Utilization of brewer’s spent grain and other selected by-products to create edible cutlery
Stachnik, Marta (2024-06-05)
Utilization of brewer’s spent grain and other selected by-products to create edible cutlery
(05.06.2024)
Julkaisu on tekijänoikeussäännösten alainen. Teosta voi lukea ja tulostaa henkilökohtaista käyttöä varten. Käyttö kaupallisiin tarkoituksiin on kielletty.
suljettu
Julkaisun pysyvä osoite on:
https://urn.fi/URN:NBN:fi-fe2024061352364
https://urn.fi/URN:NBN:fi-fe2024061352364
Tiivistelmä
Single-use plastic cutlery gained a bad reputation for its negative effect on the environment, being banned in many countries. This research uses 3D printing technology to develop prototypes of edible spoons from side streams of food and beverage production, thus a solution to plastic pollution.
A set of six food inks were developed and evaluated. The printability of the food ink was assessed through rheological measurements, while the spoons were tested for their water and oil absorption, and water solubility and were sensorily evaluated.
Rheological evaluations in oscillatory mode, simulating the printing process, revealed that inks exhibit elastic behaviour at rest, becoming viscous under shear (phase shift angle from 14° to 80°). Both storage (G') and loss (G'') moduli showed significant recipe-dependent variations. The recovery rate was notably low, despite the ink’s ability to resist deformation, which was further reflected in the sagging of the ink after the print.
After 24 hrs. when submerged spoons absorbed large amounts of water, doubling their weight, but not oil – on average 20% increase in weight, there were no significant differences in water or oil absorption between samples. However, spoons made with brewers' spent gran flour had significantly higher water solubility than other recipes.
In the sensory evaluation, spoons made with fruit pulp received the highest ratings for colour, appearance, and smell. The spoons did not noticeably alter the food’s flavour when used with plain yoghurt. The texture of all spoons was considered appealing, with the 3D printing layers being either imperceptible or pleasant.
Ink’s printability requires optimisation of G’ and cross-over point, two factors correlated with the look and shape of the spoons. Also, water absorption needs to be lowered. Sensory tests showed the need for additional flavour enhancers to offset the bitterness and sourness of the side streams. Oat flour is considered to be the reason for the inks' poor rheological properties; thus, additives to offset this negative effect are needed.
A set of six food inks were developed and evaluated. The printability of the food ink was assessed through rheological measurements, while the spoons were tested for their water and oil absorption, and water solubility and were sensorily evaluated.
Rheological evaluations in oscillatory mode, simulating the printing process, revealed that inks exhibit elastic behaviour at rest, becoming viscous under shear (phase shift angle from 14° to 80°). Both storage (G') and loss (G'') moduli showed significant recipe-dependent variations. The recovery rate was notably low, despite the ink’s ability to resist deformation, which was further reflected in the sagging of the ink after the print.
After 24 hrs. when submerged spoons absorbed large amounts of water, doubling their weight, but not oil – on average 20% increase in weight, there were no significant differences in water or oil absorption between samples. However, spoons made with brewers' spent gran flour had significantly higher water solubility than other recipes.
In the sensory evaluation, spoons made with fruit pulp received the highest ratings for colour, appearance, and smell. The spoons did not noticeably alter the food’s flavour when used with plain yoghurt. The texture of all spoons was considered appealing, with the 3D printing layers being either imperceptible or pleasant.
Ink’s printability requires optimisation of G’ and cross-over point, two factors correlated with the look and shape of the spoons. Also, water absorption needs to be lowered. Sensory tests showed the need for additional flavour enhancers to offset the bitterness and sourness of the side streams. Oat flour is considered to be the reason for the inks' poor rheological properties; thus, additives to offset this negative effect are needed.