Resistant Starch Type 2 (Green Banana)

Per 100g of green banana flour (primary source of RS2): Resistant starch: 40–58g (Type 2 amylose granules, largely resistant to enzymatic hydrolysis in the upper GI tract; bioavailability of starch calories is reduced by ~50% compared to cooked starch). Total dietary fiber: 6–16g (including both soluble and insoluble fractions beyond RS2). Total carbohydrates: 76–88g. Protein: 3–5g. Fat: 0.3–0.8g. Key micronutrients: Potassium: 900–1200mg (approximately 25–35% DV; high bioavailability ~85%), Magnesium: 80–110mg (~20–27% DV), Phosphorus: 70–90mg, Zinc: 0.6–1.0mg, Iron: 1.0–1.8mg (non-heme form, bioavailability ~5–12%, enhanced by concurrent vitamin C intake). Vitamins: Vitamin B6 (pyridoxine): 0.3–0.5mg (~18–25% DV), Vitamin C: 8–18mg (lower than ripe banana due to early harvest; some loss during drying/processing), Folate: 15–22µg, Niacin (B3): 0.5–0.7mg. Bioactive compounds: High-amylose starch granules (crystalline A/B-type polymorph structure conferring enzyme resistance), phenolic compounds: 2–5mg GAE/g (including gallic acid, catechins, and ferulic acid; bioavailability moderate, enhanced post-colonic fermentation), flavonoids: 1–3mg/100g (primarily leucocyanidin and quercetin glycosides). Short-chain fatty acid (SCFA) production upon colonic fermentation: yields approximately 150–250 mmol/kg of butyrate, propionate, and acetate combined (butyrate being the predominant SCFA at ~60–70 mmol/kg, serving as the primary energy source for colonocytes). Glycemic index of raw green banana flour: 38–48 (low GI). Caloric value: ~300–340 kcal/100g (effective caloric yield is lower due to RS2 resistance to digestion). Note: RS2 granular structure is heat-sensitive; cooking above 70°C gelatinizes starch and significantly reduces resistant starch content by 50–80%, converting RS2 to digestible starch or retrograded RS3 upon cooling.