Free Organic Acid Research Articles

Correlation between microbial community succession and flavor substances during fermentation of Yongchuan Douchi

Yongchuan douchi (YCDC) is a traditional Chinese condiment famous for its distinct flavor and texture. This study utilized high-throughput sequencing to analyze the microbial community changes during YCDC fermentation and investigate the relationship between its physicochemical properties, flavor compounds, and microorganisms. The sequencing results revealed that Staphylococcus, Bacillus, Leuconostoc, Weissella, Streptophyta, Nocardiopsis, Aspergillus, Penicillium, Starmerella, and Zygosaccharomyces were the dominant bacteria during the YCDC fermentation process. The free amino acid (FAAs), glutamic acid (Glu), asparagine (Asp), and organic acid (citric and succinic acid) levels increased gradually throughout fermentation. Additionally, 29 key flavor compounds were identified, with lipids, alcohols, aldehydes, and acids significantly affecting the flavor profile. Network graph analysis demonstrated positive correlations between Staphylococcus, Escherichia_Shigella, Brevibacterium, and 1-octene-3-ol, ethyl isobutyrate, and benzaldehyde, respectively, contributing to light, fruity, and floral aromas. Moreover, bacterial genera exhibited stronger potential correlations with flavor compounds than fungal genera. These findings enhance the understanding of microbial community succession in YCDC and offer a theoretical basis for flavor strain selection.

Characterization of the metabolic fate of sinapic acid in rats.

Sinapic acid (SA) is ubiquitously distributed in the plant kingdom as a free organic acid and more frequently as a biosynthetic pioneer for SA derivatives, e.g., SA esters. Broad biological and pharmacological activities have been disclosed for SA. Because of the metabolism lability property, metabolites instead of the parent compound should be the primary forms after oral treatment of SA, and those metabolites should also be rapidly observed from SA following administration of SA derivative. Hence, the metabolites might provide a primary contribution to the pharmacological properties of SA; however, the metabolite profile remains unclear. Here, our efforts were devoted to addressing this issue through deploying online energy-resolved mass spectrometry (ER-MS) to accomplish isomer identification which is the key issue hindering metabolite identification, notably those conjugated metabolites. After recording breakdown graphs of concerned fragment ions with online ER-MS, the positive correlations between optimal collision energy (OCE) and bond dissociation energy (BDE) were applied to assign candidate structures to isomeric signals. Moreover, in vitro metabolism with liver cellular subfractions, UV-triggered cis-/trans-configuration transformation, and wet-chemistry hydrogenation were carried out to justify the structures. As a result, sixteen metabolites (M1-M16) were found and confirmatively identified in rat plasma and urine following SA administration, and sulfation, glucuronidation, demethylation, reduction, and dihydroxylation served as the primary metabolic channels. Noteworthily, greater distribution occurred for sulfation and glucuronidation products while inferior distributions were observed for phase I metabolites, and the half-life (T1/2) of most metabolites was greater than that of SA. This study provides a comprehensive insight into the metabolic fate of SA. More importantly, the fortification of online ER-MS and quantum structure calculation to the conventional LC-MS program is eligible to achieve unambiguous identification of isomeric metabolites.

Changes in physicochemical characteristics and metabolites in the fermentation of goji juice by Lactiplantibacillus plantarum

Untargeted and targeted metabolomics based on LC-MS/MS was applied here to investigate the changes in metabolites following Lactiplantibacillus plantarum (L. plantarum) fermentation of goji juice. The changes in physicochemical characteristics, free amino acid and organic acid levels were quantified. Total phenols, total flavonoids, and antioxidant activity were increased after these L. plantarum fermentation. 31 primary metabolites were screened out by comparison between two groups using multivariate statistical analysis. L. plantarum consumed reducing sugar and most varieties of amino acids. Gamma amino butyric acid (GABA) and phenylacetaldehyde were significantly accumulated via precursor of glutamate and phenylalanine, respectively. Indole-3-lactic acid (ILA) was the characteristic secondary metabolite after fermentation. There were 6.25 and 4.19 mg/L ILA accumulated after LP-D and LP-F fermentation, respectively, whereas it was not detected in goji juice. The accumulation of tyrosol was strain-dependent. Part of the bitter-taste amino acids, including l-methinoine, l-phenylalanine and tryptophan, were converted into their corresponding acetyl-derivatives, which represented umami or kokumi taste. Overall, fermentation by L. plantarum strains altered the metabolite profile and increased the levels of several biologically active substances of goji juice. These results deepen the understanding of L. plantarum metabolism, and the bioconversion associated with flavor and bioactive compounds unraveled here can be used as references in other plant-based materials for LAB fermentation.

Discriminating the effects of microbial fortification on quality of Pixian Doubanjiang-pei manufactured by different chili varieties

In the present research, the effect of two chili varieties (Capsicum annuum L. Erjingtiao and Meiguohong) on the characteristics of the Chinese traditional condiment Pixian Doubanjiang (PXDBJ)-pei was investigated comprehensively by polyphase determination approaches. In contrast to the sample manufactured by Meiguohong, the phenols content was 2.69 times higher than that by Erjingtiao. In addition, ten volatiles, including 3-methylthiopropanol, phenyl ethyl acetate, etc., were merely detected in Meiguohong sample. However, 12 volatiles were only detected in the sample of Erjingtiao, including (R,R)-(−)-2,3-butanediol and 2-heptene aldehyde, etc. The constituents of free organic acid basically varied with chili variety, malic acid was the highest in the Erjingtiao samples, while citric acid was highlighted in the Meiguohong samples. When the fermentation of PXDBJ-pei fortified by inoculating Lactiplantibacillus plantarum 1.08 and Zygosaccharomyces rouxii S3, the predominant bacteria changed from Lactobacillus to Bacillus, the contents of esters and specific flavor compounds were definitely increased. These results suggested the unique flavors of PXDBJ-pei lay on the chili variety, and their contents can be improved by fortifying the synthetic microbiota.

Comparison of physicochemical properties of pollen substitute diet for honey bee (Apis mellifera)

• Group I showed higher total free amino acid contents than Group II and Group III. • Group I showed alike nutrition content to the commercial bee diet. • AIGT + Soytide showed a high level of total free amino acid and organic acid. • AIGT + Soytide showed the highest contents of inorganic ions. Apis mellifera L., a globally important pollinator, is crucial in the maintenance of its colonies due to a variety of stresses. Healthy nutrition is believed to help grow their population and relieve the stressors. We used our-prepared and commercial diets, and the nutrition contents were then analyzed for free sugar, organic acids, free amino acids, inorganic ions, total polyphenols, vitamin C, and the pH. The total free sugar, organic contents, free amino acids, inorganic ions, and total polyphenols were in the range of 228.59 to 661.00, 0.91 to 20.60, 6.52 to 24.36, 10.25 to 27.61, and 1.65 to 10.17 mg/g, respectively. The highest contents of free sugar, organic acids, free amino acids, inorganic ions, and total polyphenols were found in YBNH (661 mg/g), Megabee (20.60 mg/g), Beebread (24.36 mg/g), AIGT + Soytide (27.61 mg/g), and Beebread (10.17 mg/g), respectively. The pH values were maintained at 4.45 to 5.70 among all ten samples. Group I showed the same level of total free sugars (Group II and Group IV), organic acids (Group II), inorganic ions (Group II, Group III, and Group IV), polyphenols (Group II), and pH (Group IV). For the total free amino acids, Group I showed a significantly higher ( P < 0.05) level than that of Group II and Group III. Group I had a comparable nutrition content to the commercial bee diet but had a higher total free amino acid content. High levels of inorganic ions, free amino acids, and organic acids were found in the AIGT + Soytide.

Characteristics of beer brewed with unconventional yeasts and addition of grape must, pulp and marc

The aim of the paper was to determine potential of using grape pulp, marc and must in the beer production process. Samples were fermented using non-Saccharomyces yeasts (Dekkera bruxellensis 3429, Metschnikowia pulcherrima MG970690) and Saccharomyces cerevisiae Safale US-05 was used as a control. Grape marc was obtained by pressing grape must with a press. Subsequently, the grape marc, must and pulp were pasteurized and, together with wort, volumetrically introduced into fermentation flasks for fermentation. Mass changes taking place during the process were analyzed. Real extract, alcohol, free amino nitrogen (FAN) content, pH, color, sugars and organic acid profile were determined in obtained beers. The research has shown that the yeasts Dekkera bruxellensis 3429 fermented similarly to Saccharomyces cerevisiae Safale US-05. The yeast D. bruxellensis 3429 produced more alcohol in the finished beers in most cases and assimilated more FAN than M. pulcherrima MG970690. The D. bruxellensis 3429 strain most effectively used L-malic acid.

The Anatomical Differences and Physiological Responses of Sunburned Satsuma Mandarin (Citrus unshiu Marc.) Fruits.

Sunburn causes fruit browning and other physiological symptoms, reducing fruit production and quality. Therefore, we aimed to investigate the anatomical differences and abiotic stress responses in ‘Nichinan 1 gou’ satsuma mandarin (Citrus unshiu Marc.) according to the severity of sunburn damage (five grades: control, no sunburn; I to IV, increasing severity of sunburn). Additionally, the quality of sunburned and non-sunburned fruits was compared, and the sunburn-inducing temperature was estimated. Anatomical observations confirmed that with increased severity of symptoms, the damage to fruit rind surface and oil glands was increased. In the analysis of peel pigments, chlorophyll content in the rind gradually decreased compared with IV, whereas the carotenoid content gradually increased up to III. The flavonoid content in the peel and pulp was the highest in III. In the 1,1-diphenyl-2-picrylhydrazyl and 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) radical analyses, the IC50 (the concentration of compound at which the percentage of inhibition is 50%) value was the lowest in grade III in peel or IV in pulp, indicating a high free radical scavenging ability. The fruit quality analysis between sunburned and non-sunburned fruits showed differences in total soluble solid content, total acidity, firmness, coloration, and free sugar and organic acid contents, indicating a significant effect on fruit quality. In the heat tolerance tests on fruit rind in the laboratory and field, the damage was confirmed at temperatures above 47 °C.

Co‐fermentation metabolism characteristics of apple vinegar with Acetobacter pasteurianus and Lactobacillus plantarum

In this study, the growth and metabolic characteristics of Acetobacter pasteurianus and Lactobacillus plantarum used in the co-fermentation of apple vinegar were investigated. The results revealed that L. plantarum had little effect on the growth of A. pasteurianus during the co-fermentation process. The carbon sources used by L. plantarum and A. pasteurianus for growth were glucose and ethanol, respectively. Free amino acids, organic acids, and acetoin were analyzed using an amino acid analyzer, high-performance liquid chromatography, and gas chromatography, respectively. The results indicated that L. plantarum contributed to the accumulation of free amino acids during co-fermentation. Lactic acid, a key flavor substance, was accumulated mainly by L. plantarum during co-fermentation and was partly transformed into acetoin by A. pasteurianus. The acetoin content was 0.77 mg/ml, which is about twice that observed during pure fermentation with A. pasteurianus. Therefore, L. plantarum can improve the quality of apple vinegar during co-fermentation. Novelty impact statement L. plantarum had little effect on A. pasteurianus growth during co-fermentation of apple vinegar. The free amino acid and organic acid content in apple vinegar increased considerably because of the growth and metabolism of L. plantarum. The metabolites from L. plantarum could also be used by A. pasteurianus to improve the production of flavor substances during co-fermentation.

Optimization of lactic acid production from agro-industrial wastes produced by Kosakonia cowanii

Lactic acid is used for the preparation of poly-lactic acid. The objective of this research was to produce lactic acid from agro-industrial wastes as cheap, renewable substrates, and also reduce the pollution burden on the environment. Sixteen bacterial isolates were isolated from agro-industrial wastes. The chemical hydrolysis of agro-industrial wastes was achieved with hydrochloric acid, sulfuric acid, and sodium hydroxide. The highest yield of lactic acid produced was identified using 16S rRNA. The optimum conditions for lactic acid production were determined. Calcium lactate, produced from the culture fermentation was treated with sulfuric acid to precipitate the calcium sulfate. The filtrate holding free organic acid was vaporized to produce pure lactic acid. Chemical hydrolysis using 5% HCl released the highest concentration of total reducing sugar at 8015.90 and 7761.55 ​mg/L using cotton and coffee wastes, respectively. The bacterial isolate Kosakonia cowanii (B2) presented highest lactic acid concentration at 24.97 and 27.91 ​g/L after 24 and 48 ​h, respectively as a qualitative determined by HPLC analysis. The maximum lactic acid production at 28.14 ​g/L was obtained on the fermenter scale after 72 ​h by HPLC analysis.

Tissue-specific distribution of primary and secondary metabolites of Baemoochae (×Brassicoraphanus) and its changes as a function of developmental stages

The distribution and changes in the primary and secondary metabolite profiles of Baemoochae, an inter-generic hybrid of Chinese cabbage and radish, during the plant’s developmental stages were investigated. Metabolites were analyzed using gas chromatography-mass spectrometry (GC-MS) and ultra-high-performance liquid chromatography-electrospray ionization-quadrupole time-of-flight (UHPLC-ESI-qTOF MS). Free sugar, organic acid, and amino acid composition depended on the tissue type and developmental stage of Baemoochae. For example, glucose and alanine levels were higher in mature leaves than in young leaves; citric acid content in mature roots was lower than that in young roots. Several glucosinolates were identified for the first time in Baemoochae. Glucoraphasatin was predominant in both leaves and roots, regardless of plant maturity. Total glucosinolate content was significantly higher in roots than in leaves and in mature than in young plants. The roots of mature Baemoochae could be used as a rich source of glucosinolates, with several potential health-promoting effects.

Effects of the main ingredients of the fermented food, kimchi, on bacterial composition and metabolite profile

Kimchi is a fermented food prepared via spontaneous fermentation by lactic acid bacteria originating from raw ingredients. To investigate the effect of these ingredients on food fermentation, four types of food that differed only in their main raw ingredients (kimchi cabbage, green onion, leaf mustard, and young radish) were evaluated. The major microorganisms were Leuconostoc gelidum, Weissella kandleri, and Lactobacillus sakei groups. The distribution of these species depended on the sample type. All three species were primarily distributed in the food prepared from kimchi cabbage and young radish; however, the Lac. sakei group was hardly found in the food prepared using green onion and leaf mustard. Metabolite analysis results showed that the free sugar, organic acid, ethanol, and amino acid profiles differed with the sample type. This study indicates that the main ingredients could be an important factor in determining the composition of the microbial community and the metabolite composition.

Characterization of anthropogenic organic matter and its interaction with direct yellow 27 in wastewater: Experimental results and perspectives of resource recovery

The concept of natural organic matter of anthropogenic origin is introduced and its characteristics and interaction with chemical pollutants are investigated by adopting several distinct analytic methodologies. Scanning electron microscopy indicates that the used sample of anthropogenic organic matter (AOM) has an amphiphilic nature, which allows its supramolecular organization in water. Fourier transform infrared spectroscopy, in turn, gives a clear indication about the presence of polysaccharide markers, lipidic and amidic fractions, and suggests the absence of free organic acid. AOM sample and AOM mixed with dye sample were examined by the three-dimensional excitation-emission matrix fluorescence spectra and the nuclear magnetic resonance mono-dimensional spectra. The results highlighted the interactions occurring between the AOM and the reactive dye, selected as a representative chemical pollutant. Electron Spin Resonance confirms that the used AOM is able to completely include the dye in its structure. Overall, the obtained results indicate that the fate, transport, and toxicity of pollutants in the environment can be drastically influenced by the presence of AOM.

Chemical Compositional Characterization on Five Samples for Development of Artificial Bee Feed

The western honey bee, Apis mellifera L. is an essential pollinator for high yield in agriculture and provides products of economic values. Recently, the sudden decline of the bee population by numerous causes has occurred, which is called colony collapse disorder (CCD). One of the reasons in CCD, the limited nutrition in colonies declines brood rearing and shortens the lifespan of adult workers. Beekeepers need to provide artificial bee feed regularly to maintain health colony and continuity of bee-related products on apiculture. This study focuses on development of artificial bee feed, through investigation of different contents in nutritional components on five samples, namely canola pollen, mixed pollen, bee bread, MegaBee, and Test A. Among them, Test A was developed as artificial bee feed and was compared with other samples. The five samples were analyzed on free sugar, organic acid and amino acid. Sucrose content showed the largest amounts with 46.15% and 59.60% on Megabee and Test A, respectively. The Test A showed the largest account for citric acid with 92.33%. A total of 21 amino acids were detected on five samples. Among the detected 21 amino acids, proline was accounted the highest content in canola pollen, mixed pollen and bee bread with 1159.21 mg/L, 998.90 mg/L and 783.73 mg/L, respectively. Among the five samples, Test A showed the highest amount of lysine with 471.30 mg/L. Nutritional content, balance and efficiency needs to be considered for the development of artificial bee feed. This study will contribute to provide future directions on development of artificial bee feed.

UPLC-ESI-MS/MS Profile of The Ethyl Acetate Fraction of Aerial Parts of Bougainvillea 'Scarlett O'Hara' Cultivated in Egypt

The ethyl acetate fraction of Bougainvillea 'Scarlett O'Hara' cultivated in Egypt did not receive enough attention in phytochemical and biological studies. This inspired the authors to investigate the phytochemicals of this fraction for the first time using UPLC-ESI-MS/MS in negative and positive ionization modes to understand the distribution of the major secondary metabolites. The analysis revealed the tentative identification of fifty-seven compounds. The detected metabolites belonged to numerous chemical classes including seven organic acids, fourteen phenolic compounds, one betacyanin, seven anthocyanins, ten flavonoids, three saponins, six tannins, four cyclic tetrapyrolic derivatives and five miscellaneous. The LC-ESI-MS methodology in negative ionization mode was the most appropriate to detect the group of saponins (22.17%), flavonoids (14.27%), free organic (12.35%) and phenolic acid derivatives (14%). It can be seen that the highest ionization rate produced for cyclic tetrapyrolic derivatives (56.41%), anthocyanins (18.8%) and tannins (3.2%) in the positive mode chromatogram.

Biological effects of root exudates from resistant and susceptible banana varieties on Fusaiurm oxysporum f. sp. cubense and Bacillus subtilis

Root exudates of banana resistant variety ('Nantianhuang') and susceptible variety ('Guijiao No. 6') to Fusarium wilt were collected in vitro by bathing root system to examine the biological effects of root exudates from banana varieties on Fusaiurm oxysporum f. sp. cubense and Bacillus subtilis. We explored the effects of root exudates of different banana varieties on the abundance of soil microorganisms and the growth of F. oxysporum f. sp. cubense and B. subtilis. The results showed that root exudates from resistant variety could significantly reduce the abundance of soil fungi and inhibit the spore germination of F. oxysporum f. sp. cubense. Root exudates from susceptible variety could significantly stimulate mycelia growth and spores germination, whereas root exudates from the tested banana varieties could significantly increase the growth and biofilm formation of B. subtilis. By dealing with the root exudates of resistant and susceptible varieties, the growth rate of mycelia were 11.28 and 12.28 mm·d-1, and the germination rate of spores were 34.6% and 79.5%, respectively. After culturing for 12 h, the growth rates of B. subtilis (OD600) were 1.27 and 1.14, and the biofilm formation (OD570) were 1.11 and 1.30 after static culturing 72 h, respectively. There were significant differences between the values of resistant and susceptible varieties. The colonization amount of B. subtilis in the rhizosphere of susceptible variety was significantly higher than that of resistant variety. The contents of free amino acids and organic acid in root exudates of the resistant variety were higher than that of susceptible variety. The content ratio of acetic acid and proline in the root exudates of resistant variety were 3.7 times and 2.4 times of that of susceptible variety. In conclusion, root exudates of banana resistant variety could inhibit the growth of F. oxysporum f. sp. cubense. Root exudates from susceptible variety could promote the growth of F. oxysporum f. sp. cubense,while that from the tested banana varieties could all significantly enhance growth, biofilm formation and colonization ability of B. subtilis.

Influence of Potassium Nutrition and Exogenous Organic Acids on Iron Uptake by Monocot and Dicot Plants

Iron (Fe) is a vital element for the survival and proliferation of all plants; therefore, Fe-biofortification by the application of chemical and organic fertilizers is being as an effective approach to fight hidden hunger retards the growth and development of crop plants. Two experiments were carried out to investigate the effect of potassium and exogenous organic acids on iron uptake by two different plants: one is monocotyledon, maize (Zea mays L.) and the second is dicotolydon pea (Pisum sativum L.) grown under controlled conditions. The seedlings were grown in sand culture in a greenhouse experiment and irrigated with one-tenth strength modified nutrient solution of Hoagland and Arnon as a base solution (pH 7.5), containing different iron treatments (0, 1, and 5 ppm as FeSO4·7H2O) combined with potassium nutrition (0, 5, 10, and 50 ppm as K2SO4). After 30 days, the best interaction treatment was selected for further experiment including 5.0 ppm Fe as FeSO4.7H2O and 50 ppm K as K2SO4 in combination with 1 × 10-5 mole/liter of one of the following organic acids: Citric acid, Oxalic acid, Formic acid, Acetic acid, Propionic acid, Tartaric acid, Succinic acid, Fumaric acid, Malic acid, Glutamic acid, besides the free organic acid nutrient solution as a control. Results revealed that the interaction between 5.0 ppm Fe and 50 ppm K was the best interaction treatment for increasing biomass production and iron uptake of maize and pea seedlings under applied condition. Furthermore, exogenous application of organic acids improves uptake and translocation of nutrient such as iron, potassium and phosphorus by the maize and pea plants. In conclusion, potassium nutrition and exogenous organic acids have the potential to stimulate Fe-uptake of monocot and dicot plants and mediate iron-biofortified crops.

국내 시판 오렌지주스 및 자몽주스의 이화학적 특성과 항산화 활성

Thee physicochemical properties, functional ingredient content, and antioxidant activities of the commercial orange and grapefruit juice were investigated. Three types of orange (OJ1, OJ2, and OJ3) and grapefruit (GJ1, GJ2, and GJ3) juices were purchased from the market. Antioxidant activities of the commercial juices were evaluated using DPPH, ABTS, and reducing power assays. The pH of orange juice was higher than grapefruit juice and the acidity of grapefruit juice was higher than orange juice. The soluble solid and reducing sugar contents of the juices were in the range of 9.30-13.60 °Brix and 45.02-71.52 mg/mL, respectively. The total free sugar and organic acid contents of juices were 61.84-98.67 mg/mL and 1.14-1.60 mg/mL, respectively. The major free sugars were sucrose, fructose, and glucose, and six types of organic acids were detected in the commercial juices. The total polyphenol content was the highest in OJ2 (910.7 μg/mL), and the lowest in GJ3 (630.7 μg/mL). The total flavonoid content in grapefruit juices was higher than orange juices. OJ2 showed the highest antioxidant activity in DPPH and ABTS radicals scavenging assays and the reducing power assay. Our results indicate that the functional ingredient content and antioxidant activities were different even in the same type of juice.

Bioactivities, chemical composition and nutritional value of Cynara cardunculus L. seeds

In the present study, the nutritional value, bioactive properties, and chemical composition of various cardoon (Cynara cardunculus L.) genotypes cultivated in central Greece were investigated. The results demonstrated that Cynara seeds are a good source of fat and protein, while they also contain considerable amounts of K, Mg, and Fe and low amount of Na. Sucrose, oxalic acid, and α-tocopherol were the only free sugar, organic acid, and tocopherol isoform respectively, found among the studied genotypes. The most abundant fatty acids were linoleic, oleic and palmitic acid, while PUFA was the most abundant fatty acid class. All the tested seeds contained only two phenolic compounds, namely 5-O-caffeoylquinic acid and 3,5-O-caffeoylquinic acid, while significant antioxidant activities and cytotoxicity against tumor cell lines and antimicrobial effects were also observed. In conclusion, cardoon seed extracts could be exploited in the food and pharmaceutical industries as alternative sources of natural compounds with bioactive properties.

Correlation analysis of the transcriptome and metabolome reveals the regulatory network for lipid synthesis in developing Brassica napus embryos.

In this manuscript, we explored the key molecular networks for oil biosynthesis with the transcriptome and metabolome of B. napus embryo at different developmental stages. Brassica napus (B. napus) is an important oil crop worldwide, yet the molecular pathways involved in oil biosynthesis in seeds are not fully understood. In this study, we performed a combined investigation of the gene expression profiles and metabolite content in B. napus seeds at 21, 28 and 35 days after flowering (DAF), when seed oil biosynthesis takes place. The total triacylglycerol (TAG) content in seed embryos increased over the course of seed maturation, and was accompanied by changes in the fatty acid profile, an increase in lipid droplets, and a reduction in starch grains. Metabolome analysis showed that the total amino acid, free fatty acid and organic acid contents in seed embryos decreased during seed maturation. In total, the abundance of 76 metabolites was significantly different between 21 and 28 DAF, and 68 metabolites changed in abundance between 28 and 35 DAF. Transcriptome analysis showed that the set of genes differentially expressed between stages was significantly enriched in those related to lipid metabolism, transport, protein and RNA metabolism, development and signaling, covering most steps of plant lipid biosynthesis and metabolism. Importantly, the metabolite and gene expression profiles were closely correlated during seed development, especially those associated with TAG and fatty acid biosynthesis. Further, the expression of major carbohydrate metabolism-regulating genes was closely correlated with carbohydrate content during seed maturation. Our results provide novel insights into the regulation of oil biosynthesis in B. napus seeds and highlights the coordination of gene expression and metabolism in this process.

Free Sugar and Organic Acid in the Fruit of Hawthorn (Crataegus pinnatifida Bunge) Selected Clones as Honey Plant in Korea

Free Sugar and Organic Acid in the Fruit of Hawthorn (Crataegus pinnatifida Bunge) Selected Clones as Honey Plant in Korea