An experimental greenhouse at Korea Institute of Science and Technology (KIST), Gangneung, which is a multi-span Venlo-type structure, was used for the experiment ( Figure 1 ). Figure 1A shows that room climate was control by various sensors on Web based monitoring system. Temperature, relative humidity, and CO₂ concentration of the inside climate were measured by the sensor module (SH-VT250, Soha tech, Korea). It was installed at the center of the greenhouse with height of 1 meter ( Figures 1B, C ) and the specifications of the sensors are shown in Table 1 . The crop used in the experiment was “Seolhayng” strawberries were used as the crops for the experiment. The size of cultivation room is 16 m in length and 12.5 m in width ( Figure 1 ). The experiment was conducted 7 weeks after the strawberry seedlings were on Semp. 10^th 2019. A total number of 1377 plants were used in this experiment, and it was cultivated with a planting density of 7.97 plants/m². Strawberries were grown in a greenhouse under a 24/9°C, day/night temperature cycle based on the mixed soil (80% pearlite with cocopeat; 10% zeolite; and 10% peat moss). The crops were provided with nutrients with major elements (4.27 mM Ca, 11.50 mM NO3, 4.52 mM K, 1.50 mM H2PO4, 1.50 mM SO4, and 1.50 mM Mg) and minor elements (29.98 mM Fe, 20.00 Mn, 6.98 mM Zn, 1.00 mM Cu, 11.98 mM B, and 0.50 mM Mo). Drainage ratios were considered as the treatments (T) and four drainage ratios including 12.0 ± 2.0% (T1), 25.3 ± 6.6% (T2), 36.4 ± 4.4% (T3), and 56.5 ± 4.5% (T4) were applied from fruit set using the automatic nutrient solution supply (Aqua-2ZT, Shinhan A-Tec, Changwon, Republic of Korea) determined the feeding time and E.C. by the accumulated solar radiation ( Figure 1 ). The ratio of the amount of solution supplied for each experiment is shown in the following Table 1 . The drainage ratios were calculated as

where the A represent the total water supply and B means drainage after irrigation supply.

The harvested fruits were stored at room temperature for 6 days until there is decay on the strawberry surface. Each group was further divided into sub-groups according to date (0-6 days after storage, DAS) and then packed in polyethylene terephthalate (PET) containers.

Total soluble solids (TSS) were measured using a refractometer (SCM-1000, HM Digital, Korea) and expressed in percentage (%). Fruit firmness was analyzed using a fruit hardness tester (Lutron FR5105, Taiwan) and expressed as N.

To analyze fruit antioxidant and anthocyanin concentrations, 2 g of frozen fruit was extracted with 4 mL of 80% methanol containing 0.1% HCl (hydrogen chloride) in a sonicator at 40°C for 1 h. Fruit extracts were filtered with a filter membrane (0.22 μm PVDF syringe filter, Maidstone, UK) and concentrated using a nitric evaporator (Allsheng MD 200, Hangzhou, China). Concentrated samples were dissolved in DMSO.

The aromatic compounds of strawberry fruits were analyzed according to an established protocol (Cämara et al., 2006). The analysis was carried out using a gas chromatography (GC) system coupled to a time-of-flight mass spectrometer (TOF-MS) (LECO Pegasus GC HRT, Leco Corp., St. Joseph, MI, USA). Frozen sample (100 mg) was mixed with 2 mL of 30% NaCl (saturated solution) and 2 μL of 2 mg mL^-1 3-pentanol (used as the internal standard). An SPME holder equipped with a 50/30 μm fiber (DVB/CAR/PDMS, model 57348-U, Supelco Inc., PA, USA) was used for sampling. Before use, the fiber was conditioned at 250°C for 5 min. The aromatic compounds were extracted by exposure to SPME fiber maintained at 70°C and agitated at 500 rpm for 20 min. After the agitation, GC analysis was performed through capillary column (Rtx-5MS column, 30 m length, 0.25 mm diameter, 0.25 μm thickness, 5% diphenyl, 95% dimethyl polysiloxane, Restek, PA, USA) under split mode (30: 1). The front inlet temperature was set at 240°C and the transfer line temperature was maintained at 255°C. Mass range was from 36 to 450. The ion source temperature was kept at 250°C with ionization voltage of 70 eV and the helium was used as carrier gas at a flow rate of 1 ml min^-1; oven temperature program was initial at 60°C held for 1 min and then 100°C at the rate of 8°C min^-1 and then 220°C at the rate of 15°C min^-1 and then programmed to 245°C at the rate of 30°C min^-1 and finally held for 3 min. The relative quantity of these compounds was calculated based on the concentration of internal standard. Retention indices (RI) were determined from the retention times of a series of n-alkanes (C₆–C₁₉) with linear interpolation. VOCs of samples were identified on the basis of RIs and comparatively analyzed with the recorded mass spectra of each compound using mass spectrum library search (NIST).

The data were subjected to Analysis of Variance and Duncan’s new multiple range tests, performed in JMP V10.0.0 (SAS Institute, Cary, NC). In the illustrations, different capital letters between different storage duration treatments indicate significant differences and different lowercase letters indicate significant differences among treatments. Each treatment had three replicates and the experiments were carried out twice.

Higher fruit yield was obtained in T2 (25.2 ± 1.3 g) and T3 (25.5 ± 0.9 g), while lower production was observed under the T1 (22.6 ± 0.7 g) and T4 (19.3 ± 0.7 g) conditions ( Table 2 ). In addition to fruit production, the effects of different drainage ratios on the quality of strawberry fruits were investigated by firmness and TSS during the days after storage (DAS) ( Figure 2 ). For the firmness on the harvest day (0DAS), there was non-significant difference (P< 0.05) following the treatments as follows: T1 (3.67 ± 0.32 N), T2 (3.45 ± 0.31 N), T3 (3.18 ± 0.85 N), and T4 (3.14 ± 0.43 N). Additionally, the TSS on the harvest day (0 DAS) also explained no difference (P< 0.05) following the treatments; T1 (10.7 ± 1.12%), T2 (9.2 ± 0.62%), T3 (9.7 ± 1.15%), and T4 (10.3 ± 0.79%), respectively. TSS showed little effect of storage period as no significant difference (P< 0.05) was confirmed between 0 DAS and 6 DAS. But as presented in Figure 2B , the firmness gradually decreased as the storage period elapsed, and a significant difference (P< 0.05) was confirmed in all treatment groups at 6 DAS. However, T2 (1.80 ± 0.06 N) and T3 (1.81 ± 0.07 N) showed significantly lower firmness than T1 (2.08 ± 0.12 N) and T4 (2.00 ± 0.06 N) at 6 DAS.

Pelargonidin-3-O-glucoside (Pg3G) and cyanidin-3-O-glucoside (C3G) are common anthocyanin compound in all strawberry varieties. “Seolhyang” is reported to mainly contain Pg3G consistent with the distribution of Pg3G (50-90% of the total anthocyanins) in previous studies (Dzhanfezova et al., 2020). Instrumental analysis using HPLC-DAD allowed the separation of anthocyanin peaks detected at 520 nm, showing retention time of 3.294 min of C3G and 4.114 min of Pg3G. Diverse concentrations were applied to draw calibration curves (C3G: 5-50 μg mL^-1; Pg3G: 50-500 μg mL^-1) and linear calibration curves of C3G (Y = 24.057X + 4.3388, R² = 0.9997) and Pg3G (Y = 2.1287X + 4.3673, R² = 0.9995) were obtained. Following the conditions and DAS, Pg3G (1803.1-6161.0 mg kg^-1, FW) and C3G (164.0-534.0 mg kg^-1, FW) were varied ( Figure 3 ). The anthocyanins content increased up to the maximum content of each treatment after harvest and then declined later on. Two drainage conditions (T3 and T4) had the maximum anthocyanin contents at 4 DAS; however, T1 and T2 recorded the highest anthocyanins content at 5 DAS.

On the day of harvest, there was no difference (P< 0.05) in anthocyanins content and the total phenolic content (TPC) ( Supplementary Figure 1 ) according to the drainage conditions, but a significant difference in antioxidant activity was observed. The antioxidant activity of fruit has been reported to indicate storability in early harvest stages (Oz et al., 2016) and can be decided by the secondary metabolites (Park et al., 2020). There were significant differences in DPPH free-radical scavenging activity, expressed as RC₅₀ value, on harvest time (P< 0.05) ( Figure 3C ). The group with the lowest drainage ratio exhibited the highest antioxidant activity (T1 = 0.94 ± 0.04 mg mL^-1 > T2 = 1.64 ± 0.15 mg mL^-1 > T3 = 2.22 ± 0.09 mg mL^-1 > T4 = 2.48 ± 0.20 mg mL^-1).

It is well known that the variability of VOCs according to the environment and characteristic properties changing during the storage period make VOCs the quality evaluation index (Fan et al., 2021; Öz and Kafkas, 2022). Because the VOCs of strawberry fruit can be used as an indicator of over-ripening during storage, 47 VOCs from the strawberry fruits collected were identified ( Table 3 ), and these VOCs were associated with monoterpene alcohols (4), sesquiterpene alcohols (3), aldehydes (7), ketone (1), esters (25), lactone (1), monoterpene (1), sesquiterpenes (3), and furans (2).

Prior to confirm the numerical results, the percentage change of each VOC group was investigated. Regardless of the treatments and storage periods, some groups including monoterpene, sesquiterpenes, acids, lactones, and ketones did not exceed 5% in percentage content ( Supplementary Figure 2 ). Therefore, the total VOCs content was determined by aldehydes, esters, furans, monoterpene alcohols, and sesquiterpene alcohols. To visualize the variability of compound groups following the storage duration, regression model drawn.

As shown in Figure 4 , coefficient of determination (R² ) in monoterpene alcohols (R² = 0.0631; Figure 4D ) and sesquiterpene alcohols (R² = 0.0015; Figure 4E ) explained the low variability across duration. Meanwhile, aldehydes (R² = 0.6897; Figure 4A ), esters (R² = 0.7137; Figure 4B ) and furans (R² = 0.8437; Figure 4C ) exhibited strong correlation. Even in the compound groups that showed high correlation with storage period, the complex physiological processes result in the different tendency. It has been well documented that the aldehydes are produced from diverse precursors during storage and subsequent aldehydes decomposition contributes to esters and alcohols formation (Yan et al., 2018; Lu et al., 2020).

These reported trends were agreement with our results. First, aldehydes were mainly composed of hexanal and (E)-2-hexenal, which accounted for 6.6 – 60.6% and 37.2 – 91.8% of total aldehydes content, the content of other compounds was low. The total aldehydes content showed decreased until 5 DAS ( Figure 5A ) following decline tendency of (E)-2-hexenal (0 DAS: 186.11 ± 67.49 mg 100 g^-1; 1 DAS: 171.14 ± 15.39 mg 100 g^-1; 2 DAS: 165.78 ± 31.62 mg 100 g^-1; 3 DAS: 137.28 ± 50.95 mg 100 g^-1; 4 DAS: 117.81 ± 28.38 mg 100 g^-1; 5 DAS: 99.50 ± 18.51 mg 100 g^-1; 6 DAS: 100.19 ± 21.59 mg 100 g^-1, respectively) ( Figure 6B ). But total aldehydes content was increased at 6 DAS along with the hexanal, one of the main aldehydes of strawberry fruit, exhibited increase trend with the extension of the storage period (0 DAS: 32.86 ± 13.76 mg 100 g^-1; 1 DAS: 17.74 ± 4.05 mg 100 g^-1; 2 DAS: 20.62 ± 10.25 mg 100 g^-1; 3 DAS: 16.69 ± 7.53 mg 100 g^-1; 4 DAS: 10.67 ± 2.78 mg 100 g^-1; 5 DAS: 28.48 ± 18.97 mg 100 g^-1; 6 DAS: 117.82 ± 32.33 mg 100 g^-1, respectively) ( Figure 6A ). In detail, there was no significant (P< 0.05) difference on hexanal content following the treatments until 4 DAS, but a significant difference appeared from the 5 DAS (P< 0.05) (T1: 11.58 ± 1.16 mg 100 g^-1; T2: 12.58 ± 0.36 mg 100 g^-1; T3: 55.06 ± 2.74 mg 100 g^-1; T4: 34.69 ± 6.74 mg 100 g^-1, respectively).

Meanwhile, esters and furans, which are the products of degradation of aldehydes, ascribed the positive change following the storage ( Figure 5B ). In case of esters, total 25 compounds were identified ( Table 3 ) and the most important odorants of strawberry including methyl butanoate, methyl hexanoate, and ethyl hexanoate were detected (Yan et al., 2018). Consistent with previous reports (Zhang et al., 2023), the total content of esters showed a gradual increase (0 DAS: 72.50 ± 13.15 mg 100 g^-1; 1 DAS: 101.27 ± 15.44 mg 100 g^-1; 2 DAS: 117.62 ± 22.80 mg 100 g^-1; 3 DAS: 190.12 ± 48.08 mg 100 g^-1; 4 DAS: 195.35 ± 20.38 mg 100 g^-1; 5 DAS: 388.16 ± 107.98 mg 100 g^-1; 6 DAS: 827.50 ± 172.38 mg 100 g^-1, respectively). Especially, total esters amount was almost doubled every day between 4 DAS and 6 DAS, so total amount of 6 DAS was about 4.30 times higher than that of 4 DAS. But following the compounds, their contribution to total contents change was different. Methyl butanoate and methyl hexanoate, which are known as the main components of esters, presented coefficient of determination (R² ) of 0.1442 and 0.5753, respectively. So, these compounds content change was not consistent with total esters ( Figures 6C, D ). But, in this period from 4 DAS to 6 DAS, among main esters, ethyl hexanoate exhibited different change trend following the treatments ( Figure 6E ). Compared to 3 DAS, ethyl hexanoate content on 4 DAS decreased in T1 (0.16 times) and T2 (0.65 times) but increased in T3 (5.12 times) and T4 (1.48 times). These differences were more pronounced on 5 DAS through the increase ratio compared to 3 DAS. T3 and T4 rapidly increased by 38.12 and 11.99 times, but T1 and T2 exhibited low change ratios of 0.41 and 1.88 times, respectively. Addition to ethyl hexanoate, benzyl acetate ( Figure 6F ) also ascribed to have similar patterns. It also reported to increase during the post-harvest period and related to the anthocyanin biosynthesis pathway (Fu et al., 2017). T2 group, which presented the lowest anthocyanins content on 4 DAS as illustrated in Figure 2 , showed the lowest benzyl acetate content on 5 DAS.

Not only esters but also furans showed a tendency to increase as the storage period is increased ( Figure 5H ). Two furan compounds (mesifuran and furaneol) were detected in ‘Seolhyang’ cultivar and in particular, regardless of storage period and treatment mesifuran was found to account for more than 77% of the total furans content so ascribed very strong correlation with 0.9923 of R² . While mesifuran (0 DAS: 14.65 ± 8.41 mg 100 g^-1;1 DAS: 36.88 ± 5.78 mg 100 g^-1; 2 DAS: 47.86 ± 16.01 mg 100 g^-1; 3 DAS: 116.20 ± 31.44 mg 100 g^-1; 4 DAS: 154.66 ± 22.82 mg 100 g^-1; 5 DAS: 208.87 ± 27.76 mg 100 g^-1; 6 DAS: 315.77 ± 28.24 mg 100 g^-1, respectively) increased steadily during the storage period ( Figure 6G ), furaneol, the other minor compound of furans, was dramatically changed from 4 DAS (8.78 ± 7.68 mg 100 g^-1) to 5 DAS (44.26 ± 7.79 mg 100 g^-1) ( Figure 6H ).