BIODEGRADATION OF MANGO SEED STARCH FILMS IN SOIL

The typical petroleum-based plastics have triggered environmental problems. For this purpose, biodegradable polymers such as starch are often used to manufacture biodegradable plastics. At present, the efforts are underway to extract starch as a promising biopolymer from mango seeds and subsequently to produce a biodegradable starch film to be used as plastic packaging. As such, in this work, glycerol-plasticized mango starch films were prepared using a solution casting process, using different amounts of citric acid as a cross-linking agent. The blend ratio of starch to glycerol was set at 3:5 wt. each, while the amount of citric acid ranged from 0 to 10 wt.%. Then, the casted films underwent 21 days of soil burial testing in the natural environment to determine their biodegradability behavior. The soil burial test is one of the common methods chosen to assess the biodegradability of polymers. The idea is that, by burying samples in the soil for a fixed time, samples are exposed to microorganisms (i.e. bacteria and fungi) present in the soil that serve as their food source. This is somehow likely to facilitate the process of deterioration. For this reason, the soil burial test can be regarded as an authentic approach to the process of deterioration in the natural environment. The films' susceptibility to biodegradation reactions was assessed within intervals of seven days through their physical appearance and weight loss. Interestingly, it was found that the cross-linked starch films have been observed to degrade slower than the non-cross-linked starch films as burial time progressed. The declining percentages of weight loss, as well as the presence of microorganisms and eroded surface on the films observed by SEM, explained the degradation behavior of the cross-linked starch films compared to the non-cross-linked starch films. Hence it is believed that cross-linked starch-glycerol films are biodegradable in soil, henceforth, the potential to be commercialized as a biodegradable packaging material soon. At the same time, this plastic packaging is expected to be recognized as a value-added product since the raw materials ergo mango seeds utilized to develop this product are from waste, therefore, environmentally friendly. ABSTRAK: Plastik yang berasaskan petroleum telah mencetuskan masalah persekitaran. Untuk tujuan ini, polimer biodegradasi seperti kanji sering digunakan untuk membuat plastik yang boleh terurai. Pada masa ini, usaha sedang dilakukan untuk mengekstrak pati sebagai biopolimer yang menjanjikan dari biji mangga dan kemudiannya menghasilkan filem pati yang terbiodegradasi untuk digunakan sebagai kemasan plastik. Oleh yang demikian, dalam karya ini, filem pati mangga plastik-gliserol disusun menggunakan proses pemutus larutan, menggunakan jumlah asid sitrik yang berlainan sebagai agen penghubung silang. Nisbah campuran pati dan gliserol ditetapkan pada 3:5 wt.% masing-masing, sementara jumlah asid sitrik berkisar antara 0 hingga 10 wt.% berat. Kemudian, sampel plastik tersebut ditanam di dalam tanah selama 21 hari di persekitaran semula jadi untuk menentukan tingkah laku biodegradasinya. Ujian penguburan tanah adalah salah satu kaedah biasa yang dipilih untuk menilai biodegradasi polimer. Ideanya adalah bahawa, dengan menguburkan sampel di tanah untuk waktu yang tetap, sampel terdedah kepada mikroorganisma (iaitu bakteria dan jamur) yang terdapat di dalam tanah yang berfungsi sebagai sumber makanan mereka. Ini mungkin memudahkan proses kemerosotan. Atas sebab ini, ujian penguburan tanah dapat dianggap sebagai pendekatan yang sahih terhadap proses kemerosotan di persekitaran semula jadi. Kerentanan filem terhadap reaksi biodegradasi dinilai dalam selang waktu tujuh hari melalui penampilan fizikal dan penurunan berat badan. Menariknya, didapati bahawa filem-filem pati berangkai silang telah dilihat menurun lebih perlahan daripada filem-filem pati yang tidak bersilang ketika masa pengebumian berlangsung. Peratusan penurunan berat badan yang menurun, serta kehadiran mikroorganisma dan permukaan yang terhakis pada filem yang diperhatikan oleh SEM, menjelaskan tingkah laku degradasi filem pati berangkai silang berbanding dengan filem pati yang tidak bersilang. Oleh itu, dipercayai bahawa filem kanji-gliserol berangkai silang dapat terbiodegradasi di dalam tanah, dan seterusnya, potensi untuk dikomersialkan sebagai bahan pembungkusan yang boleh terurai tidak lama lagi. Pada masa yang sama, pembungkusan plastik ini diharapkan dapat diakui sebagai produk bernilai tambah kerana bahan mentah ergo mangga yang digunakan untuk mengembangkan produk ini adalah dari sisa, oleh itu, mesra alam.

Plastic Packaging: A Study on Plastic Imports in Uganda

Plastic packaging is crucial in preserving the quality of products. It has become ubiquitous, and an inseparable part of daily life and the food industry due to its aesthetic attributes, strength, affordability and convenience of use. This has thus led to the increase in demand and imports of plastics in the country. However, plastic packaging alone accounts for 47% of global plastic waste amidst documented threats of plastic waste to the environment-water-food-health nexus. Several reports indicate that between 1994 and 2017, Uganda imported a total of 1.9 million tons of plastic in both raw and finished form compared to 117 million tons across Africa. Imports and use of plastics in Uganda have increased by six-fold within the last three years hence extrapolating the growing challenge for sustainable plastic imports, product packaging, and waste management. The objective of the review therefore was to explore the future trend and impact of plastic imports and packaging in Uganda by analyzing plastic imports and the associated waste. The study further reviews the challenges arising from the growing demand for plastic packaging and presents a discussion on the solutions and potential ways forward for win-win benefits. Several strides to curb the menace of plastic waste are presented, which are manly from the private sector and plastic recycling businesses. A conclusion is made that if these efforts are to meet the intended leaps of change, the government of Uganda has to support the private organisations through grants, space allocation for collection centers and media access across the country. Furthermore, stricter regulations on excess plastic importation have to be implemented by the government as the country develops locally grown solutions to plastic packaging and use.