Ding Xiang (Syzygium aromaticum / Clove)

Ding Xiang (Syzygium aromaticum / Clove) is not typically consumed in large quantities as a food but rather used as a medicinal herb in small doses (1–6 g dried buds in TCM decoctions). Its bioactive and nutritional profile per 100 g of dried clove buds is as follows: Primary Bioactive Compounds: Eugenol (72–90% of essential oil content, approximately 15–20 g per 100 g dried buds) is the principal active constituent responsible for analgesic, anti-inflammatory, and antimicrobial effects. Eugenyl acetate (2–27% of essential oil), β-caryophyllene (5–12% of essential oil, a sesquiterpene with anti-inflammatory and CB2 cannabinoid receptor agonist activity), and oleanolic acid (a triterpene with hepatoprotective and anti-inflammatory properties). Phenolic Compounds & Antioxidants: Total phenolic content is exceptionally high at approximately 15,000–30,000 mg GAE (gallic acid equivalents) per 100 g, ranking clove among the highest ORAC-value spices. Flavonoids include kaempferol, quercetin, and their glycosides. Gallic acid, ellagic acid, and caffeic acid are also present. Tannins (10–13% by weight). Macronutrients (per 100 g dried): Energy ~274 kcal; Carbohydrates ~66 g (including dietary fiber ~33–34 g, one of the highest fiber contents among spices); Protein ~6 g; Fat ~13 g (largely from essential oil fraction); Sugars ~2.4 g. Minerals: Manganese ~60 mg (approximately 2,600% DV per 100 g, though typical medicinal doses provide far less); Calcium ~632 mg; Magnesium ~259 mg; Potassium ~1,020 mg; Iron ~11.8 mg; Phosphorus ~104 mg; Sodium ~277 mg; Zinc ~2.3 mg; Selenium ~7.2 µg. Vitamins: Vitamin C ~0.2 mg; Vitamin A ~160 IU (as beta-carotene); Vitamin K ~141.8 µg; Vitamin E (alpha-tocopherol) ~8.8 mg; Vitamin B6 ~0.39 mg; Riboflavin (B2) ~0.22 mg; Niacin (B3) ~1.56 mg; Thiamine (B1) ~0.16 mg; Folate ~25 µg. Bioavailability Notes: Eugenol is rapidly absorbed through the GI tract with good oral bioavailability, though it undergoes extensive first-pass hepatic metabolism (glucuronidation and sulfation), yielding a systemic bioavailability estimated at 40–55%. β-caryophyllene is lipophilic and benefits from co-administration with fats or oils for enhanced absorption. The high tannin content may reduce the bioavailability of co-ingested iron and certain proteins. Manganese from clove is moderately bioavailable (~3–5% absorption rate). In TCM, decoction preparation (boiling in water) extracts water-soluble phenolics, tannins, and a portion of volatile oils, though prolonged boiling reduces eugenol content due to volatilization; Ding Xiang is therefore traditionally added near the end of decoction (后下, hòu xià) to preserve its aromatic and medicinal properties.