Optimization and Application of FL-HPLC for Folates Analysis in 20 Species of Mediterranean Wild Vegetables

A Comparative Analysis of Folate and Mineral Contents in Freshly Squeezed and Commercial 100% Orange Juices Available in Europe

BACKGROUND

Orange juices are widely known for their organoleptic characteristics and potential health benefits derived from their nutritional and functional composition.

OBJECTIVES

The aim of this work was to provide comprehensive, up-to-date information on the content of folates and some minerals (Ca, K, Mg, Fe, Mn, and Zn) present in different fresh and commercial orange juices available in the European market, including juices from concentrate (FC) and not from concentrate (NFC).

METHODS

A total of twenty-five juice samples were selected, comprising the most purchased types of commercial juices from France, the United Kingdom (UK), Germany, and Spain, and four fresh squeezed juices (FSJ) made from Spanish oranges. In FSJ, nutrient stability during storage time (0-48 h) was also assessed.

RESULTS

Folate concentration was highly variable between commercial samples, with higher contents in FSJ and NFC samples, followed by FC juices. Regarding mineral content, FSJ showed significant differences with FC (except for Mg) and NFC juice samples (except for Ca and Mg), while FC and NFC had similar mineral profiles, except for Ca. Storage time had no significant impact on FSJ folates and minerals.

CONCLUSIONS

Among commercial juices, the NFC category generally showed the highest content of folates, K, Mg, and Fe, whereas FC juices showed the highest contents of Ca, Mn, and Zn. Some commercial juices met the legal use conditions for a "Source of folate" claim, whereas both commercial and fresh juices met the conditions for a "Source of potassium" claim, according to European and UK regulations.

Determination of the effect of germination on the folate content of the seeds of some legumes using HPTLC-mass spectrometry-multivariate image analysis

Legumes are the main sources of folates which are not synthesized in the human body. The five folate species: 5-methyl tetrahydrofolate, tetrahydrofolate, pteroyl glutamate, 5-formyl tetrahydrofolate and 10-formyl tetrahydrofolate were quantitatively determined in legumes seeds and sprouts by a newly developed and validated high performance thin layer chromatography method. High resolution plate imaging hyphenated to mass spectrometry was exploited for fingerprint analysis of tested samples. Results indicated that germination of all seeds resulted in a 2.5-4 fold increase in the content of total folates as well as the individual vitamers. The total amount of folate reached a maximum on the fifth day in the case of black-eyed peas (861 μg/100 g Fresh Weight), white beans (755 μg/100 g FW) and brown lentils (681 μg/100 g FW). 5-CH₃-H₄ folate was found to be the most dominating folate species reaching its maximum content in day 5 sprouts of black-eyed peas (490 μg/100 g FW).

Assessment of Health Claims Related to Folic Acid in Food Supplements for Pregnant Women According to the European Regulation

Pregnant women are a vulnerable group with increased nutritional requirements. The daily intake of folic acid, a crucial vitamin for embryonic development, must be reinforced through supplementation, as sometimes diets are not well equilibrated. As consumers increasingly rely on food supplements, it is vital to properly inform them about the health benefits provided by supplements' consumption to ensure their safe use. The objective of this work was to assess the compliance level of health claims related to folic acid in food supplements commercialized in Spain according to the European regulation. Authors performed (1) a review of health-related claims approved for folic acid in Europe, (2) a market research of food supplements commercialized in Spain with those claims, and (3) a selection of food supplements for chemical analysis in the lab to assess these claims. The results showed that nine health-related claims are currently approved for folic acid in Europe. The analytical results for folic acid content in the selected samples were consistent with the declared values and within the tolerance ranges established in the European Guidance document. All samples included accurate dosages and met the legal requirements (European Regulations 1924/2006, 432/2012, 1169/2011) for all approved claims for folic acid.

Nutritional and Phytochemical Composition of Mediterranean Wild Vegetables after Culinary Treatment

Studies are scarce on the nutritional and phytochemical composition of wild edible Mediterranean plants after culinary processing. This work provides the nutritional composition after culinary treatment (including dietary fiber and mineral composition) and bioactive compounds (folates, vitamin C and organic acids) of wild Rumex pulcher L., Silene vulgaris (Moench) Garcke. leaves, and wild Asparagus acutifolius L., Bryonia dioica Jacq., Humulus lupulus L., Tamus communis L. young shoots. Shoots better preserved their nutrients than leaves, due to their different tissue structure. Fresh and cooked wild greens present high dietary fiber values, and remained at remarkable levels after boiling. Na, K, Mg and Zn were lost in about 50% due to culinary processing, while Ca, Cu, Fe and Mn were more stable. Boiled leaves of S. vulgaris remained as a good Mn source. A portion of 100 g of most of the cooked analyzed species could cover a relevant percentage of the daily requirement of folates (R. pulcher and A. acutifolius providing more than 80%) and vitamin C (T. communis and A. acutifolius providing more than 35%).

Assessment of gut microbiota fecal metabolites by chromatographic targeted approaches

Gut microbiota, the specific microbial community of the gastrointestinal tract, by means of the production of microbial metabolites provides the host with several functions affecting metabolic and immunological homeostasis. Insights into the intricate relationships between gut microbiota and the host require not only the understanding of its structure and function but also the measurement of effector molecules acting along the gut microbiota axis. This article reviews the literature on targeted chromatographic approaches in analysis of gut microbiota specific metabolites in feces as the most accessible biological matrix which can directly probe the connection between intestinal bacteria and the (patho)physiology of the holobiont. Together with a discussion on sample collection and preparation, the chromatographic methods targeted to determination of some classes of microbiota-derived metabolites (e.g., short-chain fatty acids, bile acids, low molecular masses amines and polyamines, vitamins, neurotransmitters and related compounds) are discussed and their main characteristics, summarized in Tables.

Folic acid, minerals, amino-acids, fatty acids and volatile compounds of green and red lentils. Folic acid content optimization in wheat-lentils composite flours

The advanced biochemical characterisation of green, red lentil and wheat flours was performed by assessing their folic acid content as well as individual minerals, amino acids, fatty acids and volatile compounds. Moreover, a nutritionally improved wheat-lentil composite flour, with a content of 133.33 μg of folic acid/100 g, was proposed in order to assure the folic acid daily intake (200 μg) for an adult person. The wheat and lentil flours percentages used for the composite were calculated by using the equations for total material balance and folic acid content material balance. Bread was selected as model food for the composite flour due to its high daily intake (~ 250 g day^-1) and to its great potential in biofortification. By this algorithm, two composite flours were developed, wheat-green lentil flour (22.21-77.79%) and wheat-red lentil flour (42.62-57.38%), their advanced biochemical characteristics being predicted based on the determined compositions of their constituents. The baking behaviour of the new developed wheat-lentils composite flours with optimised folic acid content was tested. In order to objectively compare the bread samples, texture profile analysis was considered the most relevant test. A good baking behaviour was observed for the wheat-red lentil bread, while for the wheat-green lentil composite flour, encouraging results were obtained.

Wild Fragaria vesca L. fruits: a rich source of bioactive phytochemicals

Wild F. vesca fruits and the corresponding infusions could be potentially applied in functional foods (infusions) and/or nutraceuticals/pharmaceutical formulations (hydromethanolic extracts).