**5. Conclusion and outlook**

The properties of the pectin obtained from enzymatic and microwave-assisted extraction differed in several of the tested properties. Enzymatically-extracted pectin was characterized as moderately esterified (49.1% DE) with a rod-like conformation in water and with a lower average molecular weight than the microwave-assisted extracted pectin. These pectin samples had a random coil-like conformation and were highly esterified (>75% DE). In addition, the yields of the two extraction methods were significantly different. While the microwaveassisted extraction had a yield comparable to literature, the enzymatic extraction resulted in low yield which may be improved in further experiments by increasing the enzyme concentration, incubation time, or other relevant parameters. The properties of films prepared from the extracted pectin material showed significant differences. Overall, the elasticity of the films was considerably lower than the data of comparable material described in the literature. The high amount of presumably cellulose (>70% glucose monomer units) present in the extracted material might play a role for the low elasticity observed. The enzymatically-extracted pectin is a promising material to produce edible pectin films due to the high contact angles determined for the films and thus enhanced hydrophobicity and stability to water. Adding whole-grain kabog millet flour increased the hydrophobic properties of the films but concomitantly, the brittleness of the pectin edible films also increased. It would need further research to adjust the protocol to produce pectin films containing whole-grain kabog millet flour without changing their elasticity. Furthermore, it would be interesting to evaluate the antioxidant properties of compounds present in the whole-grain kabog millet applied in a film or coating. This could pave the way for fruit waste valorization and the addition of nutritional components to edible, biodegradable films.

*Extraction of Pectin from Orange Peel Wastes as an Ingredient for Edible Films Containing… DOI: http://dx.doi.org/10.5772/intechopen.108625*
