# SL28 Coffee (Coffea arabica) **Canonical URL:** https://ingredients.hermeticasuperfoods.com/ingredients/sl28-coffee **Data Source:** Hermetica Superfoods Ingredient Encyclopedia **Updated:** 2026-03-31 **Evidence Score:** 2 / 10 **Category:** Coffee Cultivars **Also Known As:** Scott Laboratory 28, SL-28, Kenya SL28, Scott Labs 28, SL28 cultivar, SL28 variety ## Overview SL28 coffee (Coffea arabica) is a Kenyan cultivar containing 1-2% caffeine by dry weight that provides alertness through adenosine receptor antagonism. It contains chlorogenic acids and other coffee polyphenols but lacks specific clinical research on health benefits. ## Health Benefits • No specific health benefits documented - No clinical trials or human studies exist for SL28 coffee specifically • General Coffea arabica caffeine content (~1-2% dry weight) - May provide alertness through adenosine receptor antagonism (evidence quality: not studied for SL28) • Contains chlorogenic acids (~5-10%) common to arabica varieties - Potential [antioxidant](/ingredients/condition/antioxidant) properties (evidence quality: not studied for SL28) • Deep root system enables drought resistance - Agricultural benefit only, no human health implications documented • No SL28-specific biomedical research - All health claims would be extrapolated from general coffee research ## Mechanism of Action Caffeine in SL28 coffee acts as an adenosine A1 and A2A receptor antagonist, blocking adenosine-induced drowsiness and promoting wakefulness. Chlorogenic acids function as antioxidants by scavenging [reactive oxygen species](/ingredients/condition/antioxidant) and may inhibit glucose-6-phosphatase activity. The polyphenolic compounds also modulate [inflammatory pathway](/ingredients/condition/inflammation)s through NF-κB inhibition. ## Clinical Summary No clinical trials have specifically examined SL28 coffee's health effects. General Coffea arabica research shows caffeine doses of 100-400mg improve alertness and [cognitive performance](/ingredients/condition/cognitive) in healthy adults. Chlorogenic acid studies typically use 140-1200mg doses for metabolic benefits, but SL28's specific chlorogenic acid content and bioavailability remain unstudied. Evidence quality for SL28-specific benefits is insufficient. ## Nutritional Profile SL28 Coffee (Coffea arabica) nutritional data is reported per 100g roasted ground coffee unless otherwise noted. Macronutrients: Protein ~13-15g (rich in melanoidins and degraded proteins post-roasting; raw green bean protein ~10-13g), Carbohydrates ~28-30g (predominantly non-digestible polysaccharides including galactomannans ~20% and arabinogalactans ~10% in green bean; sucrose largely destroyed during roasting to <1g in dark roast vs ~6-9g in green bean), Fat ~12-15g (primarily linoleic acid, palmitic acid; diterpenes cafestol and kahweol ~0.5-1.0g present in unfiltered preparations; paper filtration removes ~97% of diterpenes). Fiber: ~33-40g (primarily insoluble; significant portion survives brewing as spent grounds, minimal transfer to brewed cup ~1-2g/250ml). Bioactive Compounds: Caffeine ~1.0-1.7% dry weight in green bean (SL28 historically noted toward moderate-high end of arabica range ~1.2-1.6%); Chlorogenic acids (CGAs) ~5-10% dry weight in green bean, predominantly 5-caffeoylquinic acid (5-CQA); CGA content reduced 50-70% during medium-dark roasting; brewed cup yields ~150-350mg CGAs per 250ml depending on roast and brew method. Trigonelline ~0.6-1.2% dry weight (partially converts to niacin/nicotinic acid during roasting, yielding ~4-5mg niacin equivalents per cup). Melanoidins: 25-30% of roasted coffee dry weight; formed via Maillard reactions; exhibit [antioxidant](/ingredients/condition/antioxidant) and [prebiotic](/ingredients/condition/gut-health) properties. Minerals per 100g roasted: Potassium ~2000-2500mg (highest mineral; significant transfer to brew ~116mg/250ml cup), Magnesium ~180-200mg (~12mg/cup), Manganese ~1.0-2.0mg, Phosphorus ~160mg, Calcium ~120mg, Iron ~4-5mg (low bioavailability due to chlorogenic acid chelation, estimated 50-70% reduction in non-heme iron absorption). Vitamins: Riboflavin (B2) ~0.2mg/100g, Niacin ~10-40mg/100g (highly variable; roasting-dependent conversion from trigonelline), Pantothenic acid trace amounts. Brewed beverage context (per 250ml, medium roast, drip method): Caffeine ~80-120mg, CGAs ~200-300mg, Potassium ~116mg, Magnesium ~12mg, Niacin ~0.5mg. Bioavailability notes: CGAs show 33% bioavailability from coffee matrix; colonic microbiota metabolize remaining CGAs to dihydrocaffeic and dihydroferulic acids; caffeine bioavailability near 100% from aqueous brew; diterpene content negligible in filtered drip coffee but substantial in French press (~6mg cafestol/cup) or espresso (~1-2mg cafestol/shot). SL28-specific compositional data is extremely limited in published literature; values represent Coffea arabica species norms with SL28 likely falling within typical arabica ranges given its genetic background as a Tanganyika-derived drought-resistant selection. ## Dosage & Preparation No clinically studied dosage ranges exist for SL28 in any form, as it lacks biomedical clinical data and is not used as a standardized supplement. Typical consumption mirrors general brewed coffee (1-3 cups/day), but without standardization or health-focused dosing studies. Consult a healthcare provider before starting any new supplement. ## Safety & Drug Interactions SL28 coffee safety profile likely mirrors general coffee consumption, with moderate intake (3-4 cups daily) considered safe for most adults. Caffeine can interact with medications like warfarin, increasing bleeding risk, and may reduce absorption of iron and certain antibiotics. Pregnant women should limit intake to 200mg caffeine daily due to potential fetal development risks. Individual sensitivity varies, with some experiencing anxiety, [insomnia](/ingredients/condition/sleep), or digestive upset. ## Scientific Research No clinical trials, RCTs, or meta-analyses specific to SL28 coffee were identified in biomedical literature. PubMed searches yield no SL28-specific human trials, with research focusing solely on its agronomic and sensory qualities rather than human health outcomes. ## Historical & Cultural Context SL28 has no documented historical use in traditional medicine systems, as it was developed in the 1930s for agricultural yield and cup quality, not medicinal purposes. While general coffee has traditional uses in Ethiopian and Yemeni systems for stimulation since the 15th century, SL28 postdates these by centuries as a modern Kenyan agricultural cultivar. ## Synergistic Combinations No synergistic ingredients studied with SL28 specifically ## Frequently Asked Questions ### How much caffeine is in SL28 coffee? SL28 coffee contains approximately 1-2% caffeine by dry weight, similar to other Coffea arabica varieties. This translates to roughly 95-200mg caffeine per 8-ounce cup, depending on brewing method and bean preparation. ### What makes SL28 coffee different from other arabica varieties? SL28 is a Kenyan cultivar selected for high altitude growing conditions and distinctive flavor profile. While it shares basic coffee compounds like caffeine and chlorogenic acids with other arabica varieties, its specific phytochemical composition and concentrations have not been comprehensively studied. ### Are there any proven health benefits of SL28 coffee? No clinical studies have specifically investigated SL28 coffee's health effects. Any potential benefits would be extrapolated from general coffee research showing improved alertness, antioxidant activity, and possible metabolic effects from caffeine and chlorogenic acids. ### Can SL28 coffee help with weight loss? No specific evidence supports SL28 coffee for weight loss. General coffee research suggests caffeine may slightly increase metabolic rate and chlorogenic acids might affect glucose metabolism, but these effects are modest and not proven for the SL28 cultivar specifically. ### Is SL28 coffee safe to drink daily? SL28 coffee appears safe for daily consumption within general coffee guidelines of 3-4 cups per day for healthy adults. However, individuals with caffeine sensitivity, heart conditions, or those taking certain medications should consult healthcare providers before regular consumption. ### Is SL28 coffee safe during pregnancy and breastfeeding? SL28 coffee contains caffeine (~1-2% dry weight), which crosses the placenta and is present in breast milk, so pregnant and breastfeeding individuals should limit consumption to no more than 200mg caffeine daily per standard guidelines. Since SL28 is a coffee cultivar rather than a supplement with unique properties, standard caffeine safety recommendations for coffee apply. Consult a healthcare provider for personalized guidance during pregnancy and lactation. ### Does SL28 coffee interact with medications? SL28 coffee's caffeine content may interact with certain medications including some antidepressants, thyroid medications, and bisphosphonates by affecting absorption or metabolism. The chlorogenic acids in SL28 may also influence how the body processes medications, though this is not specific to SL28 versus other arabica varieties. Individuals taking medications should discuss coffee consumption with their healthcare provider, as interactions depend on dosage and individual factors. ### How does SL28 coffee compare to other arabica cultivars in terms of flavor and farming practices? SL28 is a hybrid arabica cultivar developed in Kenya that is prized for its disease resistance and distinctive fruity, complex flavor profile compared to other arabica varieties. It originated from a cross between Typica and French Mission plants and has become popular among specialty coffee producers for its ability to thrive in challenging growing conditions while producing high-quality beans. The cultivar's agronomic advantages have made it a favored choice in East African coffee farming despite being more resource-intensive than some other varieties. --- *Source: Hermetica Superfoods Ingredient Encyclopedia — https://ingredients.hermeticasuperfoods.com* *License: CC BY-NC-SA 4.0 — Attribution required. 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