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Gac

Gac ( cochinchinensis Spreng.), also known as spiny or baby , is a dioecious vine in the family, native to South and , prized for its ovoid that features a spiny orange-red exterior, a bright red surrounding black seeds, and an exceptionally high concentration of bioactive compounds, particularly such as and β-. The plant's vine grows up to 20 meters long, thriving in tropical and subtropical climates, and produces fruits that ripen from green to red between and February, yielding up to 60 fruits per vine in a single season. The fruit's is the most nutrient-dense part, containing levels up to 802 μg/g and up to 175 μg/g in the portion—far exceeding those in tomatoes and carrots, respectively—along with significant amounts of fatty acids (102 mg/g), (76 μg/g), phenolics, , and trypsin inhibitors. These compounds contribute to potent activity, with the ripe exhibiting a ferric reducing power (FRAP) of 531.17 μmol/g, supporting health benefits including , anticancer, , and pro-vitamin A effects that enhance levels. Traditionally, gac fruit serves as a vibrant colorant and flavor enhancer in Southeast Asian cuisines, such as Vietnam's xôi gấc (sticky rice dish) and Thai vegetable preparations, while its oil substitutes for cooking fats due to high unsaturated content (70%, including 44.5% ). In , it treats ailments, ulcers, , and cancers, with modern applications extending to nutraceuticals, , and functional foods like powders, juices, and extracts, though challenges in processing—such as degradation during storage—necessitate methods like freeze-drying to preserve bioactivity. Cultivation remains largely small-scale in countries like and , propagated from seeds or roots, with potential for expanded commercial production given its "superfruit" status.

Description

Physical Characteristics

Gac (Momordica cochinchinensis) is a , dioecious climbing that can extend up to 15 meters in length, supported by branched tendrils and arising from a tuberous . The herbaceous stems are robust and slightly hairy, enabling the plant to scramble over vegetation or trellises for support. The leaves are alternate, simple, and palmately lobed with 3–5 lobes, measuring 5–10 cm in width and featuring serrated margins and 2–4 glands on the petiole; they are dark green above and lighter below, emitting a characteristic when crushed. Flowers are unisexual and borne on separate plants, with pale yellow corollas consisting of 5 elliptical petals; male flowers occur solitary or in short racemes on peduncles up to 30 cm long, while female flowers are solitary on shorter peduncles, both approximately 2–3 cm in . The is oblong to nearly round, 10–20 cm long and typically 10 cm in diameter, covered in short, soft spines, and transitions from green to orange-red at maturity. Inside, a bright red, oily envelops the seeds, which are large (about 2.5 cm long), flat, black, and compressed with a sculptured surface, numbering 20–40 per fruit.

Habitat and Distribution

Gac ( cochinchinensis) is native to , with its range encompassing countries such as , , , , southern , , and , as well as extending to , , the , and . The plant occurs naturally in northeastern , Indochina, and parts of and . It thrives in tropical and subtropical climates, preferring temperatures consistently above 20°C (with an optimal range of 20–30°C), high humidity, and annual rainfall between 1,000 and 2,000 mm, though it can tolerate up to 3,000 mm with during dry periods. In terms of cultivation, has been introduced beyond its native range and is now grown commercially in subtropical areas including , the (particularly ), and parts of , where it supports local agricultural and medicinal uses. The plant requires well-drained, fertile loamy soils rich in , with a of 6.0–7.5 (optimally 6.5–7.0), and it tolerates poorer soils but is sensitive to waterlogging and heavy clays. Ecologically, gac functions as a climber, often ascending fences, trees, or support structures in lowland s, riverine areas, edges, roadsides, and disturbed habitats at elevations up to 1,000 m. It favors full sun exposure but can succeed with partial shade, contributing to in secondary and within its range.

Taxonomy and Nomenclature

Classification

Gac is classified in the kingdom Plantae, phylum Tracheophyta, class Magnoliopsida, order Cucurbitales, family Cucurbitaceae, genus Momordica, and species M. cochinchinensis (Lour.) Spreng.. The accepted name is based on the basionym Muricia cochinchinensis Lour., with homotypic synonyms including Muricia cochinchinensis Lour. and heterotypic synonyms such as Momordica macrophylla Hand.-Mazz., Momordica mixta Roxb., Momordica ovata Wall. ex Wight & Arn., and Momordica meloniflora Hand.-Mazz.. This taxonomic placement reflects its position as a dioecious, perennial vine within the gourd family, characterized by climbing stems and tuberous roots. Within the genus Momordica, which comprises approximately 60 species of mostly tropical climbers, M. cochinchinensis belongs to subgenus Momordica. It is phylogenetically closely related to M. charantia (bitter melon) and M. sessilifolia, as evidenced by plastome sequence analysis showing shared evolutionary history within the tribe Momordiceae. The genus Momordica is the sole member of this tribe and exhibits multiple evolutionary shifts between dioecy and monoecy, with M. cochinchinensis retaining dioecy. The family, to which gac belongs, is a diverse group of about 800 species, including economically important crops like cucumbers (Cucumis sativus) and melons (Citrullus lanatus and ). Phylogenetic studies place in the core Cucurbitoideae subfamily, with M. cochinchinensis distinguished by its spiny, indehiscent fruits and red , adaptations linked to by vertebrates in Southeast Asian ecosystems. Although no formal subspecies are widely recognized for M. cochinchinensis, regional variants exist across its native range in , differing in fruit size (ranging from 10-25 cm in diameter) and aril oil content (up to 9% of fresh weight, varying by locality). These variations, observed in populations from , , and , reflect genetic diversity without established infraspecific taxa, as confirmed by morphological and RAPD analyses.

Etymology

The scientific name Momordica cochinchinensis derives from the genus , which originates from the Latin verb mordeo meaning "to bite," a reference to the jagged or sculptured edges of the seeds in species of this genus. The specific epithet cochinchinensis refers to , the historical European name for the southern region of (encompassing parts of modern , , and ), where the plant was first observed and described. The species was initially described in 1790 by Portuguese missionary and botanist João de Loureiro in his work Flora Cochinchinensis, under the basionym Muricia cochinchinensis. Loureiro's naming reflected his observations during travels in Vietnam. The binomial was later transferred to Momordica and formalized as Momordica cochinchinensis by German botanist Kurt Sprengel in 1826. In , the is known as gấc (pronounced [ɣək˦˥]), a term of local origin that has been used traditionally to denote this fruit-bearing . Early accounts recorded the under names such as "Chinese cucumber" or "Chinese bitter cucumber," owing to its superficial resemblance to species in the genus, like cucumbers, despite belonging to the family.

Common Names

Gac, scientifically known as cochinchinensis, is referred to by various names across its native Southeast Asian range and beyond, reflecting regional linguistic and cultural differences. In , the primary common name is gac, often specified as quả gac to denote the fruit. In , it is commonly called fak khao in central regions and phak khao in northern areas. In , the is known as red melon or baby , with the term mùbiēguǒ translating to "wooden ." In , a regional name is bhat kerala, particularly in Assamese-speaking areas. Historically, it has been referred to as Cochin in English, derived from the species epithet referencing the region. Internationally, especially in English-speaking contexts, it is widely called gac fruit. Regional variations include mak khao in and makkao or mreah in .

Biology

Life Cycle and Phenology

Gac ( cochinchinensis), a perennial climber in the family, exhibits a adapted to tropical and subtropical environments, with distinct phenological stages influenced by seasonal and . The plant propagates primarily from fresh seeds or tuberous roots, demonstrating resilience through during adverse conditions. In its native range, gac completes its cycle from germination to fruit production within one , often spanning 9-11 months under optimal conditions, while the tuberous rootstock enables regrowth in subsequent years. Germination of fresh gac typically occurs within 7-14 days under warm temperatures of 25-30°C and high , achieving over 90% success rates when the hard seed coat is scarified or removed. As a species, gac also regenerates from tuberous roots, which allow the plant to die back during dry seasons and resprout vigorously upon the return of favorable . This root-mediated ensures in regions with pronounced wet-dry cycles, where above-ground vines may senesce annually but the underground structures remain viable. Vegetative growth initiates rapidly following or resprouting, particularly during the , where the extends climbing stems up to 6-10 meters using tendrils to ascend supports. This phase lasts 3-6 months until reproductive maturity, with stems developing thick, dark green foliage and lateral branches that can exceed 3 meters in length under humid, tropical conditions. Growth accelerates with ample rainfall and temperatures above 20°C, enabling the to cover supports quickly and allocate resources to . Flowering in gac is dioecious, with male flowers emerging first, typically 5-6 months after , followed by female flowers about 4 weeks later; in tropical regions, this process occurs year-round but peaks during the rainy season when moisture supports increased floral production. The flowering period extends 6-8 months per vine, aligning with the wet phase to maximize opportunities, though may be necessary in settings with limited activity. Fruit development follows successful , taking 2-3 months for initial , with fruits in an additional 45-60 days as the rind transitions from to , signaling maturity. Each , weighing 0.5-2 , develops from the of flowers, accumulating nutrients over this period before harvest. In equatorial tropics, fruiting can occur continuously with overlapping cycles, but in seasonal climates, it concentrates in the latter wet period. In , gac vines persist as perennials in tropical habitats, maintaining tuberous that store carbohydrates and nutrients for the next cycle; however, in temperate or arid areas, the above-ground parts may behave annually, dying back during cool or dry periods below 15°C and regrowing from in spring or with renewed rains. This mechanism, induced by low temperatures or water stress, protects the plant's , with surviving multiple years under suitable soil conditions.

Reproduction

Gac (Momordica cochinchinensis) is a , featuring separate and female that can only be distinguished upon flowering. In natural populations, the is typically balanced at approximately 1:1, though the ratio in seed-derived progeny is unpredictable. produce numerous flowers with stamens but no pistils, while female bear solitary flowers with pistils that require to develop fruits. Pollination in Gac is primarily entomophilous, relying on such as bees and other to transfer from to flowers. In cultivated settings, where natural activity may be limited, hand-—achieved by manually transferring to the —significantly improves fruit set and yield compared to open . Successful leads to development on female , with each mature typically containing 15 to 20 hard-coated embedded in a vibrant red . The serves a dual role in by providing nourishment that attracts dispersers while protecting the during dissemination. occurs mainly through zoochory, as birds and mammals are drawn to the fleshy, carotenoid-rich and ingest the , excreting viable at distant locations. This mechanism enhances the plant's in its native tropical habitats. Genetically, Gac displays high heterozygosity, reflecting substantial polymorphism across populations that supports adaptability but complicates efforts. The dioecious system poses challenges related to sex determination, as early identification of female plants is difficult without flowering; techniques like treatment or molecular markers have been explored to induce female or hermaphroditic traits for improved yields.

Phytochemistry and Nutrition

Chemical Composition

Gac (Momordica cochinchinensis) is particularly noted for its high content, primarily in the surrounding the seeds, where and predominate. concentrations in the range from 0.3 to 7.5 mg/g fresh weight, with levels varying from 0.2 to 5.7 mg/g fresh weight, depending on regional varieties and maturity; for instance, samples from exhibit higher values, up to 7.5 mg/g for and 5.3 mg/g for . Reported concentrations may vary based on fresh vs. dry weight and extraction methods (e.g., solvents yield higher than aqueous). These contribute to the fruit's bright red color and are more concentrated in the than in the mesocarp or rind. The also contains significant , comprising approximately 9-10% oil by fresh weight, which is rich in unsaturated s. The profile typically includes (around 29-60%), (14-20%), and (about 32%), with unsaturated s accounting for roughly 70% of the total. This oil serves as a natural carrier for the lipophilic . Other bioactive compounds in Gac include (vitamin E), present at levels up to 76 μg/g fresh weight in the aril and 357 μg/mL in the extracted oil, along with polyphenols, , and acids distributed across the fruit parts. Polyphenols and are found in the mesocarp and , while , such as I and II, are isolated from the seeds; leaves contain additional and . Extraction of these compounds often employs supercritical CO₂ for oils to preserve unsaturated fatty acids and , yielding high recovery rates (up to 79.5% under optimized conditions), while (HPLC) is used for quantitative profiling of , revealing principal peaks for and β-carotene. Concentrations of these phytochemicals show variability, with ripe exhibiting higher levels of (e.g., up to 3.7 mg/g fresh weight) and oils compared to the pulp or rind, influenced by factors like maturity stage and geographic origin.
Compound ClassKey ComponentsTypical Concentration in Aril (fresh weight)Primary Location
, β-carotene: 0.3–7.5 mg/g; β-carotene: 0.2–5.7 mg/gAril > mesocarp > rind
, , Oil: 9–10%; Unsaturated FAs: ~70% of totalAril
Otherα-Tocopherol, , , α-Tocopherol: 76 μg/g; in seedsAril, seeds, leaves

Nutritional Value

Gac fruit (Momordica cochinchinensis) offers a nutrient-dense profile, particularly in its edible aril and pulp, contributing low to moderate energy while providing essential micronutrients for dietary intake. The fruit's overall caloric content is relatively low, with the pulp providing approximately 148-164 kcal per 100 g and the aril ranging from 376-515 kcal per 100 g due to higher lipid concentrations. In terms of macronutrients, Gac is low in protein (0.84-1.9 g per 100 g in the ) and carbohydrates (3-9.2 g per 100 g across parts), with concentrated in the at 1-10 g per 100 g, predominantly unsaturated fatty acids comprising approximately 70% of total fats, with polyunsaturated fatty acids (primarily ) making up 15-35%. The excels in vitamins, especially provitamin A from beta-carotene, with the containing 17-35 mg per 100 g of edible portion, far surpassing common sources like carrots. Vitamin C levels reach 42.57 mg per 100 g in wild-grown , primarily in the pulp, while (alpha-tocopherol) is notable at 7.6-8 mg per 100 g in the . Minerals in Gac include at 228-817 mg per 100 g (highest in peel and pulp), iron at 1-2 mg per 100 g, and trace , supporting balance and metabolic functions. Gac's antioxidant capacity is substantial, driven by . The aril provides about 70 times more per unit weight than tomatoes, enhancing its role as a potent dietary .

Cultivation

Growing Requirements

Gac (Momordica cochinchinensis) thrives in tropical and subtropical climates, with optimal daytime temperatures ranging from 25°C to 35°C and a minimum of 15°C to support active growth. The plant is highly frost-sensitive and requires a frost-free growing period of 6 to 8 months to complete its vegetative development and fruiting cycle. In temperate regions, it can survive cooler winters by dying back to its tuberous roots but reshoots only in warm conditions above 20°C. For soil, Gac prefers well-drained sandy loam enriched with to promote root health and nutrient uptake. The ideal is maintained between 6.0 and 7.0 to optimize availability of essential minerals. Gac prefers annual rainfall of 1200-2500 mm, with supplemental during dry periods to maintain consistent without waterlogging, as the is moderately drought-tolerant once established but sensitive to prolonged dryness during fruit development. Gac demands full sun exposure of at least 6 hours daily to maximize and fruit coloration, though it can tolerate partial in high-humidity environments. As a vigorous climbing vine, it requires sturdy supports such as trellises or fences to elevate fruits off the ground, preventing from contact and facilitating air circulation. Fertilization focuses on nitrogen-rich applications during early vegetative to encourage extension, transitioning to phosphorus-heavy inputs during flowering and fruiting to enhance yield and quality. Organic amendments like are commonly used to sustain in traditional systems. is predominantly small-scale in native regions like and , but commercial production is expanding, including trials in as of 2025, due to its nutritional value. Pest management is essential, as Gac is susceptible to aphids, which cluster on tender shoots and leaves causing distortion, and fruit flies, which damage developing fruits through larval infestation. In traditional and organic systems, controls such as sprays or beneficial insect introductions are preferred over chemical pesticides to minimize environmental impact.

Propagation and Harvesting

Gac (Momordica cochinchinensis) is primarily propagated by seeds, though vegetative methods are preferred for ensuring female plants due to the species' dioecious nature, where only females produce fruit. For seed propagation, fresh seeds are soaked in water overnight to enhance germination, then sown 1-2 inches (2-5 cm) deep in a well-draining seed-raising mix under warm (25-35°C) and humid conditions. Germination typically occurs in 1-4 weeks, with success rates of 75-91% for fresh seeds at optimal temperatures around 30°C, though viability decreases after 18 months of storage at 21°C and 60% relative humidity. Seedlings are spaced 1.5-3 m apart to accommodate the vigorous climbing vines, which require trellising or support. Vegetative propagation via root cuttings, tubers, or vine cuttings from established female plants is more reliable for commercial production, bypassing the unpredictable 40-60% male-to-female ratio from seeds and enabling for fruit-bearing individuals. Semi-hardwood or hardwood cuttings (2-3 nodes long) are treated with (IBA) at 3000-5000 ppm and rooted in such as rockwool, potting mix, or sand, achieving rooting in 20-30 days under high humidity. Root tubers or cuttings are planted directly into soil or containers, promoting faster establishment than seeds. This approach addresses the challenge of low female plant ratios by allowing clonal multiplication of productive vines. Harvesting occurs manually when fruits reach full ripeness, indicated by a scarlet red rind and softened spines or flesh upon pressing, typically 90-100 days after or about 5 months post-flowering. In tropical regions, this aligns with seasonal production from to , requiring careful to avoid over-ripening on the vine. Yields average 10-20 kg per vine annually, equivalent to 30-60 fruits weighing 0.2-0.5 kg each, though higher outputs (up to 160 fruits) are possible under optimal conditions. The low female ratio from seed propagation necessitates ongoing sex during establishment to maximize yields. Post-harvest, the nutrient-rich is separated from seeds immediately using manual scooping to prevent degradation of and oils. Fruits or separated aril are stored at 10-20°C for 1-2 weeks to maintain quality, as lower temperatures (e.g., 4°C) induce chilling injury after 25 days, while higher humidity preserves firmness. For longer preservation, freezing the aril is recommended to retain .

Uses and Applications

Culinary Applications

In , the of Gac fruit ( cochinchinensis) is traditionally mixed with to create xôi gấc, a vibrant red sticky rice dish steamed with and often seasoned with , , and , which is prominently featured during the holiday to symbolize luck and prosperity. This dish is also prepared for other celebrations, such as weddings, where the striking red hue represents longevity and good fortune in Vietnamese . The is typically scraped from the seeds to form a paste, sometimes combined with , oil, and before incorporation into the rice, yielding approximately 5-10% oil content that enhances flavor and color stability. Beyond , Gac aril finds use in other Southeast Asian cuisines, such as in where it is incorporated into curries or desserts for natural coloration and subtle sweetness. The seeds, encased in the sweet , can be roasted and consumed as a nut-like , adding a condiment-like texture to dishes across the region. In broader applications, the pulp is blended into juices or smoothies, providing a mild, avocado-like richness that complements tropical beverages. Modern culinary adaptations leverage Gac's aril for its potent natural red , coloring rice, noodles, and beverages without synthetic additives, while the extracted is valued in cooking for its high and oxidative stability. These uses extend to innovative dishes like sauces, soups, stews, and even Western fusions such as toppings or , highlighting Gac's versatility in contemporary . Across , the fruit's role in festive foods underscores its enduring association with prosperity and communal harmony.

Medicinal and Health Benefits

Gac (Momordica cochinchinensis) has been utilized in across and for various health purposes. In folk remedies, the fruit and seeds are employed to promote vitality, treat eye disorders such as night blindness, and support overall longevity, often through incorporation into dietary preparations. In Indian traditional systems, including elements of , the fruits and leaves are applied for , skin infections, and burns, with leaves sometimes used as poultices to aid repair. Additionally, gac juice is traditionally regarded as a enhancer and remedy for prostate issues and heart disorders. The antioxidant properties of gac primarily stem from its high concentrations of and , which help mitigate by scavenging free radicals and reducing . These contribute to improved skin health by protecting against UV-induced damage and promoting synthesis, as evidenced by traditional applications and preliminary studies on cellular protection. For , the provitamin A activity of supports retinal health and prevents deficiencies leading to , with gac providing a bioavailable source that enhances serum levels. Modern research highlights gac's potential in , attributed to lycopene's superior in gac compared to tomatoes, enabling higher absorption and plasma levels that inhibit tumor cell proliferation through pathways like suppression. studies demonstrate that and seed extracts exhibit cytotoxicity against , , and cells, inducing and reducing without affecting normal cells. Seed extracts further show anti-diabetic effects by enhancing and lowering postprandial , potentially via modulation of insulin sensitivity. Human clinical trials on gac remain limited, with early studies in Vietnam during the early 2000s demonstrating its efficacy in vitamin A supplementation among children at risk of deficiency, where consumption of gac-fortified foods significantly raised plasma β-carotene and retinol concentrations, improving nutritional status and vision-related outcomes. More recent preclinical dietary interventions in animal models, such as incorporating gac aril into meals, have shown benefits in managing type 2 diabetes by improving fasting glucose and insulin sensitivity; however, human clinical trials for anti-diabetic effects remain limited, with most evidence from animal and in vitro studies. Typical dosages in these contexts range from 10-20 g of fresh aril daily, often as part of food, to achieve provitamin A benefits without excess. Gac is for consumption in moderate amounts, with no major reported in traditional use or up to 1,000 mg/kg body weight. However, its exceptionally high β-carotene content poses a risk of carotenodermia (harmless skin yellowing) or, in extreme cases, if combined with other sources, necessitating caution in supplementation for pregnant individuals or those with liver conditions.

Industrial and Other Uses

Gac aril oil is incorporated into skincare formulations for its UV-protective and anti-aging properties, attributed to high levels of and beta-carotene, which also help stabilize emulsions in cosmetic products such as soaps and creams commonly produced in . In the , Gac aril serves as a natural colorant alternative to synthetic E160d () for processed foods like juices and baked goods, while its seed oil is blended into margarines to enhance nutritional profiles with essential fatty acids. Pharmaceutical applications include Gac extracts formulated into supplements targeting eye health, owing to their rich content that supports ; several patents for carotenoid isolation from Gac have been granted since the early , facilitating commercial extraction methods. Other uses encompass the potential of Gac seed oil as a feedstock, with studies demonstrating its suitability for via ultrasonic-assisted extraction due to favorable profiles. Additionally, the rind has been traditionally employed as a for textiles and food in Southeast Asian cultures. Commercial trends show increasing exports of Gac products from , where production capacity reaches approximately 3,000 tons annually through major processors, though scaling remains challenged by the fruit's seasonal availability and variable yields.