Scientia Horticulturae 130 (2011) 801–807 Contents lists available at SciVerse ScienceDirect Scientia Horticulturae journa l h o me page: www.elsevier.com/locate/scihorti Changes in antioxidants and fruit quality in hot water-treated ‘Hom Thong’ banana fruit during storage Nittaya Ummarat a,b , Tracie K. Matsumoto c , Marisa M. Wall c , Kanogwan Seraypheap b,∗ a Biological Sciences Program, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand b Department of Botany, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand c USDA-ARS Pacific Basin Agriculture Research Center, 64 Nowelo Street, Hilo, HI 96720, USA a r t i c l e i n f o Article history: Received 14 June 2011 Received in revised form 1 September 2011 Accepted 5 September 2011 Keywords: Banana Hot water treatment Low temperature storage Antioxidants a b s t r a c t The effects of hot water treatment on antioxidants and fruit quality were investigated in banana fruit of cv. Gros Michel (Musa acuminata, AAA Group, locally called cv. Hom Thong) by immersing fruits in hot water (50 ◦ C) for 10 min, before storage at 25 ◦ C for 10 days or 14 ◦ C for the first 8 days followed by storage at 25 ◦ C for the second 8 days until ripening. Quality parameters including peel color and pulp firmness indicated that hot water treatment helped to delay banana fruit ripening at both storage conditions. Hot water treatment decreased the levels of hydrogen peroxide (H 2 O 2 ) and malonydialdehyde (MDA) during storage at 25 ◦ C. Glutathione (GSH and GSSG) contents and the ratio of GSH/GSSG during fruit approaching ripening were significantly induced in hot water-treated fruits while ascorbic acid (AA) contents were slightly increased. In addition, the combined treatment increased free phenolics and flavonoids during storage. Results suggest that hot water treatment has led to an induction of antioxidants in banana fruits as indicated by an increase of antioxidants and a decrease of H 2 O 2 during ripening, and all of which result in a delayed ripening of banana fruit. © 2011 Elsevier B.V. All rights reserved. 1. Introduction Banana is a climacteric fruit that is economically important for local and export markets worldwide. Banana is also considered a high energy food source due to elevated levels of antioxidant vita- mins, vitamin A and C (ascorbic acid), and phenolics, which are related to high antioxidant capacity (Kevers et al., 2007; Thaipanit and Anprung, 2010). Plant phenolics are commonly found in both edible and non-edible parts of plants and have accounted for a major portion of the antioxidant activity in many fruits (Babbar et al., 2011). In banana, total phenolics have been reported to be more abundant in peel than in pulp, which was consistent with the antioxidant activity (Someya et al., 2002). Antioxidant capacity of banana was reported to increase during flesh maturity and to have a higher capacity level than in some berries, herbs and vegetables (Thaipanit and Anprung, 2010). The quality of bananas rapidly decline when fully ripened. One of the limiting factors for exporting bananas to distant coun- tries is the short shelf-life mainly due to postharvest disease development during transit and storage. The major postharvest diseases are fungal diseases including anthracnose and crown rot disease caused by a fungal complex, Colletotrichum musae, ∗ Corresponding author. Tel.: +66 2 218 5495; fax: +66 2 252 8979. E-mail address: kanogwan.k@chula.ac.th (K. Seraypheap). Fusarium spp. and Lasiodiplodia theobromae (Kyu Kyu Win et al., 2007; Paull et al., 1998). Many postharvest treatments, such as the use of fungicides and heat treatments followed by low tem- perature storage, have been applied to prolong the shelf-life of banana. However, increased public concern over the presence of chemical residues on fruits and vegetables has led to the progressive use of heat treatment for postharvest disease con- trol in recent years. In addition to disease control, postharvest heat treatments of fruit have been used for insect disinfestations, enhancement of fruit tolerances to other stress and also mainte- nance of fruit quality during storage (Lurie, 1998; Paull and Chen, 2000). Several studies report that heat treatments increase heat shock proteins (HSPs), antioxidant enzymes and phytochemicals such as carotenoids and phenolic compounds. Ghasemnezhad et al. (2008) found an increase in superoxide dismutase (SOD), peroxi- dase (POD) and catalase (CAT) activities after hot water treatments in mandarins. Talcott et al. (2005) found an increase in polyphe- nols and carotenoids which resulted in greater antioxidant activity in hot water-treated mangoes, compared with control fruit. More- over, Djioua et al. (2009) reported heat treatments increased total carotenoids and vitamin C content in mango fruit. These results indicate that heat treatments prolong postharvest life of some fruits and promote an increase of bioactive compounds (Gonzalez- Aguilar et al., 2010). Heat treatments have also been reported to increase tolerance of fruit to chilling temperatures (Mirdehghan 0304-4238/$ – see front matter © 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.scienta.2011.09.006