Lupinus mutabilisoil obtained by expeller press: Yield, physicochemical characterization, antioxidant capacity, fatty acids and oxidative stability analyses

Abstract

The oil of debittered and dehulled grains from two Andean lupins (Lupinus mutabilis) from Peru, Andenes and Común,was extracted by expeller press. The extraction yield and the proximal composition of both varieties were assessed. The oil and the cake, as well as the defatted flour from the variety with the highest extraction yield, werecharacterised for physico-chemical properties, total polyphenol content and antioxidant capacity. The oil shelf-life at 25 °C was extrapolated by Rancimat test. Andenes presented an oil yield of 22.1% (vs. 18.4% of Común),CIELAB colour coordinates of L* = 36.5, a* = 2.2, b* = 20, refractive index and density at 25ºC of 1.469 and 0.903 g/mL,acid number of 3.2 mg KOH/g, free fatty acids content of 1.6%, peroxide number of 2.7 meqO2/kg, p-anisidine number of 1.3, unsaponificable content of 58%, total antioxidant capacity 21.4 μmol TE/g and total polyphenol content of 7.0 mg AGE/100 g. The predominant fatty acid, tocopherol and phytosterol in the oil were oleic acid (56.2%), γ-tocopherol (555 mg/kg) and β-sitosterol (41900 mg/100 g), respectively. The oil shelf-life at 25 ºC was 2.7 years. The Lupinus mutabilis oil extracted by expeller presented an acceptable quality with a lower environmental negative impact than the oils obtained by solvent extraction.

Modification of the Nutritional Quality and Oxidative Stability of Lupin (Lupinus mutabilis Sweet) and Sacha Inchi (Plukenetia volubilis L.) Oil Blends

“…Tarwi oil had a much lower α-, γ- and δ-tocopherols content than sacha inchi oil ( p ≤0.05). A similar profile, plus β-tocopherol, was reported for an Andenes lupin commercial sample extracted at higher temperature (70 °C) [ 26 ]. Overall, the total tocopherols concentration in tarwi oil was 294.4 mg/kg ( Table 1 ), somewhat inferior to the 570 mg/kg of a similar oil [ 26 ], possibly because of a different cropping environment and the storage conditions of the seeds before extraction.…”

“…A similar profile, plus β-tocopherol, was reported for an Andenes lupin commercial sample extracted at higher temperature (70 °C) [ 26 ]. Overall, the total tocopherols concentration in tarwi oil was 294.4 mg/kg ( Table 1 ), somewhat inferior to the 570 mg/kg of a similar oil [ 26 ], possibly because of a different cropping environment and the storage conditions of the seeds before extraction. The tocopherol content was lower than expected, considering the concentration found in debittered beans [ 16 , 32 ].…”

“…Tarwi oil contained 54.2% oleic acid and 25.7% linoleic acid, while sacha inchi oil had 47.2% linolenic acid and 34.7% linoleic acid. Overall, the monounsaturated fatty acids (MUFA) content in tarwi oil was similar to the ≈50% observed in different Lupinus mutabilis varieties [ 26 , 27 ], while PUFA (28.5%) and saturated fatty acids (SFA) (17.3%) were the same as those reported for the same species [ 18 ]. On the other hand, sacha inchi oil showed low MUFA (9.4%) and high PUFA (82.0%), close to the published results [ 14 , 15 ].…”

“…The tarwi oil results were not far from those (2.50 and 9.97 h at 140 °C and 120 °C, respectively) reported by Salvatierra-Pajuelo et al [ 38 ], but were lower than those (2.6, 13.9 and 29.0 h at 140, 120 and 110 °C, respectively) noticed by Pascual-Chagman et al [ 26 ], a difference coherent with the superior tocopherol content described above. The sacha inchi oil scores were similar to those (0.49 h at 110 °C, 1.59 h at 100 °C, 4.64 h at 90 °C and 20.5 h at 90 °C) observed by Rodríguez et al [ 39 ].…”

“…The extraction yield of the tarwi oil was 11.2 ± 0.8 g/100 g seed, while the lipid content in the cake was 9.8 ± 0.31 g/100 g; hence, the total lipids in the Andenes seeds were 21.0 g/100 g, leading to a 53% recovery, a value in the lower end of the range (50.0–75.7%) for expeller press extraction performed at 70 °C [ 26 ]. The sacha inchi yield was 38.5 g/100 g seed, with a lipid content in the cake of 12.1 g/100 g, for a total of 50.6 g/100 g seed and a 76% recovery.…”