RESUMO
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.
Assuntos
Antioxidantes/análise , Culinária , Euphorbiaceae/química , Ácidos Graxos/análise , Óleos de Plantas/química , Tocoferóis/análise , OxirreduçãoRESUMO
Brazil is an emerging virgin olive oil producer country whose oils have been scarcely studied till now and, in particular, no data are present in literature about their volatile profiles and organoleptic characteristics as well as the Pearson's correlations between chemical and sensory parameters. Hence, giving insights about these aspects was the aim of the current investigation. The volatile profiles showed the presence of the aldehydes responsible for the positive attribute of VOOs (i.e. trans-2-Hexenal and hexanal) although, in some cases, volatiles from anaerobic and aerobic fermentation were also detected. The panel test showed low values of fruity and pungent notes (mean values of 1.1 and 0.6, respectively) whereas the bitter taste was detected only in one sample, probably due to the low amount of total phenolic compounds (ranging from 40 to 280â¯mgâ¯kg-1). Accordingly to the volatiles analysis, slight defects of the oils were evidenced by the panelists. Tocopherols ranged from 123 to 222â¯mgâ¯kg-1; carotenoids from 10.69 to 26.18â¯mgâ¯kg-1, chlorophylls from 14.06 to 54.90â¯mgâ¯kg-1, antioxidant activity from 976 to 1790⯵mol TE g-1, and fatty acid ethyl esters from 2.56 to 19.22â¯mgâ¯kg-1. Positive Pearson's correlations were highlighted between hydroxytyrosol derivatives and antioxidant activity (râ¯=â¯0.9601, pâ¯<â¯.0001), trans-2-hexenal and fruity median (râ¯=â¯0.6526, pâ¯<â¯.05), acetic acid and vinegary defect (râ¯=â¯0.7854, pâ¯<â¯.0001), and fatty acid ethyl esters and vinegary defect (râ¯=â¯0.8418, pâ¯<â¯.0001). Our findings give first insights about sensory characteristics of Brazilian virgin olive oils and their association with chemical quality parameters. Finally, based on the obtained data, an improvement of preliminary operations (harvesting, storage) of the extraction process is recommended.