Biotransformation Of Isoflavones Research Articles

Quantification of soy isoflavones and their conjugative metabolites in plasma and urine: an automated and validated UHPLC-MS/MS method for use in large-scale studies.

The biotransformation of isoflavones by gut microbiota and by drug metabolizing enzymes plays a crucial role in the understanding of their potential health-promoting effects. The purpose of our work was to develop a simultaneous, sensitive, and robust automated ultra high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) method to quantify the soy isoflavones daidzein and genistein, their conjugative metabolites, as well as their major microbial degradation products in order to provide a method for use in large clinical trials or animal studies. An automated, 96-well solid-phase extraction method was used to extract the isoflavone analytes from plasma and urine. Separation of genistein, daidzein, and 19 of its metabolites, including five glucuronides, seven sulfates, and two sulfoglucuronides, as well as five microbial metabolites, was achieved in less than 25min using a sub-2μm particle column and a gradient elution with acetonitrile/methanol/water as mobile phases. Analysis was performed under negative ionization electrospray MS via the multiple reaction monitoring (MRM). Validation was performed according to the analytical method validation guidelines of Food and Drug Administration (FDA) and International Conference on Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH) consisting of selectivity, accuracy, precision, linearity, limit of detection, recovery, matrix effect, and robustness. All validated parameters essentially matched the FDA and ICH requirements. The application of this method to a pharmacokinetic study in postmenopausal women showed that isoflavones are extensively metabolized in vivo. A robust automated analytical approach was developed, which allows the handling of large sample sizes but nevertheless provides detailed information on the isoflavone metabolite profile leading to a better understanding and interpretation of clinical and animal studies.

Biotransformation of isoflavones by Aspergillus niger and Cunninghamella elegans

Isoflavones are well-known flavonoids in many Legumes. Numerous biological activities are reported, including antioxidant, anti-inflamatory, anti-cancer, and antifungal activities. Their metabolic fates of natural isoflavones were studied in mammalians and several microorganisms. However, no detailed analyses have been reported on the isoflavone and its synthetic analogues. Recently, application of microorganism on natural products bioconversion has gained strong attentions due to their advantages over plants and animals. The metabolism of isoflavone and 4′-fluoroisoflavone were tested with Aspergillus niger and Cunninghamella elegans. The structures of selected metabolites were confirmed by synthetic standards. Both fungi rapidly transformed isoflavone into several metabolites. The half-lives of isoflavone (40 mg/L) were 1.6 and 4.2 days for A. niger and C. elegans, respectively. Overall, A. niger gave much more complex metabolite profiles. Approximately 23 metabolites were tentatively identified. The major metabolites were mono- and di-hydroxylated isoflavones at initial period, whereas those of 10 days were di- and tri-hydroxy-isoflavones. Hydroxylation usually occurred in B-ring of isoflavone, confirmed by authentic standards. Among dihydroxyisoflavones, 3′,4′-dihydroxy analogue was the most abundant metabolite, followed by daidzein (4′,7′-dihydroxyisoflavone). Methoxylated metabolites slowly accumulated during culturing. In addition, several glycosides were found, including hexose conjugates of mono-/di-hydroxyisoflavone and minor amount of pentose conjugates during culturing. However, 4′-fluoroisoflavone was not transformed during the culturing period, indicating the region-selective hydroxylation on initial metabolism of isoflavones.

β-Glucosidase activity and bioconversion of isoflavones during fermentation of soymilk.

Lactobacillus rhamnosus C6 strain showed higher β-glucosidase activity as well as biotransformation of isoflavones from glycones (daidzin and genistin) to aglycones (daidzein and genistein) in soymilk. However, L. rhamnosus C2 and Lactobacillus casei NCDC297 also exhibited similar activity during soymilk fermentation. These three strains can be selected for the development of functional fermented soy foods enriched with aglycone forms of isoflavones, such as soy yoghurt, soy cheese, soy beverages and soy dahi. The study determined β-glucosidase activity of probiotic Lactobacillus cultures for bioconversion of isoflavones to aglycones in fermenting soymilk medium. Soymilk was fermented with six strains (L. rhamnosus C6 and C2, L. rhamnosus NCDC19 and NCDC24 and L. casei NCDC17 and NCDC297) at 37 °C for 12 h. The highest β-glucosidase activity and isoflavone bioconversion after 12 h occurred by L. rhamnosus C6 culture during fermentation in soymilk. Increased isoflavone aglycone content in fermented soymilk is likely to improve the biological functionality of soymilk (e.g. antioxidant activity, alleviation of hormonal disorders in postmenopausal women, etc.). Lactobacillus rhamnosus C6 culture can be used for the development of functional fermented soy-based products.

Targeted metabolomics for Aspergillus oryzae-mediated biotransformation of soybean isoflavones, showing variations in primary metabolites

This study aimed to investigate the biotransformation of soybean isoflavones to hydroxyisoflavones, and the primary and secondary metabolite change during Aspergillus oryzae KACC40247-mediated fermentation by gas chromatography-time of flight-mass spectrometry and LC-MS with multivariate analysis. The mass spectrometric analysis revealed that acetylglycosides and glycosides decreased during the first 12 h of fermentation, while the aglycones increased up to that time point. This was followed by a decrease in aglycone levels due to the formation of hydroxyisoflavones. The hydroxyflavones, 8-hydroxydaidzein, hydroxygenistein, and hydroxyglycitein, resulting from the biotransformation of the corresponding aglycones, increased up to 24 h, and then subsequently decreased. During fermentation, the levels of monosaccharides, aspartic acid, pyroglutamic acid, gamma-aminobutyric acid, and organic acids gradually decreased, whereas the levels of threonine, serine, and glycine increased. Hydroxyisoflavone was more strongly correlated with antioxidant activity than the other metabolites. Our results suggest that biotransformation has the potential to improve the nutritional properties of soy-based food.

Biotransformation and recovery of the isoflavones genistein and daidzein from industrial antibiotic fermentations

The objective of this study was to follow the metabolic fate of isoflavone glucosides from the soybean meal in a model industrial fermentation to determine if commercially useful isoflavones could be harvested as coproducts from the spent broth at the end of the fermentation. The isoflavone aglycones, genistein, and daidzein together make up 0.1-0.2% of the soybean meal by weight but serve no known function in the manufacturing process. After feeding genistein to washed cells of the erythromycin-producing organism, Saccharopolyspora erythraea, the first biotransformation product (Gbp1) was determined by X-ray crystallography to be genistein-7-O-α-rhamnoside (rhamnosylgenistein). Subsequent feeding of rhamnosylgenistein to growing cells of Saccharopolyspora erythraea led to the production of a second biotransformation product, Gbp2. Chromatographic evidence suggested that Gbp2 accumulated in the spent broth of the erythromycin fermentation. When the spent broth was hydrolyzed with acid or industrial enzyme preparations, the isoflavone biotransformation products were returned back to their parental forms, genistein and daidzein, which were then recovered as coproducts. Desirable features of this method are that it does not require modification of the erythromycin manufacturing process or genetic engineering of the producing organism to be put into practice. A preliminary investigation of five additional antibiotic fermentations of industrial importance also found isoflavone coproduct potential.

β-Glucosidase Activity of Lactobacilli for Biotransformation of Soy Isoflavones

Thirty isolates of lactobacilli were screened for β-glucosidase production and isoflavones biotransformation. The isolates exhibited enzyme activities in the range of 0.14–3.31 IU. Five highest enzyme producers were assessed for isoflavones biotransformation potential in soymilk that varied greatly among the isolates with an increase of 2–3 fold in genistein and 6–14 fold in daidzein. The biochemical and molecular identification classified the isolates as Lactobacillus rhamnosus. Among isolates, L. rhamnosus D13 was the highest enzyme producer, while L. rhamnosus D7 was the highest isoflavone aglycone producer. Our results are distinct because of no proportional relation between enzyme activity and isoflavones biotransformation. The study further confirms that the degree of biotransformation of isoflavones is characteristic of an individual strain.

Modification of Isoflavone Profiles in a Fermented Soy Food with Almond Powder

Isoflavone profiles of a fermented soy food, cheonggukjang, were modified using almond powder. Isoflavones were analyzed by high performance liquid chromatography (HPLC) with an ultraviolet detector. Malonyl derivatives of isoflavones decreased and aglycones of isoflavones increased in samples with almond powder for 48 h. As added, almond powder increased from 0%, 5%, and 10% (w/w), amounts of aglycones increased to 21.11%, 26.63%, and 32.45% for 48 h, respectively. β-Glucosidase activity in 5% and 10% almond added samples was significantly higher than samples without addition of almond (P < 0.05). The content of succinyl daidzin and succinyl genistin, new metabolites from isoflavones, in almond-added cheonggukjang was significantly lower than control samples, implying that β-glucosidase activity from almond affected negatively the formation of succinyl derivatives (P < 0.05). Principal component analysis (PCA) for isoflavone distribution showed that first principal component (PC1) and second principal component (PC2) expressed 64.78% and 22.26% of the data variability, respectively. Biotransformation of isoflavones in any fermented soy foods can be achieved using natural products containing high β-glucosidase activity such as almond. The results of this study can help to modify the structural transformation of phytochemicals in any fermented soy foods using natural products. Adjusting the content of almond powder can achieve wanted profiles, for example, high aglycones content. Also, content of metabolites such as succinyl derivatives can be controlled using proper amounts of almond and fermentation time.

Experimentally induced mastitis and metritis modulate soy bean derived isoflavone biotransformation in diary cows

The present study compared the changes in isoflavone (daidzein and genistein) and their metabolite (equol and para-ethyl-phenol) concentrations in the blood plasma of cows with induced mastitis and metritis after feeding with soy bean. Sixteen cows were divided into four groups: control for mastitis group, cows with induced mastitis group, control for metritis group, and cows with induced metritis group. All cows were fed a single dose of 2.5 kg of soy bean and then blood samples were taken from the jugular vein for 8 h at predetermined intervals. The concentrations of soy bean-derived isoflavones and their active metabolites were measured in the blood plasma on HPLC system. β-Glucuronidase activity in the blood plasma of cows was measured by fluorometric method. In the blood plasma of cows with induced mastitis and metritis, we found considerably higher concentrations and time-dependent increase in isoflavone metabolites (equol and para-ethyl-phenol) with reference to cyclic cows (P < 0.05). Moreover, we noticed significant decrease of genistein in the blood plasma of the cows with induced metritis compared with control cows (P < 0.05). In addition, in the blood plasma of the cows with induced metritis, we found an increase in β-glucuronidase activity compared with control cows (P < 0.05). In conclusion, health status of the females influenced the concentrations of isoflavone metabolites in the blood plasma of the cows. Experimentally induced mastitis and metritis increased isoflavone absorption, biotransformation and metabolism. Therefore, we suggest that cows with induced mastitis and metritis are more exposed to active isoflavone metabolite actions than healthy cows.

Changes of phytochemical constituents (isoflavones, flavanols, and phenolic acids) during cheonggukjang soybeans fermentation using potential probiotics Bacillus subtilis CS90

A potential probiotics Bacillus subtilis CS90 was isolated from Korean soybean paste ( doenjang). Biotransformation of phytochemical contents, isoflavones, flavanols, and phenolic acids, during the fermentation of soybean fermented food cheonggukjang by a potential probiotics B. subtilis CS90 was investigated. The levels of isoflavone aglycones, flavanols, and gallic acid increased, while the β-glucosidase and esterase activities, isoflavone glycosides (except for acetylglycosides), and flavanol gallates contents decreased. Total isoflavone content slightly decreased after 60 h of fermentation, while total flavanol and phenolic acid content increased. The highest levels of daidzein (aglycone type) and acetyldaidzin (glycoside type) were recorded after 48 h of fermentation. However, the total contents of glycosides, manolylglycosides, and flavanol-gallates decreased by about 80, 90, and 70% during 60 h of fermenting cooked soybeans. In addition, the contents of total phenolic increased markedly from 253 mg/kg to 9414 mg/kg while the DPPH radical scavenging activity increased from 53.6 to 93.9% during this fermentation.

Harnessing functional food strategies for the health challenges of space travel—Fermented soy for astronaut nutrition

Astronauts face numerous health challenges during long-duration space missions, including diminished immunity, bone loss and increased risk of radiation-induced carcinogenesis. Changes in the intestinal flora of astronauts may contribute to these problems. Soy-based fermented food products could provide a nutritional strategy to help alleviate these challenges by incorporating beneficial lactic acid bacteria, while reaping the benefits of soy isoflavones. We carried out strain selection for the development of soy ferments, selecting strains of lactic acid bacteria showing the most effective growth and fermentation ability in soy milk (Streptococcus thermophilus ST5, Bifidobacterium longum R0175 and Lactobacillus helveticus R0052). Immunomodulatory bioactivity of selected ferments was assessed using an in vitro challenge system with human intestinal epithelial and macrophage cell lines, and selected ferments show the ability to down-regulate production of the pro-inflammatory cytokine interleukin-8 following challenge with tumour necrosis factor-alpha. The impact of fermentation on vitamin B1 and B6 levels and on isoflavone biotransformation to agluconic forms was also assessed, with strain variation-dependent biotransformation ability detected. Overall this suggests that probiotic bacteria can be successfully utilized to develop soy-based fermented products targeted against health problems associated with long-term space travel.

Enhancing the Biotransformation of Isoflavones in Soymilk Supplemented with Lactose Using Probiotic Bacteria during Extended Fermentation

Soymilk (SM) lacks lactose; hence supplementation of SM with lactose is likely to enhance the growth of probiotic bacteria and biotransformation of isoflavone glycosides to isoflavone aglycones. In this study, 11 strains of probiotic bacteria including Lactobacillus rhamnosus, L. salivarius, L. plantarum, L. acidophilus, L. paracasei, HOWARU L. rhamnosus, L. delbrueckii subsp. bulgaricus, Bifidobacterium lactis type Bi-07, B. longum, HOWARU B. bifidum, and B lactis type Bi-04 were inoculated individually or as mixed cultures into SM and soymilk supplemented with lactose (SML). A total of 2% of lactose was added to 1 L of SM with the aim of improving the growth of probiotic organisms and promoting the biotransformation of isoflavone isomers to bioactive isoflavone aglycomes. Samples of SM were incubated at 37 degrees C and 10 mL aliquots of SM were taken at 0, 24, 48, and 72 h to monitor the growth of probiotic bacteria and changes in isoflavone contents using high-performance liquid chromatography (HPLC). Results indicated that SML fermented with probiotics had higher viable counts by >2.4 log CFU/mL than that in SM at the end of the 72 h fermentation period. Mixed cultures grew at different rates and in general Lactobacilius spp. had >1.02 log CFU/mL more cells than Bifidobacterium spp. at the end of the fermentation period. The total aglycone content in SM at 72 h of fermentation was 0.924 mg/100 mL, whereas that in SML was 1.623 mg/100 mL. Addition of lactose not only improved the growth of probiotic bacteria in SM but also enhanced the biotransformation of isoflavone glucosides to the more bioactive isoflavone aglycones. Mixed cultures did not improve the biotransformation of bioactive isoflavones when compared to single cultures.

Isoflavone 비배당화 및 항산화 활성을 지닌 Lactobacillus plantarum YS712의 선발

Lactic acid bacteria (LAB) are typical probiotic microbes that are used in various industries including fermented foods, feed additives, and pharmaceuticals. The purpose of this study was to compare the ability of isoflavone biotransformation and antioxidative activity of 17 LAB. Six strains including the Lactobacillus species exhibited a 100% hydrolysis rate for daidzein during fermentation. The content of total genistein in soymilk fermented with these strains was . The DPPH (1, 1-diphenyl-2-picrylhydrazyl) radical scavenging ability of the LAB was widely variable and ranged from 23-78%. A selected strain was isolated from kimchi and the strain was identified as Lactobacillus plantarum ssp. through the API carbohydrate fermentation pattern and 16S rDNA profile. The strain exhibited excellent acid tolerance in an artificial gastric solution. L. plantarum YS712 showed high -glucosidase activity in fermentation. The concentration of genistein and daidzein in soymilk fermented with L. plantarum YS712 increased from 3.64 to and from 58.18 to , respectively. These results demonstrate the potential of L. plantarum YS712 as a probiotic culture that can be utilized in the manufacturing of fermentation foods and dietary supplements.

Isoflavones with unusually modified B-rings and their evaluation as antiproliferative agents

Six novel isoflavone derivatives along with four known isoflavones were isolated from a culture of a highly nickel-resistant strain of Streptomyces mirabilis from a former uranium mining area. The structures of 7-hydroxy-3′,5′-dihydroxyisoflavone ( 5), 5,7-dihydroxy-3′,5′-dihydroxyisoflavone ( 6), 2′-hydroxy-3′-methoxygenistein ( 7), as well as hydroisoflavones A–C ( 8– 10) were elucidated by MS and NMR analyses. Compounds 8– 10 feature yet unprecedented types of non-aromatic, hydroxylated B rings, which result from plant isoflavone biotransformation. All new compounds display weak cytotoxic but potent antiproliferative activities. The anti-oestrogenic properties of 8 against MCF-7 human breast cancer cell line (GI 50: 6 μM) is even higher than the reference compound genistein.

Performance of Starter in Yogurt Supplemented with Soy Protein Isolate and Biotransformation of Isoflavones during Storage Period

In this study, soy protein isolate (SPI) (4%, v/w) was supplemented to the yogurt mix to increase the amount of biologically active isoflavone in yogurt (SY). The control yogurt was without any SPI supplementation (USY). The supplementation significantly (P < 0.05) increased the lactose metabolism by the yogurt starter including Lactobacillus delbrueckii ssp. bulgaricus ATCC 11842 (Lb 11842) and Streptococcus thermophilus ST 1342 (ST 1342) during the fermentation process by 4.7%. The starter produced more acetic acid and less lactic acid in SY than that in USY and altered the ratio of lactic and acetic acid during the entire storage period. The viability of both Lb 11842 and ST 1342 in SY was significantly (P < 0.05) lower than that in USY from 14 d of the storage period, however, their concentration still remained high (8.11 to 8.84 log CFU/g). The starter transformed 72.8% of total inactive isoflavone glycosides (IG) to active isoflavone aglycones (IA), increasing the IA content from 1.35 to 15.01 mg/100 g sample. During the storage period, IA concentration slowly rose from 15.02 to 15.51 mg/100 g sample.

Characterization of newly isolatedLactobacillus delbrueckii-like strain MF-07 isolated from chicken and its role in isoflavone biotransformation

Cecal microbiota of chicken was screened for bacteria involved in the biotransformation of isoflavones. A new facultative anaerobic bacterium, capable of deglycosylation of the isoflavone genistin, was isolated and identified as a Lactobacillus delbrueckii-like strain. The isolate MF-07 was Gram-positive, facultatively anaerobic, catalase negative, non-spore-forming, nonmotile and a straight rod. The polyphasic taxonomic data, along with 16S rRNA gene sequence comparison, demonstrated that the isolate MF-07 was most closely related to L. delbrueckii group of the Lactobacillus genus. Considerable amounts of genistein were accumulated with genistin as a substrate within the first 12 h of fermentation. Formononetin and daidzein were not metabolized. The influence of several carbon sources on the growth of the isolate MF-07 and biotransformation of genistin was also investigated. This is the first study in which an anaerobic Lactobacillus bacterium from the chicken intestinal tract that metabolizes genistin to produce its bioactive metabolite was identified and characterized.

Biotransformation of soybean isoflavones by a marine Streptomyces sp. 060524 and cytotoxicity of the products

A marine Streptomyces sp. 060524 capable of hydrolyzing the glycosidic bond of isoflavone glycosides, was isolated by detecting its β-glucosidase activity. 5 isoflavone aglycones were isolated from culture filtrates in soybean meal glucose medium. They were identified as genistein (1), glycitein (2), daidzein (3), 3′,4′,5,7-tetrahydroxyisoflavone (4), and 3′,4′,7-trihydroxyisoflavone (5), based on UV, NMR and mass spectral analysis. The Streptomyces can selectively hydroxylate at the 3′-position in the daidzein and genistein to generate 3′-hydroxydaidzein and 3′-hydroxygenistein, respectively. The Strain biotransformed more than 90% of soybean isoflavone glycosides into their aglycones within 108 h. 3′-hydroxydaidzein and 3′-hydroxygenistein exhibited stronger cytotoxicity against K562 human chronic leukemia than daidzein and genistein.

Biotransformation of soy isoflavones and enhanced cholesterol lowering effect with an oligofructose‐enriched inulin in equol producers

Objective: To assess whether the hypocholesterolemic effect of soy can be enhanced with an oligofructose‐enriched inulin (OF‐IN) by promoting the biotransformation of colonic soy isoflavones (i.e. equol production). Method: 23 hyperlipidemic adults (11M, 12F; 58±7y; LDL‐C, 4. 1±0.7mmol/L) completed three 4‐week phases: OF‐IN (10 g/d) and low‐fat dairy (control), and soy foods (isoflavones, 61 mg/d) with or without OF‐IN (10 g/d). Fasting blood lipids and anthropometrics were measured biweekly. Urine (24h) was collected at baseline and at the end of each phase. Results: A stepwise reduction in TChol:HDL‐C was observed for OF‐IN (0.25±0.13, P=0.08), soy (–0.07±0.08, P=0.41) and soy plus OF‐IN (–0.36±0.14, P=0.02), compared to baseline. Preliminary analysis suggested that this effect was seen most clearly in equol producers (n=7). TChol:HDL‐C for equol producers was 0.09±0.16 on OF‐IN, –0.23±0.14 on soy, and –0.72±0.42 on soy plus OF‐IN, compared to baseline. For non‐equol producers, TChol:HDL‐C was 0.41±0.17, 0.04±0.09, and –0.17±0.08, respectively. Conclusion: Intake of soy in conjunction with OF‐IN resulted in greater improvements in the lipid profile than their intake alone, suggesting a synergistic effect. This association was more prominent in equol producers possibly related to increased biotransformation of soy isoflavones.Funding: Heart and Stroke Foundation of Ontario, ORAFTI Group

Endogenous β-glucosidase and β-galactosidase activities from selected probiotic micro-organisms and their role in isoflavone biotransformation in soymilk

To compare endogenous beta-glucosidases and beta-galactosidases for hydrolysis of the predominant isoflavone glycosides into isoflavone aglycones in order to improve biological activity of soymilk. beta-glucosidase and beta-galactosidase activities of probiotic organisms including Lactobacillus acidophilus ATCC 4461, Lactobacillus casei 2607 and Bifidobacterium animalis ssp. lactis Bb12 in soymilk were evaluated and correlated with the increase in concentration of isoflavone aglycones during fermentation. The concentrations of isoflavone compounds in soymilk were monitored using a Varian model high-performance liquid chromatography (HPLC) with an amperometric electrochemical detector. In all micro-organisms, beta-glucosidase activity was found greater than that of beta-galactosidase. There was an increase in the aglycone concentration with incubation time because of the apparent hydrolytic action on isoflavone glycosides. Aglycone concentration in the soymilk with L. acidophilus 4461, L. casei 2607 and B. animalis ssp. lactis Bb12, increased by 5.37-, 5.52- and 6.10-fold, respectively, after 15 h of fermentation at 37 degrees C. The maximum hydrolytic potential was also observed at 15 h of fermentation for the three micro-organims coinciding with peak activities of the two enzymes. beta-glucosidase activity was more than 15 times higher than beta-galactosidase activity in soymilk for each of the micro-organisms during fermentation. beta-glucosidase played a greater role in isoflavone glycoside hydrolysis. Screening for beta-glucosidase and beta-galactosidase activities among probiotics in soymilk is important for the improvement of biological activity of soymilk and in the selection of micro-organisms for use in the growing industry of functional foods and beverages.

Recognizing Top JFS Papers

Among other things, Thomson's ISI Web of Knowledge is responsible for bringing the Impact Factor into mainstream use in the academy and the journal-publishing world. I have expressed on numerous occasions that I am skeptical of the Impact Factor and its influence on where authors/researchers choose to publish. However, that is a subject for further discourse in a future editorial. For this editorial I am selecting from other data that Thomson also supplies: citation data to specific papers. The Peer-Reviewed Communications Committee suggested that we identify and recognize some of the papers that have had a particularly significant effect on our knowledge by being cited by other researchers. I took up this challenge and plunged into the ISI Web of Science citation data for the Journal of Food Science. I looked at data from 2003 since that would give some time for the papers to be out there and be cited. It is my intention to do this annually immediately following the IFT Annual Meeting so that we can congratulate the authors and encourage other authors to submit their manuscripts to JFS. As of June, 2006, there were 346 citations to the top 40 papers that were cited from publishing year 2003, an average impact factor of 8.65! In the top 40 papers by citation numbers, there were 13 in cood chemistry, 10 in Food engineering, 8 in sensory and nutritive properties, 6 in food microbiology and 3 in concise reviews. Given the number of papers published in each section, one might expect such a distribution of citation excellence. The number 1 cited paper for 2003 is from the Food Chemistry section: “A Novel Technique for Limitation of Acrylamide Formation in Fried and Baked Corn Chips and in French Fries,” authored by MY Jung, DS Choi, and JW Wu of the Dept. of Food Science and Technology and Biotechnology at Woosuk Univ., Samrea, Jeonbuk, South Korea [JFS 68(4):1287-90]. This paper has been cited 46 times! The second most cites was a paper cited 15 times, and the least cited in the top 40 was cited 6 times. Congratulations to Drs. Jung, Choi and Wu for their excellent paper. The top cited papers in the other sections of JFS are: Food Engineering: “Oxidative Stability, Structure, and Physical Characteristics of Microcapsules Formed by Spray Drying of Fish Oil with Protein and Dextrin Wall Materials,” by Y Kagami, S Sugimura, N Fujishima, K Matsuda, T Kometani, and Y Matsumura [JFS 68(7):2248-55]. Food Microbiology: “Biotransformation of Isoflavones by Bifidobacteria in Fermented Soymilk Supplemented with D-Glucose and L-Cysteine,” by D Tsangalis, JF Ashton, AEJ McGill, and NP Shah [JFS 68(2):623-31]. Sensory and Nutritive Properties: 2 papers tied: “Effect of Storage Conditions on Quality Characteristics of Bologna Sausages Made with Citrus Fiber,” by JM Fernandez-Gines, J Fernandez-Lopez, E Sayas-Barbera, E Sendra, and JA Perez-Alvarez [JFS 68(2):710-5], and “Dual Fortification of Salt with Iodine and Encapsulated Iron Compounds: Stability and Acceptability Testing in Morocco and Cote d'Ivoire,” by R Wegmuller, MB Zimmerman, and RF Hurrell [JFS 68(6):2129-35]. Concise Reviews: “Active Packaging Technologies with an Emphasis on Antimicrobial Packaging and its Application,” by P Suppakal, J Miltz, K Sonneveld, and SW Bigger [JFS 68(2):408-20]. Thank you to the authors for submitting their papers to JFS. I invite you to submit your research to JFS. Maybe I'll be citing your paper in this column in three years! Have a great summer

Biotransformation of Isoflavones by the Larvae of the Common Cutworm (Spodoptera litura)

Biotransformation of the 5,7,4'-trimethoxyisoflavone (1), 6,7,4'-trimethoxyisoflavone (2), and 7,4'-dimethoxyisoflavone (3) by insects, Spodoptera litura was investigated. Compound 1 was transformed to 5-hydroxy-7,4'-dimethoxyisoflavone (4), 7-hydroxy-5,4'-dimethoxyisoflavone (5) and 4'-hydroxy-5,7-dimethoxyisoflavone (6) by S. litura. Compounds 2 and 3 were hardly metabolized by S. litura. This suggested that compound 1 was converted to compounds 4, 5 and 6 by demethylation at the C-5, C-7 and C-4' position, respectively.