Food-grade Samples Research Articles

Nutritional and Phyto-Therapeutic Value of the Halophyte Cladium mariscus L. (Pohl.): A Special Focus on Seeds.

This work searched for the phyto-therapeutic potential and nutritional value of seeds from the halophyte Cladium mariscus L. (Pohl.), aiming at its use as a source of bioactive ingredients for the food industry. Hence, the nutritional profile, including minerals, of seeds biomass was determined; food-grade samples were prepared, and their phytochemical fingerprinting assessed. Extracts were evaluated for in vitro antioxidant potential, inhibitory capacity towards enzymes related to neuroprotection, diabetes, and hyperpigmentation, and anti-inflammatory properties, along with a toxicological assessment. Sawgrass seeds can be considered a proper nutritional source with a good supply of minerals. All extracts had a high level of total phenolics (65.3-394.4 mg GAE/g DW) and showed a chemically rich and diverse profile of metabolites that have several biological properties described (e.g., antioxidant, anti-inflammatory). Extracts had no significant toxicity (cell viabilities > 80%) and were overall strong antioxidants (particularly at radical scavenging and reducing iron), effective tyrosinase inhibitors (55-71 mg KAE/g DW), showed anti-inflammatory properties (30-60% NO decrease), and had moderate capacity to inhibit enzymes related to neuroprotection (AChE 3.7-4.2, BChE 4.3-6.0 mg GALE/g DW) and diabetes (α-glucosidase 1.0-1.1, α-amylase 0.8-1.1 mmol ACAE/g). Altogether, results suggest that sawgrass seeds have the potential to be exploited as a new food product and are a reservoir of bioactive molecules with prospective applications as ingredients for value-added, functional, and/or preservative food products.

Characterization of food-grade titanium dioxide: the presence of nanosized particles.

Titanium dioxide (TiO2) is widely used in food products, which will eventually enter wastewater treatment plants and terrestrial or aquatic environments, yet little is known about the fraction of this TiO2 that is nanoscale, or the physical and chemical properties of TiO2 that influence its human and environmental fate or toxicity. Instead of analyzing TiO2 properties in complex food or environmental samples, we procured samples of food-grade TiO2 obtained from global food suppliers and then, using spectroscopic and other analytical techniques, quantified several parameters (elemental composition, crystal structure, size, and surface composition) that are reported to influence environmental fate and toxicity. Another sample of nano-TiO2 that is generally sold for catalytic applications (P25) and widely used in toxicity studies, was analyzed for comparison. Food-grade and P25 TiO2 are engineered products, frequently synthesized from purified titanium precursors, and not milled from bulk scale minerals. Nanosized materials were present in all of the food-grade TiO2 samples, and transmission electron microscopy showed that samples 1-5 contained 35, 23, 21, 17, and 19% of nanosized primary particles (<100 nm in diameter) by number, respectively (all primary P25 particles were <100 nm in diameter). Both types of TiO2 aggregated in water with an average hydrodynamic diameter of >100 nm. Food-grade samples contained phosphorus (P), with concentrations ranging from 0.5 to 1.8 mg of P/g of TiO2. The phosphorus content of P25 was below inductively coupled plasma mass spectrometry detection limits. Presumably because of a P-based coating detected by X-ray photoelectron spectroscopy, the ζ potential of the food-grade TiO2 suspension in deionized water ranged from -10 to -45 mV around pH 7, and the iso-electric point for food-grade TiO2 (<pH 4) was significantly lower than that for P25. The presence of other elements in or on the TiO2 (Si content of 0.026-0.062% and Al content of 0.0006-0.810%) was also different from the case for P25 and would influence the environmental fate of TiO2. X-ray diffraction analysis confirmed the presence of anatase and/or rutile in the food-grade materials, and although the presence of amorphous TiO2 could not be ruled out, it is unlikely on the basis of Raman analysis. The food-grade TiO2 was solar photoactive. Cationic dyes adsorbed more readily to food-grade TiO2 than P25, indicating very different potentials for interaction with organics in the environment. This research shows that food-grade TiO2 contains engineered nanomaterials with properties quite different from those of P25, which has previously been used in many ecotoxicity studies, and because food-grade TiO2 is more likely than P25 to enter the environment (i.e., potentially higher exposure levels), there is a need to design environmental (and human) fate and toxicity studies comparing food-grade to catalytic TiO2.