The study of suitability of alkaline treatment for lignin reduction in banana stem and peel using response surface methodology

Abstract

The use of banana by-products as ruminant feed has been applied in the country with high banana production. Yet, there is still a lack of research conducted to identify the digestibility of banana plantain in ruminants as high lignin content led to poor degradability by rumen micro-organism. This study investigated the suitability of lignin reduction in banana stem (BS) and peel (BP) using alkaline pre-treatment. Three parameters were tested in this study. The parameters were the concentration of sodium hydroxide (1m, 5.5m, 10m), contact time (1 hour, 6.5 hours, 12 hours) and weight of the sample (0.5g, 2.75g, 5g). The correlation coefficients for both responses were performed by using a central composite design (CCD). The correlation coefficient values for banana stem and banana peel were 0.8632 and 0.4124, respectively. The optimum lignin removal condition for banana stem predicted by response surface methodology (RSM) was found at 6% with 9.76h, 7.92m and 4.98g, and banana peel at 10.09% with 1h, 10m and 0.5g. It demonstrates that alkaline pre-treatment using sodium hydroxide can effectively remove the lignin content in banana stem and banana peel. The effectiveness, however, is also affected by the sodium hydroxide concentration and contact time, respectively, for banana stem and banana peel due to their difference in structure. In conclusion, this study found that alkaline pre-treatment reduces the lignin content in banana stems and banana peels.