Enzyme inhibitors in tuber crops and their thermal stability

Abstract

Tubers of Cassava (Manihot esculenta), yams (Dioscorea esculenta), aroids (Amorphophallus campanulatus, Colocasia esculenta, Xanthosoma sagittfolium) and Coleus (Solenostemon rotundifolius) were screened for inhibitory activities against amylase, trypsin and chymotrypsin. Coleus tuber possessed the highest anti-amylase activity, whereas Colocasia tuber was the most potent source of anti-tryptic and anti-chymotryptic activity. Xanthosoma tubers exhibited amylase inhibitory activity and Amorphophallus tubers antiprotease activity. Dioscorea esculenta had low levels of amylase and chymotrypsin inhibitors, while Cassava tubers were totally free of inhibitors. When tubers were processed by pressure cooking, there was significant reduction/complete elimination in inhibitory activity. Partial retention of inhibition was observed in the case of amylase inhibitor in Dioscorea, chymotrypsin inhibitor in Colocasia and trypsin inhibitor in Colocasia, Coleus and Amorphophallus. In vitro experiments on heat stability of the different inhibitors revealed almost similar pattern of inactivation.

Chestnut Astringent Skin Extract, an α-Amylase Inhibitor, Retards Carbohydrate Absorption in Rats and Humans

“…A significant body of research has led to the discovery of many ␣-amylase inhibitors. Several have been reported in various plants, especially grains (22,23), legumes (24,25) and root vegetables (26,27). In the present study, we discovered that a CAS extract was a strong inhibitor of ␣-amylase and could attenuate the rapid increase in blood glucose following consumption of a carbohydrate-containing meal by delaying or blocking absorption of carbohydrates.…”

Allium sativum Protease Inhibitor: A Novel Kunitz Trypsin Inhibitor from Garlic Is a New Comrade of the Serpin Family

“…When the protein was exposed to harsh temperature conditions, it deactivated thermally due to the denaturation and unfolding, because of the disturbance and breakage of covalent and non-covalent interactions [35]. A number of PPIs from plant sources have been purified and found to be highly stable and fairly active up to 70°C [36]. Thermal denaturation of our protein i.e.…”

Antibacterial, antifungal and cytotoxic activities of amblyone isolated from Amorphophallus campanulatus

“…[3–5] Analgesic activity of Amorphophallus campanulatus tuber[22] and inhibition of amylase, trypsin and chymotrypsin by Amorphophallus campanulatus tuber[23] have also been determined. The antibacterial, antifungal and cytotoxic activities of tuberous roots of Amorphophallus campanulatus were also reported.…”