Sacha inchi oil is rich in polyunsaturated fatty acids that may rust, limiting their shel flife. The Rancimat method is official, for evaluations of oxidative stability accelerated in oils. Industrially conventional techniques based on physical and chemical indicators are used; there are no studies of correlation between them and Rancimat. This work has for objective correlate the oxidative stability index (OSI) Sacha inchi oil obtained by Rancimat at temperatures of 80°, 90°, 100° and 110 °C under an air flow of 15 L/h, with the values of physic-chemical indicators such as Index peroxide, p-anisidine, totox and density. Also estimated by mathematical extrapolation, the shelf life of sacha inchi oil to usual storage temperatures. OSI values were: 0.493 ± 0.01 h at 110 ºC, 1.590 ± 0.06 h at 100 ºC, 4.645 ± 0.1 h at 90 ºC and 20.512 ± 0.02 h at 80 ºC. High correlation has been established between values of OSI vs physicochemical quality indices (0.9322 < r < 0.9965). The activation energy was found 137.90 kJ/mol, which explains the high oxidative stability for the oil, estimating a lifetime of 3.29, 1.79 and 0.79 years at 20, 25 and 30 °C respectively.

Pan de molde enriquecido con torta extruida de sacha inchi (Plukenetia volubilis L.): Química, reología, textura y aceptabilidad

Andean lupin (Lupinus mutabilis) oil is rich in monounsaturated (54.2%) and polyunsaturated (28.5%) fatty acids but has a ω-3:ω-6 ratio (1:9.2) above the recommended values for human health. Sacha inchi (Plukenetia volubilis) oil presents a high polyunsaturated fatty acid content (linolenic 47.2% and linoleic 34.7%), along a ω-3:ω-6 ratio (1:0.74) good for human consumption. The objective of this research was to study the physico-chemical properties and oxidative stability of tarwi and sacha inchi oil blends (1:4, 1:3, 1:1, 3:1 and 4:1 w:w) with suitable ω-3:ω-6 ratios. All blends showed ω-3:ω-6 ratios between 1:0.8 and 1:1.9, acceptable from a nutritional point of view, and high total tocopherols’ content (1834–688 mg/kg), thanks to sacha inchi. The oxidative stability index (OSI) of the mixtures by the Rancimat method at 120 °C ranged from 0.46 to 8.80 h. The shelf-life of 1:1 tarwi/sacha inchi oil blend was 1.26 years; its entropy (−17.43 J/mol), enthalpy (107.04 kJ/mol), activation energy (110.24 kJ/mol) and Gibbs energy (113.76 kJ/mol) suggest low oxidation reaction rates and good stability. Hence, balanced blends of tarwi/sacha inchi oils can achieve optimal nutritional properties and enhanced shelf-life.

Present work proposes the substitution of traditional food stabilizers from the hydrocolloids of algae. Hydrocolloids from Nostoc commune and Nostoc sphaericum were extracted, characterized by infrared spectroscopy, and modelled their rheological behavior. The dried extract samples were dried by lyophilization and hot air and diluted in water at concentrations of 0.15% and 0.25% and lastly stored at different temperatures (7 – 80 °C). The infrared indicated C – O – C vibrations corresponding to the glucose cycle (1020 cm-1) and C = O of carboxyl groups (1950 cm-1) are proper of hydrocolloids. Rheological models of Bingham, Ostwald and Herschel-Bulkley confirmed that the Nostoc coomune species presents a higher coefficient of plastic viscosity (η) and coefficient of consistency (k) than Nostoc commune; the freeze drying method had a positive influence and significant on these results (p < 0.05). Likewise, the hydrocolloid samples were diluted under nectar conditions (12 °Brix and 4.5 pH) taking carboxymethyl cellulose (CMC) as a control, finding that there is less influence of temperature on the consistency index of hydrocolloids in the order of Nostoc sphericum < Nostoc commune < CMC. It is concluded that the application of hydrocolloids of the genus nosctoc can be used as additives in the preparation of nectar, maintaining their rheological properties.