Fermentation for future food systems: Precision fermentation can complement the scope and applications of traditional fermentation.

Modern biotechnology holds great potential for expanding the scope of fermentation to create novel foods and improve the sustainability of food production.

Variations of nonvolatile taste components of mushrooms with different operating conditions and parameters from farm to fork.

Mushroom is a sustainable food option and a meat substitute which yet needs some strategies to enhance sensory attributes. Especially, their taste characteristics (nonvolatile taste components: soluble sugars, organic acids, free amino acids, and 5'-nucleotides) can vary significantly due to operating conditions and parameters during different stages from farm to fork. This review is aimed to provide an overall view of the determined effects of operating conditions and parameters for mushroom taste attributes, suggestions for future research from lacking variables, and some recommendations for improving the taste perception of mushrooms. Taste compounds of mushrooms alter differently based on cultivation (species, cultivation or maturity stage, substrate composition, part, grade, mycelium strain), cooking (cooking method, time, temperature), preservation, and post-harvest storage conditions (drying parameters, pretreatment, preservation method, gamma irradiation, packaging, storage time and temperature). The dominant tastes of mushrooms given by sweet and umami taste active substances can be enhanced significantly with proper control of parameters during cultivation, cooking, drying, or post-harvest storage. The parameters and variations organized in this review can be used to develop a mathematical model for obtaining optimum taste attributes of mushrooms and mushroom-based meat alternatives and to discover the variables of mushroom species not studied yet.

Recent Advances in Prodigiosin as a Bioactive Compound in Nanocomposite Applications.

Bionanocomposites based on natural bioactive entities have gained importance due to their abundance; renewable and environmentally benign nature; and outstanding properties with applied perspective. Additionally, their formulation with biological molecules with antimicrobial, antioxidant, and anticancer activities has been produced nowadays. The present review details the state of the art and the importance of this pyrrolic compound produced by microorganisms, with interest towards Serratia marcescens, including production strategies at a laboratory level and scale-up to bioreactors. Promising results of its biological activity have been reported to date, and the advances and applications in bionanocomposites are the most recent strategy to potentiate and to obtain new carriers for the transport and controlled release of prodigiosin. Prodigiosin, a bioactive secondary metabolite, produced by Serratia marcescens, is an effective proapoptotic agent against bacterial and fungal strains as well as cancer cell lines. Furthermore, this molecule presents antioxidant activity, which makes it ideal for treating wounds and promoting the general improvement of the immune system. Likewise, some of the characteristics of prodigiosin, such as hydrophobicity, limit its use for medical and biotechnological applications; however, this can be overcome by using it as a component of a bionanocomposite. This review focuses on the chemistry and the structure of the bionanocomposites currently developed using biorenewable resources. Moreover, the work illuminates recent developments in pyrrole-based bionanocomposites, with special insight to its application in the medical area.

A metabolomics approach to evaluate post-fermentation enhancement of daidzein and genistein in a green okara extract.

BACKGROUND: Okara is a major agri-industrial by-product of the tofu and soymilk industries. Employing food-wastes as substrates for the green production of natural functional compounds is a recent trend that addresses the dual concepts of sustainable production and a zero-waste ecosystem. RESULTS: Extracts of unfermented okara and okara fermented with Rhizopus oligosporus were obtained using ethanol as extraction solvent, coupled with ultrasound sonication for enhanced extraction. Fermented extracts yielded significantly better results for total phenolic content (TPC) and total flavonoid content (TFC) than unfermented extracts. A qualitative liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOF-MS) analysis revealed a shift from glucoside forms to respective aglycone forms of the detected isoflavones, post-fermentation. Since the aglycone forms have been associated with numerous health benefits, a quantitative high-performance liquid chromatography (HPLC) analysis was performed. Fermented okara extracts had daidzein and genistein concentrations of 11.782 ± 0.325 µg mL-1 and 10.125 ± 1.028 µg mL-1 , as opposed to that of 6.7 ± 2.42 µg mL-1 and 4.55 ± 0.316 µg mL-1 in raw okara extracts, respectively. Lastly, the detected isoflavones were mapped to their metabolic pathways, to understand the biochemical reactions triggered during the fermentation process. CONCLUSION: Fermented okara may be implemented as a sustainable solution for production of natural bioactive isoflavonoids genistein and daidzein. © 2021 Society of Chemical Industry.

Technology innovations for food security in Singapore: A case study of future food systems for an increasingly natural resource-scarce world.

BACKGROUND: Food security is becoming an increasingly important global issue. Anthropogenic factors such as rapid urbanization and industrialization have strained finite resources like land and water. Therefore, against the impending threat of food security, the world can no longer rely on traditional methods to meet its needs. Instead, more creative and technologically advanced methods must be adopted to maximise diminishing natural resources. Singapore is a good case study of a small city-state that is trying to increase its own self-production of food using technology. SCOPE AND APPROACH: This review highlights the technologies that Singapore have adopted in enhancing food security given its limitation in natural resources. These methodologies serve as a case study that can be used as a reference point in light of the increasingly finite natural resources. The review also presents the advantages of these techniques as well as challenges that need to be overcome for them to be more widely adopted. KEY FINDINGS AND CONCLUSION: To increase self-production of food and enhance its food security, Singapore has employed the use of technologies such as vertical farming and aquaponics in urban farming, nutrient recovery from food waste, biodegradable food packaging from durian rinds, natural preservatives, insect farming, microalgae and cultivated meat as alternative protein sources. These technologies workaround Singapore's land and natural resource constraints, which many countries around the world can adapt. However, many of them are still relatively nascent with numerous challenges, which have to be addressed before they can be widely accepted and implemented.

Bioactive peptides from food fermentation: A comprehensive review of their sources, bioactivities, applications, and future development.

Bioactive peptides (BPs) are specific protein fragments that exert various beneficial effects on human bodies and ultimately influence health, depending on their structural properties and amino acid composition and sequences. By offering promising solutions to solve diverse health issues, the production, characterization, and applications of food-derived BPs have drawn great interest in the current literature and are of particular interest to the food and pharmaceutical industries. The microbial fermentation of protein from various sources is indubitably a novel way to produce BPs with numerous beneficial health effects. Apart from its lower cost as compared to enzymes, the BPs produced from microbial fermentation can be purified without further hydrolysis. Despite these features, current literature shows dearth of information on the BPs produced from food via microbial fermentation. Hence, there is a strong necessity to explore the BPs obtained from food fermentation for the development of commercial nutraceuticals and functional foods. As such, this review focuses on the production of BPs from different food sources, including the extensively studied milk and milk products, with emphasis on microbial fermentation. The structure-activity (antihypertensive, antioxidant, antimicrobial, opiate-like, anti-inflammatory, anticancer/antiproliferative, antithrombotic, hypolipidemic, hypocholesterolemic, and mineral binding) relationship, potential applications, future development, and challenges of BPs obtained from food fermentation are also discussed.

Involvement of organic acids and amino acids in ameliorating Ni(II) toxicity induced cell cycle dysregulation in Caulobacter crescentus: a metabolomics analysis.

Nickel (Ni(II)) toxicity is addressed by many different bacteria, but bacterial responses to nickel stress are still unclear. Therefore, we studied the effect of Ni(II) toxicity on cell proliferation of α-proteobacterium Caulobacter crescentus. Next, we showed the mechanism that allows C. crescentus to survive in Ni(II) stress condition. Our results revealed that the growth of C. crescentus is severely affected when the bacterium was exposed to different Ni(II) concentrations, 0.003 mM slightly affected the growth, 0.008 mM reduced the growth by 50%, and growth was completely inhibited at 0.015 mM. It was further shown that Ni(II) toxicity induced mislocalization of major regulatory proteins such as MipZ, FtsZ, ParB, and MreB, resulting in dysregulation of the cell cycle. GC-MS metabolomics analysis of Ni(II) stressed C. crescentus showed an increased level of nine important metabolites including TCA cycle intermediates and amino acids. This indicates that changes in central carbon metabolism and nitrogen metabolism are linked with the disruption of cell division process. Addition of malic acid, citric acid, alanine, proline, and glutamine to 0.015 mM Ni(II)-treated C. crescentus restored its growth. Thus, the present work shows a protective effect of these organic acids and amino acids on Ni(II) toxicity. Metabolic stimulation through the PutA/GlnA pathway, accelerated degradation of CtrA, and Ni-chelation by organic acids or amino acids are some of the possible mechanisms suggested to be involved in enhancing C. crescentus's tolerance. Our results shed light on the mechanism of increased Ni(II) tolerance in C. crescentus which may be useful in bioremediation strategies and synthetic biology applications such as the development of whole cell biosensor.

A synthetic microbial consortium of Shewanella and Bacillus for enhanced generation of bioelectricity.

In this study, a synthetic microbial consortium containing exoelectrogen Shewanella oneidensis MR-1 and riboflavin-producing strain, Bacillus subtilis RH33, was rationally designed and successfully constructed, enabling a stable, multiple cycles of microbial fuel cells (MFCs) operation for more than 500 h. The maximum power density of MFCs with this synthetic microbial consortium was 277.4 mW/m2 , which was 4.9 times of that with MR-1 (56.9 mW/m2 ) and 40.2 times of RH33 (6.9 mW/m2 ), separately. At the same time, the Coulombic efficiency of the synthetic microbial consortium (5.6%) was higher than MR-1 (4.1%) and RH33 (2.3%). Regardless the high concentration of riboflavin produced by RH33, the power density of RH33 was rather low. The low bioelectricity generation can be ascribed to the low efficiency of RH33 in utilizing riboflavin for extracellular electron transfer (EET). In the synthetic microbial consortium of MR-1 and RH33, it was found that both mediated and direct electron transfer efficiencies were enhanced. By exchanging the anolyte of MR-1 and RH33, it was confirmed that the improved MFC performance with the synthetic microbial consortium was because MR-1 could efficiently utilize the high concentration of riboflavin produced by RH33. Biotechnol. Bioeng. 2017;114: 526-532. © 2016 Wiley Periodicals, Inc.

Effect of Supercritical Carbon Dioxide Extraction Parameters on the Biological Activities and Metabolites Present in Extracts from Arthrospira platensis.

Arthrospira platensis was used to obtain functional extracts through supercritical carbon dioxide extraction (SFE-CO2). Pressure (P), temperature (T), co-solvent (CX), static extraction (SX), dispersant (Di) and dynamic extraction (DX) were evaluated as process parameters through a Plackett-Burman design. The maximum extract yield obtained was 7.48 ± 0.15% w/w. The maximum contents of bioactive metabolites in extracts were 0.69 ± 0.09 µg/g of riboflavin, 5.49 ± 0.10 µg/g of α-tocopherol, 524.46 ± 0.10 µg/g of ß-carotene, 1.44 ± 0.10 µg/g of lutein and 32.11 ± 0.12 mg/g of fatty acids with 39.38% of palmitic acid, 20.63% of linoleic acid and 30.27% of γ-linolenic acid. A. platensis extracts had an antioxidant activity of 76.47 ± 0.71 µg GAE/g by Folin-Ciocalteu assay, 0.52 ± 0.02, 0.40 ± 0.01 and 1.47 ± 0.02 µmol TE/g by DPPH, FRAP and TEAC assays, respectively. These extracts showed antimicrobial activity against Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa ATCC 27853, Escherichia coli ATCC 25922 and Candida albicans ATCC 10231. Overall, co-solvent was the most significant factor for all measured effects (p < 0.05). Arthrospira platensis represents a sustainable source of bioactive compounds through SFE using the following extraction parameters P: 450 bar, CX: 11 g/min, SX: 15 min, DX: 25 min, T: 60 °C and Di: 35 g.

Engineering Rhodosporidium toruloides with a membrane transporter facilitates production and separation of carotenoids and lipids in a bi-phasic culture.

The oleaginous yeast Rhodosporidium toruloides has great biotechnological potential. It accumulates a high amount of lipids which can be used for biofuels and also produces carotenoids which are valuable in the food and pharmaceutical industry. However, the location of these two hydrophobic products in the cell membrane prohibits its efficient harvesting and separation. Here, the transporter Pdr10 was engineered into R. toruloides and cultured in two-phase media containing oil. This enabled the production and in situ export of carotenoids into the oil and concurrent separation from intracellular lipids in the cells. When Pdr10 strain was cultured in the two-phase media, carotenoids and fatty acids yield increased from 1.9 to 2.9 µg/mg and 0.07 to 0.09 mg/mg, respectively. A total of 1.8 µg/mg carotenoids was exported by Pdr10 strain, as compared to 0.3 µg/mg in the wild type. In the Pdr10 strain, the composition of carotenoids and fatty acid it produced also changed. Torulene became the major carotene produced instead of torularhodin. Also, the unsaturated fatty acid C18:2 became the dominant fatty acid produced instead of the saturated C16:0, which was similar to the grape seed oil used in the two-phase media. This indicated that oil was being consumed by the cells, which was supported by the increased intracellular glycerol levels detected by gas chromatography-mass spectrometry (GC-MS). Our approach represents an easy and greener extraction method which could serve to increase the yield and facilitate separation of carotenoids and fatty acids.

Comparative proteomic analysis of engineered Saccharomyces cerevisiae with enhanced free fatty acid accumulation.

The engineered Saccharomyces cerevisiae strain △faa1△faa4 [Acot5s] was demonstrated to accumulate more free fatty acids (FFA) previously. Here, comparative proteomic analysis was performed to get a global overview of metabolic regulation in the strain. Over 500 proteins were identified, and 82 of those proteins were found to change significantly in the engineered strains. Proteins involved in glycolysis, acetate metabolism, fatty acid synthesis, TCA cycle, glyoxylate cycle, the pentose phosphate pathway, respiration, transportation, and stress response were found to be upregulated in △faa1△faa4 [Acot5s] as compared to the wild type. On the other hand, proteins involved in glycerol, ethanol, ergosterol, and cell wall synthesis were downregulated. Taken together with our metabolite analysis, our results showed that the disruption of Faa1 and Faa4 and expression of Acot5s in the engineered strain △faa1△faa4 [Acot5s] not only relieved the feedback inhibition of fatty acyl-CoAs on fatty acid synthesis, but also caused a major metabolic rearrangement. The rearrangement redirected carbon flux toward the pathways which generate the essential substrates and cofactors for fatty acid synthesis, such as acetyl-CoA, ATP, and NADPH. Therefore, our results help shed light on the mechanism for the increased production of fatty acids in the engineered strains, which is useful in providing information for future studies in biofuel production.

Enhanced production of fatty alcohols by engineering the TAGs synthesis pathway in Saccharomyces cerevisiae.

The production of fatty acid-derived chemicals has received a great deal of attention in recent years. In yeast cells, the main storage forms of fatty acids are TAGs. However, the conversion of TAGs into fatty acid derivatives suffers from a practical standpoint. Herein, a more direct strategy was applied to accumulate cellular fatty acyl-CoAs in Saccharomyces cerevisiae, which are the activated forms of fatty acids and used as important precursors for various converting enzymes. The dga1 gene was deleted to block the fatty acyl-CoAs dependent pathway of TAGs synthesis and a significant decrease in lipid content was observed. The FAR gene was cloned and overexpressed in the wild type strain and gene disrupted strain, to convert the fatty acyl-CoAs to the corresponding fatty acid derivatives. The metabolic engineered pathway resulted in enhanced production of fatty alcohols. Compared with the wild type strain with overexpressed FAR gene, the yield of fatty alcohols in the Δdga1 strain with FAR was dramatically increased: the intracellular fatty alcohols increased from 26 mg/L to 45 mg/L, while the extracellular fatty alcohols increased from 2.2 mg/L to 4.3 mg/L. By optimizing the culture medium with increased carbon concentration and limited nitrogen concentration, the fatty alcohols yield in the Δdga1 strain with FAR was further increased to 84 mg/L in cells and 14 mg/L secreted in broth. The results in this study demonstrated the feasibility of using the designed strategy to solve the bottleneck in utilizing TAGs for fatty acid derivatives production.

Biogenic tellurium nanorods as a novel antivirulence agent inhibiting pyoverdine production in Pseudomonas aeruginosa.

While antibiotic resistance in bacteria is rapidly increasing, the development of new antibiotics has decreased in recent years. Antivirulence drugs disarming rather than killing pathogens have been proposed to alleviate the problem of resistance inherent to existing biocidal antibiotics. Here, we report a nontoxic biogenic nanomaterial as a novel antivirulence agent to combat bacterial infections caused by Pseudomonas aeruginosa. We synthesized, in an environmentally benign fashion, tellurium nanorods (TeNRs) using the metal-reducing bacterium Shewanella oneidensis, and found that the biogenic TeNRs could effectively inhibit the production of pyoverdine, one of the most important virulence factors in P. aeruginosa. Our results suggest that amyloids and extracellular polysaccharides Pel and Psl are not involved in the interactions between P. aeruginosa and the biogenic TeNRs, while flagellar movement plays an important role in the cell-TeNRs interaction. We further showed that the TeNRs (up to 100 µg/mL) did not exhibit cytotoxicity to human bronchial epithelial cells and murine macrophages. Thus, biogenic TeNRs hold promise as a novel antivirulence agent against P. aeruginosa.

Enhancement of free fatty acid production in Saccharomyces cerevisiae by control of fatty acyl-CoA metabolism.

Production of biofuels derived from microbial fatty acids has attracted great attention in recent years owing to their potential to replace petroleum-derived fuels. To be cost competitive with current petroleum fuel, flux toward the direct precursor fatty acids needs to be enhanced to approach high yields. Herein, fatty acyl-CoA metabolism in Saccharomyces cerevisiae was engineered to accumulate more free fatty acids (FFA). For this purpose, firstly, haploid S. cerevisiae double deletion strain △faa1△faa4 was constructed, in which the genes FAA1 and FAA4 encoding two acyl-CoA synthetases were deleted. Then the truncated version of acyl-CoA thioesterase ACOT5 (Acot5s) encoding Mus musculus peroxisomal acyl-CoA thioesterase 5 was expressed in the cytoplasm of the strain △faa1△faa4. The resulting strain △faa1△faa4 [Acot5s] accumulated more extracellular FFA with higher unsaturated fatty acid (UFA) ratio as compared to the wild-type strain and double deletion strain △faa1△faa4. The extracellular total fatty acids (TFA) in the strain △faa1△faa4 [Acot5s] increased to 6.43-fold as compared to the wild-type strain during the stationary phase. UFA accounted for 42 % of TFA in the strain △faa1△faa4 [Acot5s], while no UFA was detected in the wild-type strain. In addition, the expression of Acot5s in △faa1△faa4 restored the growth, which indicates that FFA may not be the reason for growth inhibition in the strain △faa1△faa4. RT-PCR results demonstrated that the de-repression of fatty acid synthesis genes led to the increase of extracellular fatty acids. The study presented here showed that through control of the acyl-CoA metabolism by deleting acyl-CoA synthetase and expressing thioesterase, more FFA could be produced in S. cerevisiae, demonstrating great potential for exploitation in the platform of microbial fatty acid-derived biofuels.

Metabolic engineering for enhanced fatty acids synthesis in Saccharomyces cerevisiae.

Microbial production of biofuel has attracted significant attention in recent years. The fatty acids are important precursors for the production of fuels and chemicals, and its biosynthesis is initiated by the conversion of acetyl-CoA to malonyl-CoA which requires acetyl-CoA as key substrate. Herein, the yeast Saccharomyces cerevisiae was proposed to be metabolically engineered for cytosol acetyl-CoA enhancement for fatty acid synthesis. By gene disruption strategy, idh1 and idh2 genes involved in citrate turnover in tricarboxylic acid cycle (TCA cycle) were disrupted and the citrate production level was increased to 4- and 5-times in mutant yeast strains. In order to convert accumulated citrate to cytosol acetyl-CoA, a heterologous ATP-citrate lyase (ACL) was overexpressed in yeast wild type and idh1,2 disrupted strains. The wild type strain expressing acl mainly accumulated saturated fatty acids: C14:0, C16:0 and C18:0 at levels about 20%, 14% and 27%, respectively. Additionally, the idh1,2 disrupted strains expressing acl mainly accumulated unsaturated fatty acids. Specifically in Δidh1 strain expressing acl, 80% increase in C16:1 and 60% increase in C18:1 was detected. In Δidh2 strain expressing acl, 60% increase in C16:1 and 45% increase in C18:1 was detected. In Δidh1/2 strain expressing acl, there was 92% increase in C16:1 and 77% increase in C18:1, respectively. The increased fatty acids from our study may well be potential substrates for the production of hydrocarbon molecules as potential biofuels.

Nano and Technological Frontiers as a Sustainable Platform for Postharvest Preservation of Berry Fruits.

Berries are highly perishable and susceptible to spoilage, resulting in significant food and economic losses. The use of chemicals in traditional postharvest protection techniques can harm both human health and the environment. Consequently, there is an increasing interest in creating environmentally friendly solutions for postharvest protection. This article discusses various approaches, including the use of "green" chemical compounds such as ozone and peracetic acid, biocontrol agents, physical treatments, and modern technologies such as the use of nanostructures and molecular tools. The potential of these alternatives is evaluated in terms of their effect on microbial growth, nutritional value, and physicochemical and sensorial properties of the berries. Moreover, the development of nanotechnology, molecular biology, and artificial intelligence offers a wide range of opportunities to develop formulations using nanostructures, improving the functionality of the coatings by enhancing their physicochemical and antimicrobial properties and providing protection to bioactive compounds. Some challenges remain for their implementation into the food industry such as scale-up and regulatory policies. However, the use of sustainable postharvest protection methods can help to reduce the negative impacts of chemical treatments and improve the availability of safe and quality berries.

EBV up-regulates cytochrome c through VDAC1 regulations and decreases the release of cytoplasmic Ca2+ in the NPC cell line.

EBV (Epstein-Barr virus) is considered to be a major factor that causes NPC (nasopharyngeal carcinoma), which is one of the sneakiest cancers frequently occurring in Southeast Asia and Southern China. Apoptosis and pro-apoptotic signals have been studied for decades; however, few have extended the prevailing view of EBV to its impact on NPC in perspective of apoptosis. One of the important proteins named VDAC1 (voltage-dependent anion protein 1) on the mitochondrial outer membrane controls the pro-apoptotic signals in mammalian cells. The impact of EBV infection on VDAC1 and related apoptotic signals remains unclear. In order to study the VDAC1's role in EBV-infected NPC cells, we employ siRNA (small interfering RNA) inhibition to analyse the release of Ca2+ and Cyto c (cytochrome c) signals in the cytoplasm, as they are important pro-apoptotic signals. The results show a decrease of Ca2+ release and up-regulation of Cyto c with EBV infection. After siRNA transfection, the dysregulation of Cyto c is neutralized, which is evidence that the level of Cyto c release in virus-infected NPC cells is the as same as that of non-infected NPC cells. This result indicates that EBV infection changes the cytoplasmic level of Cyto c through regulating VDAC1. In summary, this study reports that EBV changes the release of Ca2+ and Cyto c in the cytoplasm of NPC cells, and that Cyto c changes are mediated by VDAC1 regulation.

Upcycling of brewers' spent grains via solid-state fermentation for the production of protein hydrolysates with antioxidant and techno-functional properties.

Brewers' spent grains (BSG) were fermented with Rhizopus oligosporus and up to 15% of original protein was hydrolysed. Fermented BSG was then subjected to an ethanolic-alkali extraction and isolated fractions contained 61-66% protein. An evaluation of functional properties suggested that fermented extracts presented superior emulsifying abilities (15-34 m2/g of activity and 16-42 min of stability), foaming properties (16-30% capacity and 7-14% stability), and water/oil binding capacities (0.41 g/g and 0.24 g/g, respectively). They also showed significantly higher ABTS inhibition and stronger reducing power than unfermented ones, indicating that fermented BSG protein extract had greater antioxidant activities. No cytotoxic effect was detected in the range of 2-10 mg/mL. When applied in a mayonnaise formulation, fermented hydrolysates demonstrated better emulsion stability in terms of creaming, microstructure and viscosity. Thus, fermented BSG protein is a potential plant-based emulsifier for food, pharmaceutical and cosmetic applications.

Clinically relevant materials & applications inspired by food technologies.

Food science and technology have a fundamental and considerable overlap with medicine, and many clinically important applications were borne out of translational food science research. Globally, the food industry - through various food processing technologies - generates huge quantities of agro-waste and food processing byproducts that retain a significant biochemical potential for upcycling into important medical applications. This review explores some distinct clinical applications that are fabricable from food-based biopolymers and substances, often originating from food manufacturing side streams. These include antibacterial wound dressings and tissue scaffolding from the biopolymers cellulose and chitosan and antimicrobial food phytochemicals for combating antibiotic-resistant nosocomial infections. Furthermore, fermentation is discussed as the epitome of a translational food technology that unlocks further therapeutic value from recalcitrant food-based substrates and enables sustainable large-scale production of high-value pharmaceuticals, including novel fermented food-derived bioactive peptides (BPs).

Combined Pulsed Electric Field and Microwave-Assisted Extraction as a Green Method for the Recovery of Antioxidant Compounds with Electroactive Potential from Coffee Agro-Waste.

Coffee agro-waste is a potential source of polyphenols with antioxidant activity and application in the food and cosmetic trades. The usage of these byproducts persists as a challenge in the industrial landscape due to their high content of purported toxic substances hindering management. This study presents a green extractive process using pulsed electric field (PEF) and microwave assisted extraction (MAE) to recover polyphenols from coffee parchment and two varieties of pulp, posing quick processing times and the use of water as the only solvent. The performance of this process with regard to the bioactivity was assessed through the Folin-Ciocalteu assay, total flavonoid content, DPPH, ABTS and FRAP antioxidant tests. The phenolic composition of the extracts was also determined through HPLC-MS and quantified through HPLC-DAD. When compared to treatment controls, PEF + MAE treated samples presented enhanced yields of total phenolic content and radical scavenging activity in all analyzed residues (Tukey test significance: 95%). The chromatographic studies reveal the presence of caffeic acid on the three analyzed by-products. The HPLC-DAD caffeic acid quantification validated that a combination of MAE + PEF treatment in yellow coffee pulp had the highest caffeic acid concentration of all studied extraction methods.