In my last post titled: "Rationale for the modification of gluten-free flours", I extensively explained the need to enhance the baking potentials of indigenous gluten-free flours. Additionally, I mentioned in the post that a feasible approach to achieving this is through "heat-moisture treatment". This post is a continuation of the last post.
Interestingly, in 2018, my research group studied the impact of pressurised steam heat in achieving heat-moisture treatment on the structural, functional and baking properties of cassava flour. This was our first study in the area of flour modification. Consequently, our findings were published in International Journal of Biological Macromolecules, a highly reputable Food Science Research Journal in the same year. The rationale for the choice of cassava flour is its low cost, perennial availability, high starch content and unique pasting properties (Look out for my post on pasting properties. It was observed that the application of pressurised steam-heat in achieving heat-moisture treatment had a negative effect on the swelling properties of cassava flour.
Thus, this study employed "Response Surface Methodology", which combines statistics and mathematical modelling to study and optimise steam-heat-moisture treatment conditions aimed at increasing thermal stability and decreasing the retrogradation tendency of cassava flour when utilised in leavened baked food. Briefly, Retrogradation is related to the hardness/firmness and a contributor to the staling of baked food during ambient temperature storage. That is, the higher the retrogradation the higher the hardness/firmness of the crumb texture of the baked foods and the more susceptibility to staling.
The major findings from this study are follows:
- The established novel optimal steam-heat-moisture treatment condition for cassava flour was 15% moisture, 120 °C and 1bar pressurised steam heat and a treatment time of 10 minutes.
- The treatment decreased the average granule size of cassava flour by 60%
- The A-type crystal structure of cassava flour was resistant to the treatment but the relative crystallinity increased by 25%.
- The optimal dry-heat-moisture treatment conditions increased the thermal stability of cassava flour by decreasing the breakdown viscosity by 21% and increased the melting onset to conclusion temperature range from 14.66 to 18 °C.
- The treatment delayed the retrogradation tendency of the flour by decreasing the setback viscosity by 56%
Therefore, the modified cassava flour produced from this novel method can be utilised as a possible antistaling agent in baked foods. It can also be utilised in producing baked foods that require low swelling characteristics such as biscuits and cookies. It is important to mention that this modified flour will be unable to produce leavened baked food on its own and will require blending it with wheat flour at a maximum substitution of 10% for best performance.
This study is relevant to the baking industry, especially in developing countries where cassava is indigenously cultivated.
For more information on this study read the full version of the article below:
Dudu O E, Oyedeji A B, Oyeyinka S A, Ma Y (2019). Impact of steam-heat-moisture treatment on structural and functional properties of cassava flour and starch. International Journal of Biological Macromolecules, 126: 1056-1064.
0 Comments