PROXIMATE COMPOSITIONS OF A HERBAL PURPLE SWEET POTATO (IPOMOEA BATATASL.) WINE

Abstract

ABSTRACT A herbal purple sweet potato (PSP) wine was prepared from purple-fleshed sweet potato (Ipomoea batatas L.) and 18 medicinal plant parts (fruits of ink nut, Indian gooseberry, garlic cinnamon, leaves of holy basil, night jasmine, Malabar nut, roots of belladonna, asparagus, rhizome of ginger, etc.) by fermenting with wine yeast, Saccharomyces cerevisiae. The starch present in PSP was enzymatically saccharified (using commercial thermostable enzymes Termamyl [0.2%] and Dextrozyme GA [1%]) to fermentable sugars, and the homogenized medicinal plant parts were mixed to it at desirable quantities before subjected to fermentation. The herbal wine had the following compositions: total soluble sugar (TSS), 4.0 Brix; starch, 0.24 g/100 mL; total sugar (TS), 0.95 g/100 mL; reducing sugar, 0.38 g/100 mL; titratable acidity (TA), 1.25 g tartaric acid/100 mL; phenol, 0.19 g (caffeic acid equivalent)/100 mL; anthocyanin, 59.90 mg/100 mL; lactic acid (LA), 1.92 mg/100 mL; ethanol, 8.61% v/v; and pH, 3.34. The 2, 2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity of the wine was 51.35% at a dose of 250 µg/mL. The herbal wine thus prepared was presumed to contain the therapeutic and antioxidant properties of PSP as well as those of medicinal plant parts added as adjuncts. Principal component analysis reduced the 11 original analytical and proximate variables (TSS, reducing sugars, starch, TS, TA, pH, phenol, DPPH, LA, ethanol, anthocyanin) to four independent components, which accounted for 74.53% variations (PC1, 24.18%; PC2, 20.18%; PC3, 15.41%; PC4, 14.76%). PRACTICAL APPLICATIONS Herbal purple sweet potato (PSP) wine prepared from anthocyanin-rich PSP and 18 different types of medicinal plant parts is a novel and unique product with ethanol content of 8.61% v/v. The wine is rich in antioxidants such as anthocyanin and phenols and presumably possesses biological active ingredients as remedies for common ailments like cold, cough, skin diseases and dysentery.