The Secret Behind the Sweetness of Krayan Pineapple: A Highland Treasure from North Kalimantan

A visual of Krayan Pineapple growing in the private garden of Jen Alang, located in Long Bawan, Krayan, Nunukan Regency, North Kalimantan Province. Photo by Rmsp Documentation.

JAKARTA, BORNEOTRAVEL — If you ever find yourself in Nunukan, North Kalimantan, be sure to make the journey to Krayan—a pristine highland region known as the heart of Borneo. Tucked away near the border of Indonesia and Malaysia, this serene area offers more than just breathtaking landscapes and cool mountain air. 

Krayan is home to an abundance of organic agricultural products, grown naturally by the indigenous Dayak Lundayeh community. Among these treasures, one truly stands out: the Krayan Pineapple—an incredibly sweet, natural, and fully organic fruit that has captivated locals and visitors alike.

Background

Pineapple (Ananas comosus) is a tropical fruit known for its natural sugars—primarily fructose and glucose—which create its distinct sweet flavor. What sets the Krayan Pineapple apart from commercial varieties like Smooth Cayenne or Queen is not only its higher sugar content but also the unique environmental and cultural factors influencing its cultivation.

Grown in the remote highlands near the Indonesia–Malaysia border, Krayan's geography and climate are believed to play a crucial role in shaping the pineapple’s organoleptic properties. Furthermore, the traditional agricultural practices of the indigenous Dayak Lundayeh people contribute significantly to the fruit’s distinctiveness.

This article addresses the central question: What makes Krayan Pineapple so sweet? 

To answer this, we analyze environmental conditions, chemical composition, traditional farming methods, and genetic traits.

1. Environmental Conditions in Krayan Highlands

The Krayan highlands sit at an elevation of 800–1,200 meters above sea level, with a humid tropical climate, high rainfall, and mild temperatures averaging 20–26°C. According to the Tropical Fruit Research Center (2019), such elevations and cooler temperatures slow down plant respiration rates, allowing more carbohydrates from photosynthesis to accumulate as sugars in the fruit.

Soils in Krayan are mostly andosols, rich in organic matter. The North Kalimantan Agriculture Office (2021) reported optimal soil pH (5.5–6.5) and high potassium availability, a key nutrient for sugar synthesis. These factors create ideal growing conditions for pineapple plants to produce sweeter fruits.

2. Chemical Composition of Krayan Pineapple

Sweetness in pineapple is primarily measured by Total Soluble Solids (TSS), expressed in °Brix. Laboratory tests by Mulawarman University (2022) show that Krayan Pineapple averages between 16–20 °Brix—significantly higher than the 12–14 °Brix of Smooth Cayenne. The dominant sugars are fructose, glucose, and sucrose, with fructose contributing most to perceived sweetness.

The tender, juicy, and naturally sweet flesh of the organically grown Krayan Pineapple—rich in flavor and entirely chemical-free. Photo by Rmsp Documentation.

The fruit also has a relatively low citric acid content (0.6–0.8%), resulting in a higher sugar-to-acid ratio. This balance enhances the overall sweetness. These findings align with studies from the Indonesian Agricultural Research and Development Agency (2020), which suggest that highland-grown pineapples tend to exhibit a more favorable sugar-acid balance than their lowland counterparts.

3. Traditional Organic Farming by the Dayak Lundayeh

The Dayak Lundayeh community employs organic farming practices, avoiding synthetic fertilizers and pesticides. According to an ethnographic report by LIPI (2020), local farmers use compost and wood ash to enrich the soil, preserving the soil’s microbiota and improving nutrient absorption—key contributors to sugar accumulation in the fruit.

Loose plant spacing (40–50 cm) ensures ample sunlight exposure for each plant, crucial for photosynthesis and sugar production. Harvesting is done manually at peak ripeness, when the fruit’s skin turns golden yellow, indicating maximum sugar content.

4. Genetic Traits of the Krayan Variety

Preliminary genetic analysis conducted by Bogor Agricultural University (2023) indicates that the Krayan Pineapple (Ananas comosus) represents a genetically distinct local variety, not simply a clone or derivative of common commercial cultivars. The study found that Krayan Pineapple carries specific genetic markers that differ significantly from mainstream varieties such as Smooth Cayenne or MD2, both of which dominate global markets.

Among the most notable findings is the heightened expression of genes associated with sugar metabolism—particularly the sucrose phosphate synthase (SPS) gene, which plays a critical role in the biosynthesis of sucrose within plant tissues. In Krayan Pineapple, this gene appears to be more actively expressed during the fruit ripening phase, which correlates with increased sucrose accumulation and, consequently, a higher overall sugar content.

Additionally, genetic sequencing revealed that Krayan Pineapple may possess allelic variations in genes linked to photosynthetic efficiency and carbohydrate transport, which are essential for sugar mobilization from leaves to fruit. This enhanced sugar translocation mechanism could help explain the elevated °Brix values consistently observed in Krayan samples.

Unlike commercial hybrids that are bred for uniformity, shelf life, and disease resistance, Krayan Pineapple seems to have undergone natural selection and local adaptation over generations. This has resulted in a resilient genotype finely tuned to the highland environment of Krayan, giving it a distinct biochemical and agronomic profile. These genetic distinctions not only set Krayan Pineapple apart in terms of taste but also present valuable material for future plant breeding and biodiversity conservation.

Discussion: A Symphony of Nature, Culture, and Science

The extraordinary sweetness of Krayan Pineapple is the outcome of a multi-dimensional interaction between natural environment, plant physiology, indigenous agricultural practices, and genetic heritage. The highland climate—marked by cooler temperatures, rich andosol soils, and ample rainfall—creates favorable conditions for sugar synthesis and storage within the fruit. Slower plant respiration at higher altitudes allows more carbohydrates from photosynthesis to accumulate rather than be consumed for metabolic activity.

Chemically, the pineapple’s high total soluble solids (16–20 °Brix) combined with low citric acid levels result in a balanced sugar-to-acid ratio, which enhances the perceived sweetness far beyond what is typical in other varieties. The organic farming methods practiced by the Dayak Lundayeh—emphasizing compost-based fertilization, minimal chemical input, and optimal harvesting time—further support the development of high-quality fruit with minimal nutrient stress.

Genetic factors provide the final piece of the puzzle. The active expression of sucrose-producing genes and unique genetic signatures give Krayan Pineapple a molecular edge in sweetness that even elite commercial cultivars may lack. This highlights the untapped potential of local varieties in contributing to food security, genetic diversity, and premium agricultural branding.

Yet, despite these promising insights, there are still substantial challenges in data verification and scientific generalization. Research in Krayan remains constrained by limited access, infrastructure, and funding. Much of the existing knowledge relies on small-scale studies, localized field reports, and preliminary lab analyses. To fully understand and harness the potential of Krayan Pineapple, broader, interdisciplinary, and long-term research efforts are essential—particularly in areas such as genomic mapping, sugar metabolism pathways, and climate-soil interactions.

In conclusion, Krayan Pineapple is more than a delicious fruit—it is a living embodiment of Borneo’s ecological richness, indigenous wisdom, and genetic uniqueness, waiting to be more fully explored and appreciated on the global stage..

Conclusion

Krayan Pineapple’s extraordinary sweetness is the outcome of natural harmony: fertile highland soils, favorable climate, traditional organic farming, and unique genetic adaptation. Verified data show a high °Brix range (16–20) and an ideal sugar-to-acid ratio—both critical to its rich, sweet taste.

Krayan’s ecological conditions and sustainable farming techniques preserve not only the fruit’s quality but also the cultural legacy of the Dayak Lundayeh. Moving forward, further research is essential to unlock the commercial potential and ensure the conservation of this exceptional local variety. *)