Stability and bioaccessibility of micronutrients and phytochemicals present in processed leek and Brussels sprouts during static in vitro digestion.

Vegetables are frequently processed before consumption. However, vegetable functionalization continues beyond ingestion as the human digestive tract exposes vegetable products to various conditions (e.g. elevated temperature, pH alterations, enzymes, electrolytes, mechanical disintegration) which can affect the stability of micronutrients and phytochemicals. Besides the extent to which these compounds withstand the challenges posed by digestive conditions, it is equally important to consider their accessibility for potential absorption by the body. Therefore, this study investigated the impact of static in vitro digestion on the stability (i.e. concentration) and bioaccessibility of vitamin C, vitamin K1, glucosinolates, S-alk(en)yl-l-cysteine sulfoxides (ACSOs) and carotenoids in Brussels sprouts (Brassica oleracea var. gemmifera) and leek (Allium ampeloprasum var. porrum). Water-soluble compounds, glucosinolates and ACSOs, remained stable during digestion while vitamin C decreased by >48%. However, all water-soluble compounds were completely bioaccessible. Lipid-soluble compounds were also stable during digestion but were only bioaccessible for 26-81%.

Biodegradable film of carboxymethyl cellulose modified with red onion peel powder waste and boron nitride nanoparticles: Investigation of physicochemical properties and release of active substances.

The aim of this study was to modify carboxymethyl cellulose (CMC) films with onion peel extract (OPE) (0-2 g), onion peel powder (OPP) (0-2 g) and boron nitride nanoparticles (BN) (0-100 mg). 17 different CMC/OPE/OPP/BN films were provided and the physicochemical properties of films were studied. The release of active compounds of the composite film was investigated over time. The obtained results showed that OPE, OPP and BN increased the physical resistance and flexibility of the films. The percentage of moisture and solubility of the films decreased with the increase of OPE, OPP and BN. By adding BN, OPE and OPP, the structure of the film became stronger and the permeability to water vapor decreased. Addition of OPE and OPP significantly increased the antioxidant property of the film. In general, it can be said that the antioxidant substances of the onion peel are protected inside the film by preparing a CMC/OPE/OPP/BN film, which, in addition to stabilizing the antioxidants, can play an effective role in the controlled release of these antioxidant substances.

Human gut microbiota fermentation of cooked eggplant, garlic, and onion supports distinct microbial communities.

Heating and cooking vegetables not only enhances their palatability but also modifies their chemical structure, which in turn might affect their fermentation by resident gut microbes. Three commonly consumed vegetables that are known to undergo chemical browning, also known as Maillard reaction, during cooking - eggplant, garlic, and onion - were each fried, grilled, or roasted. The cooked vegetables were then subjected to an in vitro digestion-fermentation process aimed to simulate the passage of food through the human oro-gastro-intestinal tract. In the last step, the undigested fractions of these foods were anaerobically fermented by the complex human gut microbiota. We assessed the structure of microbial communities maintained on each cooked vegetable by high-throughput 16S rRNA gene amplicon sequencing, measured the levels of furosine, a chemical marker of the Maillard browning reaction, by HPLC, and determined the antioxidant capacities in all samples with ABTS and FRAP methods. Overall, vegetable type had the largest, statistically significant, effect on the microbiota structure followed by the cooking method. Onion fermentation supported a more beneficial community including an expansion of Bifidobacterium members and inhibition of Enterobacteriaceae. Fermentation of cooked garlic promoted Faecalibacterium growth. Among cooking methods, roasting led to a much higher ratio of beneficial-to-detrimental microbes in comparison with grilling and frying, possibly due to the exclusion of any cooking oil in the cooking process.

Traceability and authentication in agri-food production: A multivariate approach to the characterization ofthe Italian food excellence elephant garlic (Allium ampeloprasum L.), a vasoactive nutraceutical.

A research platform for food authentication was set up by combining stable isotope ratio analysis, metabolomics by gas and liquid mass-spectrometry and NMR investigations, chemometric analyses for food excellences. This multi-analytical approach was tested on samples of elephant garlic (Allium ampeloprasum L.), a species belonging to the same genus of common garlic (Allium ampeloprasum L.), mainly produced in southern Tuscany-(Allium ampeloprasum). The isotopic composition allowed the product to be geographically characterized. Flavonoids, like (+)-catechin, cinnamic acids, quercetin glycosides were identified. The samples showed also a significant amount of dipeptides, sulphur-containing metabolites and glutathione, the latter of which could be considered a molecular marker of the analyzed elephant garlic. For nutraceutical profiling to reach quality labels, extracts were investigated in specific biological assays, displaying interesting vasorelaxant properties in rat aorta by mediating nitric oxide release from the endothelium and exhibited positive inotropic and negative chronotropic effects in rat perfused heart.

Development of an analytic method for organosulfur compounds in Welsh onion and its use for nutritional quality analysis of five typical varieties in China.

A reliable, simple, and sensitive method capable of quantifying six organosulfur compounds (OSCs) was established. The samples were extracted by water containing 3 % formic acid with a simple vortex, ultrasound, and centrifugation step, and the solutions were analyzed by ultra-high-performance liquid chromatography separation system coupled with a triple-quadrupole mass spectrometry (UHPLC - MS/MS). Then the method was applied for the analysis of six OSCs in five varieties of two types Welsh onions in China, and the moisture content, reducing sugar, total polyphenols, and 21 free amino acids were also analyzed to study the characters of these Welsh onions intensively. Multivariate statistical analysis was used to investigate the differences in OSCs and free amino acids profiles among the samples. This study showed that enzymatic inhibition method combined with UHPLC - MS/MS is an effective technique to analyze OSCs in Welsh onion, and could be valuable for the routine quantitation of OSCs in other foods.

Optimization of microwave-assisted extraction of antioxidant compounds from spring onion leaves using Box-Behnken design.

Many studies have explored the extraction of bioactive compounds from different onion solid wastes, such as bulb, skin, and peel. However, onion leaves have received limited attention despite their potential as a valuable source of nutraceutical compounds. This study aimed to valorise, for the first time, the agricultural waste in the form of spring onion leaves (CN, Cipollotto Nocerino) to obtain antioxidant-rich polyphenolic extracts. A Box-Behnken design (BBD) was used to assess the impact of microwave-assisted extraction (MAE) variables (temperature, time, extraction volume, and ethanol concentration) on total polyphenol content (TPC) measured by Folin-Ciocalteu method and the antioxidant power determined by FRAP assay. Response surface methodology (RSM) was applied, and regression equations, analysis of variance, and 3D response curves were developed. Our results highlighted that the TPC values range from 0.76 to 1.43 mg GAE g-1 dw, while the FRAP values range from 8.25 to 14.80 mmol Fe(II)E g-1 dw. The optimal extraction conditions predicted by the model were 60 °C, 22 min, ethanol concentration 51% (v/v), and solvent volume 11 mL. These conditions resulted in TPC and FRAP values of 1.35 mg GAE g-1 dw and 14.02 mmol Fe(II)E g-1 dw, respectively. Furthermore, the extract obtained under optimized conditions was characterized by UHPLC-ESI-Orbitrap-MS analysis. LC/MS-MS platform allowed us to tentatively identify various compounds belonging to the class of flavonoids, saponins, fatty acids, and lipids. Finally, the ability of CN optimal extract to inhibit the intracellular reactive oxygen species (ROS) release in a hepatocarcinoma cell line using an H2O2-induced oxidative stress model, was evaluated. The results highlighted the potential of CN extract as a valuable source of polyphenols with significant antioxidant properties, suitable for various applications in the food and pharmaceutical industries.

Investigation of the phytochemical composition, antioxidant, antibacterial, anti-osteoarthritis, and wound healing activities of selected vegetable waste.

Agri-food wastes, produced following industrial food processing, are mostly discarded, leading to environmental hazards and losing the nutritional and medicinal values associated with their bioactive constituents. In this study, we performed a comprehensive analytical and biological evaluation of selected vegetable by-products (potato, onion, and garlic peels). The phytochemical analysis included UHPLC-ESI-qTOF-MS/MS in combination with molecular networking and determination of the total flavonoid and phenolic contents. Further, the antimicrobial, anti-osteoarthritis and wound healing potentials were also evaluated. In total, 47 compounds were identified, belonging to phenolic acids, flavonoids, saponins, and alkaloids as representative chemical classes. Onion peel extract (OPE) showed the higher polyphenolic contents, the promising antioxidant activity, the potential anti-osteoarthritis activity, and promising antimicrobial activity, especially against methicillin-resistant Staphylococcus aureus (MRSA). Furthermore, OPE revealed to have promising in vivo wound healing activity, restoring tissue physiology and integrity, mainly through the activation of AP-1 signaling pathway. Lastly, when OPE was loaded with nanocapsule based hydrogel, the nano-formulation revealed enhanced cellular viability. The affinities of the OPE major metabolites were evaluated against both p65 and ATF-2 targets using two different molecular docking processes revealing quercetin-3,4'-O-diglucoside, alliospiroside C, and alliospiroside D as the most promising entities with superior binding scores. These results demonstrate that vegetable by-products, particularly, those derived from onion peels can be incorporated as natural by-product for future evaluation against wounds and osteoarthritis.

Liquid submerged fermentation by selected microbial strains for onion skins valorization and its effects on polyphenols.

Onion skins, actually recycled as organic fertilizers, could be used as a substrate in environmental-friendly bioprocesses to recover high-value bioactive compounds and food ingredients.In this work, a bioprospecting method was carried out including 94 bacterial and 45 yeast strains from several agri-food and environmental niches to verify their ability to grow on onion skins as unique nutrients source.Red and yellow onion skins were assessed by newly selected starter-driven liquid submerged fermentation assays mainly aimed at the release and modification of polyphenols through microbial activities. Fermented onion skins were also investigated as a inexpensive favourable source of microbial enzymes (amylases, proteases, lipases, esterases, cellulases, xylanases).In red onion skins, the treatment with Lactiplantibacillus plantarum TB 11-32 produced a slight increase of bioactive compounds in terms of total phenolics, whereas with the yeast strain Zygosaccharomyces mrakii CL 30 - 29 the quercetin aglycone content increased of about 25% of the initial raw material.In yellow onion skins inoculated, the highest content of phenolic compounds was detected with the yeast strain Saccharomyces cerevisiae En SC, while quercetin aglycone increased of about 60% of the initial raw material in presence of the bacterial strain L. plantarum C 180 - 34.In conclusion, the proposed microbial pre-treatment method can be a potential strategy to re-use onion skins as a fermentation substrate, and as a first step in the development of a biorefinery process to produce value-added products from onion by-products.

Untargeted phytochemical profiling and biological activity of small yellow onion (Allium flavum L.) from different regions of Romania.

This study examined the phytochemical profiles (mainly phenolics, carotenoids, and organosulfur compounds) and biological effects of hydroalcoholic extracts of Allium flavum (AF), a species of the Allium genus commonly known as small yellow onion. Unsupervised and supervised statistical approaches revealed clear differences between extracts prepared with samples collected from different areas of Romania. Overall, the AFFF (AF flowers collected from Faget) extract was the best source of polyphenols, also showing the highest antioxidant capacity evaluated through both in vitro DPPH, FRAP, and TEAC anti-radical scavenging assays and cell-based OxHLIA and TBARS assays. All the tested extracts exhibited α-glucosidase inhibition potential, while only the AFFF extract exhibited anti-lipase inhibitory activity. The phenolic subclasses annotated were positively correlated with the assessed antioxidant and enzyme inhibitory activities. Our findings suggested that A. flavum has bioactive properties worth exploring further, being a potential edible flower with health-promoting implications.

Organosulfur Compounds of Allium Subgenus Nectaroscordum Species.

Organosulfur compounds formed upon comminuting the bulbs of two Allium subgenus Nectaroscordum species (Allium siculum and Allium tripedale) were analyzed by HPLC-PDA-MS/MS. The major organosulfur components were isolated and structurally characterized (MS, NMR), including several previously unknown compounds. It was found that the organosulfur chemistry occurring when these plants are cut is very similar to that observed in onion (Allium cepa). In all cases, however, the organosulfur compounds found in Nectaroscordum species were higher homologues of those observed in onion, being formed by various combinations of C1 and C4 building blocks derived from methiin and homoisoalliin/butiin, respectively. Thiosulfinates, bis-sulfine, cepaenes, and several cepaene-like compounds were identified among the major organosulfur components present in the homogenized bulbs. Several groups of 3,4-diethylthiolane-based compounds, structurally homologous with onionin A, cepathiolane A, allithiolanes A-H, and cepadithiolactone A, found in onion, were also detected.

Contributions of Chemical Content and Biological Activity to Plant Taxonomy Based on the Four Allium L. Taxa (Sect. Cupanioscordum - Amaryllidaceae).

Garlic and onions are used as food and for medicinal purposes worldwide. Allium L. species are rich in bioactive organosulphur compounds that exhibit many biological activities like anticancer, antimicrobial, antihypertensive, antidiabetic activities. In this study, macro- and micromorphological characteristics of four Allium taxa were examined and the results suggested that A. callimischon subsp. haemostictum was the outgroup to sect. Cupanioscordum. Also, for the genus Allium, which is a taxonomically difficult genus, the hypothesis that chemical content and bioactivity can also be used taxonomically in addition to micro and macromorphological characters has been questioned. The bulb extract was analyzed to determine their volatile compositions and anticancer activities against human breast cancer, human cervical cancer, and rat glioma cells for the first time in the literature. To detect the volatiles, the Head Space-Solid Phase Micro Extraction method was used followed by Gas Chromatography-Mass Spectrometry. The main compounds were found as dimethyl disulfide that (36.9 %, 63.8 %, 81.9 %, 12.2 %) and methyl (methylthio)-methyl disulfide (10.8 %, 6.9 %, 14.9 %, 60.0 %) for A. peroninianum, A. hirtovaginatum and A. callidyction, respectively. Additionally, methyl-trans-propenyl disulfide is detected for A. peroniniaum (36 %). As a result, all extracts have shown significant efficacy against MCF-7 cells depending on applied concentrations. The treatment of MCF-7 cells for 24 h with 10, 50, 200, or 400 µg/mL ethanolic bulb extract of four Allium species resulted in DNA synthesis inhibition. Survival rates for A. peroninianum was 51.3 %, 49.7 %, 42.2 %, 42.0 %, for A. callimischon subsp. haemostictum 62.5 %, 63.0 %, 23.2 %, 22 %, for A. hirtovaginatum 52.9 %, 42.2 %, 42.4 %, 39.9 %, for A. callidyction 51.8 %, 43.2 %, 39.1 %, 31.3 %, for cisplatin 59.6 %, 59.9 %, 50,9 %, 48.2 %, respectively. Moreover, taxonomic evaluation according to biochemical compounds and bioactivities is almost in agreement with that made according to micro and macromorphological characters.

Development of methods for quantitative determination of the total and reactive polysulfides: Reactive polysulfide profiling in vegetables.

Alliaceous and cruciferous vegetables are rich in bioactive organosulfur compounds, including polysulfides, which exhibit a broad spectrum of potential health benefits. Here, we developed novel, accurate, and reproducible methods to quantify the total polysulfide content (TPsC) and the reactive polysulfide content (RPsC) using liquid chromatography-electrospray ionization-tandem mass spectrometry, and analyzed the reactive polysulfide profiles of 22 types of fresh vegetables, including onions, garlic, and broccoli. Quantitative analyses revealed that onions contained the largest amounts of polysulfides, followed by broccoli, Chinese chive, and garlic. A strong positive correlation was observed between the TPsC and RPsC, whereas only a moderate positive correlation was found between the total sulfur content and TPsC. These results suggest that reactive polysulfide profiling can be a novel criterion for evaluating the beneficial functions of vegetables and their derivatives, which may lead to an understanding of the detailed mechanisms underlying their bioactivities.

Dissipation kinetics of co-formulation with two herbicides, clodinafop-propargyl and oxyfluorfen, in/on onion (Allium cepa) samples.

Supervised field trail on dissipation of co-formulation with herbicides clodinafop-propargyl and oxyfluorfen in spring onion showed similar pattern of dissipation during two different seasons. Residues of clodinafop-propargyl reached ≤ limit of quantitation (LOQ, 0.05 mg kg-1) on 3rd day after application at both standard and double dose during both the seasons. Oxyfluorfen residues followed first-order kinetics in both the doses during first season with half-life of 0.81 to 3.14 days. The residues of clodinafop-propargyl were detected in soil at both the doses during first season. However, residues were ≤ LOQ (0.05 mg kg-1) during second season. The residues of oxyfluorfen were detected only in double dose during first season in soil. In all other cases and in onion bulb, residues were ≤ LOQ (0.05 mg kg-1) at the time of harvest. As the residues were either ≤ LOQ (0.05 mg kg-1) on 3rd day or have a half-life of 3.14 days, the co-formulation can be used safely, provided a pre harvest interval (PHI) of 3 days is followed. On the basis of maximum residue limits (MRLs) in other commodities and from the data of present study, a default MRL of 0.05 mg kg-1 is proposed for both the pesticides.

Allium vegetables: Traditional uses, phytoconstituents, and beneficial effects in inflammation and cancer.

The genus Allium comprises of at least 918 species; the majority grown for dietary and medicinal purposes. This review describes the traditional uses, phytoconstituents, anti-inflammatory and anticancer activity, and safety profile of six main species, namely Allium sativum L. (garlic), Allium cepa L. (onions), Allium ampeloprasum L. (leek), Allium fistulosum L. (scallion), Allium schoenoprasum L. (chives) and Allium tuberosum Rottler (garlic chives). These species contain at least 260 phytoconstituents; mainly volatile compounds-including 63 organosulfur molecules-, saponins, flavonoids, anthocyanins, phenolic compounds, amino acids, organic acids, fatty acids, steroids, vitamins and nucleosides. They have prominent in vitro anti-inflammatory activity, and in vivo replications of such results have been achieved for all except for A. schoenoprasum. They also exert cytotoxicity against different cancer cell lines. Several anticancer phytoconstituents have been characterized from all except for A. fistulosum. Organosulfur constituents, saponins and flavonoid glycosides have demonstrated anti-inflammatory and anticancer activity. Extensive work has been conducted mainly on the anti-inflammatory and anticancer activity of A. sativum and A. cepa. The presence of anti-inflammatory and anticancer constituents in these two species suggests that similar bioactive constituents could be found in other species. This provides future avenues for identifying new Allium-derived anti-inflammatory and anticancer agents.

In Vitro Bioaccessibility and Anti-Inflammatory Activity of a Chemically Characterized Allium cepa L. Extract Rich in Quercetin Derivatives Optimized by the Design of Experiments.

Allium cepa L. is a highly consumed garden crop rich in biologically active phenolic and organosulfur compounds. This study aimed to assess the in vitro bioaccessibility and anti-inflammatory effect of a chemically characterized A. cepa extract rich in quercetin and its derivatives. Different varieties of A. cepa were studied; based on the highest total phenolic content, the "Golden" variety was selected. Its extracts, obtained from the tunicate bulb, tunic, and bulb, were subjected to determination of quercetin and its derivatives with LC-MS analysis and based on the highest total quercetin content, the tunic extract was utilized for further experiments. The extraction method was optimized through a design of experiment (DoE) method via full factorial design, which showed that 40% ethanol and 1 g tunic/20 mL solvent are the best extraction conditions. HPLC analysis of the optimized tunic extract identified 14 flavonols, including 10 quercetin derivatives. As far as in vitro bioaccessibility was concerned, the increases in some quercetin derivatives following the gastro-duodenal digestion process support the bioaccessibility of these bioactive compounds. Moreover, the extract significantly inhibited the production of PGE2 in stimulated J774 cell lines, while no effects of the tunic extract were observed against the release of IL-1ß, TNF-α, and nitrites. The study provided insights into the optimized extraction conditions to obtain an A. cepa tunic extract rich in bioavailable quercetin derivatives with significant anti-inflammatory effects against PGE2.

Phytochemicals from Red Onion, Grown with Eco-Sustainable Fertilizers, Protect Mammalian Cells from Oxidative Stress, Increasing Their Viability.

Red onion, a species of great economic importance rich in phytochemicals (bioactive compounds) known for its medicinal properties, was fertilized with sulphur-bentonite enriched with orange residue or olive pomace, with the aim of producing onion enriched in health beneficial compounds. There is a worldwide great demand of minimally processed food or food ingredients with functional properties because of a new awareness of how important healthy functional nutrition is in life. Phytochemicals have the capacity to regulate most of the metabolic processes resulting in health benefits. Red onion bioactive compound quantity and quality can vary according to cultivation practices. The main aims of the current research were to determine the chemical characteristics of the crude extracts from red onion bulbs differently fertilized and to evaluate their biological activity in normal and oxidative stress conditions. The lyophilized onion bulbs have been tested in vitro on two cellular models, i.e., the H9c2 rat cardiomyoblast cell line and primary human dermal fibroblasts, in terms of viability and oxygen radical homeostasis. The results evidenced different phytochemical compositions and antioxidant activities of the extracts obtained from red onions differently fertilized. Sulphur-bentonite fertilizers containing orange waste and olive pomace positively affected the red onion quality with respect to the red onion control, evidencing that sulphur-bentonite-organic fertilization was able to stimulate plant a secondary metabolism inducing the production of phytochemicals with healthy functions. A positive effect of the extracts from red onions treated with fertilizers-in particular, with those containing orange waste, such as the reduction of oxidative stress and induction of cell viability of H9c2 and human fibroblasts-was observed, showing a concentration- and time-dependent profile. The results evidenced that the positive effects were related to the phenols and, in particular, to chlorogenic and p-coumaric acids and to the flavonol kaempferol, which were more present in red onion treated with low orange residue than in the other treated ones.

Onion (Allium cepa L.) peel: A review on the extraction of bioactive compounds, its antioxidant potential, and its application as a functional food ingredient.

Functional food development is rapidly increasing as a result of consumer consciousness concerning healthy and nutritious foods. In turn, research exploring novel ingredients for formulating functional foods has been accelerated. Onion peel or skin is a byproduct obtained from onion processing that contains abundant phytochemicals, contributing to its antioxidant potential. The main focus of this review is to highlight different extraction techniques (both conventional and nonconventional) that can be implemented to extract the bioactive compounds from onion peel and assess their antioxidant activity. Furthermore, this review highlights the major areas for the application of onion peel and its extract as prospective functional ingredients, thus aiding in the preparation of designer foods with additional health benefits. The use of onion peel could also assist in redesigning popularly consumed processed foods, such as baked products, noodles or pasta, as packaging material, meat quality improvers, colorants, and juice clarifiers. This review serves as a preliminary document that can assist in exploring different ways of incorporating bioactive onion peels or skin into the functional food industry and concludes that future research can assist in the effective and efficient utilization of this resource.

Seeing the smell of garlic: Detection of gas phase volatiles from crushed garlic (Allium sativum), onion (Allium cepa), ramsons (Allium ursinum) and human garlic breath using SESI-Orbitrap MS.

Allicin is the main flavour component of crushed raw garlic. This plant defence molecule has strong antibiotic properties. While measurements in the liquid phase using LC-MS are established, accessing reactive organosulfur compounds in the gas phase is still a challenge due to heat-degradation in the gas chromatograph. Using a gentle secondary electrospray ionisation coupled Orbitrap mass spectrometry procedure (SESI-Orbitrap MS), we measured gas phase concentrations of allicin evaporating from a pure solution. Despite the mild conditions, two quantitatively major allicin-derived breakdown products were found. The SESI-Orbitrap MS technique was used to follow the known chemistry of alliin, isoallin and methiin conversion in garlic, onion and ramsons. Allicin and its metabolites were also measured over two hours in human breath after garlic consumption. These results demonstrate the utility of SESI-Orbitrap MS for analysis of sulfur-containing volatiles from plants in the genus Allium and potentially for capturing volatilomes of foodstuffs in general.

Onion and garlic polysaccharides: A review on extraction, characterization, bioactivity, and modifications.

Allium cepa (onion) and Allium sativum (garlic) are important members of the Amaryllidaceae (Alliaceae) family and are being used both as food and medicine for centuries in different parts of the world. Polysaccharides have been extracted from different parts of onion and garlic such as bulb, straw and cell wall. The current literature portrays several studies on the extraction of polysaccharides from onion and garlic, their modification and determination of their structural (molecular weight, monosaccharide unit and their arrangement, type and position of glycosidic bond or linkage, degree of polymerization, chain conformation) and functional properties (emulsifying property, moisture retention, hygroscopicity, thermal stability, foaming ability, fat-binding capacity). In this line, this review, summarizes the various extraction techniques used for polysaccharides from onion and garlic, involving methods like solvent extraction method. Furthermore, the antioxidant, anticancer, immunomodulatory, antimicrobial, anti-inflammatory, and antidiabetic properties of onion and garlic polysaccharides as reported in in vivo and in vitro studies are also critically assessed in this review. Different studies have proved onion and garlic polysaccharides as potential antioxidant and immunomodulatory agent. Studies have implemented to improve the functionality of onion and garlic polysaccharides through various modification approaches. Further studies are warranted for utilizing onion and garlic polysaccharides in the food, nutraceutical, pharmaceutical and cosmetic industries.

Dissipation and risk assessment of fluopyram and trifloxystrobin on onion by GC-MS/MS.

The dissipation and risk assessment studies on fluopyram, trifloxystrobin and their metabolites were carried out on onion under field conditions after two treatments of fluopyram 250 g/L + trifloxystrobin 250 g/L SC @ 150 and 300 g a.i. ha-1. The onion bulb samples were collected at 0, 3, 7, 14, and 21 days after second spray to study the pattern of dissipation using QuEChERS methodology for processing and analysis on GC-MS/MS. The total initial residues of fluopyram (fluopyram + fluopyram benzamide) in immature onion bulb were 2.14 and 4.93 mg kg-1, at single and double dose, respectively. The residues of 0.02 and 0.06 mg kg-1 persisted in the mature onion bulb collected at the harvest (30 days after treatment). The total initial residues of trifloxystrobin (trifloxystrobin + CGA 321113) in immature onion bulb were 0.65 and 1.97 mg kg-1, at single and double dose, respectively, which reached < LOQ and 0.06 mg kg-1 at the respective doses at the harvest time. Dissipation of fluopyram followed second-order kinetics with DT50 values of 1.83 and 1.74 days, whereas trifloxystrobin followed first-order kinetics with DT50 values of 4.73 and 4.78 days, at single and double dose respectively. Risk assessment in terms of hazard quotient was done to estimate the risk that can occur due to application of this combination pesticide. It was observed that even the spray at the double recommended dose could not have dietary risks on the consumers.