Abstract
The beer industry produces more than 100 billion litres of waste a year worldwide; it is estimated to make more than 20 million tons of solid waste. This waste is destined mainly for animal feed. However, it is of low added value, and excessive use as a feed can be potentially dangerous for the health of the animals. An alternative is to develop consumer goods from the waste which adds value and could serve as advertising material for the beer. The objective of this work was to develop and characterise a biomaterial from the brewing residue and vegetable resin and to develop products for use in pub environments. Six formulations were tested, S1 as a control with 100% of vegetable resin, S2, S3 and S4, with respectively 10, 25 and 40% of brewing waste (milled between 28 and 60 mash tiler) replacing the vegetable resin. The formulations S5 and S6 were made with 40% of brewing waste but milled between 14 and 28 tiller and > 60 tiller respectively. The mixtures were placed in rectangular shape silicon moulds. Commercially available Medium Density Fireboard (MDF) (one of the most used materials in the furniture industry) was used as a control. The density was evaluated; mould width, length and sample thickness was measured by a digital micrometre. Mechanical resistance was analysed by Universal testing machine (model DL1000, EMIC, São Jose dos Pinhais, Brazil). Each sample was loaded to 100 kgf 1mm*s-1, with probe angled at 135°. Determination of Water Resistance (WR) of the samples was evaluated by inserting in distilled water. After 48h of submersion, samples were weighed. The Solubilization capacity in water (SCW) was performed by immersing specimens in distilled water for 48 h at 25°C and subsequently drying. Colour was evaluated using a Minolta Chroma Meter CR-400 colourimeter and results were expressed by CIELAB system, in L*, a* and b* values. The acceptability test of the materials was made by 105 untrained testers. All seven samples were presented simultaneously and evaluated using a 9-point scale. Brainstorming was used as a Product development methodology to choose the best material to make a prototype in a silicon mould. The main results showed that the mechanical resistance of sample S5 was best, but their acceptance was the worst. The mechanical resistance for S2, S3, S4, S6 and MDF were the same indicating that the material could be used to make a table as well as a cup holder. Sample S6 had better acceptability and good mechanical proprieties than it was chosen as the best option. In conclusion, the method of mixing brewing waste with vegetable resin (castor bean) formed material with good mechanical and water resistance proprieties. It is an excellent alternative to increase the value of this industrial waste.
