Methods available for the measurement of antioxidant capacity are reviewed, presenting the general chemistry underlying the assays, the types of molecules detected, and the most important advantages and shortcomings of each method. This overview provides a basis and rationale for developing standardized antioxidant capacity methods for the food, nutraceutical, and dietary supplement industries. From evaluation of data presented at the First International Congress on Antioxidant Methods in 2004 and in the literature, as well as consideration of potential end uses of antioxidants, it is proposed that procedures and applications for three assays be considered for standardization: the oxygen radical absorbance capacity (ORAC) assay, the Folin-Ciocalteu method, and possibly the Trolox equivalent antioxidant capacity (TEAC) assay. ORAC represent a hydrogen atom transfer (HAT) reaction mechanism, which is most relevant to human biology. The Folin-Ciocalteu method is an electron transfer (ET) based assay and gives reducing capacity, which has normally been expressed as phenolic contents. The TEAC assay represents a second ET-based method. Other assays may need to be considered in the future as more is learned about some of the other radical sources and their importance to human biology.

https://faculty.missouri.edu/~glaserr/3700s14/Antioxidant-Capacity_jf0502698.pdf

Standardized Methods for the Determination of Antioxidant Capacity and Phenolics in Foods and Dietary Supplements

https://aggie-horticulture.tamu.edu/faculty/cisneros/Papers/Thaipong_2006.pdf

Comparison of ABTS, DPPH, FRAP, and ORAC assays for estimating antioxidant activity from guava fruit extracts

Phenolic compounds in plants and agri-industrial by-products: Antioxidant activity, occurrence, and potential uses

This publication is based on studies carried out from August 2010 to January 2011 by The Swedish Institute for Food and Biotechnology (SIK) on request from the FAO. The two studies on global food losses (one for high/medium-income countries and one for low income countries) have been carried out to serve as a basis for the international congress Save Food!, 16-17 May 2011, at the international packaging industry fair Interpack2011 in Dusseldorf, Germany.
The study highlights the losses occurring along the entire food chain, and makes assessments of their magnitude. Further, it identifies causes of food losses and possible ways of preventing them. The results suggest that roughly one-third of food produced for human consumption is lost or wasted globally, which amounts to about 1.3 billion tons per year. This inevitably also means that huge amounts of the resources used in food production are used in vain, and that the greenhouse gas emissions caused by production of food that gets lost or wasted are also emissions in vain.

Global food losses and food waste: extent, causes and prevention.

Food waste in the global food supply chain is reviewed in relation to the prospects for feeding a population of nine billion by 2050. Different definitions of food waste with respect to the complexities of food supply chains (FSCs)are discussed. An international literature review found a dearth of data on food waste and estimates varied widely; those for post-harvest losses of grain in developing countries might be overestimated. As much of the post-harvest loss data for developing countries was collected over 30 years ago, current global losses cannot be quantified. A significant gap exists in the understanding of the food waste implications of the rapid development of ‘BRIC’ economies. The limited data suggest that losses are much higher at the immediate post-harvest stages in developing countries and higher for perishable foods across industrialized and developing economies alike. For affluent economies, post-consumer food waste accounts for the greatest overall losses. To supplement the fragmentary picture and to gain a forward view, interviews were conducted with international FSC experts. The analyses highlighted the scale of the problem, the scope for improved system efficiencies and the challenges of affecting behavioural change to reduce post-consumer waste in affluent populations.

/pdf/food-waste-within-food-supply-chains-quantification-and-344f4n2oz2.pdf

Food waste within food supply chains: quantification and potential for change to 2050

The conversion of a tomato fruit from the mature green to fully ripe state involves dramatic changes in colour, composition, aroma, flavour and texture. Ripening used to be thought of simply as the result of a series of degradative processes, probably because some of the more obvious changes require the action of hydrolytic enzymes. However, it is now clear that ripening is dependent on a wide range of separate synthetic as well as degradative reactions. These include alterations in metabolism and gene expression which have a dramatic effect on fruit quality. The changes are highly coordinated; they occur in the majority of the cells of the fruit and involve every subcellular compartment. The various facets of ripening appear to be coordinated and regulated by plant hormones but may be modified by genetic and environmental factors. In this chapter the general features of tomato ripening are outlined first, together with a discussion of the cellular mechanisms regulating the process. This is followed by a consideration of the ways in which genotype, growing conditions, disease, and post-harvest history can influence specific quality attributes.

Fruit ripening and quality

http://ucce.ucdavis.edu/files/datastore/234-449.pdf

Apple aroma : alcohol acyltransferase, a rate limiting step for ester biosynthesis, is regulated by ethylene

Sliced strawberries (cvs.‘Pajaro’ and 'G-3′) and partially ripe pears (cv.‘Bartlett’) were dipped in various solutions (citric acid, ascorbic acid, and/or calcium chloride) and stored in air or in controlled atmospheres (CA) for 7 days at 2.5°C followed by one day at 20°C. Fruit slices respired at a higher rate than whole fruits at both temperatures. CA storage suppressed respiration and ethylene production rates of sliced fruits. Firmness of strawberry and pear slices was maintained by storage in air + 12% CO2 and in a 0.5% O2 atmosphere, respectively, or by dipping in 1% calcium chloride. These treatments also resulted in lighter colored pear slices than the air control treatment.

Postharvest Physiology and Quality Maintenance of Sliced Pear and Strawberry Fruits

http://ucce.ucdavis.edu/files/datastore/234-152.pdf

Controlled atmosphere-induced changes in pH and organic acid metabolism may affect color of stored strawberry fruit

Objective: Determine 1) if consumption of a meal of different fruits or berries increases plasma hydrophilic (H-) or lipophilic (L-) antioxidant capacity (AOC) measured as Oxygen Radical Absorbance Capacity (ORACFL); 2) if including macronutrients in the meal alters postprandial changes in AOC; and 3) if preliminary recommendations can be developed for antioxidant intake.Methods: Changes in plasma AOC following consumption of a single meal of berries/fruits (blueberry, dried plum, dried plum juice, grape, cherry, kiwifruit and strawberry) were studied in 5 clinical trials with 6–10 subjects per experiment. In two studies with blueberry or grape, additional macronutrients (carbohydrate, fat, protein) were included in the control and treatment meals. Blood samples collected before and after the meal were analyzed for AOC.Results: Consumption of dried plums or dried plum juice did not alter either the H- or L-AOC area under the curve (AUC). Consumption of blueberry in 2 studies and of mixed grape powder [12....

/pdf/plasma-antioxidant-capacity-changes-following-a-meal-as-a-3ahpt1bna2.pdf

Adel A. Kader

Papers

Fruit ripening and quality

Apple aroma : alcohol acyltransferase, a rate limiting step for ester biosynthesis, is regulated by ethylene

Postharvest Physiology and Quality Maintenance of Sliced Pear and Strawberry Fruits

Controlled atmosphere-induced changes in pH and organic acid metabolism may affect color of stored strawberry fruit

Plasma Antioxidant Capacity Changes Following a Meal as a Measure of the Ability of a Food to Alter In Vivo Antioxidant Status