Comparison of Hurdle Treatment and Thermal Treatment on Ascorbic Acid and Total Phenolic Content of Winter Melon Puree Stored at Different Temperature Noriham Abdullah, Wan Saidatul Syida Wan Kamarudin  , Zainal Samicho, Nurain Aziman and Khairusy Syakirah Zulkifli Faculty of Applied Sciences, Universiti Teknologi MARA, 40450 Selangor, Malaysia Abstract. Winter Melon (WM) is an important fruit in China, India, Philippines and elsewhere in Asia and due to its perishable characteristic it is a necessity to process it into a puree form. Hence in this study, WM fruit was processed into puree and hurdle technology (HT) treatment was compared with traditional thermal treatment (TT) to see the effect on Ascorbic acid (AAC) and Total Phenolic (TPC) content stored at different temperatures for 6 months of storage. HT WMP was adjusted to pH 3 using citric acid while for TT WMP was prepared by heating at 84.5⁰C for 94 seconds. Both treated WMP were stored at 25⁰C, 5⁰C and -20⁰C and were analyzed at 1 months storage intervals till 6 months. AAC test was conducted using 2, 6- dichlorophenol-indophenol titration method and TPC was determine by using Folin-Ciocalteu. A gradual decrease in AAC and TPC were observed during storage for both treatments. These changes were more pronounced at 25⁰C storage for both treatments (P < 0.05), however, TT shows high reduction of AAC and TPC (P < 0.05) at 0 months throughout 6 months of storage as compared to HT. Overall, WMP for HT stored at 5⁰C and -20⁰C shows lowest reduction for AAC and TPC for the last 6 months of storage. By processing WM into puree, it will be more convenient to use especially by the food manufacturer. In contrast to traditional TT for common fruits puree preparation, HT could imply new opportunities for WMP in developing value-added product with reasonable shelf life. Keywords: Hurdle technology, Thermal treatment, Winter melon puree, Total phenolic content, Ascorbic acid content 1. Introduction Winter melon (WM) or its scientific name Benincasa hispida belongs to a family of Curcubitaceae and its origin is from South East Asia and also can be found in area outside Asia [1]. Some scientific studies carried out reveal the potential of WM as anti-inflammatory [2], anti-diarrheal [3], anti-ulcer [4], antioxidant [5] and antimicrobial agent [5]. In Malaysia, WM is popular fruit among Chinese and Indian communities and it has potential for the food industry. It is prized for its pleasant smell and juicy flesh. However, it softens rapidly during ripening and becomes mushy and difficult to consume in fresh. Moreover due to these reasons, it will be rejected by the consumers if these fruits are bruised. Therefore, there is a need to process WM into puree form. Winter melon puree (WMP) needs a considerable treatment before canning and before storage. Therefore in this study, two treatments were proposed which are thermal treatment (TT) and hurdle technology (HT). Thermal treatment (TT) is a combination of the temp-time profile to ensure microbial destruction and to stabilise the WMP by removing microorganisms and enzyme inactivation that could produce fermentation or spoilage. Study by Sanchez et al. (1990)[6]; Umme et al. (2001)[7] and Bartolome et al. (1995)[8] reported that fruit puree processed below 93⁰C, canned and stored frozen showed no much  Wan Saidatul Syida Wan Kamarudin. Tel: +60132677647 Email Address: thermopolis_mia@yahoo.com 2012 International Conference on Environment, Chemistry and Biology IPCBEE vol.49 (2012) © (2012) IACSIT Press, Singapore DOI: 10.7763/IPCBEE. 2012. V49. 8 36