Page 518 - IJB-9-5

International Journal of Bioprinting

RESEARCH ARTICLE
3D printability and biochemical analysis of

revalorized orange peel waste

Jian Da Tan , Cheng Pau Lee , Su Yi Foo , Joseph Choon Wee Tan ,
1†
2
2
1†
Sakeena Si Yu Tan , Eng Shi Ong , Chen Huei Leo *, Michinao Hashimoto *
1
2
2
1
1 Pillar of Engineering Product Development, Singapore University of Technology and Design,
Singapore 487372, Singapore
2 Science, Math & Technology, Singapore University of Technology and Design, Singapore 4787372,
Singapore
(This article belongs to the Special Issue: Related to 3D printing technology and materials)
Abstract
Orange peels are often discarded as food waste despite being a nutritious source of
vitamins and antioxidants. These orange peel wastes (OPW) are produced in millions
of tons globally every year; discarding them results in detrimental environmental and
economical impacts. This paper discusses the application of 3D printing technology
to effectively upcycle the OPW into edible, healthy snacks for consumption. We
aimed to develop a method to enable OPW to formulate 3D-printable inks for direct
ink writing (DIW). Using DIW 3D printing, we successfully created edible constructs of
rheologically modified inks containing OPW. The formulated ink possessed an initial
viscosity of 22.5 kPa.s, a yield stress of 377 Pa, and a storage modulus of 44.24 kPa.
† These authors contributed equally
to this work. To validate the method, we conducted a biochemical analysis of the OPW at each
stage of the fabrication process. This study suggested that our ink formulation and
*Corresponding authors: 3D printing process did not affect the content of bioflavonoids and antioxidants
Michinao Hashimoto
(hashimoto@sutd.edu.sg) of the OPW. The cell viability test using human dermal microvascular endothelium
Chen Huei Leo (HMEC-1) suggested that the OPW did not exhibit cytotoxicity throughout the entire
(chenhuei_leo@sutd.edu.sg) process of the ink manipulation. Overall, this study has highlighted a potential
Citation: Tan JD, Lee CP, Foo SY, scenario to revalorize food waste into the food value chain using 3D printing toward
et al., 2023, 3D printability and more sustainable and circular food manufacturing and consumption.
biochemical analysis of revalorized
orange peel waste. Int J Bioprint,
9(5): 776. Keywords: 3D food printing; Direct ink writing; Circular economy; Orange peel
https://doi.org/10.18063/ijb.776
waste; Food sustainability
Received: January 04, 2023
Accepted: February 23, 2023
Published Online: June 16, 2023
Copyright: © 2023 Author(s). 1. Introduction
This is an Open Access article
distributed under the terms of the This paper discusses 3D food printing based on direct ink writing (DIW) technology
Creative Commons Attribution using orange peel waste (OPW). Millions of metric tons of oranges are produced each
License, permitting distribution, [1]
and reproduction in any medium, year globally, with nearly 30% by weight discarded as OPW . The objective of this
provided the original work is study is to demonstrate the ability of 3D printing to revalorize OPW to create edible
properly cited. snacks. Toward this end, we proposed to achieve four goals: (i) developing 3D printable
Publisher’s Note: Whioce inks comprising of OPW and appropriate additives, (ii) establishing the rheology
Publishing remains neutral with of OPW inks, (iii) characterizing the biochemical properties before and after the
regard to jurisdictional claims in
published maps and institutional printing process, and (iv) creating an edible snack using 3D printing. We successfully
affiliations. demonstrated the formulation of the 3D printable ink based on OPW using 1.0% w/w

Volume 9 Issue 5 (2023) 510 https://doi.org/10.18063/ijb.776