Browsing by Author "Arcot, Jayashree"
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- Determination of Folates in RicePublication . Delgado, Inês; Chandra-Hioe, Veronica; André, Catarina; Mota, Carla; Arcot, JayashreeA method was developed to determined folic acid (FA), 5-methyltetrahydrofolate (5-MTHF), tetrahydrofolate (THF), 5-Formyltetrahydrofolate (5-CHOTHF) and 10-Formyltetrahydrofolate (10-CHOTHF) using Ultra Performance Liquid Chromatography with a Mass Spectrometer Detector (UPLC-MS). The method was developed according to the literature with different transitions. These transitions were selected for the most intense daughter ion. The parent ion, fragment ion and the conditions are described in table 1. The extraction method included 3-enzimes and SPE to clean the matrix effects. SPE involved several columns but was Oasis form Waters that provided better results. Labeled internal standard were used. 13C-FA was used for FA, 5-CHOTHF and 10-CHOTHF while 13C-5-MTHF was used for 5-MTHF and THF. Analytes were separated thought an Acquity HSS T3 from Waters with water: acetonitrile gradient for 9 minutes and analyzed by negative ion electrospray (ESI-) Multiple Reaction Monitoring (MRM). Three types of rice were tested and values were confirmed with SRM 1849a. This Certified Reference Material has values for FA and 5-MTHF determined by LC/MS/MS.Comparing the results obtained for the reference material analysed with the values present in the certificate we can conclude that the extraction method and chromatographic conditions are suitable for our samples. Brown rice presents the highest content in 5-MTHF and FA. The lowest content of all analysed folate species was found in the rice bran. Brown rice seems to be a better source of folate than whole grain rice, especially for folic acid and 5-methyltetrahydrofolate. However for 10-Formyltetrahydrofolate whole brain rice has a bigger content than brown rice.
- Folates in quinoa (Chenopodium quinoa), amaranth (Amaranthus sp.) and buckwheat (Fagopyrum esculentum): Influence of cooking and maltingPublication . Motta, Carla; Delgado, Inês; Matos, Ana Sofia; Gonzales, Gerard Bryan; Torres, Duarte; Santos, Mariana; Chandra-Hioe, Maria V.; Arcot, Jayashree; Castanheira, IsabelEffects of processing on the contents of five folate vitamers in quinoa, amaranth and buckwheat were analysed using a trienzymatic extraction method followed by LC–MS/MS. Total folate (TF) content, corresponding to the sum of folic acid (FA), 5-methyltetrahydrofolate (5-MTHF) and 10-formyltetrahydrofolate (10-CHOTHF) expressed as folic acid equivalent, in raw quinoa, amaranth and buckwheat were 309 ± 8.07, 228 ± 24.2 and 153 ± 12.4 μg/100 g dw, respectively, being dominantly 5-MTHF. Boiling and steaming reduced the TF in amaranth by 58% and 22%, respectively, whereas up to a 10–15% increase was observed in quinoa. Boiling and steaming did not significantly alter the TF content in buckwheat although significant changes were observed in some individual folate vitamers. Malting, on the other hand significantly increased TF content in amaranth by 21% (276 ± 14.2 μg/100 g dw) and buckwheat by 27% (193 ± 20.0 μg/100 g dw), whereas no significant change in quinoa was observed. Based on the EFSA recommendations, a portion of amaranth and quinoa (either boiled, steamed or malted) may contribute up to more than 25% of the dietary reference value for folates, whereas buckwheat may contribute only 14% when cooked and 19% when malted. Results demonstrate that quinoa, amaranth and buckwheat are good sources of folates, regardless of processing.
- Probiotic-loaded microcapsule system for human in situ folate production: Encapsulation and system validationPublication . Ramos, Philippe E.; Abrunhosa, Luis; Pinheiro, Ana; Cerqueira, Miguel; Motta, Carla; Castanheira, Isabel; Chandra-Hioe, Maria V.; Arcot, Jayashree; Teixeira, José A.; Vicente, António A.This study focused on the use of a new system, an alginate|Ɛ-poly-L-lysine| alginate|chitosan microcapsule (APACM), able to immobilize a folate-producing probiotic, Lactococcus lactis ssp. cremoris (LLC), which provides a new approach to the utilization of capsules and probiotics for in situ production of vitamins. LLC is able to produce 95.25±26 μg·L−1 of folate, during 10 h, andwas encapsulated in the APACM. APACMproved its capacity to protect LLC against the harsh conditions of a simulated digestion maintaining a viable concentration of 6 log CFU·mL−1of LLC. A nutrients exchange capacity test, was performed using Lactobacillus plantarum UM7, a high lactic acid producer was used here to avoid false negative results. The production and release of 2 g·L−1 of lactic acidwas achieved through encapsulation of L. plantarum, after 20 h. The adhesion of APACM to epithelial cells was also quantified, yielding 38% and 33% of capsules adhered to HT-29 cells and Caco-2 cells, respectively.