Oxidative stress has been identified as the root cause of the development and progression of several diseases. Supplementation of exogenous antioxidants or boosting endogenous antioxidant defenses of the body is a promising way of combating the undesirable effects of reactive oxygen species (ROS) induced oxidative damage. Plants have an innate ability to biosynthesize a wide range of non-enzymatic antioxidants capable of attenuating ROS- induced oxidative damage. Several in vitro methods have been used to screen plants for their antioxidant potential, and in most of these assays they revealed potent antioxidant activity. However, prior to confirming their in vivo therapeutic efficacy, plant antioxidants have to pass through several physiopharmacological processes. Consequently, the findings of in vitro and in vivo antioxidant potential assessment studies are not always the same. Nevertheless, the results of in vitro assays have been irrelevantly extrapolated to the therapeutic application of plant antioxidants without undertaking sufficient in vivo studies. Therefore, we have briefly reviewed the physiology and redox biology of both plants and humans to improve our understanding of plant antioxidants as therapeutic entities. The applications and limitations of antioxidant activity measurement assays were also highlighted to identify the precise path to be followed for future research in the area of plant antioxidants.

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Significance of antioxidant potential of plants and its relevance to therapeutic applications.

Measurement of antioxidant activity

Essential oils are complex mixtures isolated from aromatic plants which may possess antioxidant and anti-inflammatory activities of interest in thye food and cosmetic industries as well as in the human health field. In this work, a review was done on the most recent publications concerning their antioxidant and anti-inflammatory activities. At the same time a survey of the methods generally used for the evaluation of antioxidant activity and some of the mechanisms involved in the anti-inflammatory activities of essential oils are also reported.

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Antioxidant and anti-inflammatory activities of essential oils: a short review.

The purpose of this review is to give the reader a thorough background to the fundamentals and applications of pressurized hot water extraction (PHWE) for the analysis of bioactive compounds. We summarize the field in the period 2009-14, and include fundamentals of water as a solvent: equipment; method optimization; applications; coupling; and, future prospects. We highlight that solvent properties of water are tunable by changing the temperature, particularly self-ionization, dielectric constant, viscosity, diffusivity, density and surface tension. Furthermore, important aspects to consider are the risk of degradation of the analytes and other potential reactions, such as hydrolysis, caramelization and Maillard reactions that may lead to erroneous results. For the extraction of bioactive compounds, we report PHWE methods based on using water of 80-175 degrees C and short extraction times. In conclusion, PHWE provides advantages over conventional extraction methods, such as being "greener", faster and more efficient. (C) 2015 The Authors. Published by Elsevier B.V. (Less)

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Pressurized hot water extraction of bioactives

At the end of the class, students will be able to answer the following questions: • What is organic agriculture? • Where do I go to get certification in organic agriculture? • How can I get more information about organic agriculture? What is organic? • The term " organic " is not synonymous to the terms " natural " or " eco-friendly. " • The label " natural " on foodstuff does not guarantee complete adherence to organic practices as defined by a law. • Produce food of high quality in sufficient quantity • Maintain biological diversity within the farming system • Maintain long-term soil fertility • Rely on renewable resources in locally organized agricultural systems • Minimize pollution and protect the environment What is allowed in organic crop production? • New varieties of crops and agricultural technologies • Crop rotations, cover crops and natural-based products that maintain soil fertility • Biological, cultural and physical methods to limit pest expansion and increase population of beneficial insects

英国有机农业（Organic farming）的新举措

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.

Review of methods to determine antioxidant capacities.

To facilitate the international food trade as well as to protect consumers from exposure to unacceptable pesticide residue levels, Codex Alimentarius Commission, European Union, and National Authorities set maximum residue limits for different food commodities. The control of pesticide residues at national and international level requires reliable and comparable analytical data that can be obtained by applying validated methods and implementing an effective internal quality control and quality assurance system in the testing laboratories. For the correct interpretation of the analytical results, measurement uncertainty should be estimated. Pesticide residue analysis includes two main steps: sampling performed outside of the laboratory and laboratory operations comprising of sample preparation, sample size reduction, sample processing, extraction, cleanup, and chromatographic determination. By taking into consideration the contribution of the individual steps to the overall uncertainty of the results, the analytical procedures can be optimized to fit for the purpose of the analysis with minimum cost. The scope of this paper is to review major steps of pesticide residue analysis in the light of current developments, to highlight the importance of identification and estimation of the uncertainties associated with the results, to describe suitable methods for their estimation, and to summarize the contribution of each step to the combined uncertainty.

An Overview on Steps of Pesticide Residue Analysis and Contribution of the Individual Steps to the Measurement Uncertainty

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.

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Occurrence of chemicals with known or suspected endocrine disrupting activity in drinking water, groundwater and surface water, Austria 2017/2018

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 β–casomorphin-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 β-casein in real milk samples; we estimated that contaminations of A2 milk with up to 1% commercial milk could be successfully detected.

Development of an LC-MS Method for the Identification of β-Casein Genetic Variants in Bovine Milk

An agar based film was prepared and incorporated with an antibacterial agent, ZnO (Zinc Oxide). Zn O was prepared by a reflux method and the product was characterized by x-ray diffraction (XRD) and scanning electron microscopy (SEM). Synthesis of the agar based film and incorporation of the ZnO particles in the film was performed in a single pot method. The dispersion of ZnO particles in the films was revealed by SEM . A qualitative and quantitative study of the antibacterial act ivity of the films was carried out, after inoculation with the bacteria Escherichia coli and Staphylococcus aureus. Visual results indicate that the synthesized films inhib it the growth of the bacteria inoculated. The optimu m effective concentration of ZnO /film was found by the Japanese Industrial Standard JIS Z2801:2000 method to be 10mg Zn O/film. According to the same standard method, the antibacterial efficacy (R) of the films against E. coli and S.aureus was calculated as >2.0. Bacteriological tests performed on films, containing 5, 10 and 15 mg ZnO/film, show that the films exh ibit a bactericidal effect at the concentrations used . The above results indicate that agar films incorporated with Zn O, are pro mising candidates in the packaging sector as antibacterial food packaging materials, to increase the safety of food.

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Samim Saner

Papers

Review of methods to determine antioxidant capacities.

An Overview on Steps of Pesticide Residue Analysis and Contribution of the Individual Steps to the Measurement Uncertainty

Occurrence of chemicals with known or suspected endocrine disrupting activity in drinking water, groundwater and surface water, Austria 2017/2018

Development of an LC-MS Method for the Identification of β-Casein Genetic Variants in Bovine Milk

Study of Antibacterial Effects of a Self-Standing Agar Based Film Incorporated with ZnO