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

Processed juices from dried prunes with or without pulp, juice from prune concentrate, and the juices of fresh prune and nine other fruits were analyzed for anthocyanins, organic acids, sugars, phenolic compounds, and amino acids. Unique characteristics of processed prune juice were the predominance of a-aminobutyric acid, citrulline, taurine, 0-phosphoethanolamine, and quinic acid and the absence of anthocyanins, (-)-epicatechin, phloridzin, and citric and tartaric acids. Comprehensive measurements of sugars, anthocyanins, nonvolatile acids, phenolic compounds, and amino acids made it possible to distinguish processed prune juices from fresh prune juice and the juices of plum, cherry, nectarine, peach, apple, pear, grape, kiwi fruit, and strawberry fruits.

http://ucce.ucdavis.edu/files/datastore/234-270.pdf?origin=publicationDetail

Compositional characterization of prune juice

Effects of postharvest handling procedures on tomato quality

Postharvest performance of organic and conventional 'Hayward' kiwifruits grown on the same farm in Marysville, California, and harvested at the same maturity stage were compared in this study. Quality parameters monitored included morphological (shape index) and physical (peel characteristics) attributes of the initial samples. Maturity indices (CO2 and C2H4 production, firmness, color, soluble solids content and acidity) and content of compounds associated with flavor and nutritional quality (minerals, sugars and organic acids, ascorbic acid, total phenolics, and antioxidant activity) were determined at 0, 35, 72, 90 and 120 days of storage at 0 ◦ C, and after 1 week of shelf-life simulation at 20 ◦ C, after each storage duration. Organically and conventionally grown kiwifruits had similar soluble solids content at harvest, but conventional kiwifruits had a higher firmness and L ∗ value, and a lower hue angle and chromaticity, resulting in a lighter green color when compared with the organic kiwifruits. These differences were maintained for all the storage durations, with the soluble solids content increasing more in conventionally grown kiwifruits. The two production systems resulted in different morphological attributes since organic kiwifruits exhibited a larger total and columella area, smaller flesh area, more spherical shape, and thicker skin compared to conventional kiwifruits. All the main mineral constituents were more concentrated in organic kiwifruits, which also had higher levels of ascorbic acid and total phenol content, resulting in a higher antioxidant activity. Sugars and organic acids composition was not affected by the production system.  2007 Society of Chemical Industry

/pdf/a-comparative-study-of-composition-and-postharvest-2nxnfp36zv.pdf

A comparative study of composition and postharvest performance of organically and conventionally grown kiwifruits

Hass' avocado (Persea americana Mill.) fruit were kept in air, 0.25% O 2 (balance N2), 20 % O2 + 80% CO2, or 0.25% O2 + 80% CO2 (balance N2) at 20C for up to 3 days to study the regulation of fermentative metabolism. The 0.25% 02 and 0.25% 02 + 80% CO2 treatments caused accumulations of acetaldehyde and ethanol and increased NADH concentration, but decreased NAD level. The 20% O2+ 80% CO2 treatment slightly increased acetaldehyde and ethanol concentrations without significant effects on NADH and NAD levels. Lactate accumulated in avocadoes kept in 0.25 % 0 2. The 80% CO, (added to 0.25% O2) did not increase lactate concentration and negated the 0.25% O 2-induced lactate accumulation. Activities of PDC and LDH were slightly enhanced and a new isozyme of ADH was induced by 0.25% O 2, 20% O2 + 80% CO2, or 0.25 % O2+ 80% CO2; these treatments partly reduced the overall activity of the PDH complex. Fermentative metabolism can be regulated by changes in levels of PDC, ADH, LDH, and PDH enzymes and/or by metabolic control of the functions of these enzymes through changes in pH, ATP, pyruvate, acetaldehyde, NADH, or NAD. Chemical names used: alcohol dehydrogenase (ADH), adenosine triphosphate (ATP), lactate dehydrogenase (LDH), nicotinamide adenine dinucleotide (NAD), reduced NAD (NADH), pyruvate decarboxylase (PDC), pyruvate dehydroge- nase (PDH).

/pdf/regulation-of-fermentative-metabolism-in-avocado-fruit-under-10jnml6w6s.pdf

Regulation of Fermentative Metabolism in Avocado Fruit under Oxygen and Carbon Dioxide Stresses

https://ucanr.edu/datastoreFiles/234-216.pdf

Adel A. Kader

Papers

Compositional characterization of prune juice

Effects of postharvest handling procedures on tomato quality

A comparative study of composition and postharvest performance of organically and conventionally grown kiwifruits

Regulation of Fermentative Metabolism in Avocado Fruit under Oxygen and Carbon Dioxide Stresses

Phenolic metabolism and ethanolic fermentation of intact and cut lettuce exposed to CO2-enriched atmospheres