Impact of oil and inulin content on the stability and rheological properties of mayonnaise-like emulsions processed by rotor-stator homogenisation or high pressure homogenisation (HPH)

Abstract

Reduced-fat mayonnaise-like emulsions with varying oil (1.5, 20 and 52 wt\%) and inulin (0, 6 and 12 wt\%) contents were produced by rotor-stator (RS) homogenisation or additional high pressure homogenisation at 103 MPa (HPH). Emulsions were stored (180 days) and assessed by visual observation and by backscattering, rheological, colour and particle size distribution determinations. Results showed that long-term stable reduced fat emulsions can be achieved by inulin addition. RS homogenisation is only able to produce stable emulsions (non-creaming and/or non-sedimenting) for the highest tested oil (52 wt\%) or inulin (12 wt\%) concentrations. When emulsions stability allowed the comparison among RS and HPH samples (non-creamed or sedimented samples), the latest showed increased viscosities and solid-like behaviours. These patterns are similar to the ones showed by commercial and traditional full-fat mayonnaises. The combination of oil and inulin concentrations with HPH can be used to develop stable reduced-fat mayonnaise with a range of rheological properties. Industrial relevance: High pressure homogenisation (HPH) is an emerging technology with potential application for pasteurisation/sterilisation of liquid products. The results obtained in this study demonstrate this technology could also be suitable for the development of stable reduced-fat emulsions with a range of textures and including functional ingredients such as inulin. HPH also allows a significant reduction in the added inulin which could decrease the costs of production.