Study of a model low-fat salad dressing formulated with inulin.

Study of a Model Low-Fat Dressing Formulated with Inulin

Faculté Universitaire des Sciences Agronomiques 1Unité de Technologie des Industries Agro-alimentaires

2Unité de Chimie Biologique Industrielle

1. Introduction

The aim of this work was to develop and evaluate a method for obtaining a low-fat “ salad dressing ” formulated with inulin. The plan based on the optimization of a basic model dressing, where the initial oil content was then reduced, and inulin was incorporated in order to replace the stability, texture and sensory properties lost from this reference model.

2. Experimental procedure

=> Optimisation of manufacturing procedure of model “salad dressing” and the initial amounts of hydrocolloids in its formulation

- tested homogenisation temperature ranges: 10-15°C and 60-65°C - tested xanthan/modified starch ratios: 1/4, 1/7 and 1/15

=> Formulation of model salad dressings supplemented with inulin

- tested oil contents: 10% and 18%

- tested inulin types: Fibruline Instant (II, DPn=6), Fibruline LCHT (DPn=20), Experimentale fraction (LC, DPn=14)

- tested inulin/oil ratios: 1/4 and 1/2

fully factorial design conceived including 12 samples formulated with inulin

=> Evaluation of model low-fat salad dressings formulated with inulin

- evaluation of droplet size and emulsion stability - evaluation of rheological characteristics

- simple preliminary sensory evaluation

4. Conclusion

This experience could be an approach to the development of a salad dressing with extra beneficial effects on health improvement (both by fat and calories reduction and by the prebiotic action of inulin).

3. Main results

=> Chosen reference model: cold manufacturing (10-15°C),

xanthan/modified starch ratio equal to 1/15 (respecting a total 4% hydrocolloids)

=> Droplet size measurements showed a size reduction while reducing initial

oil content, enhanced by a greater egg yolk/oil ratio

=> Emulsions became more stable with the increase in inulin DPn and

concentration

=> Viscosimetry tests evidenced an increase in the consistency index,

together with a reduction in the flow index as inulin DPn and concentration both increased

=> Dynamic tests confirmed that samples formulated with the intermediate

DPn inulin (DPn=14), in a concentration of 4 to 6% are those that best approach the rheological behaviour of the reference model salad dressing

=> Formulations containing 18% oil and 4 to 8% inulin were those that

exhibited the most similar sensory profile compared to the reference model.

Acknowledgement