Purification of Natural Pigments Violacein and Deoxyviolacein Produced by Fermentation Using Yarrowia lipolytica.

Violacein and deoxyviolacein are bis-indole pigments synthesized by a number of microorganisms. The present study describes the biosynthesis of a mixture of violacein and deoxyviolacein using a genetically modified Y. lipolytica strain as a production chassis, the subsequent extraction of the intracellular pigments, and ultimately their purification using column chromatography. The results show that the optimal separation between the pigments occurs using an ethyl acetate/cyclohexane mixture with different ratios, first 65:35 until both pigments were clearly visible and distinguishable, then 40:60 to create a noticeable separation between them and recover the deoxyviolacein, and finally 80:20, which allows the recovery of the violacein. The purified pigments were then analyzed by thin-layer chromatography and nuclear magnetic resonance.

Exhausted Grape Seed Residues as a Valuable Source of Antioxidant Molecules for the Formulation of Biocompatible Cosmetic Scrubs.

Grape seed of Obeidi, a white Lebanese autochthonous variety, was previously tested in different studies as a valuable source of bioactive molecules such as polyphenols, oils, and proteins by means of extraction procedures for the development of cosmetic and therapeutic products. However, an un-valorized, exhausted grape seed residue remains as "secondary waste" after the extraction processes. In this study, the exhausted seeds have been further exploited to produce cosmetic scrubs capable of releasing antioxidant molecules during the exfoliation process, in accordance with the principles of the circular economy and going toward a zero-waste process. The deep characterization of the exhausted seeds confirmed the presence of antioxidant phenolic molecules including gallic acid, catechins and protocatechuic acid (0.13, 0.126, and 0.089 mg/g of dry matter DM), and a high phenolic content (11.85 mg gallic acid equivalents (GAE)/g of dry matter (DM)). Moreover, these residues were shown to possess a sandy texture (Hausner ratio (HR): 1.154, Carr index (CI): 0.133, and angle of repose: 31.62 (°) degrees), similar to commercial natural exfoliants. In this respect, exhausted Obeidi grape seed residues were incorporated at increasing concentrations (0.5, 1, 1.5, and 2% w/w) in a cosmetic scrub, and stored for 5 weeks at 4, 25, and 50 °C for stability testing. All tested scrub formulations exhibited good spreadability with a spread diameter of 3.6-4.7 cm and excellent physical stability, as no phase separation or color change were observed after four cycles of heat shock at 4 and 50 °C. Finally, an in vivo skin irritation test showed that the scrub enriched with 1.5% of exhausted Obeidi grape seed residues was the most promising formulation, as it possessed a high amount of phenolic molecules (0.042 ± 0.001 mg GAE/mL of scrub) and good stability and could be safely applied to the skin with no irritation phenomena. Overall results underlined that exhausted grape seed residues can be transformed into promising systems for both physical and chemical exfoliation, thus confirming the importance of the effective exploitation of agro-industrial by-products for the development of high value cosmeceutics towards a more sustainable and zero-waste approach.

Phenolic Compounds Recovery from Blood Orange Peels Using a Novel Green Infrared Technology Ired-Irrad®, and Their Effect on the Inhibition of Aspergillus flavus Proliferation and Aflatoxin B1 Production.

The intensification of total phenolic compound (TPC) extraction from blood orange peels was optimized using a novel green infrared-assisted extraction technique (IRAE, Ired-Irrad®) and compared to the conventional extraction using a water bath (WB). Response surface methodology (RSM) allowed for the optimization of ethanol concentration (E), time (t), and temperature (T) in terms of extracted TPC and their antiradical activity, for both WB extraction and IRAE. Using WB extraction, the multiple response optimums as obtained after 4 h at 73 °C and using 79% ethanol/water were 1.67 g GAE/100 g for TPC and 59% as DPPH inhibition percentage. IRAE increased the extraction of TPC by 18% using 52% ethanol/water after less than 1 h at 79 °C. This novel technology has the advantage of being easily scalable for industrial usage. HPLC analysis showed that IRAE enhanced the recovery of gallic acid, resveratrol, quercetin, caffeic acid, and hesperidin. IR extracts exhibited high bioactivity by inhibiting the production of Aflatoxin B1 by 98.9%.

Inhibition of Aflatoxin B1 Synthesis in Aspergillus flavus by Mate (Ilex paraguariensis), Rosemary (Rosmarinus officinalis) and Green Tea (Camellia sinensis) Extracts: Relation with Extract Antioxidant Capacity and Fungal Oxidative Stress Response Modulation.

Plant extracts may represent an ecofriendly alternative to chemical fungicides to limit aflatoxin B1 (AFB1) contamination of foods and feeds. Mate (Ilex paraguariensis), rosemary (Romarinus officinalis) and green tea (Camellia sinensis) are well known for their beneficial properties, which are mainly related to their richness in bioactive phenolic compounds. AFB1 production is inhibited, with varying efficiency, by acetone/water extracts from these three plants. At 0.45 µg dry matter (DM)/mL of culture medium, mate and green tea extracts were able to completely inhibit AFB1 production in Aspergillus flavus, and rosemary extract completely blocked AFB1 biosynthesis at 3.6 µg DM/mL of culture medium. The anti-AFB1 capacity of the extracts correlated strongly with their phenolic content, but, surprisingly, no such correlation was evident with their antioxidative ability, which is consistent with the ineffectiveness of these extracts against fungal catalase activity. Anti-AFB1 activity correlated more strongly with the radical scavenging capacity of the extracts. This is consistent with the modulation of SOD induced by mate and green tea in Aspergillus flavus. Finally, rutin, a phenolic compound present in the three plants tested in this work, was shown to inhibit AFB1 synthesis and may be responsible for the anti-mycotoxin effect reported herein.

Optimization of Polyphenols' Recovery from Purple Corn Cobs Assisted by Infrared Technology and Use of Extracted Anthocyanins as a Natural Colorant in Pickled Turnip.

An ecofriendly extraction technology using infrared (IR) irradiation Ired-Irrad® was applied to purple corn cobs to enhance polyphenol recovery for the first time. The IR extraction efficiency was compared to that of the water bath (WB) method. Response surface methodology (RSM) using a central composite design was conducted to determine the effect of the experimental conditions (extraction time and treatment temperature) and their interactions on the total polyphenol and anthocyanin yields. Optimal extraction of total phenolic compounds (37 mg GAE/g DM) and total monomeric anthocyanins (14 mg C3G/g DM) were obtained at 63 °C for 77 min using IR as an extraction technique and water as a solvent. HPLC revealed that the recovery of peonidin 3-O-glucoside and cyanidin 3-O-glucoside was enhanced by 26% and 34%, respectively, when using IR. Finally, purple corn cobs' spray-dried extract was proven to be an important natural colorant of pickled turnip. It offers great potential for use as a healthy alternative to the carcinogenic rhodamine B synthetic dye, which was banned.

Antifungal and anti-aflatoxigenic properties of organs of Cannabis sativa L.: relation to phenolic content and antioxidant capacities.

Aflatoxin B1 is a carcinogenic mycotoxin that frequently contaminates crops worldwide. Current research indicates that the use of natural extracts to combat mycotoxin contamination may represent an eco-friendly, sustainable strategy to ensure food safety. Although Cannabis sativa L. has long been known for its psychoactive cannabinoids, it is also rich in many other bioactive molecules. This study examines extracts from various organs of Cannabis sativa L. to determine their ability to limit aflatoxin production and growth of Aspergillus flavus. The results indicate that flower extract is most effective for limiting the synthesis of aflatoxin B1, leading to an almost-complete inhibition of toxin production at a concentration of 0.225 mg dry matter per gram of culture medium. Since flower extract is rich in phenolic compounds, its total antioxidant ability and radical-scavenging capacity are determined. Compared with other anti-aflatoxigenic extracts, the anti-oxidative potential of Cannabis sativa L. flower extract appears moderate, suggesting that its anti-mycotoxin effect may be related to other bioactive compounds.

Impact of the Physicochemical Composition and Microbial Diversity in Apple Juice Fermentation Process: A Review.

Fermented apple beverages are produced all over the world with diverse characteristics associated with each country. Despite the diversifications, cider producers are confronted with similar issues and risks. The nature of the raw material, also known as the fermentation medium, plays a key role in fermentation. A well-defined composition of apples is, therefore, required to produce cider with good quality. In addition, ferment and its metabolism are important factors in the fermentation process. The producers of cider and other alcoholic beverages are looking in general for novel yeast strains or for the use of native strains to produce "authentic" and diversified beverages that are distinct from each other, and that attract more and more consumers. Research articles on cider production are infrequent compared to wine production, especially on the impact of the chemical composition and microbial diversity of apples on fermentation. Even though the processing of fermented beverages is close in terms of microbial interactions and production, the study of the specific properties of apples and the production challenges of cider production is advantageous and meaningful for cider producers. This review summarizes the current knowledge on apple composition and the impact of the must composition on fermentation and yeast growth. In addition, the microbial diversity of cider, activities, and its influence on fermentation are reviewed.

Infrared-Assisted Extraction and HPLC-Analysis of Prunus armeniaca L. Pomace and Detoxified-Kernel and their Antidiabetic Effects.

INTRODUCTION: Prunus armeniaca L. (P. armeniaca) is one of the medicinal plants with a high safety-profile. OBJECTIVES: The aim of this work was to make an infrared-assisted extraction (IR-AE) of P. armeniaca fruit (pomace) and kernel, and analyse them using reverse phase high-performance liquid chromatography (RP-HPLC) aided method. METHODS: IR-AE is a novel-technique aimed at increasing the extraction-efficiency. The antidiabetic-potentials of the P. armeniaca pomace (AP) and the detoxified P. armeniaca kernel extract (DKAP) were monitored exploring their possible hypoglycemic-mechanisms. Acute (6 h), subchronic (8 days) and long-term (8 weeks) assessment of Diabetes mellitus (DM) using glucometers and glycated hemoglobin (HbA1c) methods were applied. RESULTS: Serum-insulin levels, the inhibitory effects on alpha-glucosidase, serum-catalase (CAT) and lipid peroxidation (LPO) levels were also monitored. AP was shown to be rich in polyphenolics like trans-lutein (14.1%), trans-zeaxanthin (10.5%), trans-ß-cryptoxanthin (11.6%), 13, cis-ß-carotene (6.5%), trans 9, cis-ß-carotene (18.4%), and ß-carotene (21.5%). Prunus armeniaca kernel extract before detoxification (KAP) was found to be rich in amygdaline (16.1%), which caused a high mortality rate (50.1%), while after detoxification (amygdaline, 1.4%) a lower mortality rate (9.1%) was found. AP showed significant (p ≤ 0.05, n = 7/group) antidiabetic-activity more prominent than DKAP acutely, subchronically and on longer-terms. IR-AEs displayed more efficient acute and subchronic blood glucose level (BGL) reduction than a conventional extraction method, which might be attributed to IR-AE superiority in extraction of active ingredients. AP showed more-significant and dose-dependent increase in serum-insulin, CAT-levels and body-weights more prominent than those of DKAP. Alpha-glucosidase and LPO levels were inhibited with AP-groups more-significantly. CONCLUSION: In comparison to conventional-methods, IR-AE appeared to be an efficient and time-conserving novel extraction method. The antidiabetic-potentials of pomace and detoxified-kernels of P. armeniaca were probably mediated via the attenuation of glucose-provoked oxidative-stress, the inhibition of alpha-glucosidase and the marked insulin-secretagogue effect. Copyright © 2017 John Wiley & Sons, Ltd.

Systematic and Empirical Study of the Dependence of Polyphenol Recovery from Apricot Pomace on Temperature and Solvent Concentration Levels.

This work aims to study the impact of solvent mixture (between 0 and 50% ethanol/water mixture) and temperature (between 25°C and 75°C) levels on the solid-liquid extraction of phenolic compounds (quantity and bioactivity) from apricot pomace. Results show that the mean augmentation of 1% ethanol in the range [0-12%] enhances by three times the extraction of polyphenols compared to the same augmentation in the range [0-50%]. Similarly, the mean augmentation of 1°Celcius in the range [0-25°Celcius] enhances by two times the extraction of polyphenols compared to the same augmentation in the range [0-75°Celcius]. Moreover, 1% of ethanol exhibited a greater impact on the phenolic compound extraction than 1°Celsius. The response surface methodology showed that the optimal extraction condition was reached with 50% ethanol/water at 75°C giving a total phenolic content (TPC) of 9.8 mg GAE/g DM, a flavonoids content (FC) of 8.9 mg CE/g DM, a tannin content (TC) of 4.72 mg/L, and an antiradical activity (AA) of 44%. High-performance liquid chromatography (HPLC) analysis showed that polyphenols were influenced by the selectivity of the solvent as well as the properties of each phenolic compound. Apricot pomace extracts could therefore be used as natural bioactive molecules for many industrial applications.

The inhibition process of HIV-1 integrase by diketoacids molecules: Understanding the factors governing the better efficiency of dolutegravir.

The Human Immunodeficiency Virus-1 integrase is responsible for the covalent insertion of a newly synthesized double-stranded viral DNA into the host cells, and is an emerging target for antivirus drug design. Raltegravir (RAL) and elvitegravir (EVG) are the first two integrase strand transfer inhibitors used in therapy. However, treated patients eventually develop detrimental resistance mutations. By contrast, a recently approved drug, dolutegravir (DTG), presents a high barrier to resistance. This study aims to understand the increased efficiency of DTG upon focusing on its interaction properties with viral DNA. The results showed DTG to be involved in more extended interactions with viral DNA than EVG. Such interactions involve the halobenzene and scaffold of DTG and EVG and bases 5'G-43', 3'A35'and 3'C45'.

Importance of explicit smeared lone-pairs in anisotropic polarizable molecular mechanics. Torture track angular tests for exchange-repulsion and charge transfer contributions.

A correct representation of the short-range contributions such as exchange-repulsion (Erep ) and charge-transfer (Ect ) is essential for the soundness of separable, anisotropic polarizable molecular mechanics potentials. Within the context of the SIBFA procedure, this is aimed at by explicit representations of lone pairs in their expressions. It is necessary to account for their anisotropic behaviors upon performing not only in-plane, but also out-of-plane, variations of a probe molecule or cation interacting with a target molecule or molecular fragment. Thus, Erep and Ect have to reproduce satisfactorily the corresponding anisotropies of their quantum chemical (QC) counterparts. A significant improvement of the out-of-plane dependencies was enabled when the sp2 and sp localized lone-pairs are, even though to a limited extent, delocalized on both sides of the plane, above and below the atom bearer but at the closely similar angles as the in-plane lone pair. We report calibration and validation tests on a series of monoligated complexes of a probe Zn(II) cation with several biochemically relevant ligands. Validations are then performed on several polyligated Zn(II) complexes found in the recognition sites of Zn-metalloproteins. Such calibrations and validations are extended to representative monoligated and polyligated complexes of Mg(II) and Ca(II). It is emphasized that the calibration of all three cations was for each ΔE contribution done on a small training set bearing on a limited number of representative N, O, and S monoligated complexes. Owing to the separable nature of ΔE, a secure transferability is enabled to a diversity of polyligated complexes. For these the relative errors with respect to the target ΔE(QC) values are generally < 3%. Overall, the article proposes a full set of benchmarks that could be useful for force field developers. © 2017 Wiley Periodicals, Inc.

Could the "Janus-like" properties of the halobenzene CX bond (X=Cl, Br) be leveraged to enhance molecular recognition?

The CX bond in halobenzenes (XCl, Br) exhibits a dual character, being electron-deficient along the CX direction, and electron-rich on its flanks. We sought to amplify both features by resorting to electron-withdrawing and electron-donating substituents, respectively. This was done by quantum chemistry (QC) computations in the recognition sites of three protein targets: farnesyl transferase, coagulation factor Xa, and the HIV-1 integrase. In this context, some substituents, notably fluorine, CF3 , and NHCH3 , afforded significant overall gains in the binding energies as compared to the parent halobenzene, in the 2-5 kcal/mol range. In fact, we found that some di- and up to tetra-substitutions enabled even larger gains than those they contribute separately owing to many-body effects. Moreover, desolvation was also found to be a key contributor to the energy balances. As a consequence, some particular substituents, contributing to reduce the halobenzene dipole moment, accordingly reduced solvation: this factor acted in synergy with their enhancement of the intermolecular interaction energies along and around the CX bond. We could thus leverage the "Janus-like" properties of such a bond and the fact that it can be tuned and possibly amplified by well-chosen substituents. We propose a simple yet rigorous computational strategy resorting to QC to prescreen novel substituted halobenzenes. The QC results on the recognition sites then set benchmarks to validate polarizable molecular mechanics/dynamics approaches used to handle the entirety of the inhibitor-protein complex.

Substituent-modulated affinities of halobenzene derivatives to the HIV-1 integrase recognition site. Analyses of the interaction energies by parallel quantum chemical and polarizable molecular mechanics.

The C-X bond of halobenzenes (X = Cl, Br) has a dual character, its electron density being depleted in its prolongation and built-up on its sides. We have recently considered three protein or nucleic acid recognition sites of halobenzenes and quantified the energy gains that either electron-attracting substituents or electron-donating ones contribute due to such a character (El Hage et al., paper in revision). Nonadditivity was found to impact the total interaction energies. We focus here on one recognition site, that of the HIV-1 integrase, in which the halobenzene ring of the drug elvitegravir is sandwiched between a guanine and a cytosine base. We perform energy-decomposition analyses of the ab initio quantum-chemistry (QC) binding energies of the parent halobenzene ring and its derivatives with this G-C base pair. In these complexes, the nonadditivity of ΔE could be traced back mostly to the polarization contribution Epol. In view of large-scale applications to the entirety of the complex formed between the integrase, the viral DNA, and the whole drug, the analyses were performed in parallel with a polarizable molecular mechanics method, SIBFA. This method could faithfully reproduce most features of the QC energies. This is due to its use of QC-derived distributed multipoles and polarizabilities, which enable us to account for both nonisotropy and nonadditivity.

Effect of the drying process on the intensification of phenolic compounds recovery from grape pomace using accelerated solvent extraction.

In light of their environmental and economic interests, food byproducts have been increasingly exploited and valorized for their richness in dietary fibers and antioxidants. Phenolic compounds are antioxidant bioactive molecules highly present in grape byproducts. Herein, the accelerated solvent extraction (ASE) of phenolic compounds from wet and dried grape pomace, at 45 °C, was conducted and the highest phenolic compounds yield (PCY) for wet (16.2 g GAE/100 g DM) and dry (7.28 g GAE/100 g DM) grape pomace extracts were obtained with 70% ethanol/water solvent at 140 °C. The PCY obtained from wet pomace was up to two times better compared to the dry byproduct and up to 15 times better compared to the same food matrices treated with conventional methods. With regard to Resveratrol, the corresponding dry pomace extract had a better free radical scavenging activity (49.12%) than the wet extract (39.8%). The drying pretreatment process seems to ameliorate the antiradical activity, especially when the extraction by ASE is performed at temperatures above 100 °C. HPLC-DAD analysis showed that the diversity of the flavonoid and the non-flavonoid compounds found in the extracts was seriously affected by the extraction temperature and the pretreatment of the raw material. This diversity seems to play a key role in the scavenging activity demonstrated by the extracts. Our results emphasize on ASE usage as a promising method for the preparation of highly concentrated and bioactive phenolic extracts that could be used in several industrial applications.

Intensification of extraction process through IVDV pretreatment from Eryngium creticum leaves and stems: Maximizing yields and assessing biological activities.

"Intensification of Vaporization by Decompression to the Vacuum" (IVDV) has initially emerged as a technology primarily employed for expanding and enhancing the texture of biological products. However, its recent applications have showcased significant promise in the realm of extracting bioactive molecules from various plant materials. In this context, optimization using response surface methodology was conducted to investigate the impact of IVDV pretreatment on the extractability of phenolic compounds from Eryngium creticum leaves and stems, as well as their biological activities. Using IVDV preceding the extraction led to higher total phenolic content (TPC) and enhanced antiradical activities in treated materials compared to untreated ones. The optimal processing conditions in terms of water content, steam pressure and treatment time were determined in order to maximize TPC (89.07 and 20.06 mg GAE/g DM in leaves and stems, respectively) and antiradical (DPPH) inhibition percentage (93.51% and 27.54% in leaves and stems, respectively). IVDV-treated extracts showed superior antioxidant, antibacterial and antibiofilm capacities compared to raw extracts. Using RP-UHPLC-PDA-MS, caffeic acid and rosmarinic acid were identified in IVDV-treated leaves. IVDV can be implemented as an innovative treatment applied prior to extraction to boost the recovery of biomolecules from plant matrices.

Could an anisotropic molecular mechanics/dynamics potential account for sigma hole effects in the complexes of halogenated compounds?

Halogenated compounds are gaining an increasing importance in medicinal chemistry and materials science. Ab initio quantum chemistry (QC) has unraveled the existence of a "sigma hole" along the C-X (X = F, Cl, Br, I) bond, namely, a depletion of electronic density prolonging the bond, concomitant with a build-up on its sides, both of which are enhanced along the F < Cl < Br < I series. We have evaluated whether these features were intrinsically built-in in an anisotropic, polarizable molecular mechanics (APMM) procedure such as SIBFA (sum of interactions between fragments ab initio computed). For that purpose, we have computed the interaction energies of fluoro-, chloro-, and bromobenzene with two probes: a divalent cation, Mg(II), and water approaching X through either one H or its O atom. This was done by parallel QC energy-decomposition analyses (EDA) and SIBFA computations. With both probes, the leading QC contribution responsible for the existence of the sigma hole is the Coulomb contribution E(c). For all three halogenated compounds, and with both probes, the in- and out-of-plane angular features of E(c) were closely mirrored by the SIBFA electrostatic multipolar contribution (E(MTP)). Resorting to such a contribution thus dispenses with empirically-fitted "extra", off-centered partial atomic charges as in classical molecular mechanics/dynamics.

Optimization of a Molecularly Imprinted Polymer Synthesis for a Rapid Detection of Caffeic Acid in Wine.

Molecular imprinting is an efficient strategy to make the detection of compounds more specific and more selective. This targeted analytical strategy using molecularly imprinted polymer (MIP) synthesis needs to obtain the optimized conditions. A selective molecularly imprinted polymer was prepared for caffeic acid (CA) detection after varying the following synthesis parameters: functional monomer type (N-phenylacrylamide, N-PAA or methacrylic acid, MAA), solvent type (acetonitrile/methanol or acetonitrile/toluene), and the polymerization method (UV or thermal initiation). The optimal polymer was obtained using MAA as a functional monomer, acetonitrile/methanol as solvent, and UV polymerization. Morphological characterizations were done for the optimal CA-MIP using mid-infrared spectroscopy, scanning electron microscopy, and nitrogen adsorption. The optimal polymer showed good specificity and selectivity in the presence of interferents (antioxidants having a chemical structure close to CA) in a hydroalcoholic solution. The electrochemical detection of CA was performed by cyclic voltammetry (CV) after the interaction between CA and the optimal MIP in a wine sample. The linear range of the developed method was between 0 and 1.11 mM, the limit of detection (LOD) was 0.13 mM, and the limit of quantification (LOQ) was 0.32 mM. HPLC-UV was used to validate the newly developed method. Recovery values were between 104% and 111%.

Chemical Composition and Biological Activities of Centranthus longiflorus Stems Extracts Recovered Using Ired-Irrad®, an Innovative Infrared Technology, Compared to Water Bath and Ultrasound.

Extraction of polyphenols from Centranthus longiflorus stems was conducted using ultrasound and infrared Ired-Irrad® techniques, and compared to the conventional water bath method. Response surface methodology was used to analyse the effect of time, temperature, and ethanol percentage, as well as to optimize the three extraction methods. The highest phenolic content (81 mg GAE/g DM) and antioxidant activity (76% DPPH inhibition) were recorded with the Ired-Irrad® extract obtained under the optimal conditions: 55 °C, 127 min, 48% (v/v) ethanol. Biological activities (antioxidant, antibacterial and antibiofilm) of the three extracts were assessed. All C. longiflorus stems extracts showed limited antibacterial effects regardless of the extraction method (MIC = 50 mg/mL), whereas Ired-Irrad® extract exhibited the highest biofilm eradication and prevention capacities (93% against Escherichia coli and 97% against Staphylococcus epidermidis, respectively). This bioactivity is likely related to abundant caffeoylquinic acid and quercetin rutinoside, as identified by RP-UHPLC-PDA-MS analysis. The results obtained further promote the effectiveness of Ired-Irrad® as a highly flexible and cost-efficient extraction technique.

Sprouts Use as Functional Foods. Optimization of Germination of Wheat (Triticum aestivum L.), Alfalfa (Medicago sativa L.), and Radish (Raphanus sativus L.) Seeds Based on Their Nutritional Content Evolution.

Wheat, alfalfa, and radish sprouts are well-renowned for their high nutritional content. However, their optimal imbibition and germination durations are rarely considered in the literature. In this study, reduced imbibition times of 3 h, 10 h, and 4 h were demonstrated for the wheat, alfalfa, and radish seeds, respectively. The evolution of their crude fat, proteins, polyphenols, antioxidant activity, and vitamins were investigated over 7 days of germination. The crude fat and protein loads of these sprouts slightly varied during germination, whereas the phenolic compounds and antioxidant activity maxed out at day 7, 5, and 6 for the wheat, alfalfa, and radish sprouts, respectively, with significant levels of catechin. The vitamins highly increased, showing noteworthy yet different peaks of growth depending on the seed and the vitamin analyzed. Interestingly, alfalfa and radish sprouts, taken at their optimal germination day, would decidedly contribute to meet our Recommended Daily Allowances (RDAs) of vitamins E, A, and B6. Overall, for a greater nutritional content and a potential use of these sprouts as nutraceutical ingredients, our results suggested to leave the wheat, alfalfa, and radish seeds to germinate only over 7, 4, and 6 days, respectively, after which their nutritional quality tended to decrease.

Bioproduction of 2-Phenylethanol through Yeast Fermentation on Synthetic Media and on Agro-Industrial Waste and By-Products: A Review.

Due to its pleasant rosy scent, the aromatic alcohol 2-phenylethanol (2-PE) has a huge market demand. Since this valuable compound is used in food, cosmetics and pharmaceuticals, consumers and safety regulations tend to prefer natural methods for its production rather than the synthetic ones. Natural 2-PE can be either produced through the extraction of essential oils from various flowers, including roses, hyacinths and jasmine, or through biotechnological routes. In fact, the rarity of natural 2-PE in flowers has led to the inability to satisfy the large market demand and to a high selling price. Hence, there is a need to develop a more efficient, economic, and environmentally friendly biotechnological approach as an alternative to the conventional industrial one. The most promising method is through microbial fermentation, particularly using yeasts. Numerous yeasts have the ability to produce 2-PE using l-Phe as precursor. Some agro-industrial waste and by-products have the particularity of a high nutritional value, making them suitable media for microbial growth, including the production of 2-PE through yeast fermentation. This review summarizes the biotechnological production of 2-PE through the fermentation of different yeasts on synthetic media and on various agro-industrial waste and by-products.