Contents lists available at ScienceDirect Scientia Horticulturae journal homepage: www.elsevier.com/locate/scihorti Harvest time affects quality and storability of kiwifruit (Actinidia spp.) Cultivars during long-term cool storage Han Ryul Choi a,1 , Shimeles Tilahun a,b,c,1 , Do Su Park d , Yeon Mi Lee a , Jong Hang Choi a , Min Woo Baek a , Cheon Soon Jeong a, ⁎ a Department of Horticulture, Kangwon National University, Chuncheon, Gangwon 24341, Republic of Korea b Agriculture and Life Science Research Institute, Kangwon National University, Chuncheon 24341, Republic of Korea c Department of Horticulture and Plant Sciences, Jimma University, Jimma 378, Ethiopia d Division of Plant and Soil Sciences, West Virginia University, Morgantown, WV 26505, USA ARTICLE INFO Keywords: Brix-acid ratio PG activity Pectin Simple sugars Kiwifruit ABSTRACT In this study, the possibility of prolonging the freshness of kiwifruit cultivars for the purpose of even distribution in time and place has been investigated. Green ‘Hayward’, gold ‘Haegeum’ and red ‘Hongyang’ kiwifruit cultivars were harvested at 160, 170 and 180 days after full bloom (DAFB) and stored at 0 °C until 4 months. Firmness and firmness related parameters, biochemical parameters, physiological parameters, decay percentage and overall sensory evaluation were observed during the study. On the basis of harvesting time, the order of storability of all the three cultivars could be 160 DAFB > 170 DAFB > 180 DAFB, respectively. The study revealed that kiwifruit harvested at 160 DAFB were stored up to 4 months without affecting major quality indices during storage. However, overall sensory quality evaluation showed that kiwifruits harvested at 160 DAFB attained good eating quality after 3 months of storage in green and red kiwi cultivars, and after one month storage in gold kiwi cultivar. Hence, in order to ensure good sensory quality and to fulfill consumer's preference during distribution, further ripening studies like exogenous ethylene treatment are necessary immediately after harvest or at any time during the storage period 1. Introduction Kiwifruit (Actinidia spp.) is a perennial deciduous warm-temperate fruit that belongs to the family Actinidiaceae and it is native to northern China, Korea, Siberia, and Japan (Kwack et al., 2012). Following the establishment of breeding program in New Zealand, importation of germplasm from Asia and commercialization of kiwifruit by New Zealand growers and government agencies was done in the 1980s; ki- wifruit is also a commercially important fruit in Italy, France, Chile, Korea, and other countries (Everett et al., 2011). According to FAOSTAT (2017), worldwide annual production of kiwifruit was 4.32 million Mt from the total planted area of 247,793 ha; out of which Republic of Korea took a share of 7991 Mt from the planted area of 492 ha. The genus Actinidia comprises various species having a wide range of differences in the color of fruit skin and flesh. Green-fleshed kiwifruit cultivars Actinidia deliciosa and the yellow-fleshed Actinidia chinensis have dominated the worldwide commercial market. However, in recent years, consumers have shown increasing interest in Actinidia fruit with red skin and/or flesh (Montefiori et al., 2011). Cultivation of kiwifruit has been mainly done in the southern coastal areas of Korea due to the warm winters (Koh et al., 2003). Generally, domestic kiwifruit har- vesting starts from mid-October and is distributed up to April after long- term storage, and the imported stock is distributed from May to No- vember, which has the advantage of being able to eat kiwifruit throughout the year in Korea. So, selecting cultivars, harvesting at appropriate maturity stage and proper distribution from area of pro- duction is highly required to reduce postharvest losses and to meet the consumer’s preference for high quality fruits. Cool storage is widely used to reduce softening of kiwifruit by de- laying ripening, which would be very useful for extending its avail- ability on the market (Meena et al., 2018). Although kiwifruit is a cli- macteric fruit that produces autocatalytic ethylene during ripening (Chiaramonti and Barboni, 2010) it does not produce substantial ethylene until softening at low temperature (0 °C), and it endure ex- tended cold storage, this could be correlated to its high concentrations https://doi.org/10.1016/j.scienta.2019.05.050 Received 28 January 2019; Received in revised form 20 May 2019; Accepted 22 May 2019 ⁎ Corresponding author. E-mail address: jeongcs@kangwon.ac.kr (C.S. Jeong). 1 These authors contributed equally to this work. Scientia Horticulturae 256 (2019) 108523 0304-4238/ © 2019 Elsevier B.V. All rights reserved. T