Maria V. Chandra-Hioe

Probiotic-loaded microcapsule system for human in situ folate production: Encapsulation and system validation

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±26μg·L-1 of folate, during 10h, and was encapsulated in the APACM. APACM proved its capacity to protect LLC against the harsh conditions of a simulated digestion maintaining a viable concentration of 6logCFU·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 2g·L-1 of lactic acid was achieved through encapsulation of L. plantarum, after 20h. 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.

Evaluating folate extraction from infant milk formulae and adult nutritionals: Enzymatic digestion versus enzyme-free heat treatment

This study compares enzymatic treatments to release folic acid (FA) and endogenous 5-methyltetrahydrofolate (5-MTHF) from infant milk formulae with enzyme-free heat extraction. The limits of detection and quantitation of FA were 1.4ng/mL and 3.1ng/mL, respectively; 7.5ng/mL and 16.2ng/mL for 5-MTHF. Absolute mean recoveries were 85% (FA) and 95% (5-MTHF). The RSD of the within-run variability was 6% and the inter-day variability was 8%. Averaged measurements of FA and 5-MTHF in SRM-1849a were within the certified value range. Analysed folate levels in three brands were greater than label values, because of inherently high 5-MTHF occurring in samples. The results indicate that enzyme-free heat treatment prior to UPLC-MS/MS analysis gives better sensitivity and reduces chromatographic interferences for the determination of FA and 5-MTHF in milk formulae than enzymatic treatments. Enzyme-free heat treatment is more compatible with UPLC-MS/MS than folate extraction techniques involving the addition of enzymes to milk.

Voluntary fortification of breakfast cereals with folic acid: contribution to dietary intake in Australia

Abstract Ready-to-eat breakfast cereals have been voluntarily fortified with folic acid since 1995, with the purpose of reducing the prevalence of neural tube defects in utero. Using data from the recent Australian Health Survey, this study aimed to estimate folate intake from one serving of breakfast cereals (median amount). Various commercial brands were purchased in 2002 (n = 19) and in 2014 (n = 14); folate was determined by microbiological assay and high-pressure liquid chromatography (HPLC). Total folate (μg/100 g) in 2002 and 2014 selections were 144–633 and 147–564, respectively, and mostly comparable to nutrition labels. Folic acid (2014 selection) using HPLC, ranged from 85 to 411 μg/100 g. Intake of 51 g cereals/serving by individuals ≥2 years could contribute 75–288 μg dietary folate equivalent. It seems that folic acid intake among children (2–3 years) exceeds the recommended dietary intake, when certain brands of breakfast cereals are consumed. Accordingly, the benefits and potential detrimental effects of the voluntary fortification need to be further explored.

Thiamin: Properties and Determination

Thiamine (vitamin B 1 ), an essential water-soluble vitamin, exists as free and phosphorylated vitamers. All vitamers are sensitive to pH, heat, UV, and oxidation, making thiamine unstable. Fluorometric spectrophotometry, which takes advantage of thiochromes fluorescent properties, has traditionally been the method of choice for measuring total thiamine. Thiamine is usually released from its protein-bound forms and dephosphorylated using acid hydrolysis, enzymatic digestion, and solid-phase extraction before analysis. More recently, as analytical technologies have evolved, liquid chromatography has permitted thiamine vitamers to be separated, identified, and individually quantified using fluorescence, UV, or mass spectrometry detection.