Performance of smooth cayenne pineapple under tropical conditions: unravelling effects of postharvest duration and ripening stage

1 Introduction

Pineapple (Ananas comosus L.), belonging to the family Bromeliaceae, is one of the most important tropical fruits cultivated globally (Kumar et al., 2023). It ranks third in world tropical fruit production, after banana and mango, and is highly valued for its distinctive flavor, nutritional composition, and economic contribution to both fresh fruit and processed industries (Lobo and Siddiq, 2017). The Smooth Cayenne variety, in particular, dominates global production due to its large fruit size, high juice content, and consumer-preferred balance of sweetness and acidity (Sossa et al., 2019). In Fiji, pineapple cultivation has expanded steadily in recent decades, contributing significantly to household incomes, local markets, and the hospitality sector, with the Smooth Cayenne variety being the most commonly grown cultivar (Brown, 2008). In Fiji, pineapple is an important horticultural crop, with national production reaching 6,350 tonnes in 2021, while agricultural projections indicated production of approximately 7,734 tonnes by 2024 (Ministry of Agriculture, 2021, Ministry of Agriculture, 2023). However, increased production also increases the quantity of fruit potentially exposed to postharvest losses when handling, storage, and marketing conditions are inadequate. A recent assessment of the Fiji pineapple value chain reported losses of 17.4% at the farm level and a further 8.2% at the market-vendor stage, resulting in an overall postharvest loss of 25.6% (Prasad, 2024). These losses highlight the importance of appropriate harvest maturity and postharvest handling practices to retain quality and reduce avoidable losses, particularly where fruit is stored and marketed under ambient tropical conditions.

Fruit quality is a key determinant of market value in pineapple production, and it is largely influenced by the stage of ripening at harvest and the subsequent postharvest handling period (Wahab and Khairuddin, 2020). Ripening is a complex physiological process that involves changes in color, texture, aroma, and soluble-solids content, which are driven by enzymatic and biochemical transformations (Hailu and Bekele, 2024). Unlike climacteric fruits, pineapples do not continue to ripen substantially once harvested, but physiological changes still occur that affect storage potential and consumer acceptability (Mohd Ali et al., 2022). Therefore, the decision of when to harvest plays a critical role in balancing fruit sweetness, size, and shelf life. Previous research has shown that pineapples harvested at early ripening stages may have greater storage potential but lower soluble-solids content, whereas fruits harvested at later stages generally have higher initial soluble-solids content but may deteriorate more rapidly (Mandal et al., 2024). As pineapple is a non-climacteric fruit, it does not continue to accumulate sugars after harvest; therefore, any subsequent increase in °Brix during storage is more likely attributable to water loss and concentration of existing soluble solids and/or changes in organic acids rather than new sugar synthesis. Postharvest duration further affects fruit attributes such as total weight, crown weight, dimensions, and °Brix (Barman et al., 2015). °Brix is an important indicator of sweetness, whereas titratable acidity (TA) contributes to sourness; therefore, the balance between °Brix and TA plays an important role in determining the overall sweet–acid flavor profile and consumer acceptability of pineapple (Gao et al., 2022). Postharvest weight loss is primarily associated with water loss through transpiration, with the exposed crown potentially contributing substantially to water loss because of its large leaf surface area (Yang et al., 2024). These parameters are not only important indicators of fruit quality for consumers but also essential for growers and traders seeking to minimize postharvest losses during transport and marketing.

In Fiji, postharvest losses in pineapples remain a challenge due to limited cold storage facilities, variable harvesting practices, and reliance on local markets where fruits are often sold in ambient conditions (Kaur and Watson, 2024). Temperature management is particularly important because pineapple is susceptible to chilling injury when exposed to temperatures below its tolerance range, which can result in internal browning, water-soaked tissue, loss of skin gloss, and increased susceptibility to decay (Tarmizi and Dolhaji, 2022). With increasing demand from the tourism sector and export opportunities, optimizing harvest timing in relation to ripening stage and storage duration is vital for enhancing fruit quality and prolonging shelf life (Ministry of Agriculture and Waterways [MOAW], 2025). However, research on the interaction between these factors in Fiji’s tropical environment remains limited. This study therefore aims to evaluate the effects of postharvest duration and ripening stage on the performance of Smooth Cayenne pineapple in Fiji. Specifically, it investigates how these factors influence fruit weight, crown weight, dimensions, and °Brix content across different ripening stages. The study provides evidence-based insights and seeks to guide farmers and stakeholders in adopting appropriate harvest and storage strategies that improve fruit quality, reduce postharvest losses, and strengthen the competitiveness of Fiji’s pineapple industry.

2 Materials and methods

2.1 Experimental site

The experiment was carried out at the Seaqaqa Research Station during the year 2023 and 2024 (i.e., two seasons), under the Crop Research Division of the Ministry of Agriculture, Waterways and Sugar Industry, Fiji. The station is located approximately 57 km southwest of Labasa on the dry western side of Vanua Levu, Fiji (latitude: 16°28’34.33”S; longitude: 179° 9’27.33”E; elevation: 101 m above sea level) (Figure 1). The site experiences a tropical maritime climate, characterized by consistently warm temperatures, high relative humidity, and distinct wet and dry seasons. Average annual rainfall is 1,660.4 mm, with the majority occurring between November and April, while the drier months extend from May to October. Mean daily temperatures range from 23.9 to 31.2 °C. Seaqaqa Research Station was established in 1956 for research on pastures and annual crops such as rice and pulses. In the early 1960s, research was initiated on perennial crops such as coconuts, cotton, coffee, cocoa, citrus, pineapples, and ground nuts. Since 1967, work has concentrated on citrus, pineapples, and cashew nuts. It covers 110 ha of mainly undulating and rolling land which is typical of more than 65000 ha of potentially arable ‘Talasiga’ land in Macuata Province. The Seaqaqa Research Station has soils primarily belonging to the Ultisols and Oxisols orders, with smaller areas of Inceptisols and Entisols. Ultisols make up about 53% of the area, including Oxic Paleustults and Typic Paleustults, while Oxisols cover 43%, consisting of Typic Acrustox, Typic Haplustox, and Aquic Umbriorthox. This soil is well-suited to pineapple production due to its good drainage and fertility. These environmental and edaphic conditions collectively provide an ideal setting for evaluating the postharvest performance of Smooth Cayenne pineapple under Fiji’s tropical conditions.

2.2 Plant material and experimental design

Smooth Cayenne pineapple (Ananas comosus L. Merr.) fruits were collected from a uniform production block at the Seaqaqa Research Station, Fiji, during the peak fruiting season. Forty physiologically mature fruits were harvested and visually inspected, and only fruits showing no visible symptoms of disease or decay, bruising, mechanical damage, or other external defects were selected. The selected fruits were further screened for uniformity in size, shape, and external appearance. The fruits were classified into four ripening stages based on the proportion of external yellowing: S1 (25% ripe, with slight yellowing at the fruit base), S2 (50% ripe, with approximately half of the fruit yellow from the base toward the midsection), S3 (75% ripe, with approximately three-quarters of the fruit yellow and the upper portion remaining green), and S4 (100% ripe, with the fruit fully yellow). The experiment was arranged in a completely randomized design (CRD), with ripening stage as the treatment factor. Ten fruits were assigned to each ripening stage, giving a total of 40 experimental units. Each fruit was considered an independent experimental unit. Following harvest, the same 40 fruits were maintained under ambient storage conditions and monitored repeatedly throughout the postharvest storage period. Measurements were recorded daily from Day 0 to Day 14, resulting in 15 observation points for each fruit. Thus, the daily observations represented repeated measurements of the same fruits rather than additional independent replications.

2.3 Postharvest handling and data collection

After harvest, the selected fruits were thoroughly washed with clean water to remove soil particles and field debris, then air-dried at room temperature having ambient conditions at 27 ± 2 °C and 85 ± 5% RH. No refrigeration or controlled atmosphere techniques were applied, as the study aimed to assess fruit performance under practical, farmer-level and market-level storage conditions. Data were recorded at daily intervals throughout the 14 day storage period. The quality parameters assessed included fruit weight, measured in kilograms using a digital weighing balance, and crown weight, determined after carefully separating the crown from the fruit. Total fruit weight was calculated as the combined weight of the fruit and crown. Fruit weight and crown weight were recorded separately; therefore, total fruit weight was expected to equal the sum of these two components. Fruit dimensions, including length and diameter, were measured in centimeters using a Vernier caliper to evaluate changes in size and structure during storage. Among the biochemical quality attributes, only °Brix was measured. Titratable acidity, individual sugars, total sugars, organic acids, and starch were not measured. Therefore, °Brix was used as an indicator of soluble-solids concentration rather than a direct measurement of sugar accumulation. Shelf life was evaluated based on visual symptoms of deterioration, including shriveling, fungal decay, and general loss of market acceptability. These observations allowed for a comprehensive assessment of both physical and biochemical changes in Smooth Cayenne pineapples across different ripening stages and storage durations.

2.4 Statistical analysis

All data were analyzed using R software (R Core Team, 2025). One-way analysis of variance (ANOVA) was used to compare fruit quality parameters among the four ripening stages (S1–S4) at each observation day. Treatment means were compared using the least significant difference (LSD) test at the 5% probability level (P < 0.05). To evaluate temporal trends and the combined effects of ripening stage and postharvest duration, multiple linear regression analysis was performed with total fruit weight as the dependent variable and storage day, ripening stage, and their interaction as explanatory variables. The interaction term was included to determine whether the relationship between storage duration and total fruit weight differed among ripening stages. Model significance was evaluated using the F-test, and regression coefficients were interpreted based on their magnitude, direction, and statistical significance. This regression approach provided a multifactorial assessment of storage duration, ripening stage, and their interaction, complementing the day-specific comparisons obtained from one-way ANOVA. Additionally, Kaplan–Meier survival analysis was used to estimate postharvest shelf life across the four ripening stages (S1–S4). The time to spoilage was recorded, and survival curves were generated to assess differences in deterioration over the storage period.

3 Results

3.1 Variability in fruit weight, crown development and brix during early ripening (S1 - 25% ripening)

Fruit weight, crown development, and °Brix exhibited marked variability across harvest days at the S1 stage (25% ripening) (Table 1). Total fruit weight ranged from 1.39 kg on day 4 to a maximum of 2.42 kg on day 6, with individual fruit weight following a similar pattern and peaking at 2.10 kg. Significant differences (P < 0.05) were detected for total fruit weight, with day 6 recording the highest value, whereas fruits harvested on days 4 and 10 were comparatively lighter. Crown weight was greatest on day 5 (0.34 kg) and lowest on day 10 (0.19 kg), although most other days were statistically similar, indicating moderate stability in crown development during early ripening. Total fruit length and fruit length showed modest fluctuations, with the longest fruits observed on day 6 (46.00 cm and 18.00 cm, respectively), corresponding with the peak in fruit weight. The shortest fruits occurred on day 4 (37.00 cm total length). Fruit circumference and diameter did not differ significantly (P > 0.05) across sampling days, suggesting that these dimensions were less responsive to harvest timing at 25% ripening. °Brix content ranged from 12.60% on day 3 to 16.70% on days 5 and 9. The highest °Brix values coincided with moderate fruit weights, indicating that sugar accumulation was not directly correlated with maximum fruit size.

Table 1. Effect of days at S1 (25%) ripening on fruit weight, crown weight, dimensions, and °Brix.

Values are presented as mean ± standard error (SE). Means followed by different letters within a column are significantly different at P < 0.05 according to LSD test.

3.2 Influence of harvest timing on fruit mass and sugar accumulation at S2 (50% ripening)

The effect of harvest days at the S2 stage (50% ripening) on fruit weight, crown weight, fruit dimensions, and °Brix showed distinct variation across the 15-day sampling period (Table 2). Total fruit weight ranged from 1.13 kg on day 11 to a maximum of 2.84 kg on day 2. Individual fruit weight followed a similar trend, peaking at 2.47 kg on days 2 and 3, while the lowest weight (1.01 kg) occurred on day 11. Significant differences (P < 0.05) were detected among sampling days, with early harvests (days 2-3) producing substantially heavier fruits compared with mid- to late-period harvests. Crown weight remained relatively stable throughout the sampling period, ranging between 0.12 kg and 0.38 kg, with no significant differences except for the lowest value recorded on day 11. This stability indicates that crown development was less sensitive to harvest timing during S2 ripening. Fruit dimensions exhibited moderate variability. Total fruit length ranged from 34.00 cm (day 11) to 47.50 cm (day 3), while fruit length varied between 15.00 cm (day 12) and 32.00 cm (day 1). Fruit circumference and diameter showed comparable trends, with day 2 recording the largest diameter (14.10 cm) and day 11 the smallest (10.50 cm). These results suggest that fruit elongation and expansion continued during early S2 ripening but declined in later stages. °Brix ranged from 13.00% on day 2 to 17.00% on days 5 and 12. Notably, some of the heaviest fruits (days 2-3) displayed lower °Brix values, whereas fruits harvested later in the period exhibited higher sugar content despite reduced fruit weight.

Table 2. Effect of days at S2 (50%) ripening on fruit weight, crown weight, dimensions, and °Brix.

Values are presented as mean ± standard error (SE). Means followed by different letters within a column are significantly different at P < 0.05 according to LSD test.

3.3 Changes in fruit traits during advanced ripening stage (S3 - 75% ripening)

Fruit traits assessed at the S3 stage (75% ripening) showed significant variability in fruit weight, crown weight, physical dimensions, and °Brix across the 15-day sampling period (Table 3). Total fruit weight ranged from 0.37 kg on day 15 to a maximum of 2.78 kg on day 3, while individual fruit weight peaked at 2.37 kg on day 3 and declined to 1.01 kg on day 14. Significant differences (P < 0.05) were detected among days, indicating that fruit mass was highly responsive to harvest timing during advanced ripening. Crown weight remained relatively stable, varying from 0.06 kg to 0.41 kg, with the lowest values recorded on the final harvest days (days 14-15). This pattern suggests a reduction in crown biomass toward late ripening. Fruit dimensions also exhibited moderate fluctuations, with maximum total fruit length (50.00 cm) and circumference (45.50 cm) recorded on day 3, corresponding with the highest fruit weight. The smallest dimensions occurred on days 13-15, reflecting shrinkage and loss of turgidity in over-mature fruits. °Brix ranged from 15.00% to 18.40%, with the highest values observed on day 5. Notably, peak brix did not coincide with maximum fruit weight, suggesting that sugar accumulation continued even as fruit size plateaued or declined.

Table 3. Effect of days at S3 (75%) ripening on fruit weight, crown weight, dimensions, and °Brix .

Values are presented as mean ± standard error (SE). Means followed by different letters within a column are significantly different at P < 0.05 according to LSD test.

3.4 Stability of fruit mass and continued sugar accumulation at full maturity (S4 - 100% ripening)

At the S4 stage (100% ripening), fruit weight, crown weight, dimensions, and °Brix exhibited moderate variation across the 10-day harvest period (Table 4). Total fruit weight ranged from 1.82 kg on day 7 to a maximum of 2.58 kg on day 4, while individual fruit weight varied between 1.47 kg (day 7) and 2.30 kg (day 4). Statistical analysis revealed no significant differences (P > 0.05) among most days, indicating relative stability in fruit mass at full ripening. Crown weight was consistent across harvest days, ranging from 0.26 kg to 0.61 kg, with the highest value recorded on day 8. This variability may be associated with water retention or senescence processes typical of the final ripening stage. Fruit dimensions showed limited variation, with total fruit length ranging from 40.00 cm (day 9) to 47.50 cm (day 2). Fruit diameter peaked at 15.40 cm on day 2 and was lowest (11.50-12.40 cm) on later harvest days. These results indicate that fruit expansion had largely stabilized at S4, with minor reductions likely due to water loss or softening. °Brix ranged from 13.20% (day 3) to 18.40% (day 8), demonstrating continued sugar accumulation even at the fully ripe stage. The highest °Brix did not coincide with the largest fruit weight, suggesting an inverse relationship between fruit size and sweetness.

Table 4. Effect of days at S4 (100%) ripening on fruit weight, crown weight, dimensions, and °Brix.

Values are presented as mean ± standard error (SE). Means followed by different letters within a column are significantly different at P < 0.05 according to LSD test. Measurements for S4 (100% ripening) from Day 11 to Day 15 were not taken because the fruits were completely spoiled and were no longer suitable for assessment.

3.5 Effect of ripening stage on fruit quality attributes

The influence of ripening stage on fruit weight, dimensions, crown weight, and °Brix revealed significant differences among stages (Table 5). Total fruit weight increased progressively from S1 (1.84 kg) to S4 (2.18 kg), with S4 exhibiting significantly higher weight than S1 and S3 (P < 0.05). The regression trend indicates a negative relationship between the number of days and total fruit weight across all stages, with the rate of decline varying among them (Figure 2A). While S3 showed the steepest decrease, S4 maintained a relatively stable pattern with minimal reduction, suggesting that fruits at this stage sustained higher weight over time compared with earlier stages. Individual fruit weight followed a similar trend, peaking at 1.84 kg at S4, indicating that mass accumulation continued through the ripening process, with maximum weight achieved at full maturity. Figure 2B shows a negative relationship between the number of days and fruit weight across all stages, though the slopes varied. Stage S3 exhibited the steepest decline, indicating a faster reduction in fruit weight with time, whereas S1 and S2 showed relatively mild slopes, and S4 maintained a gentle decline, suggesting greater mass stability at advanced ripening. Crown weight also increased significantly at S4 (0.35 kg) compared with earlier stages, suggesting continued biomass development or retention of water and structural components at full ripeness. In contrast, S1, S2, and S3 showed relatively similar crown weights, indicating stability in crown development during early to mid-ripening. The regression trend illustrates a slight negative relationship between the number of days and crown weight across all stages (Figure 2C). Although the slopes were shallow, S3 displayed the steepest decline, while S4 maintained a stable pattern, suggesting that crown tissue remains more resilient at advanced ripening.

Table 5. Effect of ripening stage on fruit weight, dimensions, crown weight, and °Brix.

Values are presented as mean ± standard error (SE). Means followed by different letters within a column are significantly different at P < 0.05 according to LSD test.

Fruit dimensions varied significantly across ripening stages (Table 5). Total fruit length was highest at S4 (44.20 cm) and S2 (43.50 cm), while S3 recorded the lowest value (39.90 cm), indicating that fruit elongation is largely achieved by mid- to late ripening. Regression trends showed a slight decline or stabilization of fruit length over time across stages, with S3 exhibiting the steepest negative slope, suggesting that elongation slows or ceases as ripening progresses (Figure 2D). Fruit circumference and diameter followed a similar trend, with the largest values observed at S4 (41.80 cm and 12.90 cm, respectively), reflecting continued fruit expansion and turgor maintenance at full maturity. Regression trends indicated generally stable or slightly declining values across harvest days, with S3 showing the steepest negative slopes for both parameters (Figures 2E, F). This suggests that early and mid-ripening stages maintain relatively constant dimensions, whereas later stages may experience gradual shrinkage due to softening and moisture loss as fruits approach over-maturity. °Brix increased progressively from 15.00% at S1 to 16.40% at S4, with the highest value recorded at full ripening (Table 5). The regression trend showed an upward trajectory across stages, particularly at S2 and S4, indicating that sugar accumulation continued throughout ripening (Figure 2G). In contrast, S3 exhibited a slight negative slope, suggesting temporary fluctuations in sugar concentration that may reflect dilution effects or transient metabolic adjustments.

3.6 Postharvest shelf-life

The Kaplan–Meier survival analysis was used to estimate and compare the postharvest shelf life of fruits across four ripening stages (S1-S4) under ambient storage conditions. The survival curves revealed distinct patterns of deterioration among stages, reflecting variations in fruit physiology and susceptibility to spoilage. At S1, fruits exhibited the longest postharvest stability, maintaining a survival probability of 1.0 (100%) for approximately 7.5 days (Figure 3A). Deterioration began gradually thereafter, with the survival probability declining to 0.5 by day 10 and reaching zero by day 13, indicating a median shelf life of approximately 10 days. Fruits at S2 maintained full quality for the first 5 days, after which spoilage progressed rapidly. The survival probability decreased to 0.5 by day 7 and reached zero by day 10, corresponding to a median shelf life of 7 days (Figure 3B). Compared with S1, fruits at S2 deteriorated more quickly, suggesting greater physiological activity and increased susceptibility to senescence processes. At S3 (75% ripening), the spoilage rate increased significantly compared with earlier stages. All fruits remained in good condition up to day 5, after which a sharp decline in survival probability to 0.25 was observed, indicating rapid deterioration of most samples. The survival curve then plateaued at 0.25 until day 15, suggesting that a single fruit resisted spoilage longer than the others (Figure 3C). The median shelf life was estimated at approximately 5 days, reflecting high perishability and reduced storage stability at this ripening stage. Fruits at S4 (100% ripening) exhibited a spoilage pattern similar to that of S3. All fruits maintained acceptable quality until day 5, followed by an abrupt decline in survival probability to 0.25 and complete spoilage by day 9 (Figure 3D). The median shelf life was again estimated at around 5 days. The consistency between S3 and S4 in both median survival time and deterioration trend suggests a physiological threshold beyond which fruits are unable to maintain postharvest quality under ambient conditions. Across all ripening stages (S1-S4), the Kaplan-Meier curves indicated a progressive decline in shelf life with increasing ripeness, reflecting the accelerating rate of senescence and spoilage as fruits approach full maturity.

4 Discussion

4.1 Physiological and biochemical drivers of variability in fruit growth and quality attributes across ripening stages

The observed variability in fruit weight and dimensions during early ripening likely reflects active physiological changes, including cell expansion, water accumulation, and changes in fruit composition (Hung et al., 2024). The observed differences in fruit mass among observation days should not be interpreted as continued postharvest biomass accumulation, because harvested pineapple fruit does not continue to grow. Conversely, the elevated °Brixlevels on days 5 and 9 indicate higher soluble-solids concentration rather than continued sugar accumulation, which may be associated with changes in fruit water status during storage. These findings highlight that changes in soluble-solids concentration and physical characteristics do not necessarily progress synchronously, a pattern consistent with earlier reports showing that soluble solids may increase independently of fruit mass (Centeno et al., 2011; Burdon et al., 2016). The results emphasize the importance of precise harvest timing to balance fruit maturity, soluble-solids content, and market quality in supporting previous observations that fruit quality attributes are strongly influenced by physiological maturity and postharvest dynamics (Prasad et al., 2018).

The variability in fruit mass and soluble-solids concentration during S2 ripening indicates an active transition between the growth and maturation phases. The higher fruit weights observed during early harvest days (days 2–3) suggest that physiological maturity at 50% ripening strongly influences fruit mass accumulation, consistent with previous findings that fruit weight typically peaks during the early stages of ripening (Kamol et al., 2014; Kumara and Hettige, 2020). However, fluctuations in fruit weight during postharvest storage should not be interpreted as continued biomass accumulation or fruit growth. The reported values represent the mean weight of the same 10 fruits within each treatment measured repeatedly at each observation date. The subsequent decline in fruit size and length toward later harvests may be associated with progressive moisture loss and changes in fruit condition during storage, as reported in pineapple during postharvest storage (Fauzan and Budirokhman, 2025). In contrast, the increase in °Brix during mid- to late-period harvests suggests an increase in soluble-solids concentration, which may be associated with water loss and moisture redistribution rather than intensified sugar accumulation after harvest. The inverse relationship between fruit size and soluble-solids concentration can vary independently of fruit growth due to shifts in fruit water status and compositional changes during ripening (Durán-Soria et al., 2020; Ren et al., 2023).

The pronounced variability in fruit weight and dimensions during S3 indicates that fruits had reached an advanced physiological stage where growth had slowed, and metabolic processes shifted toward ripening and senescence. The decline in fruit mass observed after day 3 supports previous findings that fruit weight typically decreases after reaching peak maturity due to water loss, reduced cell turgor, and tissue degradation (Alós et al., 2019; Baseer et al., 2024). Similarly, the reduction in crown weight during late ripening may be associated with water loss and progressive changes in crown tissue condition rather than nutrient redistribution, which was not measured in this study. The contraction in fruit dimensions during the later observation days further supports the possible contribution of moisture loss and changes in tissue condition, consistent with similar patterns reported in other fruits and postharvest quality changes in pineapple during storage (Rahman et al., 2014; Siddiqui et al., 2018; Fauzan and Budirokhman, 2025). In contrast, the increase in °Brix despite declining pineapple fruit mass indicates an increase in the concentration of existing soluble solids, potentially associated with water loss and moisture redistribution, rather than continued carbohydrate accumulation or new sugar synthesis after harvest (Azhari and Basri, 2025). Collectively, these results indicate that fruits harvested during early to mid-S3 ripening (around days 3–5) exhibit a favorable balance between physical quality and soluble-solids concentration, whereas late-stage harvests result in diminished physical quality despite stable or elevated °Brix values. This reinforces the importance of precise harvest timing to maintain both marketable appearance and desirable soluble-solids concentration during advanced ripening.

The results at S4 demonstrate a comparatively stable pattern in fruit mass and dimensions, suggesting that major changes in fruit size had largely occurred by full maturity, consistent with the established use of physical and chemical characteristics to assess physiological maturity in Smooth Cayenne pineapple (Bartholomew and Sanewski, 2018). The absence of significant weight differences among harvest days supports the notion that fruit growth plateaus at full maturity, as cellular expansion ceases and water content stabilizes (Ezura and Hiwasa-Tanase, 2009; Nardozza and Burdon, 2023). Minor declines in fruit size and diameter during later harvests likely result from gradual dehydration and softening of parenchymal tissues, processes commonly associated with late-stage ripening (Saladié et al., 2007). The continued presence of relatively high °Brix values despite stable fruit mass indicates differences in soluble-solids concentration rather than ongoing sugar accumulation after harvest, consistent with the established relationship between maturity and soluble-solids content in Smooth Cayenne pineapple (Sylla et al., 2026). This difference between soluble-solids concentration and fruit size has been widely reported in other tropical and climacteric fruits, where water redistribution and changes in tissue composition contribute to enhanced soluble solids during the final ripening phase (Chen et al., 2021; Fernie and Martinez-Rivas, 2025). Findings highlight that fully mature fruits maintain stable structural integrity but undergo continued postharvest changes in soluble-solids concentration and tissue condition. While harvesting at this stage ensures high initial soluble-solids content and desirable maturity, delayed harvest may increase the risk of postharvest softening and reduced shelf life.

4.2 Physiological and quality transitions across ripening stages

The observed differences in fruit weight, dimensions, and crown mass across ripening stages reflect dynamic physiological and biochemical transitions during fruit maturation. The differences in total and individual fruit weight across ripening stages primarily reflect maturity-related differences at harvest rather than continued postharvest mass accumulation. Because the same fruits were repeatedly measured, occasional increases in mean fruit weight between observation days should not be interpreted as biological growth or new biomass formation. The reduced rate of decline in fruit weight at S4 suggests variation in the extent of postharvest weight loss compared with earlier stages, likely due to the establishment of stronger cell wall integrity and reduced transpiration rates. The steep reduction in fruit weight observed at S3 progressive postharvest deterioration, during which water loss and respiration contribute to declining fruit mass This trend parallels findings in other tropical fruits where mid-ripening marks the onset of metabolic transitions from growth-related to degradation processes (Burdon et al., 2016; Baseer et al., 2024). Pineapple-specific studies have reported increasing weight loss during storage and differences in weight loss among maturity stages, supporting the importance of fruit maturity in determining subsequent postharvest behavior (Xing et al., 2022). The relatively stable pattern in S4 implies that mature fruits retained their physical characteristics for longer during the observation period rather than maintaining mass equilibrium through continued biochemical activity. The significant increase in crown weight at S4 may reflect differences in crown water status or tissue condition. The importance of the pineapple crown to postharvest quality has been demonstrated previously, with crown removal reported to accelerate quality deterioration and shorten shelf life (Liu et al., 2017).Such patterns have been associated with nutrient and moisture redistribution to support residual metabolic functions (Paull and Chen, 2003). The minor decline in crown mass at S3 further suggests that crown tissue undergoes transient dehydration before reaching maturity. Results demonstrate that fruit and crown physical characteristics and their subsequent changes during storage, rather than continued biomass accumulation, are strongly influenced by ripening progression. Understanding these transitions provides a physiological basis for optimizing harvest timing to balance fruit maturity, soluble-solids content, and structural quality in Smooth Cayenne pineapple.

The increase in fruit dimensions and °Brix across ripening stages highlights the coordinated progression of physical and biochemical maturation in Smooth Cayenne pineapple. The larger fruit length, circumference, and diameter observed at S4 confirm that expansion and cell wall development persist until late ripening, after which structural growth plateaus (Thakur and Kumar, 2017). The minor reductions in fruit dimensions at S3 and later harvests likely result from water loss and tissue softening, processes characteristic of over-mature fruit nearing senescence (Prasad et al., 2018). The stabilization of fruit dimensions after mid-ripening suggests that cell expansion ceases once turgor and water content reach equilibrium. Such patterns are consistent with previous studies showing that pineapple fruits undergo limited morphological change beyond 75–100% maturity (Burdon et al., 2016). The negative slopes in regression trends, particularly at S3, indicate changes in fruit dimensions during the observation period but do not by themselves establish a specific physiological mechanism. The progressive increase in °Brix from S1 to S4 reflects differences in soluble-solids concentration associated primarily with maturity at harvest rather than active sugar synthesis or conversion of stored starches after harvest (Gao et al., 2022). Consistent studies identified soluble-solids content as an important indicator of physiological maturity in Smooth Cayenne pineapple (Fauzan and Budirokhman, 2025).The highest °Brix at S4 demonstrates that fully mature fruits had the highest soluble-solids concentration, rather than necessarily indicating peak sweetness. The intermediate °Brix values at S2 and S3 indicate that soluble-solids concentration does not necessarily change synchronously with physical growth, corroborating findings that fruit soluble-solids concentration may vary independently of size (de Freitas et al., 2024). Since only °Brix was measured, the present study cannot distinguish changes in individual sugars or quantify changes in total sugar concentration. Therefore, increases in °Brix during storage should be interpreted as changes in soluble-solids concentration rather than direct evidence of sugar accumulation. Measurements of titratable acidity, individual sugars, total sugars, and organic acids would provide a more complete assessment of biochemical changes during pineapple ripening and postharvest storage. The slight negative slope observed for S3 suggests transient fluctuations in soluble solids concentration, possibly due to changes in fruit water status and moisture redistribution rather than temporary metabolic shifts during the ripening transition (Li et al., 2024). Collectively, these results demonstrate that while fruit dimensions stabilize at full maturity, postharvest changes in soluble-solids concentration may continue, primarily reflecting water loss and moisture redistribution rather than active sugar accumulation.

4.3 Postharvest behavior and shelf-life dynamics across ripening stages

The observed differences in shelf life across ripening stages highlight the strong influence of physiological maturity on postharvest behavior. Fruits harvested at S1 (25% ripening) retained quality for a significantly longer period, likely due to their less advanced maturity and greater physical firmness at harvest, rather than assuming lower respiration rates or reduced ethylene sensitivity (Ansari and Tuteja, 2015). The gradual decline in survival probability after day 7 corresponds with progressive postharvest deterioration associated with moisture loss, changes in tissue condition, and microbial development, processes documented in pineapple during storage (Alonso-Salinas et al., 2024; Sanchez et al., 2026). In contrast, the shorter shelf life observed at S2 (50% ripening) suggests that as fruits advance toward mid-ripening, the balance between physiological maturity and metabolic stability shifts toward rapid deterioration. The decline in survival probability after day 5 can be attributed to moisture loss, tissue softening, and progressive deterioration of structural integrity, all of which reduce structural quality and promote microbial spoilage (Das and Sharma, 2025). The marked reduction in shelf life observed at S3 and S4 underscores the susceptibility of advanced-ripening fruits to rapid senescence under ambient storage. At these stages, changes in tissue condition, moisture loss, and microbial development may collectively contribute to the observed decline in quality, although the individual physiological processes were not directly measured in this study (Lohita and Srijaya, 2024). Pineapple-specific postharvest studies similarly demonstrate progressive quality deterioration during storage, including weight loss and changes in flesh quality (Hassan et al., 2011). The abrupt decline in survival probability after day 5 indicates that once physiological defenses are compromised, deterioration proceeds rapidly and irreversibly. The parallel spoilage trajectories of S3 and S4 suggest similar limitations in postharvest resilience under the ambient storage conditions used in this study. Pineapple postharvest literature indicates that advanced maturity and unfavorable storage conditions can increase susceptibility to quality deterioration and shorten marketable life (Kamol et al., 2014; Mohd Ali et al., 2022). This finding is consistent with pineapple-specific evidence showing that fruit maturity at harvest influences subsequent weight loss and soluble-solids content during storage, with differences among maturity stages affecting postharvest quality (Sukporn et al., 2019). The progressive decline in median shelf life from S1 (10 days) to S4 (5 days) reflects a typical ripening–spoilage continuum, emphasizing that each incremental stage of maturity entails a trade-off between initial soluble-solids concentration and storability. Fruits harvested at S1 exhibit the longest postharvest stability but may have lower initial °Brix, while those at S4 attain higher initial soluble-solids concentration but deteriorate more rapidly. These results reinforce the need for targeted postharvest management practices to extend storage life of advanced-ripening fruits. Strategies such as appropriate temperature management, waxing, modified-atmosphere approaches, and edible coatings have been investigated for maintaining pineapple quality and extending postharvest storage life (Liao et al., 2023; Sanchez et al., 2026) Adoption of such techniques could therefore enhance the commercial viability of fruits harvested at later ripening stages without compromising quality.

5 Conclusions

At early ripening (S1, 25%), fruit weight and length showed fluctuations across observation days, and these variations should not be interpreted as continued postharvest biomass accumulation. Notably, higher °Brix values were observed on days 5 and 9, reflecting changes in soluble-solids concentration rather than continued sugar accumulation after harvest. In S2 (50% ripeness), fruits were generally heavier during the earlier observation period, whereas higher °Brix was observed during the mid- to late-period observations, indicating that changes in soluble-solids concentration did not necessarily occur synchronously with physical fruit characteristics. As ripening advanced (S3, 75%), fruit weight and size showed declines after the initial observations, while °Brix remained relatively high, indicating advanced physiological maturity and higher soluble-solids concentration. At full ripeness (S4, 100%), fruit dimensions and crown weight showed comparatively stable patterns, while °Brix remained comparatively high, reflecting changes in soluble-solids concentration associated with fruit maturity and postharvest water status rather than ongoing sugar accumulation. These trends indicate that physical fruit characteristics and soluble-solids concentration do not necessarily change in parallel during ripening and subsequent storage. Differences among ripening stages primarily reflect maturity at harvest, while fluctuations during storage should be interpreted as postharvest changes in fruit condition rather than continued fruit growth or biomass accumulation. The Kaplan-Meier survival analysis further revealed that ripening stage strongly affected postharvest shelf life. Fruits harvested at S1 exhibited the longest storability, maintaining acceptable quality for up to 13 days, with a median shelf life of 10 days. In contrast, fruits at S2 showed moderate shelf life (with a median of approximately 7 days), while those at S3 and S4 deteriorated rapidly, with most spoilage occurring within 5 days. The sharp declines in survival probability at later stages highlight the vulnerability of more advanced-ripening fruits to postharvest deterioration and microbial decay under ambient conditions. These findings highlight the importance of aligning harvest timing not only with fruit maturity and soluble-solids content but also with market logistics and storage capacity. The study provides useful evidence for selecting harvest stages according to the desired balance between physical fruit quality, soluble-solids concentration, and postharvest shelf life. Early- to mid-stage harvests generally favor greater storability and may provide greater flexibility for marketing, while later stages provide higher initial soluble-solids concentrations but shorter postharvest shelf life. This information is particularly valuable for producers aiming to target different market segments, whether for fresh consumption, where extended shelf life is important, or for processing industries that may prioritize fruits with higher initial soluble-solids content.

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Footnotes

Edited by: Vikas Dadwal, Texas A and M University, United States

Reviewed by: Amit Kumar Kesharwani, Louisiana State University, United States

Ashwani Punia, Institute of Himalayan Bioresource Technology (CSIR), India