ORIGINAL ARTICLE Changes in physicochemical properties and starch crystallinity of sponge cake containing HPMC and extra virgin coconut oil during room temperature storage Naratip Poonnakasem 1 | Kalaya Laohasongkram 1 | Saiwarun Chaiwanichsiri 1,2 | Witoon Prinyawiwatkul 2 1 Department of Food Technology, Faculty of Science, Chulalongkorn University, Bangkok, Thailand 2 School of Nutrition and Food Sciences, Louisiana State University Agricultural Center, Baton Rouge, Louisiana Correspondence Saiwarun Chaiwanichsiri, Faculty of Science, Chulalongkorn University, Bangkok, Thailand. Email: saiwarun.c@chula.ac.th and Witoon Prinyawiwatkul, School of Nutrition and Food Sciences, Louisiana State University Agricultural Center, Baton Rouge, LA. Email: wprinya@lsu.edu Funding information Chulalongkorn University, Thailand Abstract Starch retrogradation is an important factor affecting cake firmness. Effects of hydroxy-propyl- methylcellulose (HPMC) at 0.5% (w/w) or extra virgin coconut oil (EVCO) at 20% (w/w), either alone or together, on physicochemical properties and starch crystallinity of sponge cake during storage was investigated. Addition of EVCO increased specific volume and expansion ratio, while addition of HPMC increased water activity of the freshly baked sponge cake. Changes in firmness, moisture, and spin-lattice relaxation time from nuclear magnetic resonance (T 1 ) of sponge cakes followed a first-order kinetic reaction. Use of HPMC and/or EVCO in sponge cake could retard the firmness rate in the following order: EVCO 1 HPMC, < EVCO < HPMC < control (no HPMC and EVCO). The Avrami model satisfactorily fitted the retrogradation kinetics data. The growth of remainder crystals was slower in the presence of EVCO 1 HPMC, while both the nucleation and growth rates of new crystals were slower with 20% EVCO. Practical applications Deterioration of sponge cake during storage is a major problem and can be costly to the bakery industry. HPMC and Extra virgin coconut oil could retard a firmness rate of sponge cake during storage. The kinetic modeling can be applied for tracking quality changes in sponge cake. Lipid decreases starch crystal growth and a nucleation rate in sponge cake. Firmness of sponge cake is directly related to the degree of starch crystallization. This research can be beneficial to the indus- trial cake production for improvement of product shelf life. 1 | INTRODUCTION Sponge cake is one of the favorite foods in the Western world. It is known for its spongy texture, and is made from wheat flour, sugar, eggs, baking powder, and butter or oil (Poonnakasem, Pujols, Chaiwanichsiri, Laohasongkram, & Prinyawiwatkul, 2016). Some ingre- dients play an essential functional role in structural quality, especially fine bubbles in the crumb of cake products leading to soft texture (Chaiya, Pongsawatmanit, & Prinyawiwatkul, 2015). During storage of fresh sponge cake, its desired texture and aroma associated with fresh- ness decrease. This short shelf life is a major problem and can be costly to the bakery industry. Hydrocolloids have been reported to decrease the staling rate of bread due to their functional attributes such as water binding and textural improvement (Poonnakasem 2013). A better bread volume (Rosell, Rojas, & Benedito de Barber, 2001) and a reduced crumb hardening rate (Guarda, Rosell, Benedito, & Galotto, 2004) were obtained when 0.5% (w/w) hydroxy-propyl-methylcellulose (HPMC) was added. Unlike bread, staling mechanism of cake has not been clearly understood (Gray & Bemiller 2003). The staling rate of cakes is slower than in breads due to a higher ratio of sugar and fat in the formulation (Gelinas, Roy, & Guillet, 1999). Poonnakasem, Laohasongkram, and Chaiwanichsiri (2015) studied the effect of several hydrocolloids on physical properties of sponge cake and found that the addition of 0.5% (w/w) HPMC imparted a better firmness retarding property. Lipids in baked products affect volume and produce a signifi- cant anti-staling effect. It has been established that lipids can form complexes with amylopectin, resulting in a slower firming rate (Smith & Johansson, 2005). In this study, extra virgin coconut oil (EVCO) was J Food Process Preserv. 2018;e13600. https://doi.org/10.1111/jfpp.13600 wileyonlinelibrary.com/journal/jfpp V C 2018 Wiley Periodicals, Inc. | 1 of 9 Received: 24 October 2017 | Revised: 20 December 2017 | Accepted: 21 December 2017 DOI: 10.1111/jfpp.13600