Scoby

From Peel To Peel - An experimental approach for packaging

Recent statistics show that almost a third of the waste produced in Italy is food-related. Such a portion contributes daily to the highly alerting environmental threats we are facing. This does not only concern the disposal of waste but the complete life cycle of objects around us which begins with the extraction of resources, the manufacturing process, the consumption, and the complete cycle around it.

Recognising the food industry as one of the largest waste-producing sectors, this project investigates sustainable alternatives using microbial cellulose as a substitute for the most commonly used plastic and paper.

Microbial cellulose, is made by the fermentation of bacteria and yeasts with fruit and vegetable leftovers therefore, it was explored through a series of experiments and tryouts in order to discover its behaviour and potential.

Munari says: 'Nature is the first producer of packaging in the world: every peel, shell or skin aims to protect its content.'

Starting from this standpoint, the project suggests a 'closed-cycle system' to produce microbial cellulose in a local setting (South Tyrol), producing food-related packaging and disposables. The final results show how Munari’s statement could be almost literally implemented, and introduces products that are contained by their own peels or scraps embodying a potentially direct relation between content and container.

Additional information

Microbial cellulose (MC) is a typology of cellulose which is secreted by several species of microorganisms and appears in the state of translucent jelly biofilms or ribbons. However, cultures of cooperating bacteria (like Komagataeibacter xylinus) and yeasts (Saccharomyces Cerevisiae) called SCOBY (Symbiotic Colony Of Bacteria and Yeasts).

SCOBY, being an acetic ‘mother’ is renowned for being used for edible purposes namely, to brew the Kombucha beverage, which is a fermented green/black tea, and to produce Nata de Coco from coconut wastewater, a low calories and fibre-rich dessert which is popular in the Philippines, Vietnam, Thailand and Indonesia.

Commonly used current systems in Kombucha drink and Nata de Coco industrial pro-duction are based on a MC fermentation method called static culture that uses tanks or trays. This procedure starts with the preparation of the liquid medium, which is poured into the meant container. An amount of SCOBY is immersed inside, and a breathable cloth or cover is put on the container to protect the culture from contamination. The culture is kept in static conditions (possibly supported by a system to control the temperature) for a period of 7 to 21 days - for the fermented beverage. At the end of the process, a generated MC biofilm floats on top of the liquid, usually covering the complete surface.

The jelly-like biofilms can be processed into diverse substances that could be either edible, or not, ranging from powder to flakes and sheets, from gel to solid foam and composites. Being characterised by a three-dimensional fibre-configuration, a hydrophilic capacity and nutritional properties, MC is suitable for diverse applications such as food- ingredients (prebiotic, integrator, fat replacer, texturizer), (non)edible materials (filler, emulsifier, compostable substances), products like single-use packaging, cosmetics, components for electronics, medical and pharmaceutical applications. MC is made almost entirely of nanofibres and its cellulose content is purer in comparison to the one extracted from vegetative sources.

MC production appears to be more sustainable and resource-efficient when comparing the two typologies. MC is cultivated or ‘grown’ as microorganisms nourish on the nutrients present in a liquid medium and secrete fibres of which volume is multiplied up to centimetres in thickness. Tea and sugar are commonly used to feed SCOBY however, they are very production-expensive so, other water-based nourishments can be prepared with diverse carbon (sugar containing) sources. It was investigated by diverse scholars that liquid medium prepared substituting virgin sugar with food-production byproducts like molasses and pomace, were suitable and effective for SCOBY fermentation. This practice of further utilising ‘waste’ would not only enhance the inherent value of primary resources but would also lower production costs, introduce profitable upcycling processes fostering local production possibilities. Circular production systems revaluing waste can improve current linear production cycles where valuable substances are systematically not used for their full potential and are downcycled. Indeed, the implementation of MC production could foster a more conscious use of resources generating a positive ecological and even social impact by reducing the total dependence on import, while supporting local economic resilience.

Information submitted by the maker and edited by the Future Materials Bank.

Ingredients

Credits

FROM PEEL TO PEEL was developed as a BA thesis project at the Faculty of Design and Art of the Free University of Bozen-Bolzano | Supervisors: Prof. Nitzan Cohen, Prof. Dr. Seçil Uğur Yavuz | Collaborators: Food Technology Team of the Free University of Bozen-Bolzano.