Investigation of Physiochemical and Storage Conditions on the Properties of Extracted Tiger Nut Oil From Different Cultivars

Abstract

nut oil was extracted from (black, brown and yellow) cultivars using n-hexane. Physiochemical properties (refractive index, specific gravity, acid value, free fatty acid, peroxide, saponification and iodine values of the oil samples were determined. Storage studies on the tiger nut oils were done by monitoring changes in the thiobarbituric acid, peroxide value, free fatty acid and moisture content for twelve (12) weeks. The refractive index, specific gravity, acid value and free fatty acid value ranged between 1.46 ̵ 1.47, 0.89 ̵ 0.90, 0.4 ̵ 1.40mg/g, and 0.20 ̵ 0.75% respectively. The peroxide, saponification and iodine values ranged between 3.99 ̵ 4.43meq/kg, 183.25 ̵ 202.87mg/kOH/g and 29.69 ̵ 31.74g/l2/g respectively. The major fatty acids (FAs) of the tiger nut oil were oleic (77.71%), palmitic (16.17%), and stearic (5.08%) acids for the black cultivar, oleic (64.12%), palmitic (11.86%), linoleic (11.87%) and dihum ̵ g ̵ linolenic (1.71%) for the brown cultivar while the yellow cultivar had oleic (68.89%), linoleic (12.77%), palmitic (13.33%) and stearic (4.46%). During storage peroxide value, free fatty acid, moisture content and thiobarbituric acid of the oil were within the maximum limits as recommended by CODEX Alimentarius.

Quality Characteristics of Stored Varieties of Tiger Nut Oil

“…Cyperus esculentum is a perennial grass-like plant with spheroid tubers, pale yellow they are edible, sweet, nutty, flavoured tubers which contain adequate nutrients (Nina et al, 2020).…”

“…According to Nina et al (2020), three varieties of tiger nuts namely: black, brown and yellow. Only yellow and brown could be readily found.…”

“…However yellow cultivar is preferred for its yields of milk and functional bioactive components properties (Ndubuisi, 2009;Adejuyitan et al 2009). According to Nina et al (2020), oil obtained from tiger tuber has better quality. Tiger nut oil could remain in a uniform liquid form at refrigeration temperature, and therefore has been opined suitable for food applications due to its high oleic acid and low polyunsaturated fatty acid (linoleic acid and linolenic acid) contents (Ezebor et al, 2005;Nina et al, 2020).…”

“…According to Nina et al (2020), oil obtained from tiger tuber has better quality. Tiger nut oil could remain in a uniform liquid form at refrigeration temperature, and therefore has been opined suitable for food applications due to its high oleic acid and low polyunsaturated fatty acid (linoleic acid and linolenic acid) contents (Ezebor et al, 2005;Nina et al, 2020). The presence of polyunsaturated fatty acids and gamma-tocopherol contents in tiger nut stabilizes its oxidative tendencies.…”

“…The presence of polyunsaturated fatty acids and gamma-tocopherol contents in tiger nut stabilizes its oxidative tendencies. It is a quality oil and recommended for cooking compared to other oils because it resistant to chemical agent decomposition even at high temperatures (Nina et al, 2020;Shaker et al, 2009). However could be altered by visceral enzymes either in-vitro or in-vivo.…”