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The distinction between climacteric and non-climacteric behavior sits at the heart of why harvest timing matters so much for pineapple. Fruits classified as climacteric, such as banana or mango, experience a pronounced respiratory surge after harvest and can continue to ripen appreciably once detached from the plant. Pineapple, by contrast, is generally treated as non-climacteric or only weakly climacteric, which means that sugars accumulated before harvest largely represent the sweetness ceiling the fruit will ever reach. Once the fruit is cut, starch reserves in the flesh are limited, so there is little substrate available for postharvest sugar synthesis. This physiological reality explains a seemingly paradoxical observation in the Fiji study: °Brix values in some treatments, most notably the S2 fruit harvested at the 50 percent ripening stage, continued to climb during storage and reached 17.00 °Brix by Day 12. Rather than new sugar being manufactured inside the fruit, this rise is best understood as a concentration effect. As water is lost through transpiration, the same pool of dissolved solids occupies less volume, so the refractometer reading climbs even though the absolute quantity of sugar has not increased. Changes in organic acid metabolism can also shift the perceived balance, since acids are respired over time and their decline can make a fruit taste sweeter even at a constant sugar concentration.

Water loss itself deserves closer attention because it drives several of the physical changes documented in the study. The pineapple crown, with its large surface area of leaves, is not merely an ornamental appendage; it can act as a substantial conduit for moisture, drawing water from the fruit or losing it directly to the surrounding air. Under the ambient conditions of the trial, held at 27 ± 2 °C and 85 ± 5 percent relative humidity, the vapor pressure deficit between the fruit surface and the atmosphere determines the rate of transpiration. Warm air holds more moisture, and when that air is not saturated, water migrates out of the fruit. The observed declines in fruit weight and dimensions after the early-storage peaks, particularly in the S3 treatment where weight and dimensions were greatest around Day 3 and then fell away, are consistent with this process. Weight loss not only reduces saleable mass, which matters economically when fruit is traded by the kilogram, but also causes visible wilting, shell shriveling, and a loss of the glossy appearance that consumers associate with freshness.

The °Brix measurement itself merits explanation for readers less familiar with postharvest physiology. A degree Brix corresponds roughly to one gram of sucrose per one hundred grams of solution, and although a refractometer reading actually reflects all dissolved solids, including organic acids and other compounds, sugars dominate the signal in pineapple juice. Because sweetness perception depends on the ratio of sugars to acids rather than on sugar content alone, °Brix on its own is an incomplete descriptor of eating quality. Two fruits with identical soluble-solids readings can taste very different if one carries substantially more titratable acidity. The authors of the study acknowledge this limitation directly, noting that titratable acidity, along with firmness, weight loss, microbial deterioration, and physiological disorders, should be incorporated into future work. The sugar-to-acid ratio, often called the maturity index in commercial practice, is the metric that most closely tracks consumer acceptability in pineapple, and its absence from the current dataset means the flavor implications of the observed °Brix trajectories remain provisional.

The finding that shelf life shortened as harvest maturity advanced follows a well-established pattern in tropical fruit handling, but the magnitude of the trade-off is what gives the result practical weight. Fruit harvested at S1, the 25 percent ripening stage, retained storability longer than any other treatment, giving handlers the widest window for transport, holding, and retail display. Fruit harvested at S4, fully ripe at harvest, offered the highest initial soluble-solids concentrations but the least flexibility, since any delay in marketing pushed the fruit past acceptable quality. This trade-off maps directly onto the structure of Fiji’s pineapple supply chain. Fruit destined for distant export markets or for processors who can hold product in cold storage can tolerate, and indeed may require, earlier harvest. Fruit sold into local municipal markets, roadside stalls, or the hospitality sector, where the interval between harvest and consumption is short, can be picked riper and still reach the consumer in good condition. The study’s central recommendation, that harvest maturity should be matched to the intended marketing channel, is essentially an instruction to treat ripening stage at harvest as a logistics decision rather than a purely agronomic one.

The context of Fiji’s postharvest losses sharpens the significance of these findings. The value-chain assessment cited in the article reported losses of 17.4 percent at the farm level and a further 8.2 percent at the market-vendor stage, for a combined 25.6 percent. In practical terms, roughly one quarter of the national pineapple crop never reaches a consumer in saleable condition. With national production recorded at 6,350 tonnes in 2021 and projected to approach 7,734 tonnes by 2024, even modest improvements in postharvest handling translate into meaningful absolute quantities of recovered fruit and income. Because the study was conducted entirely under ambient conditions rather than in refrigerated storage, its results describe the reality faced by most smallholder producers and informal market vendors in the country, for whom cold chain access is limited or absent. Ambient storage at tropical temperatures accelerates respiration, transpiration, and microbial growth simultaneously, compressing the window in which fruit remains marketable.

Temperature management deserves particular emphasis in this context because pineapple occupies an awkward middle ground among tropical fruits. It is chilling-sensitive, and exposure to temperatures below its tolerance range can trigger internal browning, water-soaked flesh, loss of shell gloss, and heightened susceptibility to decay. This rules out the aggressive low-temperature storage that works for temperate fruits, forcing handlers to operate within a narrower thermal band. The susceptibility to chilling injury also means that simply installing refrigeration is not a complete solution; storage protocols must respect the fruit’s physiological limits. Research into improved storage technologies, which the authors flag as a priority, would need to account for this constraint, exploring approaches such as controlled atmosphere storage, waxing, modified-atmosphere packaging, and careful humidity management that slow water loss without pushing temperatures into the injury zone.

The crown’s role in the water economy of the fruit is a detail with direct commercial implications. In many markets, pineapples are sold with crowns attached for aesthetic reasons and as a freshness indicator, yet the crown’s leaf surface area makes it an active site of transpiration. Removing or trimming the crown can reduce overall water loss and extend effective shelf life, a practice already common in some export supply chains. The study’s measurement of crown weight across ripening stages and storage days provides a foundation for quantifying this trade-off in the Fijian context, though the authors note that crown weight showed comparatively minor fluctuations in the fully ripe S4 treatment, suggesting that crown behavior may interact with fruit maturity in ways that warrant further investigation.

The repeated-measures design of the study, in which the same forty fruits were tracked from Day 0 through Day 14, offers both strengths and limitations worth appreciating. Following individual fruits over time captures the trajectory of change within each specimen and reduces confounding from between-fruit variation, which is substantial in pineapple given the fruit’s size and the variability of field conditions. However, ten fruits per ripening stage is a modest sample, and pineapple weight alone can vary by several hundred grams between individuals from the same field. The authors appropriately call for larger fruit populations evaluated across multiple seasons and locations before the findings are generalized. Seasonal effects on sugar accumulation, rainfall patterns during fruit development, and site-specific soil conditions can all shift the baseline °Brix and the rate of postharvest change, so single-season, single-location results should be treated as indicative rather than definitive.

The decision to continue observations past the estimated end of shelf life for some treatments, even though some shelf-life estimates concluded by Day 5, adds value by documenting how quality deteriorates rather than simply where it stops being acceptable. This kind of extended observation is useful for understanding failure modes. If weight loss accelerates in the later days of storage, or if °Brix plateaus once the concentration effect of water loss is exhausted, those patterns inform the design of storage interventions and the setting of realistic market deadlines. It also provides a caution against over-interpreting late-storage readings, since fruit that has passed its commercial window may still register respectable soluble-solids values while being unmarketable for reasons the current measurements do not capture, such as off-odors, fermentation, or visible decay.

Placing the findings in a broader agronomic frame, the ripening stages used in the study, expressed as percentages of full ripeness, correspond to observable shell color and flesh characteristics that growers can assess in the field. Harvest maturity indices for pineapple typically rely on shell color development, flesh firmness, and soluble solids, and the alignment between the S1 through S4 categories and these field-assessable traits determines how readily the study’s recommendations can be adopted by farmers without laboratory equipment. If S1 fruit can be reliably identified by shell appearance alone, the recommendation to harvest early for long-distance or delayed marketing becomes immediately actionable. If not, extension services would need to support growers with simple refractometers or standardized visual scales.

Finally, the economic logic of the trade-off deserves restatement in plain terms. Every additional day of ambient storability purchased by harvesting earlier comes at the cost of initial sweetness, since the non-climacteric fruit cannot make up the deficit after harvest. Every additional degree of sweetness secured by harvesting later comes at the cost of days lost from the marketing window. Neither choice is universally correct; the optimal point depends on the distance to market, the availability of cooling, the price premium for riper fruit, and the tolerance of the target consumer for slight under-ripeness. What the Fiji study contributes is a quantified starting point for that calculation under genuinely ambient tropical conditions, which is precisely the environment in which most of the country’s pineapple is actually handled and sold.

Subject of Research: …

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

Article References: Performance of smooth cayenne pineapple under tropical conditions: unravelling effects of postharvest duration and ripening stage. (n.d.). https://doi.org/10.3389/fhort.2026.1941588

Image Credits: AI Generated

DOI: 10.3389/fhort.2026.1941588

Keywords: pineapple, postharvest, Smooth Cayenne, shelf life, Brix, Fiji, ripening stage, tropical storage, Kaplan-Meier, food loss, Performance, smooth