Antioxidant capacity is related with compounds capable of protecting a biological system against the potentially harmful effect of processes or reactions involving reactive oxygen and nitrogen species (ROS and RNS). These protective effects of antioxidants have received increasing attention within biological, medical, nutritional, and agrochemical fields and resulted in the requirement of simple, convenient, and reliable antioxidant capacity determination methods. Many methods which differ from each other in terms of reaction mechanisms, oxidant and target/probe species, reaction conditions, and expression of results have been developed and tested in the literature. In this review, the methods most widely used for the determination of antioxidant capacity are evaluated, presenting the general principals, recent applications, and their strengths and limitations. Analysis conditions, substrate, and antioxidant concentration should simulate real food or biological systems as much as possible when selecting the antioxidant capacity method. The total antioxidant capacity value should include methods applicable to both lipophilic and hydrophilic antioxidants, with regards the similarity and differences of both hydrogen atom transfer and electron transfer mechanism. The methods including various ROS/RNS also have to be designed to comprehensively evaluate the antioxidant capacity of a sample.
Bovine β-casein is a highly polymorphic protein, with A1 and A2 representing the most frequent variants identified in Western cattle breeds. Depending on the presence of histidine or proline at position 67 of the sequence, β-casein variants can be grouped in two families: those within the A1 family (A1-like), possessing histidine, and those within the A2 family (A2-like), with proline. Upon gastrointestinal digestion, specific peptides endowed with opioid-like activity, called β-casomorphins, may be released from β-casein. Interestingly, the presence of histidine at position 67 seems to favor the release of a peptide called βcasomorphin-7, which has been proposed as a risk factor for the development of some non-communicable diseases. Based on these assumptions, the A2 milk market (i.e., a milk containing only A2 β-casein) is spreading worldwide. In the scientific community, however, the impact of A1 β-casein on human health remains a matter of debate. Aim of the present study was to develop an analytical method based on mass spectrometry to distinguish between bovine A2 milk and commercial milk, typically composed of a mixture of A1-like and A2-like β-casein. By enzymatically hydrolyzing β-casein, a specific peptide containing the critical mutation at position 67 has been identified. This peptide constituted a suitable marker to determine the presence of A1-like and/or A2-like β-casein in bovine milk. The developed method proved appropriate for the detection of βcasein in real milk samples; we estimated that contaminations of A2 milk with up to 1% commercial milk could be successfully detected.
Summary
Endocrine disrupting chemicals (EDCs) can cause adverse effects in individuals and their offspring. In 2017 and 2018, we performed a survey on representative samples of Austrian drinking water (n = 20), groundwater (n = 22), and surface water (n = 12), the latter including bathing water (n = 5) and rivers (n = 7). We analyzed 54 samples for 28 parameters, including estrogens, polybrominated diphenylethers (PBDEs), phthalates, perfluoroalkyl substances, alkylphenols, bisphenol A and triclosan, correlating to 1512 measurements. In 39 of the 54 samples (72.2%), at least one endocrine disrupting or potentially disrupting chemical was found at or above the limit of quantification. None of the samples yielded estrogens or triclosan in detectable levels. Bisphenol A (BPA) was detected in 4 (20.0%) samples of drinking water, in 1 (4.5%) groundwater sample, and in 1 (20%) bathing water sample, with a maximum concentration of 0.021 μg/l found in one drinking water. Two drinking water samples yielded BPA in concentrations above the limit value of 0.01 μg/l, recently proposed by the European Commission for drinking water. Therefore, the ultimate public health goal must be to further reduce and restrict the production of EDCs and therewith decrease and eventually eliminate the contamination of drinking water resources.
According to ILSI Europe policies, the Expert Group is composed by at least 50% of external nonindustry members. Once the expert group was formed, the research project was handed over to them to independently refine the research question. Subsequently, the expert group carried out the work, that is, collecting/analyzing data/information and writing the scientific paper independently of other activities of the task force. The research reported is the result of a scientific evaluation in line with ILSI Europe's framework to provide a precompetitive setting for public-private
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