Kinetic, rheological and thermal studies of flaxseed (Linumusitatissiumum L.) oil and its utilization.

Abstract

In present study kinetic, thermal and rheological characteristics of oil isolated from flaxseed were studied and because of high content of α-linolenic acid (essential omega-3 fatty acid), flaxseed oil was incorporated in muffins by replacing fat/shortening at different levels (10%, 20%, 30% and 40%). To evaluate rheological behaviour, the experimental data of flow behaviour for flaxseed oil was fitted to Power law model, consistency index (K) and flow behaviour index (n) and Arrhenius parameters (activation energy and frequency factor) were evaluated. The n value of the oil treated at 10, 15, 20, 25 and 30 °C were found between 0.8 to 0.9, which suggested the non-Newtonian fluid behaviour of flaxseed oil. Thermal properties of flaxseed oil was evaluated using DSC (differential scanning calorimetry). The flaxseed oil possessed three endothermic and one shoulder peak. Gas chromatography revealed the fatty acids composition qualitatively and quantitatively and flaxseed oil is dominated by unsaturated fatty acids. Saturated oil was replaced with flaxseed unsaturated fat and results showed that substituting oil with flaxseed fat at level upto 20% produced muffins possessed the better texture, colour, aroma, mouth feel and overall quality score. Practical application: Modern diet lifestyle demands of healthy natural foods represent a challenge for food manufacturers to lead towards the healthy new trends. Fats imparts lubrication, texture, flavour and acceptability therefore used as major ingredients in bakery goods. Fats contains saturated fatty and dietary intake of saturated fatty acids in excess amount leads to many health disorders. Therefore, substitution of saturated fatty acid with PUFAs (omega-3 and omega-6) for the protection against diseases and metabolic disorders may be a solution for healthy and nutritious product development.