Generation of sustainable active food packaging materials from agricultural wastes

Introduction: The non-degradability of plastic food packaging materials and associated environmental challenges motivated interests in the search for alternative food packaging materials that are biodegradable and/or environmentally friendly. Aim: This project investigated the utility of cassava waste (cassava peel) in producing sustainable active food packing materials using various plasticisers as well as the effects of supplementation of cassava peel starch-based films with plant extract and essential oil on film’s physical, optical, chemical, and functional characteristics. Results: Significant amount of starch was extracted from cassava peels (19.7%, P<0.05) with higher cyanide content (3.4-fold, P<0.001) compared to cassava pulp starch. Cassava peel starch had higher amylose content (30.0±1.7%, w/w) compared with starch from cassava pulp (18.7±0.9%w/w), corn (24.0±1.5% w/w) or potato (18.7±1.2%% w/w). Cassava peel starch-based films made with glycerol (0.22±0.00mm - 0.27±0.02mm ) and maltitol (0.23±0.03mm – 0.28±0.01mm) had similar thickness but films made with invert sugar were thinner (0.08±0.01mm and 0.11±0.00mm). A similar trend was observed for cassava starch-based films and control films made with potato and corn starch. Burst force of starch-based films reduced as the concentration plasticisers increases (15 – 40%w/w, irrespective of the plasticiser used) with cassava peel starch-based films having lower burst force (201.7±25.8 – 2585.0±177.0 for films made with glycerol, 45.9±6.9 – 2119.0±172.5 for films made with maltitol, and 89.9±19.0 – 743.3±26.9 for films made with invert sugar). A similar trend was observed for films made with cassava peel starch. The percentage of water-soluble materials in starch-based films increases with increasing plasticiser concentrations, irrespective of the type of starch or plasticiser used. For cassava peel starch films, this ranged from 37.64±1.77 - 47.06±2.84% glycerol films, 25.83±2.18 - 35.03±1.64% for maltitol films, and 16.03±0.95 - 48.35±4.11% for invert sugar films. Water absorption capacity of starch-based films also reduced as the concentration of plasticiser increased irrespective of the source of starch or the type of plasticiser used. Screening conducted revealed that glycerol films have better overall properties compared to films made with maltitol and invert sugar; and was selected for other studies conducted. The supplementation of starch-based films with leaves powder or essential oils from E. camaldulensis and A. indica did not alter thermal, chemical, and water vapour transmission rates of cassava and cassava peel starch-based films. The supplementation of cassava peel starch-based films with essential oils from A. indica and E. camaldulensis oil prevented the deterioration of strawberries (33.3% and 66.7%), cherry tomatoes (66.7% and 100%) and lettuce (66.7%) significantly compared to unpackaged fruits and vegetables. Also, cassava peel starch-based films supplemented with A. indica and E. camaldulensis oils prevented the loss of total soluble contents in cherry tomatoes (70.3% and 89.2%) and weight loss in strawberries (60.3% and 64.2%) significantly. All starch-based films produced in this study degraded within 10 days under soil at ~30oC. Conclusion: This study revealed the potential utility of starch extracted from agricultural wastes in producing food packaging materials and encourages further exploration of biodegradable films developed in this thesis for application as food packaging materials.

Citation

Ojo, C.C. (2025) Generation of sustainable active food packaging materials from agricultural wastes. University of Wolverhampton. https://wlv.openrepository.com/handle/2436/626197

Publisher

University of Wolverhampton

URI

https://wlv.openrepository.com/handle/2436/626197

Type

Thesis or dissertation

Language

en

Description

A thesis presented for the degree of Doctor of Philosophy in the School of Engineering, Faculty of Science and Engineering, University of Wolverhampton.

Collections

Theses and Dissertations