| dc.description.abstract | Recently, there has been a great deal of interest in the utilization of materials, and in
specific by-products, derived from the food industry, with the aim of improving the
recycling process, reducing the environmental pollution, and benefiting industries,
providing them interesting solutions and opportunities for elevating their sustainability
status. The objective of this thesis, is related exactly to this theme, as a possible
exploitation of by-products, originated from the brewing industry is examined.
Furthermore, the most significant and abundant remaining product, after the completion
of the brewing process, is the Brewers’ Spent Grain, which is considered to be rich in
protein and fiber content, having the potential to play a beneficial role, by reusing it for
the production process of other food products. So, in this thesis project, addition of BSG
ingredients to the formula for the making process of reconstituted potato crisps was
made and some valuable outcomes were pointed out. The reconstituted potato crisps,
are produced with a different way from the potato chips, as potato flakes and flours of
dried grains are mixed with the addition of water, emulsifier and a starch hydrolysate
solution, resulting in a dough, that will be rolled into a sheet, cut into oval shape pieces
and then deep fried in hot oil. Regarding the steps followed in this thesis, at first the
dried-raw materials of this formula and two new ingredients derived from the Brewers’
Spent Grains (one rich in protein that was named ¨EP¨ and one rich in fiber that was
named ¨EF¨) were analyzed, in order to identify their physical and chemical properties.
In specific, some analyses were carried out in the lab, for the determination of their
moisture and viscosity content, their water absorption index and their particle size
profile. The most interesting results were those for the viscosity content and the water
absorption index, as the BSG ingredients resulted in negative values for the viscosity,
cause they had zero starch content due to the mashing stage, which had taken place in
the brewing process, while they gave quite high values for the water absorption. The
latter was justified after research on the ability of dietary fiber to absorb water. Although
their values were much different from the usual raw materials, these results did not play
a crucial role for the production of the reconstituted crisps, as they led to a decent final
product. Then, we proceeded with some pilot scale tests in the process kitchen, in order
to find out if there is practical use of the BSG ingredients into the formula of the crisps.
The results were actually impressive and promising, as we could achieve a product
similar to the original, with just a few differences in their properties and their sensory
characteristics. The particular properties of the crisps made with the addition of BSG
ingredients, after some statistical analyses that were conducted, were the crisp length
and the stack height, while a difference in the sensory characteristics of the final crisps
were observed too. Also, crisps made with the implementation of EP and EF
ingredients, boosted the final nutrient content, with an increase in protein and fiber, but
also the saturated fats were increased, which is considered a huge drawback for the
nutrient status of the final crisp. However, the obtained results, do not present an
obstacle for further investigation and investment to this project, as with few
modifications, really profitable outcomes could be drawn. | el |
