Citation: Dogan, A.; Erkan, M. Responses of High Carbon Dioxide Concentration on Postharvest Quality of Fresh Fig Fruit during Storage. Horticulturae 2023, 9, 293. https:// doi.org/10.3390/horticulturae9030293 Academic Editors: Yang Bi, Yongcai Li and Di Gong Received: 30 December 2022 Revised: 11 February 2023 Accepted: 18 February 2023 Published: 22 February 2023 Copyright: © 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). horticulturae Article Responses of High Carbon Dioxide Concentration on Postharvest Quality of Fresh Fig Fruit during Storage Adem Dogan 1,2 and Mustafa Erkan 2, * 1 Department of Plant and Animal Production, Elmalı Vocational School, Akdeniz University, Antalya 07700, Turkey 2 Department of Horticulture, Faculty of Agriculture, Akdeniz University, Antalya 07058, Turkey * Correspondence: erkan@akdeniz.edu.tr; Tel.: +90-0242-310-24-28 Abstract: The aim of this study was to determine the effects of high CO 2 with the constant O 2 level on the postharvest quality of fig cv. Bursa Siyahi. For this purpose, the atmospheric com- positions of 3% O 2 + 10% CO 2 (PA-1), 3% O 2 + 15% CO 2 (PA-2), 3% O 2 + 20% CO 2 (PA-3), and 21% O 2 + 0.03% CO 2 (RA) were tested under a palliflex controlled atmosphere (PA) storage system at 0 ◦ C for 28 days. At the end of the storage, weight loss increased during the storage period, but this increase slowed down in all tested PAs compared to RA. PA-1 and PA-2 delayed softening while PA-3 accelerated this process. There were no side effects in fruits stored under PAs for taste. The lowest total microorganism and decay rates were found in PA-2 and PA-3. The fig fruits stored under PAs had higher sugar and organic acid contents compared to the figs stored under the RA. Respiration rate decreased in all PAs compared to the RA. Ethylene productions increased with senescence in all atmospheres, but PA-3 inhibited this increase. Consequently, 15% CO 2 (PA-2) can be used to maintain postharvest quality of Bursa Siyahi fresh fig for 28 days at 0 ◦ C. Keywords: Ficus carica L.; postharvest losses; respiration rate; softening; storage condition; sugar content 1. Introduction Turkey provides approximately 24% of the world total fig production with 320,000 tons [ 1]. A large part of this production is considered dried fruit; however, the demand for fresh con- sumption has shown an increasing trend in the past decade. Bursa Siyahi is the dominant fresh consumption cultivar and fresh fig exportation of Turkey is based on this cultivar. This cultivar is highly attractive and demanded due to its delicious taste, flavor, and bio- chemical properties as well as attractive colors [2]. However, it is highly perishable due to its delicate fruit characteristics such as soft fruit tissue, thin peel, and ostiole-end opening. The expected postharvest life of fresh fig is limited to generally one or two weeks in ambient atmosphere at 0 ◦ C[3]. The most common postharvest problems of fresh fig are water loss, softening, peel cracking, ostiole leakage and internal/external decays. Fig fruit is extremely sensitive to various pathogens, such as Alternaria spp., Botrytis spp., Fusarium spp., Aspergillus spp., Penicillium spp., and Rhizopus spp. [2,4–6], that cause economic losses especially in shelf-life at high temperatures. Karabulut et al. [7] reported that postharvest losses can reach up to 30–50% in shelf-life following 5–7 days of cold storage or transportation, especially when fruits are harvested during the rainy season. Controlled atmosphere (CA) storage including low O 2 and high CO 2 have positive effects to maintain fruit quality and disease control in many horticultural commodities [8]. On the other hand, extremely high CO 2 levels may have an unfavorable effect on texture and promote off-flavor development [9]. Fresh fig fruit tolerates a high level of CO 2 in the storage atmosphere like other berries. Colelli et al. [10] tested the atmosphere enrichment with 15 and 20% CO 2 in the Mission fig variety at different storage temperatures for Horticulturae 2023, 9, 293. https://doi.org/10.3390/horticulturae9030293 https://www.mdpi.com/journal/horticulturae