Wild edible plants and foods continue to be underrated due to supply or consumption constraints, poor consumer awareness, and unrecognized nutritional value despite diverse recommendations. The study determined the physicochemical properties of wild terrestrial edible orchid tubers used to produce Nyam ngub, a seasonal delicacy endogenously processed and eaten as meat surrogate.
Tubers were collected from AbongPhen, Kedjom Ketingoh, Tubah subdivision, North West Region, Cameroon, washed, and peeled to separate into peelings, whole and peeled tubers. Phytochemicals were screened by standard techniques while the secondary metabolites were assessed by FTIR. The proximate, mineral, and amino acid compositions and functional properties were evaluated by referenced methods.
Phytochemical screening indicated that betacyanin, anthocyanin, carotenoids, mucilage, protein, carbohydrates, and fats were present, but oxalate, phytate, and polyphenols were absent. FTIR scanning presented peaks between 3903.75 cm-1 and 402.77cm-1. The peaks at 3305.05cm-1, 3291.77 cm-1, and 3290.10 cm-1 were specific to N-H stretch of amines and amides while 500cm-1 and 430cm-1 were attributed to poly-disulfide and aryl sulfide. The results of triplicate tests for unpeeled, peeled tubers and peelings showed that dry matter and ash were significantly different (p≤0.005) with unpeeled, peeled tubers and peelings yielding 88.23±0.60% and 2.42±0.56%; 84.78±0.94% and 2.03±0.11%; and 72.75±0.71% and 3.26±0.73, respectively. The total and reducing sugar contents were, respectively, 57.56±2.37g/1000mL and 5.78±0.75g/1000mL; 69.88±2.58g/1000mL and 2.03±0.11g/1000mL; and 67.85±3.53g/1000mL and 4.88±0.71g/1000mL. The crude fibre and fats contents were 1.29±0.24g/100g and 2.87±0.64g/100g; 0.92±0.05 g/100g and 0.80±0.40g/100g; and 3.47±1.14g/100g and 1.68±0.04g/100g. The total nitrogen, calcium, magnesium, potassium, and phosphorous were 0.81±0.06%, 0.05±0.00%, 0.6±00, 0.68±0.00%, 0.01±0.00%, respectively. The sodium, zinc, copper, manganese, and iron contents were 484.85±45µg/g, 41.31±1.86µg/g, 2.83±0.00µg/g, 24.47±0.94µg/g, and 260.01±11.13µg/g.
Orchid tubers represent a source of diverse nutrients that can contribute to food security and represent a means to raise the status of traditional foods and reawaken neglected or forgotten cultures.
