Changes in stability, tocopherols, fatty acids and antioxidant capacity of sacha inchi (Plukenetia volubilis) oil during French fries deep-frying

Abstract

Sacha inchi (Plukenetia volubilis) oil (SI) is appreciated for its nutritional and sensorial characteristics. The aim of this study was to evaluate SI changes during French fries deep-frying at 170 °C or 180 °C up to 119 and 50 min, respectively; commercial soybean oil (SO) was tested as control. SI had high α-linolenic acid (53.8%), linoleic acid (33.4%) and total tocopherols (2540.1 mg/kg). During frying tocopherol content, oil stability and antioxidant capacity (ABTS, DPPH) decreased following zero-order kinetics; γ-tocopherol showed the strongest decrease. Notwithstanding the high SI unsaturation and the commercial antioxidant (TBHQ) in SO, SI showed slightly higher or similar hydrolysis (free fatty acids and diacylglycerols), similar primary (K₂₃₂, oxidized-triacylglycerols) and lower secondary (K₂₆₈, triacylglycerol oligopolymers) oxidation. Because of the high tocopherol content, SI showed lower degradation than SO. Thus, SI is suitable for short-term deep-frying; additionally, it may enhance the nutritional value and the flavour of fried foods.

Keywords: Kinetics; Linoleic acid (PubChem CID: 5280450); Linolenic acid (PubChem CID: 5280934); Lipid hydrolysis; Lipid oxidation; Oleic acid (PubChem CID: 445639); Palmitic acid (PubChem CID: 985).; Polar compounds; Rancimat; Tocopherol; α-Tocopherol (PubChem CID: 14985); γ-Tocopherol (PubChem CID: 92729); δ-Tocopherol (PubChem CID: 92094).