Effect of drying methods on long term storage of hazelnut

Abstract

This research was conducted to determine the chemical traits of Drdu Levant hazelnuts that were dried with sun-drying [on concrete ground (CG), grass ground (GG)], or in drying machine (DM) during 24 months of storage (2014)(2015)(2016) at 20-25 °C and 70-90% relative humidity. Drying process continued 39 h for CG and GG, and 23 h for DM. Sun-drying were performed in similar sunshine and environmental conditions. Nut quality traits in protein, lipid, moisture contents, water activity, free fatty acids (FFA), peroxide value (PV), rancimat value (RV), and amount of aflatoxin were investigated during storage. The lowest FFA (0.35%, oleic acid) was recorded for GG, and the lowest PV (0.35 meqD 2 kg -1 ) was recorded for CG. On addition, DM method contained much more RV (3.87 h) than those dried by CG and GG. After 24 months of storage, kernel FFA (0.38%, oleic acid) and RV (3.59 h) were lower than the acceptable limit values after storage (0.40% and 3 h, respectively). On conclusion, in-shell hazelnuts can be stored at an ambient temperature for 24 months without there being any significant changes in chemical traits.Dverall, DM appears to be a promising strategy for hazelnut drying. Practical Application: Determination better drying method and change of chemical traits for period of 24 months storage Turan; Karaosmanoğlu Food Sci. Technol, Campinas, 39(Suppl. 2): 406-412, Dec. 2019 407/412 407

Effect of Drying Methods on Some Chemical Characteristics of Hazelnuts (Corylus avellana L.) During Storage

“…This increase is variable depending on the temperature and relative humidity of the storage conditions (Tavakolipour et al, 2010). All of the FFA obtained from our study were found to be under 0.4 % (Ghirardello et al, 2013), which is critical acidity for nut industry and % 0.7 (Turan, 2017), which is considered the critical threshold for the hazelnut industry.…”

“…Koc Güler et al (2017) and Turan (2017) reported similarly that the peroxide value increased with fluctuation throughout the storage period. Because during the storage of hazelnut both peroxide formation and peroxide decomposition reactions occur at the same time (Demirci Ercoskun, 2009;Turan, 2017). For this reason, after reaching a peak value of PV, it falls to a value close to zero percent.…”

“…Effect of drying methods on free fatty acid, peroxide value and rancimat value during 24 months storage periods. Many studies show that FFA increases during storage (Karaosmanoglu, 2012;Turan andIslam, 2016 andKoc Güler et al, 2017). This increase is variable depending on the temperature and relative humidity of the storage conditions (Tavakolipour et al, 2010).…”

“…In these areas, it is divided into three sections according to the distance from the coast and its height. The areas 0-250 m above sea level and 10 km inner area are coastal section, 251-500 m height and 10-20 km inside area, middle section and 501-750 m height and more than 20 km inner area is called the high section (Turan, 2017). According to hazelnut quality specifications, Giresun and Levant quality are divided into two.…”

“…The inability to use modern techniques in cultural practices reduces the quality of the nut on one side and increases the postharvest losses on the other. Especially, mistakes made during the drying stage lead to significant quality losses in hazelnut, leading to major problems in product preservation and marketing stages (Turan, 2017). Thus, rapid postharvest processing of hazelnut, particularly drying, is crucial for the quality of the last product during storage.…”