Analysis of volatile organic compounds in Korean-bred strawberries: insights for improving fruit flavor.

Introduction: The strawberry industry in South Korea has witnessed a significant 65% growth over the past decade, surpassing other fruits and vegetables in production value. While sweetness and acidity are well-recognized flavor determinants, the role of volatile organic compounds (VOCs) in defining the desirable flavor profiles of strawberries is also crucial. However, existing research has predominantly concentrated on a limited range of commercial cultivars, neglecting the broader spectrum of strawberry varieties. Methods: This study embarked on developing a comprehensive VOC database for a diverse array of strawberry cultivars sourced both domestically and internationally. A total of 61 different strawberry cultivars from Korea (45), the USA (7), Japan (8), and France (1) were analyzed for their VOC content using Tenax TA Thermo Desorption tubes and Gas Chromatography-Mass Spectrometry (GC-MS). In addition to VOC profiling, heritability was assessed using one-way ANOVA to compare means among multiple groups, providing insights into the genetic basis of flavor differences. Results and discussion: The analysis identified 122 compounds categorized into esters, alcohols, terpenes, and lactones, with esters constituting the majority (46.5%) of total VOCs in Korean cultivars. 'Arihyang', 'Sunnyberry', and 'Kingsberry' exhibited the highest diversity of VOCs detected (97 types), whereas 'Seolhong' showed the highest overall concentration (57.5mg·kg-1 FW). Compared to the USA cultivars, which were abundant in γ-decalactone (a peach-like fruity aroma), most domestic cultivars lacked this compound. Notably, 'Misohyang' displayed a high γ-decalactone content, highlighting its potential as breeding germplasm to improve flavor in Korean strawberries. The findings underscore the importance of a comprehensive VOC analysis across different strawberry cultivars to understand flavor composition. The significant variation in VOC content among the cultivars examined opens avenues for targeted breeding strategies. By leveraging the distinct VOC profiles, particularly the presence of γ-decalactone, breeders can develop new strawberry varieties with enhanced flavor profiles, catering to consumer preferences for both domestic and international markets.

Anti-Inflammatory Flavonoids from Agrimonia pilosa Ledeb: Focusing on Activity-Guided Isolation.

To elucidate the anti-inflammatory properties and constituents of Agrimonia pilosa Ledeb. (A. pilosa), a comprehensive investigation was conducted employing activity-guided isolation. The anti-inflammatory effects were evaluated through an in vitro nitric oxide (NO) assay on lipopolysaccharide (LPS)-treated RAW 264.7 macrophage cells. Seven bio-active compounds with anti-inflammatory properties were successfully isolated from the butanol fraction and identified as follows: quercetin-7-O-ß-d-rhamnoside (1), apigenin-7-O-ß-d-glucopyranoside (2), kaempferol-7-O-ß-d-glucopyranoside (3), quercetin (4), kaempferol (5), apigenin (6), and apigenin-7-O-ß-d-glucuronide-6″-butylester (7). All isolated compounds showed strong NO inhibitory activity with IC50 values ranging from 1.4 to 31 µM. Compound 6 demonstrated the most potent NO inhibition. Compound 7, a rare flavonoid, was discerned as a novel anti-inflammatory agent, ascertained through its inaugural demonstration of nitric oxide inhibition. Subsequently, a comprehensive structure-activity relationship (SAR) analysis was conducted employing eight flavonoids derived from A. pilosa. The outcomes elucidated that flavones exhibit superior NO inhibitory effects compared to flavonols, and the aglycone form manifests greater potency in NO inhibition than the glycone counterpart. These results highlight A. pilosa as a promising source of effective anti-inflammatory agents and indicate its potential as a health-beneficial dietary supplement and therapeutic material.

Carbon dioxide treatment modulates phosphatidic acid signaling and stress response to improve chilling tolerance and postharvest quality in paprika.

Introduction: Paprika (Capsicum annuum L.) is prone to chilling injury (CI) during low-temperature storage. Although recent findings suggest that CO2 treatment may protect against CI, the effects of short-term CO2 treatment on CI and the underlying molecular mechanisms in paprika remain unknown. Therefore, this study aimed to examine the effect of short-term CO2 treatment on CI and postharvest quality in paprika during storage at cold storage and retail condition at physio-biochemical-molecular level. Methods: Paprika was treated with 20 and 30% CO2 for 3 h and stored at 4°C for 14 days, followed by additional storage for 2 days at 20°C (retail condition). Fruit quality parameters, including weight loss, firmness, color, and pitting were assessed, and the molecular mechanism of the treatment was elucidated using transcriptomic and metabolomic analyses. Results: Short-term treatment with 20 and 30% CO2 effectively maintained paprika quality during cold storage and retailer conditions, with reduced surface pitting, a common symptom of CI. Additionally, transcriptomic and metabolomic analyses revealed that 20% CO2 treatment induced genes associated with biosynthesis of phosphatidic acid (PA), diacylglycerol, triacylglycerol, and stress response, metabolites associated with phasphatidyl inositol signaling, inositol phosphate metabolism, and starch and sucrose metabolism. Conclusion: CO2 treatment activates PA biosynthesis through PLD and PLC-DGK pathways, and induces inositol phosphate, starch, and sucrose metabolism, thereby regulating chilling stress response via the ICE-CBF pathway. These findings suggest that short-term CO2 treatment enhances resistance to cold-induced injury and preserves postharvest quality in non-climacteric fruits, such as paprika, through activation of PA signaling, which improves membrane stability during cold storage and distribution.

The effect of additional shading utilizing agriphotovoltaic structures on the visual qualities and metabolites of broccoli.

Agriphotovoltaic (APV) systems allow the simultaneous production of crops and electricity in the same land area. Since the reduction of yield caused by APV systems is important for food security, studies to improve the yield have been conducted steadily. However, there have been limited data on the appearance, quality, and metabolomic changes of crops. Therefore, in this study, we evaluated the visual qualities and metabolites as well as the yield of broccoli grown using an APV system during the fall season. In addition, additional shading treatment was performed, and the same qualities were evaluated. In the spring season, an additional cultivar that does not express anthocyanins was cultivated. Glucosinolate content was more sensitive to the seasonal environment and the type of cultivar than it was to treatment type. The additional shading treatment had a positive effect on the visual qualities of anthocyanin-expressing broccoli cultivar regardless of the season, and we observed that even a cultivar that does not express anthocyanins can be greener. Regardless of cultivar, higher chlorophyll content was detected in broccoli florets with additional shading treatment under the APV system. In addition, reduced anthocyanin content was observed (6.1 mg g-1 DW; about 20% of that obtained on open-field). Aspartic acid content was enhanced upon additional shading treatment. Pathway analysis revealed changes in anthocyanin, alanine, aspartic acid, and glutamic acid metabolism. Overall, our findings suggests that it is possible to produce crops with better visual qualities by utilizing APV systems.

Effect of Anti-Obesity and Antioxidant Activity through the Additional Consumption of Peel from 'Fuji' Pre-Washed Apple.

There is limited information on the health effects of apple peel taken from 'Fuji' (Malus pumila Mill) apples washed with ozonated water. To clarify the health-promoting effects of peel, the triterpenoids (ursolic acid and oleanolic acid) were quantified with gas chromatograph-mass spectrometry. Anti-obesity effects of apple peel extract on the 3T3-L1 pre-adipocyte cell were compared with apple flesh, whole apple, and ursolic acid. The peel extract treatment with 3.30 ± 1.05 µM of ursolic acid significantly suppressed (p < 0.05) the lipid accumulation compared with the content in flesh, and a similar level was reached in the 5 µM ursolic acid positive control group. In the peel extract and ursolic acid treatment groups, the C16:0 concentration was significantly inhibited (p < 0.05), implying the anti-obesity effect of ursolic acid on the 3T3-L1 cell. Moreover, apple peel contributed 41% of the total flavonoids content and 31% of the phenolic contents of the whole apple, but only accounted for less than 10% of the whole apple (weight basis). This study's results offer basic data on pre-washed apple as a health functional food, offering information about the health benefits of apple peel, calculated based on the partial ratio in the whole apple.

Impact of an Agriphotovoltaic System on Metabolites and the Sensorial Quality of Cabbage (Brassica oleracea var. capitata) and Its High-Temperature-Extracted Juice.

To date, the impacts of agriphotovoltaic (APV) condition on the production yield of crop have been studied; however, the effect of APV production on the sensorial quality and consumer acceptability of the produce remains unexplored. Therefore, to address this knowledge gap, we cultivated "Winter Storm" cabbage under solar panels (20.16 kW) and in open field in 2020. The weight and diameter reduction rate of fresh cabbage grown under APV condition compared to open-field conditions were 9.7% and 1.2%, respectively. The levels of glucosinolates and their hydrolysis products were not significantly different in the fresh cabbage between the two conditions. The amount of volatile organic compounds, which may affect the perception of smell, were significantly higher in the cabbage juice prepared from the ones grown in open-field conditions than in the juice prepared from cabbages grown under APV conditions (n = 3, p < 0.01). However, untrained subjects could not distinguish the difference in the quality of the 2 sets of cabbage juices in the triangle test (n = 70, p = 0.724). Regardless of the distinguishing features of color, aroma, and taste, the subjects did not have any preference between the two different cabbage juices.

Seasonal Effects of Glucosinolate and Sugar Content Determine the Pungency of Small-Type (Altari) Radishes (Raphanus sativus L.).

Kimchi made from small-type (Altari) radishes grown in late spring is more pungent than that made from autumn-grown Altari radishes, which poses a major challenge in the kimchi industry. The mechanism through which the pungency of Altari radish changes seasonally has not been intensively investigated. In this study, three small-type radish cultivars with different pungency levels were cultivated in spring and autumn to identify the factors affecting the seasonal-dependent pungency of small-type radishes. The contents of pungency-related metabolite glucoraphasatin and other polar metabolites were analyzed. Although a previous study reported that the glucoraphasatin concentration affects the pungency of radish, in the current study, the concentration of neither glucoraphasatin nor its hydrolysis product (raphasatin) could fully explain the change in the pungency associated with radish cultivars grown in the two seasons. The change in the pungency of radish by season may be explained by the ratio of raphasatin content to total sweetness of sugars. In addition, the polar metabolites that differ with season were analyzed to identify seasonal biomarkers and understand the seasonal changed physio-biochemistry.

Metabolomics and Physiological Approach to Understand Allelopathic Effect of Horseradish Extract on Onion Root and Lettuce Seed as Model Organism.

In the present study, we assessed the allelopathic effects of various concentrations (0%, 0.1%, 0.2%, and 0.3%) of horseradish root extract (HRE) on onion root. The average growth of onion root tips during the 0% HRE treatment (deionized water treatment) was 0.9 cm/day, which was the highest among the growth rates obtained with all HRE treatments. Moreover, the average growth during 0.3% HRE treatment was 0.1 cm/day. During cell cycle analysis, the mitotic phase fraction of the control (deionized water treatment) cells was 6.5% of all dividing cells, with this percentage being the highest among the values obtained for all treatment groups. In the control group, all cell cycle phases were identified; however, in the 0.1%, 0.2%, and 0.3% treatment groups, telophase was not identified. The ROS accumulation area of the onion root decreased, as the HRE treatment concentration increased. In the control root, the area of dead tissue was 0%; however, in the 0.1% and 0.2% HRE treatment roots, the ratio was 5% and 50%, respectively. These findings indicate that the allelopathic effect of HRE depends on the concentration of HRE applied to the onion root.

Metabolite and Elastase Activity Changes in Beach Rose (Rosa rugosa) Fruit and Seeds at Various Stages of Ripeness.

Rose hips are the fruits of the beach rose (Rosa rugosa). To determine the optimal harvest time and to obtain the maximum functional compounds, rose hips at various stages of ripeness (immature, early, mid, and late) were harvested, and the flesh tissue and seeds were separated. The rose hip flesh showed the highest total phenolic content at the mid-ripeness stage (8.45 ± 0.62 mg/g gallic acid equivalent concentration (dry weight)). The early-, mid-, and late-ripeness stages of rose hip flesh did not show significantly different 2,2-diphenyl-1-picrylhydrazyl antioxidant capacities. The elastase inhibitory activity of the 95% ethanol extract from the rose hip seeds was highest at the mid-ripeness stage; however, the elastase inhibitory activity of the rose hip tissue was not significantly different from that of the seeds. Pathway analysis using MetaboAnalyst showed that sucrose, fructose, and glucose gradually increased as the fruit ripened. Ursolic acid was detected in the seeds but not in the flesh. Of the fatty acids, linoleic acid concentrations were highest in rose hip seeds, followed by linolenic acid, oleic acid, and palmitic acid. Fatty acids and ursolic acid might be the active compounds responsible for elastase inhibitory activity and can be utilized as a functional cosmetic material.

Influence of Genotype on High Glucosinolate Synthesis Lines of Brassica rapa.

This study was conducted to investigate doubled haploid (DH) lines produced between high GSL (HGSL) Brassica rapa ssp. trilocularis (yellow sarson) and low GSL (LGSL) B. rapa ssp. chinensis (pak choi) parents. In total, 161 DH lines were generated. GSL content of HGSL DH lines ranged from 44.12 to 57.04 µmol·g-1·dry weight (dw), which is within the level of high GSL B. rapa ssp. trilocularis (47.46 to 59.56 µmol g-1 dw). We resequenced five of the HGSL DH lines and three of the LGSL DH lines. Recombination blocks were formed between the parental and DH lines with 108,328 single-nucleotide polymorphisms in all chromosomes. In the measured GSL, gluconapin occurred as the major substrate in HGSL DH lines. Among the HGSL DH lines, BrYSP_DH005 had glucoraphanin levels approximately 12-fold higher than those of the HGSL mother plant. The hydrolysis capacity of GSL was analyzed in HGSL DH lines with a Korean pak choi cultivar as a control. Bioactive compounds, such as 3-butenyl isothiocyanate, 4-pentenyl isothiocyanate, 2-phenethyl isothiocyanate, and sulforaphane, were present in the HGSL DH lines at 3-fold to 6.3-fold higher levels compared to the commercial cultivar. The selected HGSL DH lines, resequencing data, and SNP identification were utilized for genome-assisted selection to develop elite GSL-enriched cultivars and the industrial production of potential anti-cancerous metabolites such as gluconapin and glucoraphanin.

Optimization of allyl isothiocyanate sanitizing concentration for inactivation of Salmonella Typhimurium on lettuce based on its phenotypic and metabolome changes.

Allyl isothiocyanate (AITC), a natural compound, is a promising food additive and preservative because of its safety and effectiveness. In order to determine optimal AITC concentrations for disinfection of food pathogen on lettuce without compromising postharvest quality, various concentrations of AITC (0, 1, 2.5, 5 and 7.5 µL L-1) were applied to Salmonella Typhimurium inoculated lettuce in air-tight box at 7 °C. As a result, the decline in visual quality, weight loss via cell membrane damage, and significantly reduced antioxidant activity were observed in lettuce treated with an AITC concentration of 2.5 µL L-1, 5 µL L-1 or higher. Moreover, metabolome analysis showed pattern of increased respiratory and cell damage, such as lipid peroxidation. Based on physiological changes, 1 µL L-1 was determined as the optimal AITC concentration that significantly reduced S. Typhimurium population (4.01 log CFU g-1) on lettuce.

Carbon Dioxide Pretreatment and Cold Storage Synergistically Delay Tomato Ripening through Transcriptional Change in Ethylene-Related Genes and Respiration-Related Metabolism.

The effects of CO2 pretreatment before cold storage on tomato quality were investigated using physicochemical and transcriptome changes. Harvested tomatoes were treated with 30% or 60% CO2 for 3 h before storage at 4 °C for 14 d (cold storage), followed by transfer to 20 °C for 8 d (ambient conditions). The CO2-treated fruits were firmer with a better appearance than untreated fruits, even after being transferred from 4 °C storage to 20 °C for 8 d. CO2 pretreatment coupled with cold storage synergistically delayed tomato ripening by reducing respiration and lowering lycopene production. The tomatoes treated with 30% and 60% CO2 had fewer pits than untreated fruits after cold storage, even after being transferred to ambient conditions. Moreover, the 60% CO2 treatment significantly suppressed the decay rate. Transcriptome and metabolome functional enrichment analyses commonly showed the involvement of CO2-responsive genes or metabolites in sucrose and starch metabolism, as well as biosynthesis of secondary metabolites-in particular, glycolysis reduction. The most frequently detected domain was the ethylene-responsive factor. These results indicate that altered ethylene biosynthesis and ethylene signaling, via ethylene-responsive transcription factors and respiration-related pathways, appear to control CO2-induced fruit quality.

Modified Atmosphere and Humidity Film Reduces Browning Susceptibility of Oriental Melon Suture Tissue during Cold Storage.

Oriental melons have a relatively short shelf life as they are harvested during the summer season and susceptible to cold-induced injuries. Typical chilling injury when stored at 4 °C is expressed as browning of the fruit suture. To prolong the shelf life and reduce browning of the fruit, the effects of modified atmosphere packaging (MAP), X-tend modified atmosphere (MA)/modified humidity (MH) bulk packaging (XF), and polyethylene (PE) packaging, on oriental melons were investigated during storage at 4 °C and 10 °C for 14 days and under retail display conditions at 20 °C. The O2 concentrations in PE packages stored at 4 °C and 10 °C ranged from 17.4 to 18.5%, whereas those in XF packages were reduced to 16.3-16.6%. The CO2 content of XF package (4.2-4.6%) was higher than that of PE package (1.4-1.9%) stored at 4 °C or 10 °C. Relative humidity (RH) saturated in the PE packages but not in the XF packages after seven days of storage. Furthermore, PE packages performed better at maintaining melon weight and firmness than XF packages during storage at 10 °C for 14 days and under retail display conditions at 20 °C. PE and XF packages effectively reduced the browning index of the peel and white linear sutures of oriental melons compared with the unpackaged control during cold storage at 4 °C, and this observation was maintained at the retail display condition at 20 °C. The enhanced CO2 levels, reduced O2 levels, and optimal RH values that were provided by the MAP, prevented the browning symptoms, and improved the marketability and shelf life of oriental melons.

Adhesion and removal of E. coli K12 as affected by leafy green produce epicuticular wax composition, surface roughness, produce and bacterial surface hydrophobicity, and sanitizers.

Contaminated leafy vegetables have been associated with high-profile outbreaks causing severe illnesses. A good understanding of the interactions between human pathogen and produce is important for developing improved food safety control strategies. Currently, the role played by produce surface physiochemical characteristics in such interactions is not well-understood. This work was performed to examine the effects of produce physiochemical characteristics, including surface roughness, epicuticular wax composition, and produce and bacteria surface hydrophobicity on attachment and removal of vegetative bacteria. Escherichia coli K12 was used as a model microorganism to evaluate attachment to and removal from five leafy green vegetables after washing with selected sanitizers. A detailed epicuticular wax component analysis was conducted and the changes of wax composition after sanitation were also evaluated. The results showed that E. coli K12 removal is positively correlated with alkanes, ketones, and total wax content on leaf surfaces. Vegetables with high surface wax content had less rough leaf surfaces and more bacterial removal than the low wax produce. Produce surface roughness positively correlated to E. coli K12 adhesion and negatively correlated to removal. The cells preferentially attached to cut vegetable surfaces, with up to 1.49 times more attachment than on leaf adaxial surfaces.

Protein quality and safety evaluation of sarcoplasmic protein derived from silver carp (Hypophthalmichthys molitrix) using a rat model.

Consisting of 25 to 30% of protein in carp, water-soluble sarcoplasmic proteins lost in wash water, have been recovered and freeze-dried into a protein-rich powder. Study objectives were to evaluate protein quality and safety of a silver carp sarcoplasm derived protein powder (CSP) compared to commercial protein supplements, casein, and whey. In vivo protein quality assessment of CSP showed a lower (P < 0.05) protein digestibility corrected amino acid score compared to the commercial protein sources. Despite greater (P < 0.05) fecal amino acid excretion in casein-fed rats, there were no significant differences in liver and muscle amino acid profiles. All low (10% kcal) protein diets supported growth with the normal range. However, whey protein supplementation resulted in greater (P < 0.05) adiposity. CSP, casein, or whey-fed rats showed no differences in major organ weights, renal damage biomarkers, or bone indices. Collectively, results indicated CSP was safe with protein quality comparable to casein. PRACTICAL APPLICATION: As much as 40 percent of protein in fish can be lost due to sarcoplasmic protein solubilization in processing wash water. Silver carp sarcoplasm protein powder may have similar commercial potential as a sustainable and nutritious alternative to whey and casein proteins. This project aimed to verify the protein quality and safety of this economical protein source.

Methyl Jasmonate Treatment of Broccoli Enhanced Glucosinolate Concentration, Which Was Retained after Boiling, Steaming, or Microwaving.

Exogenous methyl jasmonate (MeJA) treatment was known to increase the levels of neoglucobrassicin and their bioactive hydrolysis products in broccoli (Brassica oleracea var. italica), but the fate of MeJA-induced glucosinolates (GSLs) after various cooking methods was unknown. This study measured the changes in GSLs and their hydrolysis compounds in broccoli treated with MeJA and the interaction between MeJA and cooking treatments. All cooked MeJA-treated broccoli contained significantly more GSLs than untreated broccoli (p < 0.05). After 5 min of cooking (boil, steam, microwave), MeJA-treated broccoli still contained 1.6- to 2.3-fold higher GSL content than untreated broccoli. Neoglucobrassicin hydrolysis products were also significantly greater in steamed and microwaved MeJA-treated broccoli. The results show that exogenous MeJA treatment increases neoglucobrassicin and its hydrolysis compounds in broccoli even after cooking. Once the positive and negative effects of these compounds are better understood, the results of this experiment can be a valuable tool to help food scientists, nutrition scientists, and dieticians determine how to incorporate raw or cooked broccoli and Brassica vegetables in the diet.

Ultrasonic-assisted extraction and antioxidant activity of polysaccharides from Eucommia ulmoides leaf.

Eucommia ulmoides is valuable medicinal plant in China. In this study, ultrasonic technology was used to extract polysaccharides and orthogonal design was applied to choose the optimal extraction conditions. The optimal extraction conditions of E. ulmoides polysaccharides were made up of the ratio of water to raw 30, extraction time 80 min, extraction temperature 60°C and extraction power 200 W. Under these conditions, the extraction polysaccharides content reached 164.95 mg/g. In addition, the potential antioxidant activity of crude polysaccharides (Cp) and pure polysaccharides (Pp) was demonstrated by evaluating reducing power assay, DPPH radical-scavenging assay, OH radical-scavenging assay and ABTS radical-scavenging assay. The results showed that E. ulmoides polysaccharides had significantly impact on the scavenging of DPPH radicals, OH radicals and ABTS radicals, expecially in DPPH radicals with an IC50 values of 0.005 mg/mL and 0.011 mg/mL in Cp and Pp, respectively. However, they were less effective in reducing power assay with low IC50 values of 1.091 mg/mL and 1.041 mg/mL separately. These results indicated that polysaccharides from E. ulmoides leaf could be applied as potential antioxidant.

Roles of Vegetable Surface Properties and Sanitizer Type on Annual Disease Burden of Rotavirus Illness by Consumption of Rotavirus-Contaminated Fresh Vegetables: A Quantitative Microbial Risk Assessment.

Enteric viruses are often detected in water used for crop irrigation. One concern is foodborne viral disease via the consumption of fresh produce irrigated with virus-contaminated water. Although the food industry routinely uses chemical sanitizers to disinfect post-harvest fresh produce, it remains unknown how sanitizer and fresh produce properties affect the risk of viral illness through fresh produce consumption. A quantitative microbial risk assessment model was conducted to estimate (i) the health risks associated with consumption of rotavirus (RV)-contaminated fresh produce with different surface properties (endive and kale) and (ii) how risks changed when using peracetic acid (PAA) or a surfactant-based sanitizer. The modeling results showed that the annual disease burden depended on the combination of sanitizer and vegetable type when vegetables were irrigated with RV-contaminated water. Global sensitivity analyses revealed that the most influential factors in the disease burden were RV concentration in irrigation water and postharvest disinfection efficacy. A postharvest disinfection efficacy of higher than 99% (2-log10 ) was needed to decrease the disease burden below the World Health Organization (WHO) threshold, even in scenarios with low RV concentrations in irrigation water (i.e., river water). All scenarios tested here with at least 99.9% (3-log10 ) disinfection efficacy had a disease burden lower than the WHO threshold, except for the endive treated with PAA. The disinfection efficacy for the endive treated with PAA was only about 80%, leading to a disease burden 100 times higher than the WHO threshold. These findings should be considered and incorporated into future models for estimating foodborne viral illness risks.

Effects of MCHM on yeast metabolism.

On January 2014 approximately 10,000 gallons of crude 4-Methylcyclohexanemethanol (MCHM) and propylene glycol phenol ether (PPH) were accidentally released into the Elk River, West Virginia, contaminating the tap water of around 300,000 residents. Crude MCHM is an industrial chemical used as flotation reagent to clean coal. At the time of the spill, MCHM's toxicological data were limited, an issue that has been addressed by different studies focused on understanding the immediate and long-term effects of MCHM on human health and the environment. Using S. cerevisiae as a model organism we study the effect of acute exposure to crude MCHM on metabolism. Yeasts were treated with MCHM 550 ppm in YPD for 30 minutes. Polar and lipid metabolites were extracted from cells by a chloroform-methanol-water mixture. The extracts were then analyzed by direct injection ESI-MS and by GC-MS. The metabolomics analysis was complemented with flux balance analysis simulations done with genome-scale metabolic network models (GSMNM) of MCHM treated vs non-treated control. We integrated the effect of MCHM on yeast gene expression from RNA-Seq data within these GSMNM. A total of 215 and 73 metabolites were identified by the ESI-MS and GC-MS procedures, respectively. From these 26 and 23 relevant metabolites were selected from ESI-MS and GC-MS respectively, for 49 unique compounds. MCHM induced amino acid accumulation, via its effects on amino acid metabolism, as well as a potential impairment of ribosome biogenesis. MCHM affects phospholipid biosynthesis, with a potential impact on the biophysical properties of yeast cellular membranes. The FBA simulations were able to reproduce the deleterious effect of MCHM on cellular growth and suggest that the effect of MCHM on ubiquinol:ferricytochrome c reductase reaction, caused by the under-expression of CYT1 gene, could be the driven force behind the observed effect on yeast metabolism and growth.

Methyl jasmonate treated broccoli: Impact on the production of glucosinolates and consumer preferences.

Applying methyl jasmonate can mimic the defense response to insect damage in broccoli and enhances the production of glucosinolates, especially inducible indolyl GS-neoglucobrassicin. Previous studies have suggested that glucosinolates and their hydrolysis products are anti-carcinogenic. Therefore, MeJA treatment may increase the nutritional quality of broccoli. However, there are few reports on the sensory evaluation and consumer acceptance of MeJA-treated broccoli. In this study, an untrained consumer panel could not detect any taste differences between steamed MeJA-treated and untreated broccoli, even though the steamed MeJA-treated broccoli contained 50% more glucosinolates than untreated broccoli. The partial least square-regression model suggested that neoglucobrassicin-derived hydrolysis compounds were the major metabolites that determined overall preference for raw MeJA-treated broccoli potentially due to their potential negative sensory qualities. The results imply that MeJA treatment can increase the nutritional quality of broccoli without sacrificing taste in precooked meals or frozen vegetables.