Flat pasta noodles are grooved to allow curls, spirals, and tubes to form while cooked allowing for reductions in packaging space and subsequent waste production.
Figure 1. Pasta in its varying shapes, bends, and twists.
People love eating pasta and have come to know and love it for its interesting shapes that span from tubes in penne to spirals in rotini. But what makes these shapes unique also makes their requirements for packaging much more significant. Typically, they require larger bags or boxes the more intricate the shaping, leading to issues in manufacturing and waste production. For some varieties of shaped pasta, upwards of 60 percent of packaging space ends up being just air due to the complex shapes that lead to inefficiencies in packing space.
A research team led by the Morphing Matter Lab at Carnegie Mellon University (CMU) is working on the development of materials including pasta that start off flat but produce the characteristic shapes we love when cooked. Yao and colleagues worked on pasta dough that was made entirely of semolina flour and water, where they stamped a series of grooves onto one side of each of the noodles. They found that as the pasta absorbed the water during cooking, the liquid couldn’t penetrate as fully onto the grooved side, causing less swelling or expanding than the smooth side. This also increased the time it took for that area of the pasta to cook and resulted in asymmetric swelling that bends and morphs the flat noodles into a variety of curves. By carefully planning where the grooves are placed, the researchers were able to control the shape of the pasta as it cooked.
Figure 2. Morphing pasta shapes simulation.
This technique seems great in terms of a food application, but it isn’t just limited to pasta. Grooves can be used to control and morph the shape of virtually any swellable material in a similar fashion. Another series of experiments were performed on silicone rubbers like Polydimethylsiloxane (PDMS), a common silicone rubber used in cosmetics and defoaming agents. In a variety of solvents, flat silicone rubber sheets with similar grooving techniques found similar results to the self-shaping pasta. However, while the pasta held its shape, the silicone rubber found itself eventually absorbing enough solvents over time to equally swell and flatten out again. The authors explained these differences as being the direct result of the gluey nature of cooked pasta. This attribute helps to lock in the introduced bends in the cooking proceeds, fusing neighboring grooves together.
Although the silicone rubbers could not maintain the same bending ability and permanent shaping, the researchers found that removal of PDMS from the solvent causes the bends to move back in the opposite direction. This acts as a solvent-dependent and reversible bending process that is promising for use in applications like grabbers in small robotic hands. This application has yet to be employed but is a future body of work waiting to be explored.
The plastic materials used in food packaging are a major contributor to landfill and ocean waste yearly. The group believes creating self-shaping pasta is crucial to reducing waste from shape dependent packaging and will save space in shipping and storage. They also envision that this strategy can lower carbon footprints globally, working towards a greener future.
The findings of this research have been published in the Journal of Science Advances:
Tao, Y.; Lee, Y. C.; Liu, H.; Zhang, X.; Cui, J.; Mondoa, C.; Babaei, M.; Santillan, J.; Wang, G.; Luo, D.; et al. Morphing Pasta and Beyond. Sci. Adv. 2021, 7 (19). DOI: 10.1126/sciadv.abf4098.
Kommentare