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The present thesis deals with the technological aspects of the debittering process of lupin in a food sovereignty framework. Of all investigated lupin species,Lupinus mutabilishas the best nutritional composition, which is similar to that of soya bean (Glycine max). Lupins can be used to fortify the protein content of many products. In addition, specific lupin protein concentrates or isolates display functional properties of industrial interest (as emulsifier, gelling and foaming agent). On the other hand, lupins contain bitter alkaloids that have to be removed prior consumption because are toxic (the fatal acute dose of lupin alkaloids was reported as 10 mg kg-1 body weight (bw) for infants and children, and 25 mg kg-1 bw for adults). However, alkaloids also have medical uses for their hypocholesterolemic, anti-arrhythmic and immunosuppressive activity. Bitter lupins have been detoxified by biological, chemical or aqueous processes. However, our research concentrated on the aqueousprocessing because this is the only way to produce debittered lupin for human consumption in an environment-friendly manner.The process investigated involved soaking, cooking, and washing of the raw seeds. This process showed to be inefficient because it took 5.7 ±1.0 days, used water at almost 62 times the weight of the raw dry and bitter lupine, and caused a 22% loss of total solids, principally fat, minerals, and carbohydrates. In addition, the microbiological quality deteriorated during this debittering process. Mathematical modeling based on Fickian diffusion suggested that the diffusion coefficient of alkaloids would be expected to vary between 10-10 and 10-11 m2s-1 because the process is carried out in unsteady conditions. In this scenario, it was clear that a new technology for debittering lupins is needed. For this purpose ahydro-agitator was designed, built and used to test the effect of different washing conditions on alkaloids content, solids in the product, final weight, processing time and water and energy consumption. Results were modeled and optimal processing conditions were inferred from a technological point of view; the optimum solution comprised 18h of soaking, 1h cooking, 3 changes of water/day and 22h of agitation/day. For estimating the washing time a mathematic function was inferred (∂c / ∂t = kc;k= -0.188- 4.973-3*Agitation – 0.0043 * Changes - 1.681-3 Agitation*Changes). Then, the products obtained from different processing conditions were evaluated by consumers on the basis of their willingness to pay in relation to their appreciation scores and product price. Results were modeled. Treatments with more processing increased the product price and diminished liking level. However, the willingness to pay is the combined effect of both variables. For example, people would accept an increase in price of 0.3$/kg if the liking level increases from “like slightly” to “like moderately”. The new developed technology could be used to optimize processes such as hydration and/or removal of undesired materials of legumes and other seeds. The approach used in this study also seems suitable to estimate relationships between processing conditions, liking, price and willingness to pay in other products. The generated information can be helpful in decision making, such as selection of consumers´ preferred process and liking in relation to pricing.
|Qualification||Doctor of Philosophy|
|Award date||28 Oct 2013|
|Place of Publication||S.l.|
|Publication status||Published - 2013|
- lupinus mutabilis
- food processing
- food crops
- food sovereignty
Technological options for the production of enriched lupine-based foods geared to consumer sensory preferences and nutritional status.
1/01/07 → 28/10/13