effectiveness of biodegradable plastic in preventing food spoilage-2011

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Zhang 1 and Jill Carter 1 1 Shrewsbury High School, 64 Holden Street, Shrewsbury, MA 01545 Summary: The purpose of this study was to compare 100% polylactic acid (PLA) biodegradable plastic with a low- density polyethylene plastic (LDPE) in terms of their eectiveness against food spoilage. The interests of this study were: 1) the type of plastic that is more eective in preventing food spoilage, and 2) the materials’ properties, which are key factors in preventing food spoilage. Three trials were conducted testing the two plastics, in which an apple half was wrapped in either 100% biodegradable plastic, LDPE plastic, or no plastic at all (control). Over a period of 11 days, the daily mass of the apple was measured to determine the type of plastic that was more eective in preventing food spoilage. The results showed that in the long term (11 days), the LDPE plastic was more eective in preventing food spoilage than the biodegradable plastic. By day 11, the apples in LDPE plastic lost about 4.84% of their original mass, the apples in biodegradable plastic lost 18.25% of their mass, and the control apples lost about 56.11% of their mass. However, in the short term (1-3 days), both the apples in LDPE plastic and the apples in the biodegradable plastic lost a similar amount of their mass (2-4%) while the control apples lost about 20% of their mass. The results demonstrate that the biodegradable plastic can prevent food spoilage as eectively as the LDPE plastic in the short term. Hopefully, this will increase the appeal of biodegradable bags to consumers due to its ability to reduce the amount of trash in landlls. 5HFHLYHG 6HSWHPEHU $FFHSWHG 1RYHPEHU 3XEOLVKHG 0DUFK &RS\ULJKW =KDQJ HW DO $OO -(, DUWLFOHV DUH GLVWULEXWHG XQGHU WKH DWWULEXWLRQ QRQFRPPHUFLDO QR GHULYDWLYH OLFHQVH KWWSFUHDWLYHFRPPRQVRUJOLFHQVHV E\QFQG 7KLV PHDQV WKDW DQ\RQH LV IUHH WR VKDUH FRS\ DQG GLVWULEXWH DQ XQDOWHUHG DUWLFOH IRU QRQ FRPPHUFLDO SXUSRVHV SURYLGHG WKH RULJLQDO DXWKRU DQG VRXUFH DUH FUHGLWHG

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This study was published by the Journal of Emerging Investigators, a science journal for high-schoolers, run by Harvard Medical School students. In this study, polylactic acid and traditional petrol-based plastics were compared in their ability to prevent food spoilage. Although both were comparable in the short term, a traditional plastic was much more effective in the long term, with a lower WVTR.

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Page 1: Effectiveness of Biodegradable Plastic in Preventing Food Spoilage-2011

1March 20, 2012

E!ectiveness of Biodegradable Plastic in Preventing Food SpoilageCatherine R. Zhang1 and Jill Carter1

1Shrewsbury High School, 64 Holden Street, Shrewsbury, MA 01545

Summary:The purpose of this study was to compare 100% polylactic acid (PLA) biodegradable plastic with a low-density polyethylene plastic (LDPE) in terms of their e!ectiveness against food spoilage. The interests of this study were: 1) the type of plastic that is more e!ective in preventing food spoilage, and 2) the materials’ properties, which are key factors in preventing food spoilage. Three trials were conducted testing the two plastics, in which an apple half was wrapped in either 100% biodegradable plastic, LDPE plastic, or no plastic at all (control). Over a period of 11 days, the daily mass of the apple was measured to determine the type of plastic that was more e!ective in preventing food spoilage. The results showed that in the long term (11 days), the LDPE plastic was more e!ective in preventing food spoilage than the biodegradable plastic. By day 11, the apples in LDPE plastic lost about 4.84% of their original mass, the apples in biodegradable plastic lost 18.25% of their mass, and the control apples lost about 56.11% of their mass. However, in the short term (1-3 days), both the apples in LDPE plastic and the apples in the biodegradable plastic lost a similar amount of their mass (2-4%) while the control apples lost about 20% of their mass. The results demonstrate that the biodegradable plastic can prevent food spoilage as e!ectively as the LDPE plastic in the short term. Hopefully, this will increase the appeal of biodegradable bags to consumers due to its ability to reduce the amount of trash in land"lls.

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