (80 MPa, 25 °C, 10 passes) induces a remarkable 8-fold reduction in mean particle size, reduced surface tension, improved physical stability, uniform color, increased total phenolic content (+31%), antioxidant activity (+30%), dietary fiber content (+9%), and lycopene bioaccessibility during the intestinal digestion phase compared to untreated samples. These encouraging outcomes support the proposition of integrating HPH technology into an environmentally friendly industrial process for the full valorization of tomato processing residues. By utilizing water as the sole solvent, this approach aims to yield a functional ingredient characterized by greater nutritional and health-promoting values.

Impact of High-Pressure Homogenization on Enhancing the Extractability of Phytochemicals from Agri-Food Residues

The primary objective of the Sustainable Development Goals is to reduce food waste by employing various strategies, including the reuse of agri-food residues that are abundantly available and the complete use of their valuable compounds. This study explores the application of high-pressure homogenization (HPH), an innovative nonthermal and green treatment, for the recovery of bioactive compounds from agri-food residues. The results demonstrate that the optimized HPH treatment offers advantages over conventional solid/liquid extraction (SLE), including shorter extraction time, solvent-free operation, low temperatures, and higher yields of phenol extraction (an approximately 20% improvement). Moreover, the micronization of agri-food residue-in-water suspensions results in a decrease in the size distribution to below the visual detection limit, achieved by disrupting the individual plant cells, thus enhancing suspension stability against sedimentation. These findings highlight the potential of HPH for environmentally friendly and efficient extraction processes.

Waste and by-products as sources of lycopene, phytoene, and phytofluene - Integrative review with bibliometric analysis

Food loss and waste are severe social, economic, and environmental issues. An example is the incorrect handling of waste or by-products used to obtain bioactive compounds, such as carotenoids. This review aimed to present a comprehensive overview of research on lycopene, phytoene, and phytofluene obtained from waste and by-products. In this study, an integrative literature approach was coupled with bibliometric analysis to provide a broad perspective of the topic. PRISMA guidelines were used to search studies in the Web of Science database systematically. Articles were included if (1) employed waste or by-products to obtain lycopene, phytoene, and phytofluene or (2) performed applications of the carotenoids previously extracted from waste sources. Two hundred and four articles were included in the study, and the prevalent theme was research on the recovery of lycopene from tomato processing. However, the scarcity of studies on colorless carotenoids (phytoene and phytofluene) was evidenced, although these are generally associated with lycopene. Different technologies were used to extract lycopene from plant matrices, with a clear current trend toward choosing environmentally friendly alternatives. Microbial production of carotenoids from various wastes is a highly competitive alternative to conventional processes. The results described here can guide future forays into the subject, especially regarding research on phytoene and phytofluene, potential and untapped sources of carotenoids from waste and by-products, and in choosing more efficient, safe, and environmentally sustainable extraction protocols.

Encapsulation of Rosemary Extracts using High Voltage Electrical Discharge in Calcium Alginate/Zein/Hydroxypropyl Methylcellulose Microparticles

The increased demand for functional food with added health benefits is directing industrial procedures toward more sustainable production of naturally added bioactive compounds. The objective of this research was to investigate the potential of bioactive compounds from rosemary extract obtained using high-voltage electrical discharge as a green extraction method, for microencapsulation as a protective method for future application in functional food. Four types of microparticles were made via the ionic gelation method using alginate (Alg), zein (Z), and hydroxypropyl methylcellulose (HPMC) biopolymers and were analyzed considering the physicochemical properties. The diameter of dry microparticles ranged from 651.29 to 1087.37 μm. The shape and morphology analysis of microparticles showed that the obtained microparticles were quite spherical with a granular surface. The high encapsulation efficiency was obtained with a loading capacity of polyphenols up to 11.31 ± 1.47 mg GAE/g (Alg/Z microparticles). The microencapsulation method showed protective effects for rosemary polyphenols against pH changes during digestion. Specifically, the addition of both zein and HPMC to calcium-alginate resulted in microparticles with a prolonged release for better availability of polyphenols in the intestine. This research background indicates that the release of rosemary extract is highly dependent on the initial biopolymer composition with high potential for further functional food applications.

Biopolymer- and Lipid-Based Carriers for the Delivery of Plant-Based Ingredients

Natural ingredients are gaining increasing attention from manufacturers following consumers’ concerns about the excessive use of synthetic ingredients. However, the use of natural extracts or molecules to achieve desirable qualities throughout the shelf life of foodstuff and, upon consumption, in the relevant biological environment is severely limited by their poor performance, especially with respect to solubility, stability against environmental conditions during product manufacturing, storage, and bioavailability upon consumption. Nanoencapsulation can be seen as an attractive approach with which to overcome these challenges. Among the different nanoencapsulation systems, lipids and biopolymer-based nanocarriers have emerged as the most effective ones because of their intrinsic low toxicity following their formulation with biocompatible and biodegradable materials. The present review aims to provide a survey of the recent advances in nanoscale carriers, formulated with biopolymers or lipids, for the encapsulation of natural compounds and plant extracts.

High pressure homogenization to boost the technological functionality of native pea proteins

Pea proteins are being increasingly used for the formulation of plant-based products, but their globular structure and the presence of aggregates can affect their technological properties. In this study, the effect of high pressure homogenization (HPH) at different intensities (60 and 100 MPa) was investigated as a pre-treatment to modulate the techno-functional properties of a pea protein isolate (IP) extracted through an alkaline extraction/isoelectric precipitation process. SDS-PAGE, circular dichroism, thermal properties, total free sulfhydryl groups, antioxidant capacity and reducing properties were evaluated along with technological indices as solubility, WHC and OHC, interfacial tension and emulsifying capacity. HPH treatments were able to unfold and modify proteins structure, leading also to a change of the relative abundance of pea protein globulins (SDS-PAGE) and of the vicilin to legumin ratio. Solubility, WHC and OHC were improved, while interfacial tension and emulsifying capacity were weakly affected. However, an enhanced physical stability over time of the emulsions prepared with the 60 MPa-treated protein was found, likely as an effect of the decreased ratio between vicilin and legumin after treatment. Results of this study will contribute to deepen the effect of the HPH technology used as pre-treatment, adding useful results and expanding knowledge about the structure and techno-functional properties of native and modified pea proteins.

Structural and functional properties of alginate obtained by means of high hydrostatic pressure-assisted extraction

The effects of the high hydrostatic pressure (HPP) pre-treatment on the alginate extraction were seen to greatly depend on the recalcitrant nature of two algae species. Alginates were deeply characterized in terms of composition, structure (HPAEC-PAD, FTIR, NMR, SEC-MALS), functional and technological properties. The pre-treatment significantly increased the alginate yield in the less recalcitrant A. nodosum (AHP) also favoring the extraction of sulphated fucoidan/fucan structures and polyphenols. Although the molecular weight was significantly lower in AHP samples, neither the M/G ratio nor the M and G sequences were modified. In contrast, a lower increase in alginate extraction yield was observed for the more recalcitrant S. latissima after the HPP pre-treatment (SHP), but it significantly affected the M/G values of the resulting extract. The gelling properties of the alginate extracts were also explored by external gelation in CaCl₂ solutions. The mechanical strength and nanostructure of the hydrogel beads prepared were determined using compression tests, synchrotron small angle X-ray scattering (SAXS), and cryo-scanning electron microscopy (Cryo-SEM). Interestingly, the application of HPP significantly improved the gel strength of SHP, in agreement with the lower M/G values and the stiffer rod-like conformation obtained for these samples.

A Comprehensive Overview of Tomato Processing By-Product Valorization by Conventional Methods versus Emerging Technologies

The tomato processing industry can be considered one of the most widespread food manufacturing industries all over the world, annually generating considerable quantities of residue and determining disposal issues associated not only with the wasting of invaluable resources but also with the rise of significant environmental burdens. In this regard, previous studies have widely ascertained that tomato by-products are still rich in valuable compounds, which, once recovered, could be utilized in different industrial sectors. Currently, conventional solvent extraction is the most widely used method for the recovery of these compounds from tomato pomace. Nevertheless, several well-known drawbacks derive from this process, including the use of large quantities of solvents and the difficulties of utilizing the residual biomass. To overcome these limitations, the recent advances in extraction techniques, including the modification of the process configuration and the use of complementary novel methods to modify or destroy vegetable cells, have greatly and effectively influenced the recovery of different compounds from plant matrices. This review contributes a comprehensive overview on the valorization of tomato processing by-products with a specific focus on the use of "green technologies", including high-pressure homogenization (HPH), pulsed electric fields (PEF), supercritical fluid (SFE-CO₂), ultrasounds (UAE), and microwaves (MAE), suitable to enhancing the extractability of target compounds while reducing the solvent requirement and shortening the extraction time. The effects of conventional processes and the application of green technologies are critically analyzed, and their effectiveness on the recovery of lycopene, polyphenols, cutin, pectin, oil, and proteins from tomato residues is discussed, focusing on their strengths, drawbacks, and critical factors that contribute to maximizing the extraction yields of the target compounds. Moreover, to follow the "near zero discharge concept", the utilization of a cascade approach to recover different valuable compounds and the exploitation of the residual biomass for biogas generation are also pointed out.

Valorization of Agro-Industrial Wastes by Ultrasound-Assisted Extraction as a Source of Proteins, Antioxidants and Cutin: A Cascade Approach

The use of agro-industrial wastes to obtain compounds with a high added-value is increasing in the last few years in accordance with the circular economy concept. In this work, a cascade extraction approach was developed based on ultrasound-assisted extraction (UAE) for tomato, watermelon, and apple peel wastes. The protein and antioxidant compounds were obtained during the first extraction step (NaOH 3 wt.%, 98.6 W, 100% amplitude, 6.48 W/cm², 6 min). The watermelon peels (WP) showed higher proteins and total phenolic contents (857 ± 1 mg BSA/g extract and 107.2 ± 0.2 mg GAE/100 g dm, respectively), whereas the highest antioxidant activity was obtained for apple peels (1559 ± 20 µmol TE/100 g dm, 1767 ± 5 µmol TE/100 g dm, and 902 ± 16 µmol TE/100 g dm for ABTS, FRAP and DPPH assays, respectively). The remaining residue obtained from the first extraction was subsequently extracted to obtain cutin (ethanol 40 wt.%, 58 W, 100% amplitude, 2 W/cm², 17 min, 1/80 g/mL, pH 2.5). The morphological studies confirmed the great efficiency of UAE in damaging the vegetal cell walls. WP showed a higher non-hydrolysable cutin content (55 wt.% of the initial cutin). A different monomers’ profile was obtained for the cutin composition by GC-MS, with the cutin from tomato and apple peels being rich in polyhydroxy fatty acids whereas the cutin extracted from WP was mainly based on unsaturated fatty acids. All of the cutin samples showed an initial degradation temperature higher than 200 °C, presenting an excellent thermal stability. The strategy followed in this work has proved to be an effective valorization methodology with a high scaling-up potential for applications in the food, pharmaceutical, nutraceutical, cosmetics and biopolymer sectors.

Carotenoid Recovery from Tomato Processing By-Products through Green Chemistry

The recovery of bioactive compounds from agro-industry-derived by-products sustains circular economy principles by encouraging maximized recycling and minimized waste. Tomato processing by-products are abundant in carotenoids, which have several health-promoting properties, and their reintegration into functional food products represents a major interest for scientists and manufacturers. In the present study, carotenoids were recovered from tomato processing by-products based on the principles of green chemistry by using generally recognized as safe (GRAS) solvents, freeze-drying as pretreatment, and ultrasound in the recovery procedure. Spectrophotometric measurements and HPLC were used to identify and quantify total and individual carotenoids from the extracts. The highest values for lycopene (1324.89 µg/g dw) were obtained when ethyl lactate was applied as a solvent, followed by ethyl acetate with slightly smaller differences (1313.54 µg/g dw). The extracts obtained from freeze-dried samples presented significantly lower amounts of lycopene, indicating that carotenoids are highly susceptible to degradation during lyophilization. Flaxseed, grape seed, and hempseed oils were enriched with carotenoids and their rheological measurements showed favorable viscoelastic properties, especially hempseed and flaxseed oil, with viscosity under 50 mPa·s. Considering the results and the economic perspective of carotenoid recovery from tomato processing by-products, ethyl acetate is suitable, sustainable, and environmentally friendly for carotenoid extraction.

Optimization of Pulsed Electric Fields-Assisted Extraction of Phenolic Compounds From White Grape Pomace Using Response Surface Methodology

This study was focused on the optimization of the pulsed electric fields (PEF)-assisted extraction process using central composite design for response surface methodology from response surface methodology (RSM) with the aim to sustainably intensify the extractability of phenolic compounds from white grape pomace. The cell disintegration index (Zp) was used as response variable to identify the optimal PEF pre-treatment conditions of grape pomace in terms of field strength (E = 0.5–5 kV/cm) and energy input (WT = 1–20 kJ/kg), to be applied prior to the subsequent solid-liquid extraction (SLE) process. for both untreated and PEF-treated samples SLE process was optimized to determine the most effective combination of extraction temperature (20–50°C), extraction time (30–300 min), and solvent concentration (0–100% ethanol in water). Total phenolic content (TPC), flavonoid content (FC), and antioxidant activity (FRAP) of the obtained extracts were determined. The extracted compounds from untreated and PEF-treated samples at the optimal conditions were analyzed via HPLC-PDA analysis. Results revealed that, at a fixed extraction temperature (50°C), the application of PEF at optimal processing conditions (E = 3.8 kV/cm, WT = 10 kJ/kg) prior to SLE has the potential to reduce the solvent consumption (3–12%) and shorten the extraction time (23–103 min) to obtain the same recovery yield of phenolic compounds. Under optimized conditions, the extracts derived from PEF-treated samples showed significantly higher TPC (8%), FC (31%), and FRAP (36%) values, as compared to the control extraction. HPLC analyses revealed that epicatechin, p-coumaric acid, and quercetin were among the main phenolic compounds extracted, and no degradation phenomena occurred due to PEF application.

Challenging Sustainable and Innovative Technologies in Cheese Production: A Review

It is well known that cheese yield and quality are affected by animal genetics, milk quality (chemical, physical, and microbiological), production technology, and the type of rennet and dairy cultures used in production. Major differences in the same type of cheese (i.e., hard cheese) are caused by the rennet and dairy cultures, which affect the ripening process. This review aims to explore current technological advancements in animal genetics, methods for the isolation and production of rennet and dairy cultures, along with possible applications of microencapsulation in rennet and dairy culture production, as well as the challenge posed to current dairy technologies by the preservation of biodiversity. Based on the reviewed scientific literature, it can be concluded that innovative approaches and the described techniques can significantly improve cheese production.

An Edible Oil Enriched with Lycopene from Pink Guava (Psidium guajava L.) Using Different Mechanical Treatments

According to the regulations of the United States Food and Drug Administration (FDA), organic solvents should be limited in pharmaceutical and food products due to their inherent toxicity. For this reason, this short paper proposes different mechanical treatments to extract lycopene without organic solvents to produce an edible sunflower oil (SFO) enriched with lycopene from fresh pink guavas (Psidium guajava L.) (FPGs). The methodology involves the use of SFO and a combination of mechanical treatments: a waring blender (WB), WB+ high-shear mixing (HSM) and WB+ ultrafine friction grinding (UFFG). The solid:solvent (FPG:SFO) ratios used in all the techniques were 1:5, 1:10 and 1:20. The results from optical microscopy and UV–vis spectroscopy showed a correlation between the concentration of lycopene in SFO, vegetable tissue diameters and FPG:SFO ratio. The highest lycopene concentration, 18.215 ± 1.834 mg/g FPG, was achieved in WB + UFFG with an FPG:SFO ratio of 1:20. The yield of this treatment was 66% in comparison to the conventional extraction method. The maximal lycopene concentration achieved in this work was significantly higher than the values reported by other authors, using high-pressure homogenization for tomato peel and several solvents such as water, SFO, ethyl lactate and acetone.

Cellulose Isolation from Tomato Pomace Pretreated by High-Pressure Homogenization

This work proposes a biorefinery approach for the utilization of agri-food residues, such as tomato pomace (TP), through combining chemical hydrolysis with high-pressure homogenization (HPH), aiming to achieve the isolation of cellulose with tailored morphological properties from underused lignocellulose feedstocks, along with the valorization of the value-added compounds contained in the biomass. Cellulose was isolated from TP using sequential chemical hydrolysis in combination with mechanical pretreatment through HPH. The chemical and structural features of cellulose isolated from TP pretreated by HPH were compared with cellulose isolated from untreated TP through light scattering for particle size distribution, optical and scanning electron microscopy, and Fourier-transform infrared spectroscopy (FT-IR) analysis. HPH pretreatment (80 MPa, 10 passes) not only promoted a slight increase in the yield of cellulose extraction (+9%) but contributed to directly obtaining defibrillated cellulose particles, characterized by smaller irregular domains containing elongated needle-like fibers. Moreover, the selected mild chemical process produced side streams rich in bioactive molecules, evaluated in terms of total phenols and reducing activity. The liquors recovered from acid hydrolysis of TP exhibited a higher biological activity than those obtained through a conventional extraction (80% v/v acetone, 25 °C, 24 h at 180 rpm).

Impact of processing on the production of a carotenoid-rich Cucurbita maxima cv. Hokkaido pumpkin juice

Pumpkin juice with high carotenoid content can be attractive natural alternative for artificial food colourants. We evaluated the impact of processing treatments on aqueous carotenoid extraction from pumpkins, aiming to enhance carotenoid transfer into the juice fraction. Crushed whole pumpkins were processed by high pressure homogenization (HPH) for mechanical cell disruption, by enzymatic treatment for cell wall polysaccharide degradation or by a pulsed electric field (PEF) treatment for cell membrane electroporation. Processed purees were separated into juice and pomace and carotenoids were quantified by HPLC-DAD. Whereas only 54-60% of the carotenoids in non-processed puree was transferred into the juice, HPH- and enzyme-assisted processing of purees significantly increased juice yields and total soluble solids, and consequently, carotenoid concentrations in these juices up to 90-98% and 72-90%, respectively. No significant improvement was observed for PEF-treated samples. Results obtained can be industrially useful in producing natural colouring plant concentrates as clean-label ingredients.

Emerging Green Techniques for the Extraction of Antioxidants from Agri-Food By-Products as Promising Ingredients for the Food Industry

Nowadays, the food industry is heavily involved in searching for green sources of valuable compounds, to be employed as potential food ingredients, to cater to the evolving consumers’ requirements for health-beneficial food ingredients. In this frame, agri-food by-products represent a low-cost source of natural bioactive compounds, including antioxidants. However, to effectively recover these intracellular compounds, it is necessary to reduce the mass transfer resistances represented by the cellular envelope, within which they are localized, to enhance their extractability. To this purpose, emerging extraction technologies, have been proposed, including Supercritical Fluid Extraction, Microwave-Assisted Extraction, Ultrasound-Assisted Extraction, High-Pressure Homogenization, Pulsed Electric Fields, High Voltage Electrical Discharges. These technologies demonstrated to be a sustainable alternative to conventional extraction, showing the potential to increase the extraction yield, decrease the extraction time and solvent consumption. Additionally, in green extraction processes, also the contribution of solvent selection, as well as environmental and economic aspects, represent a key factor. Therefore, this review focused on critically analyzing the main findings on the synergistic effect of low environmental impact technologies and green solvents towards the green extraction of antioxidants from food by-products, by discussing the main associated advantages and drawbacks, and the criteria of selection for process sustainability.

O/W Pickering Emulsions Stabilized with Cellulose Nanofibrils Produced through Different Mechanical Treatments

This work aimed at studying the stabilization of O/W Pickering emulsions using nanosized cellulosic material, produced from raw cellulose or tomato pomace through different mechanical treatments, such as ball milling (BM) and high-pressure homogenization (HPH). The cellulose nanofibrils obtained via HPH, which exhibited longer fibers with higher flexibility than those obtained via ball milling, are characterized by lower interfacial tension values and higher viscosity, as well as better emulsion stabilization capability. Emulsion stability tests, carried out at 4 °C for 28 d or under centrifugation at different pH values (2.0, 7.0, and 12.0), revealed that HPH-treated cellulose limited the occurrence of coalescence phenomena and significantly slowed down gravitational separation in comparison with BM-treated cellulose. HPH-treated cellulose was responsible for the formation of a 3D network structure in the continuous phase, entrapping the oil droplets also due to the affinity with the cellulose nanofibrils, whereas BM-treated cellulose produced fibers with a more compact structure, which did adequately cover the oil droplets. HPH-treated tomato pomace gave similar results in terms of particle morphology and interfacial tension, and slightly lower emulsion stabilization capability than HPH-treated cellulose, suggesting that the used mechanical disruption process does not require cellulose isolation for its efficient defibrillation.

Tailoring Alginate/Chitosan Microparticles Loaded with Chemical and Biological Agents for Agricultural Application and Production of Value-Added Foods

This work reviews the recent development of biopolymer-based delivery systems for agricultural application. Encapsulation into biopolymer microparticles ensures the protection and targeted delivery of active agents while offering controlled release with higher efficiency and environmental safety for ecological and sustainable plant production. Encapsulation of biological agents provides protection and increases its survivability while providing an environment safe for growth. The application of microparticles loaded with chemical and biological agents presents an innovative way to stimulate plant metabolites synthesis. This enhances plants’ defense against pests and pathogens and results in the production of higher quality food (i.e., higher plant metabolites share). Ionic gelation was presented as a sustainable method in developing biopolymeric microparticles based on the next-generation biopolymers alginate and chitosan. Furthermore, this review highlights the advantages and disadvantages of advanced formulations against conventional ones. The significance of plant metabolites stimulation and their importance in functional food production is also pointed out. This review offers guidelines in developing biopolymeric microparticles loaded with chemical and biological agents and guidelines for the application in plant production, underlining its effect on the plant metabolites synthesis.

Impact of High-Pressure Homogenization Parameters on Physicochemical Characteristics, Bioactive Compounds Content, and Antioxidant Capacity of Blackcurrant Juice

High-pressure homogenization (HPH) is one of the food-processing methods being tested for use in food preservation as an alternative to pasteurization. The effects of the HPH process on food can vary depending on the process parameters used and product characteristics. The study aimed to investigate the effect of pressure, the number of passes, and the inlet temperature of HPH processing on the quality of cloudy blackcurrant juice as an example of food rich in bioactive compounds. For this purpose, the HPH treatment (pressure of 50, 150, and 220 MPa; one, three, and five passes; inlet temperature at 4 and 20 °C) and the pasteurization of the juice were performed. Titratable acidity, pH, turbidity, anthocyanin, vitamin C, and total phenolics content, as well as colour, and antioxidant activity were measured. Heat treatment significantly decreased the quality of the juice. For processing of the juice, the best were the combinations of the following: one pass, the inlet temperature of 4 °C, any of the used pressures (50, 150, and 220 MPa); and one pass, the inlet temperature of 20 °C, and the pressure of 150 MPa. Vitamin C and anthocyanin degradation have been reported during the HPH. The multiple passes of the juice through the machine were only beneficial in increasing the antioxidant capacity but negatively affected the colour stability.

Impact of High-Pressure Homogenization on the Extractability and Stability of Phytochemicals

High-pressure homogenization (HPH) and high-pressure processing (HPP) are emerging technologies for the food industry. Both technologies employ high pressure to preserve foods. However, the principal mechanism of HPH is based on shear stress distribution in a material instead of a decrease in volume due to an increase in pressure as occurring in HPP. HPH can be used in extraction or preservation of bioactive compounds and phytochemicals. This review first describes the mechanism of HPH processing. Next, this review discusses the impact of HPH on extractability and stability of phytochemicals such as carotenoids, vitamin C, polyphenols, and anthocyanins in various food matrices. In general, the use of HPH slightly improved or maintained the extractability of the phytochemicals. Similarly, HPH slightly reduced or maintained the stability of the phytochemicals but this is dependent on the food matrix and type of phytochemical. HPH has a great potential to be used to improve the extractability and maintaining the stability of these phytochemicals or to be used together with milder thermal processing. Besides understanding the impact of HPH on the extractability and stability of phytochemicals, the impact of HPH on the nutritional quality of the food matrices needs to be thoroughly evaluated.

Towards sustainable management of tomato pomace through the recovery of valuable compounds and sequential production of low-cost biosorbent

The present study focused on the full valorization of the tomato by-product, also known as tomato pomace consisting mainly of tomato peels and tomato seeds, by recovering natural antioxidants and edible oil, and subsequently reutilizing the leftover solid residues for the production of low-cost biosorbent. The tomato peel extract recovered using ethanol as food-grade solvent contained high phenol and flavonoid contents (199.35 ± 0.35-mg gallic acid equivalents (GAE)/g and 102.10 ± 0.03-mg quercetin equivalent (QE)/g, respectively). Even its lower content of lycopene (3.67 ± 0.04 mg/100 g), tomato peel extract showed potent antioxidant activity and can be therefore used as natural antioxidants either for food or cosmetic applications. High nutritional quality edible oil (17.15%) was extracted from tomato seeds and showed richness in unsaturated fatty acids (74.62%), with linoleic acid being the most abundant polyunsaturated fatty acid (49.70%). After recovery of these valuable compounds, the extraction solid leftovers were used to produce low-cost biosorbent tested for dye removal. Results showed that the highest biosorption yields were increasingly attributed to the acidic, direct, anthraquinone, then reactive dyes. Overall, the obtained results strongly support the complete utilization of tomato pomace for the recovery of valuable compounds and the sequential production of low-cost biosorbent.

Encapsulation of two fermentation agents, Lactobacillus sakei and calcium ions in microspheres

Alginate microspheres loaded with two fermentation active agents, calcium cations and strain LS0296 identified as Lactobacillus sakei, have been prepared and characterized. The role of calcium cation is twofold, it acts as gelling cation and as fermentation active agent. Encapsulation and the presence of calcium ions in the same compartment do not inhibit the activity of LS0296. Molecular interactions in microspheres are complex, including mainly hydrogen bonds and electrostatic interactions. In vitro calcium cations and strain LS0296 release profiles were fitted to the Korsmeyer-Peppas empirical model. The calcium cation release process is driven at first by Fickian diffusion through microspheres and then by anomalous transport kinetics. The in vitro LS0296 release process is driven by Fickian diffusion through microspheres showing a much slower releasing rate than calcium cations. The release of LS0296 strain is followed by a decrease in the pH value. Results obtained give us a new insight into complex interactions between bacterial cultures and microsphere constituents. Prepared formulations of calcium alginate microspheres loaded with LS0296 could be used as a new promising tool and a model for different starter cultures encapsulation and use in the production of fermented foods.

High Homogenization Pressures to Improve Food Quality, Functionality and Sustainability

Interest in high homogenization pressure technology has grown over the years. It is a green technology with low energy consumption that does not generate high CO2 emissions or polluting effluents. Its main food applications derive from its effect on particle size, causing a more homogeneous distribution of fluid elements (particles, globules, droplets, aggregates, etc.) and favoring the release of intracellular components, and from its effect on the structure and configuration of chemical components such as polyphenols and macromolecules such as carbohydrates (fibers) and proteins (also microorganisms and enzymes). The challenges of the 21st century are leading the processed food industry towards the creation of food of high nutritional quality and the use of waste to obtain ingredients with specific properties. For this purpose, soft and nonthermal technologies such as high pressure homogenization have huge potential. The objective of this work is to review how the need to combine safety, functionality and sustainability in the food industry has conditioned the application of high-pressure homogenization technology in the last decade.

Mechanical cell disruption of mustard bran suspensions for improved dispersion properties and protein release

Mustard bran, a by-product of mustard production, is still rich in valuable compounds. The high-pressure homogenization treatment was tested as a mechanical cell disruption (MCD) technique to unlock valuable intracellular compounds. An aqueous suspension of mustard bran was treated by shear mixing, followed by high-pressure homogenization at different pressure levels (50-150 MPa) and number of passes (1-10), and using different homogenizing systems. The moderate-intensity treatment (up to 100 MPa and 3 passes) can deliver significant changes in the mustard bran suspension, inducing (a) a more homogeneous and smooth appearance due to the disruption of individual cells, (b) a better structuring ability in the suspension, through the increase in viscosity and storage and loss moduli G' and G'', as well as (c) a remarkable enhancement of protein release, up to 72% of total proteins. The controlling factor in the extent of MCD was found to be the specific energy transferred to the mustard bran suspensions, whereas no significant differences were recorded when varying the homogenization system. The MCD process of mustard bran, based on its physical treatments using only water as a suspension medium, can be regarded as a safe, clean and environmentally friendly technology platform, which contributes to reaching the zero-waste concept by transforming agro-food by-products into value-added ingredients, with enhanced functionality and bioactive content.