Reduction of anthranilic acid to 2-aminobenzaldehyde by the white-rot fungus Bjerkandera adusta DSMZ 4708.

The biocatalytic aerobic "in-water" reduction of anthranilic acid to 2-aminobenzaldehyde by growing cultures of the basidiomycetous white-rot fungus Bjerkandera adusta has been studied. The high specific activity of Bjerkandera adusta towards the carboxylic group of anthranilic acid that allows avoiding the formation of the corresponding alcohol has been demonstrated using different substrate concentrations. The presence of ethanol as co-solvent allows increasing the yield of target product. In contrast to chemical reducing agents that usually yield 2-aminobenzyl alcohol, an overreduction of anthranilic acid is completely suppressed by the fungus and gives the target flavor compound in satisfactory preparative yields. It was shown that the activity of Bjerkandera adusta towards anthranilic acid does not apply to its m- and p-isomers.

Integrating metabolomics and transcriptomics to analyze the differences of breast muscle quality and flavor formation between Daweishan mini chicken and broiler.

The quality and flavor of chicken are affected by muscle metabolites and related regulatory genes, and the molecular regulation mechanism of meat quality is different among different breeds of chicken. In this study, 40 one-day-old Daweishan mini chicken (DM) and Cobb broiler (CB) were selected from each group, with 4 replicates and 10 chickens in each replicate. The chickens were reared until 90 d of age under the same management conditions. Then, metabolomics and transcriptomics data of 90-day-old DM (n = 4) and CB (n = 4) were integrated to analyze metabolites affecting breast muscle quality and flavor, and to explore the important genes regulating meat quality and flavor related metabolites. The results showed that a total of 38 significantly different metabolites (SDMs) and 420 differentially expressed genes (DEGs) were detected in the breast muscle of the 2 breeds. Amino acid and lipid metabolism may be the cause of meat quality and flavor difference between DM and CB chickens, involving metabolites such as L-methionine, betaine, N6, N6, N6-Trimethyl-L-lysine, L-anserine, glutathione, glutathione disulfide, L-threonine, N-Acetyl-L-aspartic acid, succinate, choline, DOPC, SOPC, alpha-linolenic acid, L-palmitoylcarnitine, etc. Important regulatory genes with high correlation with flavor amino acids (GATM, GSTO1) and lipids (PPARG, LPL, PLIN1, SCD, ANGPTL4, FABP7, GK, B4GALT6, UGT8, PLPP4) were identified by correlation analysis, and the gene-metabolite interaction network of breast muscle mass and flavor formation in DM chicken was constructed. This study showed that there were significant differences in breast metabolites between DM and CB chickens, mainly in amino acid and lipid metabolites. These 2 kinds of substances may be the main reasons for the difference in breast muscle quality and flavor between the 2 breeds. In general, this study could provide a theoretical basis for further research on the molecular regulatory mechanism of the formation of breast muscle quality and flavor differences between DM and CB chickens, and provide a reference for the development, utilization and genetic breeding of high-quality meat chicken breeds.

Correlation Analysis between Microbial Communities and Flavor Compounds during the Post-Ripening Fermentation of Traditional Chili Bean Paste.

Chili bean paste is a traditional flavor sauce, and its flavor compounds are closely related to its microflora. This study focused on investigating the content of bioactive compounds, flavor compounds, and microbial communities during the post-ripening fermentation of chili bean paste, aiming to provide a reference for improving the flavor of chili bean paste by regulating microorganisms. Compared to no post-ripening fermentation, the content of organic acids increased significantly (p < 0.05), especially that of citric acid (1.51 times). Glutamic acid (Glu) was the most abundant of the 17 free amino acids at 4.0 mg/g. The aroma profiles of the samples were significantly influenced by fifteen of the analyzed volatile compounds, especially methyl salicylate, methyl caproate, and 2-octanol (ROAV > 1). Latilactobacillus (27.45%) and Pseudomonas (9.01%) were the dominant bacterial genera, and Starmerella (32.95%) and Pichia (17.01%) were the dominant fungal genera. Weissella, Lacticaseibacillus, Pichia, and Kazachstania had positive effects on volatile flavoring compounds, which enriched the texture and flavor of the chili bean paste. Therefore, the microbial-community activity during the post-ripening fermentation is the key to enhance the flavor quality of the product.

Identification and comparison of aroma and taste-related compounds from breast meat of three breeds of Korean native chickens.

This study was aimed to identify and compare the taste-related compounds (nucleotide-related compounds, free amino acid contents, and fatty acid composition) and aroma (volatile organic compounds [VOC]) compounds in the chicken breast meat from 3 kinds of Korean native chicken (KNC), namely Hanhyup 3 (HH3), Woorimatdag 1 (WRMD1) and Woorimatdag 2 (WRMD2). Among the 3 breeds, WRMD1 had significantly higher IMP and AMP contents than HH3. WRMD2 exhibited higher levels of umami and sweet-taste amino acids and oleic acid composition compared to HH3 (P < 0.05). HH3 showed a higher composition of unsaturated fatty acids than WRMD2 (P < 0.05). On their discrimination by flavor composition, some compounds including aspartic acid were analyzed as important compounds. Regarding aroma compounds, unique aroma compounds were detected for each breed and some compounds such as isopropyl myristate, p-cresol, (S)-(+)-3-Methyl-1-pentanol, and cyclic octa-atomic sulfur were expected to be utilized as key compounds in discrimination of the 3 breeds. From the result of this study, the differences on the flavor compounds of three breeds were elucidated and key compounds for their discrimination were presented.

Comparative analysis for nutrients, flavor compounds, and lipidome revealed the edible value of pond-cultured male Pelodiscus sinensis with different ages.

Pelodiscus sinensis is an aquatic product with a long growth cycle in pond culture and high nutritional value meat. The flavor compounds, nutrients, and lipidome were investigated to explore the edible value changes of turtle meat aged 3 to 6 years (Y3 to Y6). Typically, P. sinensis meat is rich in high-quality protein (EAAI ≥81.22, AAS ≥86.47). Y6 has the highest level of Se, protein, amino acids, and high unsaturated fatty acids, including EPA + DHA. Y5 has the most delicious amino acids, polyunsaturated fatty acids, and key odorant content. The stronger flavor of Y5 may be mainly related to C18:2n6t and C18:2n6c. Further, triacylglycerols (TAG) and phosphatidylcholine (PC) were significant changes in Y5. Additionally, PI (16:0/18:1) was identified as the potential biomarker. These results provided available information on P. sinensis marketing age and revealed the potential impact of nutrients on the formation of VOCs.

Volatilome and flavor analyses based on e-nose combined with HS-GC-MS provide new insights into ploidy germplasm diversity in Platostoma palustre.

Platostoma palustre (Mesona chinensis Benth or Hsian-tsao, also known as "Xiancao" in China), is an edible and medicinal plant native to India, Myanmar, and Indo-China. It is the main ingredient in the popular desserts Hsian-tsao tea, herbal jelly, and sweet herbal jelly soup. P. palustre is found abundantly in nutrient-rich substances and possesses unique aroma compounds. Variations in the contents of volatile compounds among different germplasms significantly affect the quality and flavor of P. palustre, causing contradiction in demand. This study investigates the variation in the volatile compound profiles of distinct ploidy germplasms of P. palustre by utilising headspace gas chromatography-mass spectrometry (HS-GC-MS) and an electronic nose (e-nose). The results showed significant differences in the aroma characteristics of stem and leaf samples in diverse P. palustre germplasms. A total of sixty-seven volatile compounds have been identified and divided into ten classes. Six volatile compounds (caryophyllene, α-bisabolol, benzaldehyde, ß-selinene, ß-elemene and acetic acid) were screened as potential marker volatile compounds to discriminate stems and leaves of P. palustre. In this study, leaves of P. palustre showed one odor pattern and stems showed two odor patterns under the influence of α-bisabolol, acetic acid, and butyrolactone. In addition, a correlation analysis was conducted on the main volatile compounds identified by HS-GC-MS and e-nose. This analysis provided additional insight into the variations among samples resulting from diverse germplasms. The present study provides a valuable volatilome, and flavor, and quality evaluation for P. palustre, as well as new insights and scientific basis for the development and use of P. palustre germplasm resources.

Identification of Characteristic Bioactive Compounds in Silkie Chickens, Their Effects on Meat Quality, and Their Gene Regulatory Network.

Silkie chicken, an important chicken breed with high medicinal and nutritional value, has a long history of being used as a dietary supplement in China. However, the compounds with health-promoting effects in Silkie chickens remain unclear. In the present study, we conducted a comprehensive analysis of metabolic and lipidomic profiles to identify the characteristic bioactive compounds in Silkie chickens, using a common chicken breed as control. The results showed that the levels of 13 metabolites including estradiol, four lipid subclasses including cardiolipin (CL), eight lipid molecules, and three fatty acids including docosahexaenoic acid (C22:6) were significantly increased in Silkie chickens, which have physiological activities such as resisting chronic diseases and improving cognition. These characteristic bioactive compounds have effects on meat quality characteristics, including improving its water-holding capacity and umami taste and increasing the content of aromatic compounds and phenols. The differentially expressed genes (DEGs) between the two chicken breeds revealed the regulatory network for these characteristic bioactive compounds. Fifteen DEGs, including HSD17B1, are involved in the synthesis of characteristic metabolites. Eleven DEGs, including ELOVL2, were involved in the synthesis and transport of characteristic lipids and fatty acids. In summary, we identified characteristic bioactive compounds in Silkie chickens, and analyzed their effects on meat quality characteristics. This study provided important insight into Silkie chicken meat as a functional food.

Marine Fish Oil Replacement with Lard or Basa Fish (Pangasius bocourti) Offal Oil in the Diet of Tiger Puffer (Takifugu rubripes): Effects on Growth Performance, Body Composition, and Flesh Quality.

Lard (LD) and Basa fish offal oil (BFO) have similar fatty acid profiles, both containing high contents of saturated fatty acids (SFA) and monounsaturated fatty acids (MUFA). The present study aimed to investigate the efficacy of partial or complete replacement of marine fish oil (MFO, herring oil) by LD or BFO in the diets of tiger puffer. The control diet contained 49.1% crude protein and 9.28% crude lipid content including 6% added MFO. In other diets, 1/3, 2/3, and 3/3 of the added MFO was replaced by LD or BFO, respectively. Each diet was fed to triplicate tanks of juvenile fish (initial body weight, 13.88 g). A 46-day feeding trial was conducted in a flow-through seawater system. Each diet was fed to triplicate 200-L rectangular polyethylene tanks, each of which was stocked with 30 fish. Fish were fed to satiation three times a day. The complete replacement of added MFO (replacing 65% of the total crude lipid) had no adverse effects on fish growth performance in terms of survival (>94%), weight gain (360-398%), feed intake (2.37-3.04%), feed conversion ratio (0.84-1.02), and somatic indices. The dietary LD or BFO supplementation also had marginal effects on fish body proximate composition, biochemical parameters, muscle texture, and water-holding ability, as well as the hepatic expression of lipid metabolism-related genes. Partial (2/3) replacement of added MFO by LD or BFO did not significantly reduce the muscle n-3 LC-PUFA content, indicating the n-3 LC-PUFA sparing effects of SFA and MUFA in LD and BFO. In general, dietary LD or BFO reduced the peroxidation level and led to significant changes in the muscle volatile flavor compound profile, which were probably attributed to the change in fatty acid composition. The results of this study evidenced that LD and BFO are good potential lipid sources for tiger puffer feeds.

Investigation into the characteristic volatile flavor of old duck.

In order to explore the characteristic aroma flavor and its formation mechanism of old ducks, two ages (30 days and 60 days) of young ducks and three ages of old ducks (300 days, 900 days, and 1500 days) were selected and studied. An electronic nose was applied to evaluate the overall aroma flavor, and the result showed significant differences between the five duck samples. By gas chromatography-mass spectrometry (GC-MS), forty-eight volatile flavor compounds were detected, including seven aldehydes, six esters, five alcohols, five nitrogen compounds, twenty-one hydrocarbons, and four others. Among these compounds, twelve components, such as hexanal and dimethyl anthranilate, were considered as the characteristic flavor compounds along with duck aging. Furthermore, correlation analysis indicated that meat's unsaturated free fatty acids, especially linoleic acid (C18:2), were responsible for the duck's characteristic flavor formation. These data contribute to the flavor research and identification of old ducks.