The Development of a Pectin-Based Food Ink from Locally Sourced Durian Rind Waste for Possible Use as a 3D Printable Food Material

Durian (Durio zibethinus) is a popular seasonal fruit in Southeast Asia. Pectin can be extracted from the rind. Pectin is an excellent source of fibre and is available in two forms: high and low methoxyl pectin. Both of these types of substances can be employed as gelling agents. As such, the purpose of this research is to partially characterise durian pectin in order to facilitate the development of a pectin-based edible ink formulation. Four formulations of pectin-based food ink were developed and evaluated using a rheometer to determine the viscoelastic properties, a Fourier transform infrared (FTIR) to determine the chemical functional groups available, and thermogravimetric analysis to determine the thermal stability using durian rind waste pectin and commercial pectin. The results indicated that durian pectin contains a low amount of methoxyl (LM) at 2.48 ± 0.31%, which is appropriate for the development of food ink, whereas commercial pectin has a high methoxyl (HM) content of 28.72 ± 0.47%. With viscosities of 31759.20 Pa/s and 7482.62 Pa/s, formulations 3 and 4 of LM pectin exhibited the highest viscoelastic properties. The third and fourth formulations of HM pectin, as well as the third and fourth formulations of LM pectin, contain components that include the alcohol, carbonyl compound, and carbonyl group are found in both pectin granules. The LM pectin formulation 2 offers the highest thermal stability (32.00% residual weight) and the lowest weight loss percentage (57.15%). Due to its capacity to form gel, the LM result demonstrated potential for use in the formulation of edible ink. Additionally, it can be used as a polymeric crosslinker in conjunction with other materials.