Research Article Received: 14 June 2013 Revised: 26 November 2013 Accepted article published: 13 December 2013 Published online in Wiley Online Library: (wileyonlinelibrary.com) DOI 10.1002/jsfa.6536 Effect of photo-selective nettings on post-harvest quality and bioactive compounds in selected tomato cultivars Maphoko Kamogelo Selahle, Dharini Sivakumar ∗ and Puffy Soundy Abstract BACKGROUND: Photo-selective coloured netting is referred to as a ‘new agro-technological’ concept adopted to manipulate light quality changes that can induce favourable responses in plants. RESULTS: Tomato (Solanum lycopersicum L.) cultivars AlvaV, Irit and SCX 248 grown under the black net (commercial net, 25% shading) showed higher weight loss, loss of firmness, ascorbic acid content and decline in the ratio of soluble solids content/titrable acidity during post-harvest storage (low-temperature storage at 10 ◦ C and 90% relative humidity for 21 days followed by market shelf conditions at 25 ◦ C for 2 days). During post-harvest storage, lycopene, β -carotene, total phenolic content and antioxidant scavenging activity were higher in cvs AlfaV and Irit grown under the black or pearl nets. However, the β -carotene, total phenolic content and antioxidant scavenging activity were higher in SCX 248 grown under the red net during post-harvest storage. Cultivar AlfaV grown under the red and pearl nets had a higher number of odour active aroma compounds during post-harvest storage. Panellists preferred cv. AlfaV grown under the pearl nets after storage based on taste, overall appearance and firm textured fruits. CONCLUSION: Pearl photo-selective nets retained the overall fruit quality and bioactive components in cvs AlfaV and Irit during post-harvest storage. Red photo-selective nets, however, showed greater influence on retention of overall fruit quality and bioactive compounds in cv. SCX 248 during post-harvest storage. c  2013 Society of Chemical Industry Keywords: aroma; soluble solids concentration; Solanum lycopersicum; total phenols; flavonoids; β -carotene; lycopene INTRODUCTION Fruits and vegetables are rich in micronutrients and phyto- chemicals which possess antioxidant properties. Increasing the availability of antioxidants in diets can increase resistance to oxidative stress, thereby providing substantial protection against deadly diseases such as cancers, cardiovascular diseases and neurological disorders. 1,2 Tomatoes (Solanum lycopersicum L.) are one of the most important fruits worldwide and are very valuable from a nutritional and sensory point of view. They are known to constitute an excellent source of carotenoids (especially lycopene, β -carotene, a precursor of vitamin A), phenolics (flavonoids) and vitamin C. 2 – 4 A 100 g tomato provides 20–40% of the US recommended daily intake for vitamins A and C. 2 Carotenoids and flavonoids act as strong antioxidants that protect cells from reactive oxygen species. 5 Lycopene is one of the major bioactive compounds in tomatoes and is responsible for the attractive red colour in tomatoes. Increased serum levels and intake of lycopene have been found to reduce the risk of developing different types of cancers in humans, 6,7 and the consumption of lycopene in fresh tomatoes was associated with a reduced risk of cardiovascular disease. 8 In ripened tomatoes, rutin [quercetin 3-O-rutinoside; quercetin3-(6-rhamnosylglucoside)] has been reported to be the major flavonoid compound. 9,10 Flavonoids consist of a group of compounds containing a C6–C3–C6 structure and were reported to possess antioxidative, antiproliferative, and anti-inflammatory properties. 11 Although the growing conditions, genotypes, and the maturity stage at harvest affect the content of bioactive compounds in fruit and vegetables, post-harvest storage conditions were also reported to affect the antioxidant activity and phenolic compounds. 12 The variation of lycopene, antioxidant activity, total soluble solids and weight loss of tomato occur during post-harvest storage. 13 The use of shading nets for the cultivation of horticultural crops is becoming a popular non-chemical approach and aims to provide physical protection from weather conditions (excessive solar radiation and temperature), environmental hazards (wind and hail) or birds and insects that transmit viral diseases, while also promoting desired physiological responses linked to light quality. 14 It has been demonstrated that tomato production under photo-selective shade nets increases the marketable yield and protects the fruit from sunscald injury, 15,16 blossom end rot and cracked skin. 17 Use of photo-selective shade netting decreases and alters the quality of light to a varying extent, thus causing a ∗ Correspondence to: Dharini Sivakumar, Postharvest Technology Group, Department of Crop Sciences, Tshwane University of Technology, Private Bag X680, Pretoria 0001, South Africa. E-mail: dharinisivakumar@yahoo.co.uk Postharvest Technology Group, Department of Crop Sciences, Tshwane University of Technology, Private Bag X680, Pretoria 0001, South Africa J Sci Food Agric (2014) www.soci.org c  2013 Society of Chemical Industry