The heterocyclic aromatic amine (HAA) 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is converted into 7-hydroxy-5-methyl-3-phenyl-6,7,8,9-tetrahydropyrido[3',2':4,5]imidazo[1,2-a]pyrimidin-5-ium chloride (PhIP-M1) via a chemical reaction with 3-hydroxypropionaldehyde or acrolein derived from glycerol by reuterin producing gut bacteria. Because it is unknown whether this reaction also applies to other HAAs, seven foodborne HAAs (2-amino-9H-pyrido[2,3-b]indole (AαC), 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1), 2-amino-3-methyl-3H-imidazo[4,5-f]quinoline (IQ), 2-amino-3,4-dimethyl-3H-imidazo[4,5-f]quinoline (MeIQ), 2-amino-3,8-dimethyl-3H-imidazo[4,5-f]quinoxaline (MeIQx), 9H-pyrido[3,4-b]indole (norharman), and 1-methyl-9H-pyrido[3,4-b]indole (harman)) were anaerobically incubated with Lactobacillus reuteri DSM 20016 in the presence of glycerol. The extent of conversion, as analyzed by HPLC-DAD/FLD, was dependent on both the studied HAAs and the glucose/glycerol ratio, indicating reuterin to be involved in HAA metabolism. Based on HRMS analyses, PhIP-M1-type metabolites were detected for AαC, Trp-P-1, IQ, MeIQ, MeIQx, harman, and norharman. In the case of AαC, this was confirmed by metabolite isolation (AαC-M8, 2,3,4,10-tetrahydro-1H-indolo[2,3-b][1,8]naphthyridin-2-ol) and one- (H) and two-dimensional (HSQC, HMBC, COSY, DOSY) NMR spectroscopy. In addition, based on HRMS and/or NMR spectroscopy, a new type of HAA metabolite, resulting from the reaction with two molecules of 3-hydroxypropionaldehyde or acrolein, is hypothesized for AαC, Trp-P-1, IQ, MeIQ, and MeIQx.

Thymus carnosus Boiss. is a near-threatened species, and, as for many species, its potential for medicinal purposes may be lost if measures towards plant protection are not taken. A way of preserving these species is to increase knowledge about their medicinal properties and economic potential. Thus, with the objective of studying the potentiality of introducing T. carnosus as a crop, the stability of the phytochemical profile of T. carnosus was studied during a period of three years by comparing the phytochemical profile of extracts obtained from plants harvested in two different edaphoclimatic locations, as well as by comparing the respective bioactivities, namely, antioxidant, antidiabetic, antiaging, and neuroprotective activities. It was reported, for the first time, the effect of annual variation and geographic location in the phytochemical composition of aqueous decoction and hydroethanolic extracts of T. carnosus. In addition, the presence of two salvianolic acid B/E isomers in T. carnosus extracts is here described for the first time. Despite the variations in phytochemical composition, according to harvesting location or year, T. carnosus extracts maintain high antioxidant activity, assessed by their capacity to scavenge ABTS•+, •OH , NO•, O2•− radicals, as well as to prevent β-carotene bleaching. All extracts presented significant potential to inhibit acetylcholinesterase (AChE), tyrosinase, and α-glucosidase, denoting neuroprotective, anti-aging, and anti-diabetic potential. In conclusion, the vegetative stage and location of harvest are key factors to obtain the maximum potential of this species, namely, a phytochemical profile with health benefit bioactivities.

The partial substitution of starch with dietary fiber (DF) in extruded ready-to-eat texturized (RTE) cereals has been suggested as a strategy to reduce the high glycemic index of these food products. Here, we study the impact of extrusion processing on pure chokeberry (Aronia melanocarpa) pomace powder (CPP) rich in DF and polyphenols (PP) focusing on the content and profile of the DF fractions, stability of PP, and techno-functional properties of the extrudates. Using a co-rotating twin-screw extruder, different screw speeds were applied to CPP with different water contents (cw), which resulted in specific mechanical energies (SME) in the range of 145–222 Whkg−1 and material temperatures (TM) in the range of 123–155 °C. High molecular weight soluble DF contents slightly increase with increasing thermomechanical stress up to 16.1 ± 0.8 g/100 g dm as compared to CPP (11.5 ± 1.2 g/100 g dm), but total DF (TDF) contents (58.6 ± 0.8 g/100 g dm) did not change. DF structural analysis revealed extrusion-based changes in the portions of pectic polysaccharides (type I rhamnogalacturonan) in the soluble and insoluble DF fractions. Contents of thermolabile anthocyanins decrease linearly with SME and temperature from 1.80 ± 0.09 g/100 g dm in CPP to 0.24 ± 0.06 g/100 g dm (222 Whkg−1, 155 °C), but phenolic acids and flavonoids appear to be largely unaffected. Resulting techno-functional (water absorption and water solubility) and physical properties related to the sensory characteristics (expansion, hardness, and color) of pure CPP extrudates support the expectation that granulated CPP extrudates may be a suitable food ingredient rich in DF and PP.

Xyloglucans are the dominant hemicelluloses in the primary cell wall of dicotyledonous plants, fulfilling numerous functions. However, routine methods of cell wall analytical chemistry such as methylation analysis are time-consuming and often not adequate to capture the structural diversity of xyloglucans. Here, a xyloglucan profiling method based on the enzymatic release of xyloglucan oligosaccharides by a xyloglucan-specific endo-β-(1→4)-glucanase and subsequent analysis of these oligosaccharides by high-performance anion-exchange chromatography (HPAEC) with parallel pulsed amperometric and mass spectrometric detection was developed. For this purpose, a set of 23 authentic xyloglucan oligosaccharides was generated, structurally characterized by mass spectrometry and NMR spectroscopy, and established as analytical standard compounds. Coupling of HPAEC with parallel electrochemical and MS detection was demonstrated to be an excellent tool to analyze xyloglucan-derived oligosaccharides. The applicability of the method was demonstrated by characterizing the xyloglucan architecture from a set of nine economically relevant food plants from the botanical orders Caryophyllales (rhubarb, buckwheat, amaranth, and quinoa), Cucurbitales (Hokkaido squash), Laurales (avocado), Myrtales (pomegranate), and Sapindales (mango and orange) for the first time. In future studies, this method can ideally be used to monitor structural alterations of xyloglucans as a result of genetic engineering, plant/tissue maturation, and processing of plant material.